AMMO

The original 5D is a great camera. The 5DMKII just has that little bit extra. The difference between the MKII and the MKII is not that great to justify spending £2,300.00 on a body alone. The MKII was also £2,300.00 when it came out. It was a real game changer as Hollywood adopted it big time for video. I met the DP from the TV series 24 who was bolting six or seven 5D2 bodies in cars where normal cameras wouldn't fit. They also made a whole episode of House using a 5D MKII. An amazing camera. Here is a photo of the actual camera I am selling. Edited by - AMMO on 23 May 2013 10:15:03

Open to offers.

Price reduced to £1,075.00 to include delivery.

Thanks Myles The 5D2 is a fantastic camera, probably the best I've ever owned (and I've owned a few over the years). I had an original 12 MP 5D that was very good but the 5D2 is much better in my opinion. The 5D2 is the first digital camera that made me think that film is a thing of the past. The camera is so good that if photographs don't come out properly it's probably you, not the camera. The images that come out of it are comparable to a 6x6 Hasselblad or Rollei film camera from years gone by. I've had 30" x 45" exhibition quality prints made from 400 ISO files that are pretty amazing.

Very little use as it is my backup body. Only 4374 shutter actuations. Original box with instructions etc. Camera is in excellent as new condition. £1,095.00 + delivery Edited to say that this is a full frame 21MP 36x24mm sensor camera. Also shoots HD 1080 video. Not a grey import. Full information and specs. here Can send photos of camera if required. Any questions please ask. Edited by - Ammo on 16 May 2013 10:36:39

Still for sale. Toying with the idea of fitting the 210 Duratec engine to my car and selling the 260 bhp one that is currently fitted to it. If anyone is interested in either of these engines please feel free to call 01394 383499 / 07860 494064.

Nice video

BTT Priced now at £4,000.00 to include injectors and coils. Will also add coolant outlet and coolant bypass hose.

Thanks for the positive comment ruff seven I've had a few emails and there seems to be some confusion as to what is included. To help clarify photo here If it isn't in the photo it isn't included. So no starter motor, alternator, ECU, loom, throttle bodies, bellhousing, exhaust, engine mounts, etc. You will need to purchase all these things separately if you are converting a K or a Crossflow. Thanks for looking.

If you say so Mav. I believe you! It's the funds not the wife. Price now reduced to £4,250.00. If injectors and coils not required I'll accept £4,000.00. Can send photos to anyone that is interested.

Still trying to get to the bottom of the missing BMEP from my engines. I still don't believe the claims for the Audi engines who are quoting torque figures that are very hard to believe. Is it that my text books and information are out of date and that 230psi BMEP and torque per litre figures should no longer be used? If so what are the higher figures? Is it really between 250 and 270 psi? I wish someone in the know would tell me. If you really could get 108 ft lb of torque per litre N/A then why are people like Millington not getting 270 ft lb of torque out of a 2.5? Or anyone I know getting 250 ft lb out of a 2.3 litre Duratec. Most sensible people I know are quoting sensible figures for these engines. I spoke to an engine designer that was involved with BTCC and asked him the question about the figures we see quoted. His reply was short and to the point. "They're lying". Whether the lie is intentional or not is another matter. In my racing years I met a lot of people who believed their own BS with an almost religious fervor. Dyno errors or a dynos that reads high could be a reason. Coast down on a rolling road or transmission absorption figures that are wrong. Incorrect corrections for atmospheric conditions perhaps? A combination of the two and power and torque figures will rise. I had my Mini rolling road tested years ago by a very competent guy and successful racer. There is no doubt in my mind that his rolling road read high. I reckon my Mini made around 82 bhp. His rolling road said 104 bhp. His set up skills were second to none. Carburation and ignition were perfect. His rolling road figures? Hmmmm. A 950cc Guzzi on a Sun Ram 12. We'd made an adapter to be able to run it on a car rolling road. Made a credible 85 bhp at the rear wheel. When the dyno operator told me that was 125 bhp at the crank I just laughed. Losing 40 bhp in the transmission is nonsense. I tended to work on around 7 bhp transmission loss on a motorcyle of that power. That would make the crank power 92 bhp. We had previously seen 91 bhp on a Shencke engine brake with a similar engine. So close enough. If I was gullible and wanted to believe my own superior tuning skills I would have gone around quoting this silly 125 bhp figure. 40bhp is almost 30 KiloWatts. The power has to be lost somehow. It is lost in heat. Imagine sitting on a motorcycle that is giving off as much heat as 30 1,000 watt heaters from the transmission. Your arse would melt. A motorcycle engine builder friend also says that he has to contend with competitors that make extravagant claims for their engines. Most motorcycle rolling roads measure rear wheel power. By then adding a percentage loss you can make up a crank power figure. He said that the percentage transmission losses people are quoting would make the chain glow red hot. As I have mentioned before we have raced against people who used to quote higher figures than us but we used to go past them in a straight line. When we were winning races by 10 to 15 seconds the guys with more power were finishing tenth. They could talk the talk but not walk the walk. Rider ability was quoted as our advantage. I admit we had better riders, but in a straight line when you are neck and neck? My conclusion is that we live in world of BS. If someone quotes a figure, another guy quotes another higher figure. There is an escalation of BS that bears no relation to reality. That seems to me what has happened in BTCC. As people are gullible they like to believe this stuff. The Max Power guys need something to talk about down the pub. You can spend all your working life measuring airflow, dyno testing, measuring everything that can give you a small advantage. You do your best work and get a credible result. Then someone comes along with some graph paper and a crayon and draws a nice smooth line with more torque and power than you can ever possibly get that makes you look like a useless twat who will never be as good as those other guys. So what happens to the guy that is honest and quotes honest figures? The only way you can show people is to get out on the track and kick everyone elses arse into next week. But even there people will find reasons why you are faster. Whilst looking into these things I tried to call an aquaintance that has a lot of experience with engines. Ex Cosworth, Swindon and Mountune. A realist. He was the one that told me that VX BTCC engines made 280 bhp at 8,500 rpm. But to sell engines you have to quote higher. When comparing notes on Duratecs our findings and figures matched pretty closely. He had sensibly stopped building engines and was involved with new things. His wife answered the 'phone and I was totally shocked to hear that he had passed away six months earlier at only 50 years of age. I didn't ask how he died as it might have been seen as morbid curiosity. She did say it was very sudden. I did ask his wife how she was and if she was OK financially. I was relieved to hear that from a financial point of view she was OK. She sounded quite emotional on the 'phone. Understandably so. I told her that her husband was one of the good guys and that I admired his talents and his honesty. She seemed to appreciate that. I found the news quite upsetting and spent the rest of the day thinking about the guy. All that work and knowledge is now gone. I also thought that some of the things I have been writing about and getting off my chest recently are not really that important in the great scheme of things. Sorry to end on a bit of downer but it is good sometimes to have a reality check. As I have said before, racers (that includes engine tuners as far as I'm concerned) have a character flaw that wants them to show everyone that they are better than the next guy. Is it really that important? Also sorry if all the posts sound a bit me me me. "I did this" and "I did that" seems to appear a bit too often even for my taste. All I can write about is what I have done and what I have witnessed. I would like to thank the people who have emailed me personally who have read my scribblings and said that they have enjoyed reading what I have to say. Ex club members and non club members who can't post here. I appreciate it very much. I think I have said enough for now. I got what I wanted to say off my chest. I hope you haven't found reading this too tedious. AMMO

