andy_h Posted June 29, 2008 Share Posted June 29, 2008 Got my 7 rolling road tested yesterday by Tom Airey at Airey Tuning. Couple of power runs to see what it was doing (a very disapointing 140 bhp (I knew it was down on power). After re-jetting, re-set fuel regulator, reset carbs, changed spark plugs for good quality 40 quid set, another power run and 50 bhp was added. so we're at 190 BHP. Some distance from the aledged 250bhp it was sold to me on Tom says I could get another 10 or 20bhp but I'd need to re-set the cams (retard afew degrees) to increase revs as my power curently peaks at 6,300rpm. He says I'm getting valve bounce at peak as the springs are getting a bit weak. The scary bit was sitting on the rear NS corner during the power runs to keep traction with the speedo reading nearly 140MPH!!! The oil catchtank was venting a bit but aparently nothing to worry about, TADTS. A test drive proved a huge diference with much much better pick up and response, and it reved much better after 5k. When I returned Tom re-checked plug colour and all was as it should. Roll on Classic Le Mans.... we're ready (after an engine oil change, brake pad check/change, re fit boot floor blah blah...) White road legal 2.0 HPC VX race car 😬 Edited by - andy_h on 29 Jun 2008 20:39:02 Link to comment Share on other sites More sharing options...
neilg Posted June 29, 2008 Share Posted June 29, 2008 Well done Andy, they are scary aren't they, i think it's better not to be there cos you think the engines are gonna blow captain. It was well down on power , must have felt really slow what with all that weight to lug around. 😳 😳 Hope you're well , just getting used to the 'bird at the moment, it seems everyone wants a ride in it. I do notice not so many want a second ride though!! I would love to go to Classic Lemans but busy at that time although i'm hoping to go to Goodwood Fest of Sd in a couple of weeks. Cheers Neil By the way your picture in my Pistonheads advert must have done the trick cos the car was sold within a couple of weeks!! Link to comment Share on other sites More sharing options...
Beelzebub Posted June 29, 2008 Share Posted June 29, 2008 ISTR someone's flywheel came of whilst on Steve greenalds rollers 😳 Link to comment Share on other sites More sharing options...
Peter T Posted June 29, 2008 Share Posted June 29, 2008 Yes mine. Link to comment Share on other sites More sharing options...
Beelzebub Posted June 29, 2008 Share Posted June 29, 2008 Did he brown his pants Link to comment Share on other sites More sharing options...
andy_h Posted June 29, 2008 Author Share Posted June 29, 2008 Hi Neil, Glad you're having fun with your new Bird. just don't let the wife know you have a new mistress 😬 I bet the difference between it and the Gulf 7 is huge. I was thinking of lots of 'what ifs' on the way to he rolling road but I'd prefer to attend than had the keys over. Then if anything does go at least I see it happen Must of been a big brown moment when the flywheel went. Take it nobody got hurt. Neil, why did you go for a bird engine 7? I understood they're unreliable and don't last very long? White road legal 2.0 HPC VX race car 😬 Link to comment Share on other sites More sharing options...
BYKer Will Posted June 29, 2008 Share Posted June 29, 2008 Andy Andy Andy- you will upset him saying things like that. 😬 I think it is the combination of 11000 plus rpm, 170 bhp, 430kg, 6 speed sequential and handling as good as it gets that attracted him to a bird. Yes they can break but so can everything and even if they go pop a new engine and box with low miles is well under a grand and easy to fit. Will Link to comment Share on other sites More sharing options...
stevefoster Posted June 29, 2008 Share Posted June 29, 2008 Interesting. Would that explain why the interrupter fuel pump managed before... I take it the 190 was on a Redtop or similar? Add lightness, says the man with a VX :-) My 2002/2003 racing pics here General pics (mostly of 7's and cars). here Link to comment Share on other sites More sharing options...
Paul Deslandes Posted June 29, 2008 Share Posted June 29, 2008 If you're on carbs and a standard Caterham Vx inlet manifold you'll struggle to get more than 210. I had my head and inlet manifold gas flowed and the flow rate went from 108 to 138 cu.ft/min. The inlet manifold was the limiting factor. If you don't get the manifold fixed you're wasting your money on anything else as it can't breath and simply won't work. Link to comment Share on other sites More sharing options...
