aerobod - near CYYC

My 2012 R400D doesn’t have them, either.

With the Advel head holes on mine being 9mm about 12mm deep, then around 7mm beyond that depth, I just used M10x1.5 bolts that are 25mm long with copper crush washers. Amazon says I should have my M18x1.5 tap and die today, so I can make a jig this week to accurately tap the block holes. My plan is to force a 10mm hex key into a 10mm hole in a slice of 25mm 6061-T6 rod, then machine it and cut the thread, before pulling the plug off the hex key and dressing it with a small file for a sliding fit on the key.

I find it similar to doing a 100 page technical consulting report - difficult to get started, good when in the groove and concentrating hard, satisfying when complete.

The Advel main oil gallery plugs were easy to remove using an M10 thread I had put into each one. I estimated that it took about 3000N of force to pull them out using a few blocks to pull evenly as the M10 nut was tightened: The oil gallery to the chain tensioner is only 10mm behind the face of the block on the front face. On the rear face there isn't much more room to the rear main bearing oil gallery: In terms of the use of threaded plugs for the ends of the block main oil gallery, the rear plug has plenty of room for a head, so a flange bolt or even a standard hex bolt with a copper washer can be used. the nearest component is the flywheel about 20mm from the mounting face. The front plug dimensions have to be quite exacting, the head can protrude no more than 2mm from the block to avoid hitting the timing chain guide, the thread length can be no more than 10mm into the block to avoid blocking the timing chain oil gallery. This plug can be used without a washer and blue thread sealant should be enough to allow future removal, a slight oil weep is not a problem as it is in an oily area and it can't back out due to the timing chain guide over the top of it. I will make both plugs from 25mm 6061-T6 rod with M18x1.5 threads.

Thanks for the encouragement Neil, I’m glad the 20 hours of head fettling is over, probably the biggest single job in the build. I think I have at least 0.5mm to the groove of the closest part of the O-ring, hopefully no rework needed there, as I didn’t enlarge the ports vertically. The untapped blind hole on the inlet manifold has a fix on the way, I’m waiting for an Amazon alloy motorcycle M10 brake caliper bolt that will fill the first 15mm of the hole, bonded in with red loctite to the bottom of the hole, the head cut off, then drilled through 6.8mm and to the same depth in the head as the other holes, then tapped M8 for the longer throttle body bolts.

Finished off the head porting and smoothing today. I first started off with the old head to check the wall thickness around the water jacket around the spark plug hole, finding that I don’t want to completely remove the “bumps” in the inlet, as the wall thickness would be less than 2mm if I did, will remove about half the “bump” thickness and have more than 3.5mm wall thickness to the water jacket: Started off port-matching the exhaust, kept it to 41.5mm, about 1mm smaller than the header pipes and 3mm smaller than the exhaust gasket to allow for any slight misalignment and avoid a step, but still 25% larger area than the standard 37mm ports, the #4 port EGR interference-fit blank I made blended in nicely without the hassle of welding and re-machining the mating surface: The inlet ports were port-matched to the Jenvey 48mm throttle bodies next, ensuring the slight lip at the top was left intact, as there isn’t a lot of distance from the edge to the sealing O-ring: The exhaust valve seats in the combustion chamber have a lip about 1mm high that will impede flow at low valve openings, so this lip was rounded (lip removed on left, still in place on the right): The combustion chamber was then sanded (but not polished), removing about 0.1cc overall, so no significant effect on compression, old valves were put into the combustion chamber being worked on to avoid damage to the valve seats: The valve seats were then blended inside the ports, ensuring the “bumps” around the spark plug water jacket weren’t too aggressively flattened: The exhaust ports were then blended and slightly enlarged: Then the same was done to the inlet ports: With a knife-edge in the inlet to separate the flow between the two valves: The head is now ready for valve seat testing to see that they fully seal, then a full clean in hot soapy water and blow dry with an airline, before being ready for assembly:

I will probably pull the Advel bodies with a 10mm bolt and remove with my slide hammer, as you say there will always be some doubt that the 3mm wall might not be enough without the Advel barrel in it. Will likely replace with M18x1.5 plugs as that is a commonly available size (if I need a low profile one I can machine it from some 25mm aluminium I have). The 3/8” NPT taper plug solution is just too small for the 16mm hole and 1/2” NPT looks a bit deep to not interfere with the chain tensioner oil feed, which is right behind the Advel plug body.

