aerobod - near CYYC

I think someone who has experience with that particular sump may chime in, as my knowledge is not specific. The oil should help the threads not pull out, especially if you have 12mm or more of thread engagement. I would inspect the thread and replace the bolt if it is taken out. Brake cleaner sprayed up to the top of the blind hole, followed by the tip of a rag or cotton bud will clean oil out of the thread if inspection is required.

I’m the annoying bugger that keeps people awake, Mike. Helps that I’m 10 time zones behind the UK at the moment. I think 10Nm should be safe.

12Nm is about the max torque limit for an unlubricated M6x1.00 8.8 bolt, Mike, you would need a 10.9 bolt to get to about 16Nm and 12.9 for 20Nm. The thread in aluminum should also be a minimum of 2d (12mm) engagement depth at max torque, a bit higher if using more than an 8.8 bolt.

Also, best not to lubricate PTFE lined bearings, manufacturers typically say that any additional lubrication can negatively affect the PTFE liner properties and bearing operation.

Nanking AR-1s are more of a track focused R-compound tyre, a bit more grippy than the R888R. 185/60-13 on front 13x6” wheel, 235/45-13 on rear 13x8” wheel. I’ve been very pleased with the two sets I’ve worn through so far, actually not far off the grip levels of the Hankook slicks that I previously used that are no longer obtainable.

The distance between the two weight planes is minimal and I haven’t had any vibration issues, one block of weights double taped to avoid any ejection is simpler. It works fine for my track use.

I’ve had them place the weights closer to the centre, before, too, Peter, but the polar moment of inertia of the wheels is low compared with most modern car wheels, that it makes little difference for track use, they are fine with the weights close to the face at 200km/h, there is more imbalance likely from OPR than variation in the weight position, I have found.

What I do is tell the tyre fitter to “centre balance only” when I take the wheels in, Neil. I also usually put painters tape around the inside edge of the rim with “no weights in this area” written on it.

185/60-13 front /6” and 235/45-13 /8” rear, Peter.

With the AR-1s on track, I initially ran Caterham typical pressures around 18 PSI cold and found the front tyres especially had a lot of uneven wear. Dropped the pressure as low as 14PSI cold and still had uneven wear, went up to 21PSI cold (about 26PSI hot) and the wear evened out on the next set. I do run 3 degress front and 2.7 degrees rear of camber and slight toe-out both front and rear, though, so my wear may not be representative of all suspension setups.

Didn’t have much time to work on the engine this week, but managed to produce a couple of M18 oil gallery plugs for the block and using a jig, tap the block galleries. The hex was pressed into the end of the plugs by drilling a 10mm hole 10mm deep in the blanks cut 1mm longer than the plug depth, then abusing the vice with a rubber mallet to tighten a 10mm allen socket into the blank. Removing the blank from the bit took a bit more effort using wedges and a hammer. The rest of the plug was them machined to size and threaded M18x1.5. The jig has an M18 thread created squarely on the drill table, then clamps to a nearby hole to ensure the threads in the block are cut squarely: The thread on the front of the block has the timing chain tensioner oil gallery only 10mm below the surface, so the plug will only go that deep in the hole: The plug on the back of the block needs a copper washer due to being inside the bell housing and can have a 4mm thick head due to plenty of clearance to the flywheel: But the plug on the front of the block only has 2mm clearance under the timing chain guide, so has to have a thin head with no washer, but if it weeps it doesn’t really matter, as it is inside the timing case: While I had the lathe/mill covered in metal, I thought I would also machine the small relief needed in the top of the accessory belt tensioner, to clear the end of the Jenvey throttle body shaft:

Besides looking for any disconnected connectors, I would check the fuses are OK. If the dashlights and instruments are not working, a fuse is likely blown. This same fuse is probably powering the immobiliser.

The blind hole between #1 and #2 cylinder inlets in the head is problematic for mounting Jenvey throttle bodies that require 7 bolt holes instead of the 5 holes used by the standard Ford inlet manifold. I used an M10x1.5 motorcycle aluminium brake banjo bolt to fill the blind hole that is 7.8mm diameter and only just over half the depth of the 24mm M8 threaded holes used for mounting the inlet manifold. I drilled a 6mm hole through the middle of the bolt to use as a guide, tapped the head blind hole M10 and then tightened in the bolt until it bottomed with red thread locker: The hole was then drilled diameter 6.8mm an additional 11mm deep into the head, the banjo bolt head cut off and the stub chamfered down to the head level, followed by tapping M8. It is now just the same as the other 6 inlet manifold bolt holes:

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.