neilg Posted June 30, 2008 Share Posted June 30, 2008 Andy, Will's spot on on the mark. Besides i was getting bored of 135 bhp, open diff, narrow track, poverty brakes and big lights 😬 😬 😬. Like all good mistresses, they might be high maintanance but it's the hit when your're in them that makes them worth while.( ooh and definately err) apparently?? Anyway gotta spare engine, gearbox, starter motor , full set of carbs, inlet manifold, radiator and oil cooler for £ 800-00 so if she blows I'm ready. Have to say after a few more blats at the weekend that it's BLOOOOOODY brilliant. That sequential.... Neil PS Sounds like you've gotta get your dremmel out old boy. Link to comment Share on other sites More sharing options...
andy_h Posted June 30, 2008 Author Share Posted June 30, 2008 I think it is the combination of 11000 plus rpm, 170 bhp, 430kg, 6 speed sequential and handling as good as it gets that attracted him to a bird. Yes they can break but so can everything and even if they go pop a new engine and box with low miles is well under a grand and easy to fit. I had no idea they were this good and so cheap... so why are car engines so dam expensive in comparison 🤔 I see the future.... we're all on Bike Engines 😬 Interesting. Would that explain why the interrupter fuel pump managed before... That's the point, I don't believe the solid state Facet (interupter) ever could/did manage. Even if it could it wouldn't have for very long as I doubt it could keep up flow to keep the carbs bowls full. Including the comments above, I don't believe my engine was/is capable of 240 to 250bhp. 200 to 210 may be. So either the rolling road result the car was sold to me on by previous owner was for another 7, or the result was very dodgy. Either way I've been conned *mad* Too late now My rolling road result giving 190bhp is with an Airtek pump. I've also added a filter on the input side. White road legal 2.0 HPC VX race car 😬 Link to comment Share on other sites More sharing options...
alan c Posted June 30, 2008 Share Posted June 30, 2008 Andy - is that figure with standard cams? If so do you have a note of the settings used for the carbs. I have a VX that is running with the Stage I upgrade that Caterham offered with a claimed 218 bhp. I know the carb settings mine is running on and what CC did to some to get closer to the claim so it would be interesting to compare these with yours. On a recent RR session mine peaked at 183 bhp just before the limiter came in at 7300 but the curve for the last 1000 rpm is not very smooth so I suspect valve springs may be an issue for mine as well. As for being scary mine managed to break its throttle cable on the first power run 😳 Alan Link to comment Share on other sites More sharing options...
Paul Deslandes Posted June 30, 2008 Share Posted June 30, 2008 In a conversation with Darren at CC parts a while back he reckoned that a significant difference in the power output of the race engine versus the standard carb car was the dry sump which liberates about 12bhp. ISTR that standard was 175 on carbs, 165 injection and 190 in race trim on 48 DCOEs/dry sump. Link to comment Share on other sites More sharing options...
alan c Posted June 30, 2008 Share Posted June 30, 2008 Paul, That comment ties in with what I had heard. My understanding is that at least one engine was sent back to Swindon and as well as changes to the jets etc it came back with a dry sump. It never made the 218 bhp claimed but it was a lot closer. Alan Link to comment Share on other sites More sharing options...
Neil Felstead Posted June 30, 2008 Share Posted June 30, 2008 Paul, Was it a case of matching the standard CC inlet manifold to the head or use an alternative inlet manifold that makes all the difference? cheers Neil Link to comment Share on other sites More sharing options...
Paul Deslandes Posted June 30, 2008 Share Posted June 30, 2008 Neil Simon Armstrong at Ultimate Performance near Northampton took my head and manifold away and put them on his flow bench and reckoned no matter what I did with cams nor indeed the head would make any difference as the manifold was strangling the induction. He thought I'd be lucky to see 210 although my manifold may have been a particularly bad one. At first we thought I was going to have to replace the manifold with something much better but he managed to work out a profile that made an enormous difference to the manifold flow. He then worked on the head which included opening up the ports and all the usual tricks for improving the head flow. He was then able to match the manifold to the head. That's a long way of saying he did both! I'm running on 48m Jenvey throttle bodies and SBD cams that got me 254bhp at Track N' Road. I've changed the cams and exhaust since to get the bottom end torque up and the top end power is down to about 243 but the driveability on hillclimbs is vastly improved. Its the old story of 'if it can't breath it won't go'. Paul Link to comment Share on other sites More sharing options...
Ian R Posted June 30, 2008 Share Posted June 30, 2008 Andy Well done, that's a big improvement. When mine was standard from Caterham on 45 carbs and dry sump it made 189bhp and that was considered top for carbs, standard cams/head and 4-1 exhaust. With the Jenvey fuel injection conversion, but still keeping a standard head and Caterham inlet manifold, but using SBD hydraulic cams and pocket pistons, it makes 216bhp at TracknRoad. Anything after that, as people say, then starts to need modifications in numerous areas, and starts to cost! See you next Thursday on the Ferry! Ian (C4T VX) (If you want to go faster, you will have to add lightness!) Link to comment Share on other sites More sharing options...
Neil Felstead Posted June 30, 2008 Share Posted June 30, 2008 Paul, Thanks for the info, I have DCOE 45's I didn't have time to match the inlet to the head before it went off to 'Track n' Road' judging by your comments I will get the dremmel out! Cheers Neil Link to comment Share on other sites More sharing options...
andy_h Posted June 30, 2008 Author Share Posted June 30, 2008 Alan, I don't know what the cams are as I didn't build the engine. However, Tom assessed my cams at 107 degrees and he suggested they need retarding a few degrees to get a bit more revs. I don't know the carb setting as I was in oare of Tom and is old school with 40 years experience and the tails he was telling. So I didn't take notes of jet sizes etc as he was doing it. Sorry. My engine is dry sumped, with MBE ignition, and pair of 45's I don't know if my inlet manifold has been modded. How do you tell? White road legal 2.0 HPC VX race car 😬 Link to comment Share on other sites More sharing options...
andy_h Posted June 30, 2008 Author Share Posted June 30, 2008 Thanks Ian, feck...... next Thursday.... it's getting close now.... (mix of excited and feeling of not being anywhere near ready re packing etc). At least the car is ready. Should have said, mine also has it's orginal racing days 4-1 exhaust. I'm sure their is a huge amount that could be done to improve in many different areas to gain a couple of BHP here and their (4-2-1 exhaust, flow head, etc etc), but as you say it'll cost and with twins on the way my pocket money will be cut ☹️. This also reduces the reliability. The main thing is I'm happy with my (new) current set up so I'll stick with it for now. I'll look at doing the cam retard and springs when the engine gets a refresh (couple of years away). White road legal 2.0 HPC VX race car 😬 Link to comment Share on other sites More sharing options...
I reply to every thread Posted June 30, 2008 Share Posted June 30, 2008 The Swindon 218 and 235 specs refer to what the engine should produce with an ideal inlet & exhaust. Once fitted to a Caterham they didn't have that, particularly on the inlet side. I had a lot of work to get mine to 232 from the standard 175, Head, Swindon cams, springs, titanium caps, pistons, dry sump, TB's, solid lifters etc etc. The bottom line is that if you have hydraulic lifters you haven't got more than say 210 bhp. If you have carbs you are unlikely to have much more than 225bhp and driveability is likely to be compromised. I'm sure James (Fletcher) may disagree though. There haven't been many VX XE's in Caterhams with a genuine 250bhp. Link to comment Share on other sites More sharing options...
Ian R Posted June 30, 2008 Share Posted June 30, 2008 I've got the biggest cams SBD do with hydraulic tappets, mine gives 216BHP and 171ft/lb which is spot on what SBD claim the first upgrade kit will give (215bhp/175ft lb). Ian (C4T VX) (If you want to go faster, you will have to add lightness!) Link to comment Share on other sites More sharing options...
Gambo Posted June 30, 2008 Share Posted June 30, 2008 My car, sorry ex-car. Was running SBD 225cams with hydralic lifters. If my memory serves me correctly I bought the cams from Paul D. Enigine made 227bhp /177lbft on Steve G's rollers. Standard zorst is carp. I plumped for SBD manufatured by BTB. Best upgrade of the lot though was fuel injection. Even before I did ANY work to the engine, I put that on. NOt really any more power, alittle at the top, but not what Steve broughton would lead you to belive, but the engine was SOOOO much nicer to drive and responsive. No longer RED 2.0 HPC 230BHP here Link to comment Share on other sites More sharing options...
Midnight Posted June 30, 2008 Share Posted June 30, 2008 Apart from the possibility of engine problems on the rolling road, the thought of what would happen if the car left the rollers at speed I don't think I would have been able to stop from 100mph in the 6 foot between me a fairly solid looking brick wall and I don't think the chains holding it down would've been too much help on my last session. Link to comment Share on other sites More sharing options...
Ian R Posted June 30, 2008 Share Posted June 30, 2008 forgot to mention I had the recommended 4-2-1 and 7" can made by Powerspeed to help fully liberate as much power/torque as possible from the mods! Andy - you know how well it goes you could not catch me at Llandow... 😬 Ian (C4T VX) (If you want to go faster, you will have to add lightness!) Link to comment Share on other sites More sharing options...
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