With the larger block Advels I found there is enough meat on them to just tap M10, as the body is still firmly in place, the centre doesn’t do anything to hold it there after it has expanded it when fitted. If the plug body can take the 25Nm of torque I will put on the flange bolt, I will leave them as is I think.

Sounds good Neil, for OEM bolts I had concluded the Burton and Cosworth info was incomplete. I’ll be using the 45Nm/90/90 Ford spec in the manual for non-spindle tightening. I just finished drilling out the Advel plugs in the front and rear of the block and tapping them M10 for flange bolts. It is interesting extracting the remains of the Advel plugs inside the gallery, as it is too big to pass through the M10 threaded hole, but I found using a magnetic wand inserted up inside the oil filter adapter feed hole to the gallery managed to retrieve them with a bit of messing around. Will have to see if the fixed part of the chain guide clears the head of the flange nut on the front gallery plug, if not an M10 grub screw with red loctite will be needed.

Last night I spent quite a while trying to solve a bit of a conundrum - are the Burton Power and Cosworth torquing instructions for the main bearing bolts correct, or is the Ford/Mazda Duratec manual correct? What I found in a Mazda forum is that there are two types of OEM bolt used, stretch bolts and non-stretch bolts. The stretch bolts are torqued beyond the yield point with 180 degrees of rotation after a 45Nm jointing torque with no thread lubrication (other than the protective coating the bolts are supplied with), the non-stretch bolts are torqued below the yield point with 90 degrees of rotation below a 20Nm jointing torque with oiled threads. The bolts from a Mazda perspective can be identified by length - 110mm shank for a stretch bolt, 104mm for a non-stretch bolt. The ones Raceline supplied to me are 110mm. Interestingly the Ford bolts I took out are 106.7mm long, probably 106mm nominal with a 0.7mm stretch from previous plastic torquing. These are the instructions I found on the Mazda forum, posted a number of years ago, the "Plastic region tightening bolt" matches with the Ford/Mazda Duratec manual instructions that I will use: Tightening torque Plastic region tightening bolt (Bolt stem length 110 mm) Standard: .................... 110.0-110.6 (4.33-4.35) Maximum: .................... 111.3 (4.38) (1) .................... 44 46 N-m (4.5-4.6 kgf-m, 32.5-33.9 ft-lbt) (2) .................... 175°-185° Elastic region tightening bolt (Bolt stem length 104 mm) (1) Apply engine oil to all bolts. (2) .................... 3-7 N-m (30.6-71.3 kgf-cm, 26.6-61.9 in-lbt) (3) .................... 23-27 N-m (2.4-2.7 kgf-m, 17-19.9 ft-lbt) (4) .................... 38-42 N-m (3.9-4.2 kgf-m, 28.1-30.9 ft-lbt) (5) Loosen all the bolts. (no remaining torque.) (6) .................... 3-7 N-m (30.6-71.3 kgf-cm, 26.6-61.9 in-lbt) (7) .................... 18-22 N-m (1.9-2.2 kgf-m, 13.3-16.2 ft-lbt) (8) .................... 87.5°-92.5°

They are the Caterham part numbers: https://caterhamparts.co.uk/looms/6194-engine-loom-420-race-car.html https://caterhamparts.co.uk/looms/3827-engine-loom-road-08-r300-a-r500-duratec.html

The 992 was fitted to my 2012 car, John, I think the switch-over to 9A4 was closer to the R400 becoming a 420R.

No, it would be an optional extra with the Porsche for £2000 to do it that way, £4000 if you opted for the fire extinguisher mounted on top of it, plus another £1000 for optional cloth door pulls to save 40 grams of weight 😉

The whole steering geometry would need to be recalculated, including steering rack position, tie rod effect on steering toe and bump steer, and Ackermann geometry, to see the overall effect.

My 2012 R400 also had cap head bolts. This is the current Caterham part: https://caterhamparts.co.uk/propshaft/651-setscrew-m10x1-caphead-propshaft-to-differential.html The ‘blue bolts’ label may be due to having medium strength thread locker on the bolts. I just clean the removed bolt threads and re-apply some more thread locker, no need for replacement bolts, as they aren’t stretch bolts going by the torque of 74Nm in the assembly guide (I’ve also seen 60Nm quoted). An M10x1 12.9 bolt can take a torque of 95Nm before it enters the plastic zone for stretch-bolt single use purposes.