Someone said they would buy this engine from me at the end of February. That's not happened so back to the top. I have a feeling the guy's wife put her foot down and told him he wasn't allowed! Is there anyone out there that is unmarried or doesn't have to ask for permission who would like this engine?

BTT Bare main casing still available if anybody needs one. Seems a shame to bin it but I need the space. £10.00 donation to NTL. Delivery at cost, collection or GONADS.

On all the dry sumped engines I have built I removed the plastic breather box completely and replace it with a blanking plate. You could just remove the hose and blank the breather box and plenum. I'm sure that would be OK.

Hi Fred No need to say sorry. I didn't interpret your post as “SBD are better than Raceco”. Such a thing never entered my head, so don't worry. Looking again at the graph here of the 280 bhp 2 litre it's pretty obvious that power is still rising and will peak in the region of 9,000 + rpm. In fact that engine is probably already a 290 something engine if we revved it. The 9,500 rpm figure comes from what I consider the safe mean piston speed in the region 26 metres per second. This is already a higher piston speed than a lot of high rpm engines. It would be nice to have another 500 rpm past peak power for gear shifting. I'd really like to go to 10,000 pm if I could but I'm not sure I would be comfortable with it. Regarding valve springs I also differ in opinion. Valve springs already exist to do the job. Since my first trip to Daytona in 1989 I have owned an American made Rimac valve spring tester. I have done a lot of spring tests and have tested most springs available for the Duratec and other springs available from elsewhere. Other engine builders often used to send me springs for testing. The involvement with motorcycles means that I am used to running higher rpm. I had a 2 valve Guzzi with a 13mm valve lift running to 10,000 rpm in the late 80s. The 4 valve Guzzi ran to 9,200. I've run a 13.5mm cam in a Duratec with my own spring package. What amazes me is that many engine builders put valve springs in engines that the cam supplier suggests without actually knowing the full lift, over the nose poundage. This and the distance to coil bind are the two of the most important parameters. I know the on the seat and full lift poundages for all the engines I build. My guess is that a lot of people don't bother doing this and just bung in the springs they are given. I also had a tool made for checking valve spring coil bind on the engine. There is a critical full lift to coil bind measurement I use. When you look at the engine from the outside it looks like any other Duratec. You can't see the extra hours that have been put in doing all the checks that will give you some sort of fighting chance to make the engine survive. The Duratec is fitted with a high velocity Hy-Vo chain as standard. The same type of chain that is fitted to thousands of racing motorcycles that turn more rpm than the Duratec ever will. There are two different sorts of Hy-Vo chain fitted to Duratecs. An 8mm and a 6mm pitch chain. The 8mm chain is the one I use. Old Guzzis ran a roller chain and it was pretty useless as it would stretch and rattle in no time. Replacing the Duratec chain isn't on my list. If the chain is properly tensioned there is no room for it to jump off the sprocket. For the manual tensioner conversion I have been fitting for quite a while there is a tensioning procedure that I developed that ensures the tension is correct when the engine is hot. It we don't want the cam timing to fluctuate is is essential that the chain tension is correct. The only problem with the stock tensioner that I have actually witnessed was that the ratcheting mechanism allowed the chain to over tension. The mechanical conversion stops this happening. In one case of a chain over tensioning I heard of a chain snapping on the dyno. Glad it wasn't my engine as it made a terrible mess apparently. Different engine builders and tuners will have different findings and experience with engines. Their opinions will differ. That's OK. Nothing wrong with having a different point of view or approach. It is only right that they should persue their own courses and find out for themselves what works and what doesn't. If everyone ended up building the same engine it would be very boring.

Good luck with the project 2CV. Thanks for the offer of sending over your old engine. I might take you up on it at some point. Fred SBD are to be complimented on their results. They are a much bigger and more successful concern than Raceco ever was or ever will be. They have more resources at their disposal to do this sort of work. Funnily enough when Raceco was at its height in the mid 90s and employed 5 staff we were also based in Surbiton. Just up the road from SBD. Now Raceco is just one person. Me. A couple of things I would like to point out though. What SBD have done is their engine in their own way. Their design philosophy is completely different to mine. They have bigger ports and bigger valves. Almost the opposite of what I want to do. I want to do my engine differently, using stock valve sizes and smaller ports to achieve similar results at a lower, more affordable price. The target power is going to be 295 bhp which I am confident can be done. People that know me know that I tend to be conservative with my numbers. If we can break 300 bhp that would be a bonus. The big valve heads I have done in the past cost around £2,500. I can hand port a head with standard valves for around £800.00. That is a big saving. The money saved can be put towards a crank that will hopefully make the engine bullet proof. I'm thinking more on the lines of an endurance race engine. In the old days we would strip and check our engines every race. I have been told that BTCC engines last only 800 kilometers before they go off and lose 20 bhp. Customers nowadays expect to race a whole year before coming back for a refresh. They also want the engine to be making as much power at the end of the season as it did at the beginning. Experience has taught me that there is more than one way to skin a cat. In my first year of racing the Moto Guzzi in 1986 I built an engine that we tested at Leon Moss' Ledar dyno. It ran 40mm carbs with long bellmouths. We had straight pipes made and chopped them off an inch at a time until we found maximum power. When we went an inch too far and lost power we welded an inch back on. In those days there was no noise testing, you could run with no silencers and you could make as much racket as you wanted. The bike was very loud and would hurt your ears. Did sound nice from the pit wall when it was on song though. The next race was Snetterton. In the paddock was another Guzzi of a fellow competitor. He turned up with short bellmouths and a longer exhaust system, also just a straight pipe, no silencers. I was pretty confident he had got it wrong. In the race the bikes were neck and neck. On the back straight, which is the final proving ground as far as I'm concerned, the bikes were equal. Nothing at all in it. Neither would stomp away from the other. It taught me that there is more than one way to get the same or similar result. Ten years and ten race seasons later, after a race at Snetterton, Geoff Baines who was racing a Ducati came up to me and said "Your bike is a rocket, Paul (Lewis) came up alongside me, waved, popped a wheelie and pulled away from me on one wheel". Still make me smile to this day. We won the championship that year, Geoff came second. I want to do my Duratec engine my way, using my own intellect. Copying other people or using other people's parts doesn't interest me one little bit. Regarding my engine design philosophy I do have some track record. Winning championships with 2 and 4 valve Guzzis and helping others win races and championships with bikes and cars. What I am doing is using tried and tested ideas behind tuning the Moto Guzzi Daytona and the Ducati Supermono and apply them to the Duratec. The Supermono is an interesting case because it won the singles race at Daytona. If there ever was a speed circuit that is it. The long banking really sorts out the men from the boys. The bike also came third at Daytona in the BEARS (British, European and American Race Series) that was open to twins and triples. It also came second in the Isle of Man. The difference between the Ducati and the Guzzi and the Duratec is that years on we have a cylinder head with standard valves and a few mods that flows more than both the Guzzi and the Ducati did. Thanks to Ford. They did a great job. The head is great out of the box. Of course I secretly hope that my Duratec engine will do well when it is finally built how I want and it finally gets tested. I am also (reluctantly) willing to accept failure if it doesn't work. As I hate failure I will do everything I can to make sure that doesn't happen. Edited by - AMMO on 28 Feb 2013 08:50:43

Giles The book was Desktop Dynos. Computer engine simulation has probably moved on since then. I have a friend that works at Lotus that reckons that their software can even predict the sound the engine is going to make. Personally I'd rather build the engine as I said before. "I want a roadcar with 300bhp, loads of low down torque, and it must be indestructable. Also, it must be quiet when I'm cruising and return 40mpg. Oh... and my budget's £3k". You forgot "and it has to pass the MOT" Something you use to inflate bicycle tyres is a "simple air pump". Internal combustion engines are much more complex. For me the complexity is to do with component selection and all the variables you can have. Induction lengths and exhaust tuned lengths, cams and cam timing, valve sizes, airflow, throttle body sizes. A proper development program would cost lots of money having components made and take weeks of dyno testing. I did a three day stint at Emerald that cost me around £1,500.00 at mate's rates as it was all I could afford. If I was rich I would gladly throw 20K at it to find useful information out. As I have built a lot of different engines with different bores and strokes, valve sizes, cams, exhausts etc. I can take an educated guess at what is likely to happen. The prominent former member of the club / decorator guy Tony mentioned asked me to build him an engine that made between 260 and 270 bhp. It made 265 bhp on the dyno with another 5 bhp to come once it had bedded in. Those sort of engines you can churn out all day as we know more or less what there is to know about them. But even those haven't really been fine tuned. Another guy asked me to build him a 280 bhp engine. It made 265bhp too. When we looked at the exhaust he had bolted to it the header lengths were all over the place. Cylinder no.1 was 36" long, no. 2 31", no.3 37" and no. 4 31". To avoid getting the "you said it was going to make x power" conversation with the customer, especially for the 300 bhp + engines, I decided to have my own exhaust made. Cost a fortune with little profit in it but it had to be done. But even that was based on an educated guess based on experience. "Make me headers to these dimensions" and it worked. Had we had a budget we would have tried different things. At the end of the day it is good enough, but who knows if it could have been made better. That is the point of it all. To do as good as or a better job than the next guy. People who go racing have a character flaw. They want to prove they are better than the next guy. We did a lot of winning in the old days. It is addictive and becomes an obsession. A Duratec that turns 9,500 rpm reliably lap after lap is an unknown to me and that's why it is more interesting. It is also an obsession. For that engine which unfortunately I don't get to build until next winter I am going to look at every single aspect that will give me an edge. I probably won't be able to charge the customer for every hour that goes into it, but from a personal satisfaction point of view I am itching to do it and have been for a few years now. The 2 litre Duratec is unfinished business. As I have said before I was knocking out engines with 75 bhp per cylinder almost twenty years ago. If we had the budget the engine would have been much further down the line by now. 2 CV, regarding throttle bodies and the software prediction of 62mm. I have tried 60mm throttle bodies on a 580cc Ducati single in 1998. The stock body was 50mm which I had taper bored to 54mm. At the time Ducati offered 60mm throttle bodies as part of a race kit for the World Superbike V Twin. We found two guys racing the singles that were willing to fork out the 2.5K required to buy the big bodies. End result was that they made the same power (75bhp at the rear wheel, up from 63.5bhp) as the 54mm but that the 54mm held onto the power for another 500 rpm. I'm glad someone else paid for the throttle bodies! I also know someone who has tried 60mm bodies on a Duratec and says that they didn't work for him. He now uses 53mm ones, I use 54mm. So we pretty much came to the same conclusion. He also does motorcycles. His 600cc four cylinder engines run 40mm bodies. I think if you have your feet in two camps, cars and motorcycles, you tend to favour the larger bodies. Here the flow bench can be your friend as it seems to me that you really don't want to put something on the engine that restricts the flow. There is also no point it putting something on that is too big though. What we found with 2 valve motorcycles and carburettors years ago is that the carb works OK at around 95% of the valve size. So the Guzzi we raced successfully and won championships with had 44mm inlet valve and a 40mm Dellorto that I bored out to 41.5mm. For your engine 95% of your 40m valve size would be a 38mm. My guess is that in real life this is going to be a bit too big. For the road I would use something like a 34mm to maximum 36mm. That's for a slide carb. For a CV carb with a butterfly you could possibly go bigger. You could probably pick up some CV carbs off eBay quite cheap. Unblocking the induction on your engine would probably give you a big gain on it's own. If you go too big the engine probably won't pull the skin off a rice pudding at low rpm. Again it is looking at the engine as a whole and getting everything to work together. I have a funny urge to go out and buy a 2CV. Your project has got me curious. If you do get an engine in bits at some point I wouldn't mind having a look inside. Going back to looking at pretend engines on a computer, it's basically the same as looking at women on the internet. Not the same as the real thing. Which reminds me, I have an appointment with a very pretty brunette for lunch.

Giles The figure of .43 is not linked to lift but the calculation Superflow use to predict bhp from airflow in cfm at 10" test pressure. Theoretically the engine can make .43 of a horsepower for every cfm. Garry7, I think you did the right thing in getting a Duratec. I'm sure that the Sigma is a lovely engine but the capacity limits torque and power. If you are happy with the power the Sigma puts out or its tuning potential that's fine, but the Duratec offers so much more scope. I have some engine customers abroad who have fitted my kits of parts to the 175 bhp engine that converted them to 280 bhp engines for the track. These are clever race engine builders in Italy and Prague. I have visited them and have seen the quality of their porting. They all made the predicted 280 bhp +. How many other engines out there that produce 145 bhp in a road car can be relatively easily uprated to almost double their power in N/A form? Starting from Caterham's bottom of the range 175 bhp engine we are talking over 100 bhp more. It is an amazing engine and that's pretty much why I have been a big fan of the Duratec since I first clapped eyes on one in bits in 2001. Giles, to expand on what you have said I can give a practical example. I flow bench tested two heads years ago. A stock 2 litre Zetec and a Suzuki GSXR 750 race head. If I remember correctly they had the same valve sizes and flowed approximately the same. They both have the potential to make the same power but at different rpm and with different torque. Let's say around 160 bhp. The Zetec will make maximum power at around 6,500-7,000 rpm and the Suzuki will make it at 15,000 rpm but with a lot less torque. The head pretty much dictates the power, the capacity dictates the rpm and torque. As for the exhaust valve sizes, these are usually in the region of 85% of the inlet size. The Duratec has 35mm inlets and 30mm exhausts. The figure of 85% seems to work pretty well. Flow for the exhaust valve in comparison to the inlet can be around 70%. There are differing opinions to what you actually need. Some say as little as 65%, others swear that you need 80%. Somewhere around 70% seems to work. The exhaust system, cam and cam timing, induction all have an effect on how the exhaust port behaves. Some say having a smaller port with a bigger, slightly mismatched exhaust has an anti-reversion effect. Some say you need a bigger port with no mismatch. You could test all the variables until the cows come home. 2CV. The tortuous intake, carb and air cleaner will be restrictive. Every time you make the air change direction you lose some flow. The Belgian guys run a pretty straight shot with a tuned length on their 2CV. That will be worth quite a bit over standard. When we were racing air cooled two valve twins the best we saw was 95 bhp per litre. I stopped development on 2 valvers in 1993 when we started racing a four valve engine. Haven't looked back since. 2 valve engines don't interest me much. If you could get around 55 bhp out of your 2 CV you would be doing well in my opinion. I played around with a computer program that came with a book from the US that was geared for 2 valve V8's. This was a long time ago. The program was in DOS. I still have the book and 3.5" floppy disc somewhere. As I was involved with 2 valve twins it suited me. You could jiggle cam timing and induction and exhaust lengths. It was sort of fun but the figures it gave were not really credible. The conclusion I came to was that there is no substitute for actually building the engine and sticking it on the dyno, messing around with cam timing, induction and exhaust lengths to see what the engine actually does. For your engine I personally wouldn't set my aims too high. Even just another 30 or 40% increase in power would be nice to have and would be more affordable. If you want to chase the revs you are going to need a crank. I would look at what can be done with the stock crank first. Pretty much what I have done with the Duratecs I have built. I've stuck three different types of steel cranks in engines of varying capacities that were over 280 bhp. They worked sort of OK. The only one I would trust is the one I had designed and made for the 2.2 litre. The 2 litre is the only one I haven't run with a steel crank. To safely yield the benefits of the higher rpm and to be able to sleep at night that is the way to go. If you can't afford a crank don't rev it. That's what we have done with the stock crank that is limited to 8,500 rpm and it is lasting very well. Four seasons of racing in one case and 16,000 km of track miles in another. The 16,000 km engine went pop recently. It made a terrible mess when it dropped a valve. I put it down to the daftness of the customer who didn't have the engine re-built when he should have done. Now he needs a new block, head and loads of work. If he had refreshed the engine at a more reasonable mileage he would have had a much smaller bill for new valves, springs, shells, rings etc. Nobody should run a race engine for 16,000 km. If nothing else it has proved how durable the engines can be. For any engine to work all the components have to work in unison. Rather than grab a bit from here and a bit from there, look at the engine as a whole and what you want it to do. It has to be designed as a package from the start. My personal opinion is that you shouldn't take little stabs at it. Life is too short. Decide what you want to do and do it. My customers wanted to do a bit this year and a bit next year and a bit the year after that. Why? Just get on with it. Borrow the money if you have to, use a credit card, take out a loan. I never asked a customer to do something I hadn't done myself. Some went away, saved up the money and came back with the dosh two years later. Some just got the credit card out and paid that off a bit at a time. As far as I know for the married ones this never actually ended up in divorce, but in some cases it might have been a contributory factor.

Giles I have no practical experience of Helholtz resonators although I have mentioned them in the past. I have done work on airboxes on race motorcycles. On bikes you have little room but what seems to work is running a big airbox if you can, several times the capacity of the engine if possible, and making sure you have a cold air feed. I tested and appraised the airbox on the Rizla Suzuki that John Reynolds won the British Superbike championship on and a Ducati Supermono that won at Daytona. Both bikes had the air horns and throttle bodies modified by me. On the flowbench the airboxes offered little or no restriction. In the case of the Suzuki that used the bottom of the fuel tank as the top of the airbox we lost only 1 cfm when the long inlet ducts were fitted. Quite impressive I thought. In the case of the Nissan I can't remember it having an airbox as such. I do remember that the head was reversed and that there was a box bolted onto the individual throttle bodies. It had a large front facing flat element K&N or similar filter that was exposed. Air pressure under race conditions never went up more than a few millibars. The velocity in the ports is much higher than the road speed. I think I calculated that you had to be doing 185 mph to match the airspeed in the intake ports of a well developed race engine. I personally can't see vast increases in power from an airbox. Small increases perhaps but nothing in the region of 20 or 30 bhp. They also seem to smooth things out and the torque and power curves are less spiky. I really don't know enough on the subject but more to the point I haven't done enough testing to comment with convinction. I do know that you can easily lose power with a badly designed airbox. This I have seen. With Caterhams the subject of airboxes comes up when there is a need to silence the intake noise. When we needed to silence a 307 bhp engine we fitted the biggest (and unfortunately ugliest) box we could find. It was actually one intended for a six cylinder engine as I thought the one available for the four cylinder engine was too small. It didn't help that we were running 8 injectors with some outside the trumpets so apart from being long it also stuck out a mile. The airbox was huge but it is what I reckoned it needed. The engine was heading towards 2.5 litres in capacity and ran 54 mm taper throttle bodies at the time. The later 54mm bodies outflow even the old ones we used. The engine used a lot of air. It is easy to lose 20 bhp with an airbox and having worked very hard to get 307 bhp I wasn't going to throw power away. Luckily we only lost 5 bhp so we could still call it a 300 bhp engine. Elie Honda motorcycles used to quote figures for their bike engines that didn't take into account the losses of the alternator and water pump apparently. I take parasytic losses quite seriously as running the alternator and water pump can lose you a few bhp. I have never tested how much power they use but I can't see it being that much. The extra power you get is the icing on the cake when you are looking for the last few bhp. I agree with you that it is probably only 5 or 10 bhp. Possibly less? That's a guess. Without doing the testing I wouldn't like to bet on it. Birkin Race engines tend to make their power higher up than road engines. The more airflow you have the more tendency there is to make torque and power higher up the rev range. On a road engine with restricted air flow, small valves, undersize ports, restrictive air cleaners you can see the power peak at lower rpm. Removing the restrictions and the power moves up the rev range. A simplistic explanation would be the difference between your Zetec and a Duratec. You could say that the Duratec is like a Zetec with bigger valves and ports. The restrictions have been removed. The result is that when the Zetec power peaks at around 7,500 rpm or there abouts the Duratec still isn't over and done with at 8,500 rpm. That is principally because of the additional airflow. As for the upgrade to the 280 bhp engine, the torque will remain exactly the same unless we can screw the extra foot lb or two out of it (which is unlikely). The rpm will make the difference because we will be able to use the power that is already there at higher rpm but are afraid to use. Remember that dynos do not measure power. They measure torque. The formula for power is torque in ft lbs x rpm / 5250. The more you can move the torque higher up and increase the revs the more power you will make. F1 engines make high power figures with little torque because they can rev to 18,000 rpm. For example if we can make 280 bhp at 8,500 rpm with a 2 litre Duratec that means we have 172 ft lb of torque. 172 ft lb of torque at 18,000 rpm for an F1 engine is 589 bhp. If we can keep the torque from falling too far there are power advantages in being able rev the engine more. The graph clearly shows the power still rising at 8,500. here A slight over rev of 280 rpm gave another 6.5 bhp. If the torque doesn't plummet and we can rev the engine more we will see more power. "when you look at some of the dyno charts of your motors the max torque is very close to max revs." That is the point. Power and torque should be further apart. When we eventually reach maximum power with more rpm the power and torque will be further apart. How do you measure efficency? BMEP.

Giles The inlet valve area can more or less determine the potential horsepower of an engine. For years I have been using a simple calculation to give me some sort of idea what power the engine is likely to make. The information came in the Superflow flowbench manual when I bought my first flowbench in the late 80s. Basically you take the valve area in square inches and multiply that by the cfm (cubic feet per minute) the head is likely to flow. This will be somewhere between 50 and 60 cfm per square inch of valve area at 10" test pressure. In the early days of two valve engines I used to use the 50 cfm figure with time and experience I tend to go more towards the 60 cfm figure, especially with 4 valve engines. If you take the case of the Duratec with stock 35mm inlet valves the valve area is almost 3 square inches of intake valve area and a well ported head makes 178 cfm. So pretty close to the 60 cfm per square inch figure. The problem with the head is that it makes maximum flow at something like 16 or 17mm lift. With more realistic lifts the flow will be less. By taking the flowbench flow figure and multiplying by .43 you get the potential power figure per cylinder. Taking a more realistic flow figure of say 165 cfm x .43 for a lower lift we get 70.95 bhp per cylinder x 4 = 283.8 bhp. Which is roughly where we are with the 2 litre engine at the moment. Flowbenches do not tell you everything but are a good tool to give you an indication that you are heading in the right direction when you modify a head. The fact that you get a certain amount of cfm from a head doesn't guarantee a power figure. It can be more or less. If all the other components have been selected properly, cams, induction and exhaust, you can get more power than the flowbench indicates. Some people manage perfectly well without a flowbench. The best MGB head I ever saw were done by a couple of old fellas in a shed in Birmingham. They had never seen a flowbench but the head was spot on, both on the flowbench and the dyno. The idea of flowbenches is not a new one. I was told that Harry Ricardo was flow testing cylinder head ports in the 1920's. By using a known quantity of water in a tank connected to the port he could see how much time it would take the tank to empty using a stopwatch. The better the flow the least time it would take to empty the tank. In fact I like to think of a flowbench as a tool to measure restrictions rather than outright flow. Which is pretty much what old Harry was doing 90 years ago. The same way you get BS figure quoted from dynos you can get BS figures quoted from flowbenches. I was given some heads to test by someone once that had been ported by someone who had a flowbench. The figure quoted was 126cm. When tested the heads flowed only 105 cfm. The guy porting the head was relying on nobody testing it afterwards. I've heard of people having flowbenches in the corner of the workshop because, I quote, "I don't use it but it makes the punter think we know what we are doing". Jonathan I have spoken to a few people and basically there is no real money in publishing a book. The advice Dave Walker from Emerald gave me is to by all means write the articles and to put the articles on my website. The website is always painfully out of date and I should be putting more effort into it. "I'd encourage you to put them on the web with free access, good proofreading and lots of pictures." It's a good idea, but it takes time and I do have a habit of procrastinating. I have new products to go on the website and even the photos for the old products like the silencers and throttle bodies are out of date. The racing successes and photo galleries need updating, etc. I suppose for the last two years I have been treading water trying to decide in which direction to swim. I thought I had lost interest in engines. The truth is that I have lost interest in road engines in the 210-270 bhp that more or less anyone can build. Racing is the ultimate test, so that's what I will concentrate on for a while. Development and design is what interests me not being a fitter of other people's parts to a known specification. Engine tuning is about going forward and trying new things, not nailing the same old stuff together. Otherwise your mind atrophies. Thanks for the feedback guys. Especially Tony for his honesty and frankness. I'm thinking of changing my signature from AMMO to DOT.

Klunk, it is good to have some feedback and to know that someone is actually reading this stuff. Sometimes I think that I probably sound like a deluded old twat that is talking to himself. People who know me personally might actually agree with this last statement.

I did more BMEP calculations this morning. For years I have been quoting figures for the Nissan touring car engine. This was the engine to beat. I have been saying that the power for this engine was 312-314 bhp with a rev limit of 8,500 rpm. I have also stated that after further development the engine allegedly made 324 bhp. Some months ago I tried to call Graham Dale-Jones who was one of the people who developed this engine at IES, but he has sold the company and moved on. I sold a mate's Superflow 901 dyno to IES and did a little bit of development work there circa 1998. I know Graham a little bit and always used to pop in for a cuppa if I was passing but haven't done so for years. I'd sometimes sit in his office and have a natter. I also know the guys at AER who took over the development of the Nisan so they are next on my list of people to talk to. Basically, to make 314 bhp at 8,500 you would have to have 193 ft lb of torque at the point of maximum horsepower. 238 psi BMEP. At the point of maximum torque the BMEP would be even higher. I tried to get some more figures for this engine. I was told a couple of days ago by someone I respect that in its final guise it had 200 / 205 ft lb of torque at 6,000 / 6,200 rpm and 331 bhp @ 8250. This would give 253 psi BMEP at the point of maximum torque. If you work out the torque figure at the point of maximum power you get 210 ft lb. The torque figure at max bhp is higher than the torque figure at max torque. That sounds very wrong to me. BMEP is now 260 psi. Can this be right with everyone else quoting 230 psi maximum? Pulled this from a thread dated 2003 here "Standard specification in the Touring Car format is a 2.0-liter, so the car has a modified version of the 1,998cc-inline four-cylinder setup that is subject to explicit specifications. One regulation states that teams cannot alter the position of the valve centers, limiting the size of the valves that can be used, however leaving the specific size and configuration of the valves up to the developer. In Audi’s case, this meant 4-valves per cylinder for a 16-valve setup. With regulations in mind, every possible modification is made to the engine in an effort to optimize power and reliability as much as possible. In full race specification, the modified engine produced 296bhp at 8,250rpm and 188lb ft torque (225Nm) at 7,000rpm. For the 1997 season, power was bumped up to 305bhp at 8,250rpm and 217lb ft torque (260Nm)." If you do the numbers for the 296 bhp engine with 188 ft lb at 7,000 rpm you get 233 psi BMEP at the point of maximum torque. To make 296 bhp at 8,250 rpm you still need 188 ft lb of torque at maximum rpm. This also sounds wrong to me. Torque should have fallen by the point of max power. For the 305 bhp engine you get 268 psi BMEP with 217 ft lb of torque at the point of max torque. At a max power of 305 bhp @ 8,250 rpm you need 194 ft lb of torque = to 240 psi BMEP. The latter figure of 240 psi BMEP is more credible according to some but the 268 psi figure is in the realms of science fiction. Do these Touring Car guys know something we don't, when everyone else accepts that 230 psi BMEP is around the maximum you can expect? The Vauxhall detractors always said that the BTCC engines only made 280 bhp. I know an ex Swindon guy that confirmed this to me. I also heard of a VX engine that was being transported overnight that sort of ended up at a competitor's dyno and made 280 bhp. Could be an Essex tale with no truth in it, but still a story I like to tell. I watched some old BTCC videos on YouTube. If the Nissan had that much more power than the VX why wasn't it much faster and piss off into the distance? One thing that strikes me about the bumper cars is that they all seem pretty even in speed. If there was 50bhp difference between the VX and the Nissan I would have thought that there would have been a larger difference in speed. I hope I have done the maths right and that the figures are correct. If I have made a mistake I would be happy to be corrected. If these guys are truly getting 250 to almost 270 psi BMEP from their engines I would like to get some for my race engines too. Maybe I'll ask Santa to bring me some for Xmas when I should be starting to upgrade my puny 280 bhp 2 litre Duratecs. They really could do with some as they only have an average of 185 ft lb of torque and 228 psi BMEP. Edited to correct spelling and sentences that made no sense at all! Edited by - AMMO on 24 Feb 2013 10:14:58

I was kind of hoping that posting would start a technical debate like the ones we used to have. As for BS numbers we used to get that all the time in racing. At the end of the day all the calculations, flowbench and dyno testing are pretty meaningless. The real test is the back straight at Snetterton where we did a lot of our racing in the early days. When we had 78bhp out of the old 2 valve Guzzi we went past guys who quoted 90 bhp. When we got the engine up to 91bhp we went past guys with over 100 bhp. I did a V8 4.2 Ford race project. Assessment, porting, plenum mods, cams, etc. Up from 327 bhp to 397bhp on restrictors. Everyone else was quoting 440bhp. From the outside the stock cast plenum looked standard. On the inside it was a different matter. Flag drops, BS stops. I was told that the car went past everyone else, sounded completely different and revved 1,500 rpm more. Been doing more BMEP calculations this morning specifically related to the BTCC engines which makes me rethink some of the statements I made in the past. Will fire up the BMEP thread again. From a totally selfish point of view, even if nobody else participates it helps me organise my thoughts and put them down in writing.

What's wrong with the standard starter motor? That's all I've ever used on my engines that are fitted with a standard size flywheel.

A friend once commented that my sons and I run a kind of mutual appreciation society. We get on very well. I attribute a lot of my son's personal success from a very early age to the fact that since they were little they came to the race track and saw my team win races. They saw it required a lot of hard work. I am sure it has given them a "can do" attitude. They also saw that we had a lot of fun doing it. Life is a balance between work and play. I am sitting in my youngest son's flat in London as I write. He is just got up and about to have breakfast before going to work. Just asked him the question about my "can do" theory and seeing the racing as a young boy. His answer without hesitation was "Yes, definitely". On Sunday I went to a memorial lunch with the Team Bike / Team MCN crowd. People came from far and wide to remember some of the guys that are no longer with us from those days. One of the guys was a rider, then mechanic Dave Chisman. The event is held on his birthday. His mum who is in her 80's always attends. This was the 26th year. Also to remember Howard Lees and Kenny Irons. Once the glasses had been raised some of the old stories started coming out. They still make us laugh to this day. Getting a lot of the things we in writing is a good idea. Some of the stories around the racing are really funny and would be good to share. I spoke to rider turned journo Mat Oxley at the lunch. He says that there is less money in writing than there was ten years ago. The advances and royalties on books are hardly worth having but if I do it it will be for the same reason I have done most things in my life. For fun and because I enjoy doing them. His parting words were if you want to make money writing books write one about Valention Rossi. They sell. Tuning engines, racing and all the other things I have done I did for the sense of satisfaction not neccessarily for the financial remuneration. That is why if there is no money in a job and it is also no fun I won't do it nowadays. I get up at 4 am to look at dyno graphs because the passion has come back after a couple of years of not really thinking about engines that much. A friend, mentor and teacher to me was Manfred Hecht of Raceco Cycles based in Brooklyn, New York. When I asked him how much money he made tuning Guzzis he said "You don't think I do this for the money do you? If I wanted to make money I would do something else". Manfred worked from 9 am to 9 pm every day of the week. I was introduced to him by Guzzi tuner John Wittner in 1986. Manfred did John's heads. It is because of Manfred that I eventually bought my first flowbench and started porting heads. In the late 80s we paid Manfred $1,000.00 to port a pair of Guzzi heads we supplied. I asked for a trade discount. He said no, because you will only ever buy one pair of heads and after you see how they are done you will do your own. In all the years I dealt with him I never got a penny discount. I used to import his parts into the UK and Manfred imported my parts into the US. Manfred taught me not to discount, there is little enough money in the jobs nowadays. To be magnanimous and give away money as if it grew on trees is not that smart. When people don't charge enough they go to the wall. If I can't make a profit I won't do the job. I'd rather have a nice lunch and watch a cowboy film and fall asleep on the sofa in the afternoon. Financially the result is the same but without getting your hands dirty. When I asked Manfred what secrets or principles he used for porting, rather than tell me he said to look at a Jaguar D type head. This was in the days before the internet so I went to the library (or it might have been Chater and Scott's in Isleworth as I lived around the corner at the time) and after going through a lot of books found one cross sectional drawing of the port, manifold and carburettor. This gave me some sort of idea but the drawing was quite small. Not knowing what to do next I decided to call up Jaguar and asked if the guys who did the D-types were still around. They said no that they had retired but gave me a number I could reach them on. I called the number and got this really nice old boy on the 'phone and told him what I was trying to do. He spent time explaining things to me. What he told me can be summed up in very few words. The critical dimensions of the throat and ports in relation to the valve size. These "magic numbers" are the ones I have been using since the late 80s and seem to always work. Apart from the fact that they are not "magic" at all. They are well documented. The Ford Duratec is pretty much spot on with the critical dimensions. Anything you do is to improve what is already there. It is possible to get the intake up to 178 cfm @ 10" with the stock valve and without resorting to ports that are that much bigger. The heads with bigger ports give worse flow figures at low and mid lifts. They make big numbers at lifts we don't have cams for at around 15 or 16mm. As realistically you are not going to use cams like this best it is best to stick to sensible dimensions for the port, save time and money and keep the gas velocity high as ultimately this is what will help fill your cylinder and help volumetric efficiency.