One issue you might have with the impact gun, Mark, is that the head may be too large to get the hex bit squarely into the bolt, risking rounding it off. The break-away torque should be easy to overcome with a breaker bar, but the car will need to be at least 50cm off the ground to get enough access, so needs axle stands that are larger than the standard ones.

Is the saddle bush common to both the Type 9 and Caterham 6-speed box? If so, is this the correct bronze part: https://www.burtonpower.com/hd-brass-saddle-gearlever-to-selector-shaft-type-9-e-gbt9539.html ? Thanks for the help!

This weekend was spent creating a few tools,, fitting the spigot bearing and alterations to the head oil feed and EGR channel blanking. The spigot bearing fitting tool (also doubling up as the clutch alignment tool) and the blanking plug for the S-VVT solenoid were machined: The blanking plug is a good sliding fit, tight enough to hold in the bearing cap when oiled and not fall out, but able to be fitted with hand pressure to avoid distorting the cap: A 23.1mm diameter x 7.3mm thick blank was machined and driven into the EGR feed hole in the #4 exhaust port. A bit of grinding was needed to flatten the bottom of the notch first, and then some exhaust copper sealing compound applied before the blank was driven in. It protrudes 0.3mm above the head surface, so with the 0.5mm exhaust gasket and a bit of copper sealing compound applied, the remaining slight gap will be sealed up. The edge of the blank will be smoothed when the head porting is done: The spigot bearing and fitting tool spent an hour in the freezer, with the end of the crankshaft heated with a heat gun for a few minutes before fitting the bearing. Only a couple of quick blows with a rubber mallet was needed to seat the bearing: The tool worked well to drive the bearing in 4.55mm deep (spec is 4.52mm +/-0.52mm). I did check then check again the seal was facing outwards: I created a jig to bolt to the end of the head to allow a milling cutter to be used to create a 12.7mm diameter flat. The jig was then flipped over to drill a 4mm hole right through the lateral oil gallery into the vertical S-VVT oil feed. The hole was then tapped M5 and a small grub screw clamped with a flange nut and red thread locker sealed up the outer part of the hole. The lower part of the S-VVT oil feed was threaded M10 so I can fit an M10 flange bolt with a copper washer: The main longitudinal oil gallery plugs on the back of the head were both drilled out and threaded M10 to allow proper cleaning of the oil galleries (thanks to 7WotW for the suggestion), they will also receive bolts with copper washers to seal them up again: The initial test with air and all cam bearing oil feeds except for #1 inlet sealed with tape showed that flow through the modified oil galleries works correctly.

Oil would be better than grease, but a wet plastic bag is also good. the rollers though are easily the lowest friction method that is easy to achieve for the price of a bit of dowelling and plywood.

To solve the lateral "stiction" problem I just use a flat piece of 0.5" thick plywood with 4x 1" wooden dowels underneath it. One side of the car has the scales resting on 1.5" thick wood pads, the other side with the scales on the 1.5" thick roller pads. Otherwise the setup envisioned sounds similar to what I have used for years, although I have 3x 23kg bags of "play sand" (designed for creating kiddie sand pits it seems) for ballast.

Both Toyo and Nankang quote the section width at 189mm in 185/60-13 size, but it may depend on the rim width the tyre is fitted to. My wing stays are also setup for 195/45-15 tyres, so I may have a bit more clearance with the AR-1s due to that.

Hi Jody, If you are looking for grippy dry road orientated tyres, the Nankang AR-1s have worked very well for me. they are available in 185/60-13 for a front 13x6 wheel and 235/45-13 for a rear 13x8 wheel.

I'm too old for that John, start getting my 2nd pension courtesy of HMG in another 16 months. I did receive a new set of lathe tools yesterday to replace all my worn out ones, so a bit of life left in my retirement tinkering, but not sure where that will take me yet. I tend to get bored doing the same technical thing more than once, though.

Perhaps you have discovered the early career of an ECU programmer who worked for BMW, was seconded to Rover, then later went to work for VW, Andrew? 😀

I did manage to prep the head for porting and overall smoothing of the inlet tract into the combustion chamber. All oil and coolant channels have been taped over to keep debris out: The inlet ports will just need a small amount removed in the lower corners to match the 48mm Jenvey throttle bodies: The exhaust ports are currently only 37mm diameter, they will be opened up to 42mm diameter to match the exhaust header pipes: