aerobod - near CYYC

Marked out the air filter backing plate, deciding that I need to drop the centreline a little below the throttle body centreline to give enough bonnet clearance. Used a 2” hole saw to cut the intake holes for the 48mm throttle bodies and 6mm holes for the 5mm horn securing bolts: I used a bit of RTV between the backing plate and throttle bodies and blue thread locker with Belleville serrated locking washers on the bolts. The intake air temp sensor is just visible in the backing plate between #1&2 intakes. Needed to cut a small angle on the bottom of the backing plate below #4 cylinder to give a bit of clearance to the diagonal frame tube below it: With the Jenvey DTH throttle bodies on the Duratec, the intakes are not evenly placed, being 97.5mm between #2&3 and 90mm between #1&2 and #3&4. Just as well I measured all of them instead of assuming constant pitch, before cutting the backing plate holes: The horn sticks out quite a bit from the body on #1: The underside of the bonnet should be around 5mm above the central air filter securing tab: Ready for measuring and cutting the bonnet hole next: The TPS was also fitted. The existing Econoseal flat 3-pin connector had to be replaced as the directional keys on the side were the opposite of the 3-pin connectors I had spare. The TPS also had a round Econoseal connector on it. I cut both off and used the Econoseal connectors I had on hand:

To remove slight rubbing of my modified throttle pedal cable end on the steering shaft and flange near the throttle stop, I modified the bolt used and added a couple of reliefs to the cable nipple holder, I also machined off 1.2mm from the pedal pivot bush to remove virtually all the lateral movement of the pedal: A couple of mm of the flange near the throttle stop was ground away and given a bit of paint: On full throttle the low profile bolt head clears the steering shaft by a couple of mm:

I found the fuel pipe and diff clearance to the boot floor was the problem in my older R400 build, so I went for a more radical solution by removing a non-structural portion of the diff cover:

A bit of fiddling around with cardboard templates and some careful measurement this weekend, but a successful creation of a new throttle linkage mount. I milled a few components to create the mount: The finished components and extra bolts to assemble: The components assembled with the Jenvey CLS1 linkage before fitting to the engine. The lower mounting bolt attaches to the Jenvey top manifold bolt between cylinders 1&2 (using a 40mm bolt instead of the standard 25mm one). The upper mounting bolt is 30mm long to replace the 20mm long fuel rail mounting bolt: The mounting faceplate has notches to clear the idle air bleed screws: Before the fuel rail is fitted, washers of the same thickness as the fuel rail mount are used to align the mount with the manifold bolt and tighten it, before removing the fuel rail part of the mount to fit the fuel rail: With the fuel rail fitted, all the mount bolts can be tightened and the clearance of the linkage checked and adjusted. The spherical joint on the cable quadrant in the centre can be seen clearing the fuel rail by about 5mm, as it is moved to full throttle: Next issue to tackle is the upper radiator hose getting in the way of the air filter backing plate: It was an easy fix by removing about 40mm from the hose length at the radiator end and tie wrapping the hose to various chassis points and other hoses and looms to prevent any vibration and chaffing: There is now enough clearance for the air filter backing plate: Another little issue that I wanted to rectify was the throttle pedal cable attachment. I’ve already had a snapped throttle cable due to the standard bodged saw cut and hole in the end of the pedal that stresses the cable end due to it not pivoting freely. I machined a pair of clamps to retain the nipple, but allow it to pivot. The clamp is bolted through the pedal shaft end that is cut off 8mm below the normal cable hole. The hole in the pedal shaft is drilled at 22.5 degrees from the car centreline, to match the angle that the throttle cable enters the pedal box: The cable can now pivot freely at the pedal end, although I need to fit a lower profile nut and bolt to avoid contact with the steering shaft at full throttle, than the standard M5 bolt I mocked up the clamp with:

Or Google “pounds sterling symbol” and copy and paste the £ into the message.

Another rebuild project is my garage laptop that is needed for Easimap, I need a reliable machine for the upcoming rolling road session. Last weekend I decided that the 10-year old cheap Asus laptop is no longer doing the job well with a screen that has a black failure area, a hard drive with increasing errors and general slow running. I found a refurbished Thinkpad T14 laptop with a 3-month warranty that at $525 (£305) is about 1/3 of the new price, having a 12-core CPU, 16GB of RAM and 512GB SSD and Windows 11 Pro. The laptop looks brand new and was likely a corporate lease return that sat somewhere during it’s corporate life with little use, It has enough RAM to run VirtualBox well, so I backed up Windows 11, installed Fedora 39 on it, then reinstalled Windows 11 in as a virtual machine. Messing around with Secure Boot and TPM took a couple of evenings to get the device drivers to load properly and I still have a weeks worth of evenings to do clean installs of all my car related software besides Easimap:

Thanks for the info John. I have kept the in-head injectors and rail, so have more space than you did on top of the Jenveys, but will have to tilt the top of the linkage to the outside of the car. My S3 chassis and other pipes and cables crowd the space too much under #3&4. On top of #3&4 may work, but on top of #1&2 have only a 180 degree bend in the throttle cable (it clears above the belt tensioner), compared with needing a 360 degree loop if I have the cable enter from the firewall end:

I thought it was going to be easier than expected to fit the throttle linkage to the throttle bodies. I mounted it underneath the body pair on #1&2 cylinders: With the top radiator hose tie wrapped against the side of the engine bay where it passes the link, there is just a few mm of clearance. Unfortunately in that position, there is no room for the air filter backing plate, as the hose can’t go lower by putting it under the diagonal brace in front of the oil tank. The next possible position is above the throttle body, but any straightforward mounting is not possible due to interference with the fuel rail. I think I have found a position just under the fuel rail if I angle the linkage just right, but I will need to fabricate a fairly complex bracket to hold it using either the fuel rail or manifold bolts (with increased length). As originally expected, it is one of the most awkward fettling tasks to tackle. Bits of aluminium to be cut and milled this weekend, hopefully I have enough pieces of scrap laying around to avoid going to Metal Supermarkets, as it is always a zoo there on Sat and closes early, too….

10 bar is rather a high pressure on the reservoir for bleeding, I normally use 1 bar. The technique sounds right, but the fluid flowing back into the reservoir is probably due to the high bleed pressure. The stream out the bleed nipple should be bubble free. If you are pressing the clutch during bleeding, I wouldn’t release it with the bleed nipple open, as air can be sucked in around the bleed nipple thread (same goes for when bleeding the brakes).

I think that many variants of the Duratec have a natural vibration in the 2000 to 3000RPM range, especially the variants without balancer shafts. Quite a lot of discussion on Mazda groups about it. My R400 engine had it around 2500RPM from new that induced a “buzz” through the chassis, especially on the overrun. If it is only apparent at lower RPMs, internal engine balance likely won’t have any effect on it.

On the subject of the harmonic balancer, for anyone using this thread for some hints on rebuilding their Duratec, I think there is a big issue if using an ARP bolt. ARP quote a torque of 190Nm for their bolt with molybdenum lubricant (https://tech.arp-bolts.com/instructions/251-2501.pdf), the lubricant adds about 25% clamping load over using just the corrosion inhibitor coated standard Ford bolt, or 238Nm of equivalent torque. When I tightened the standard Ford stretch bolt to 100Nm plus 90 degrees, it needed about 450Nm of torque. Using the ARP bolt could lead to a totally inadequate clamping force of only about 50% of the specification. I’m glad Raceline talked me out of using the ARP bolt, with their experience being that the standard bolt when tightened to spec with the friction washers is good for any of their engine builds up to the 280bhp version.

I was thinking about machining the pulley down or using a lighter one, but with the standard cast crankshaft revving to R500 speeds, there is a risk of harmonics causing damage if the harmonic balancer is changed or eliminated.

Main job for today was to use the swarf generator to create a new water pump pulley: Started with a 5” diameter bar of 6061-T6, decided to make the pulley 117.5mm in diameter to give 12% under drive compared with the standard 105mm one. Made it 28.5mm thick to give the same 25mm inset to the pump mounting flange with a 3.5mm thick face: Plenty of clearance for the increased pulley size: The standard belt length still works with the tensioner close to its maximum anticlockwise rotation and the alternator on it’s inner top mounting hole, requiring the belt to be slipped on to the water pump pulley last:

Hi Neil, I will be adjusting the fuel map on the road using my wideband system in the first few km after the cam 20min bedding that Raceline specifies. Then it will be used at full throttle with lots of closed throttle on the overrun up to 2/3 of the redline to adjust the fuel maps, then on to the rollers for max revs once the 2nd stage fuel map adjustments have happened.

As usual with the Calgary weather, near record highs approaching 20C today and tomorrow, then Tuesday weather breaks and stays below freezing for a week with over 30cm of snow forecast, then stays near freezing for the rest of the month. I’m planning on doing the startup and 500km running-in before the rolling road session in April, so will be waiting for the normal April big melt first. I have my cheap 18.9 litre barrel of Shell Rotella 15w40 diesel oil with high ZDDP and 3 oil filters ready to go, once the weather cooperates!

My son was coming over to help me install the engine, but he was pretty sick today and SWMBO said that I should do it on another day, as although he was still going to come over SWMBO put the kibosh on that. I decided to go ahead anyway, with the most difficult task getting the engine on the stand out of the house and down the stairs into the garage. Using the engine crane as a second pair of hands to support the front of the stand worked well, taking the stand down one step at a time, then lowering the crane to level the stand with the next stair: The flywheel and clutch was fitted, the crankshaft pulley holding tool made it easy to torque the ARP flywheel bolts to 130Nm without needing a flywheel locking tool: I gave the bellhousing a bit of a clean and installed a new clutch release bearing: Lowering the engine in was actually easier on my own than I thought it would be. It actually was easier joining the gearbox and engine than it was to separate them when I took the engine out. An engine leveller is essential for a single handed install, though, as jiggling opportunities to get things aligned are a lot more difficult without a second pair of hands: I was happy I got everything connected and installed other than the exhaust, intake (including injectors and coils) and oil tank and oil lines. The next task is to fettle the throttle bodies. I’ve also got a 5” diameter slab of aluminium I’m going to machine into a larger diameter water pulley, so that I can turn it 9% slower than the standard pulley to alleviate any cavitation risk with the higher redline:

There will be two effects due to the ‘S’ position starting with the arms inclined down to the deDion and the ‘R’ position being level. First is in bump steer the car will turn away from the side that the bump is on in ‘S’ and towards the side of the bump in ‘R’. In cornering the car will turn more tightly into the corner as it rolls in ‘S’, but will be more neutral in ‘R’.

I decided to do a bit of a tidy-up with the engine wiring loom, giving the wires a scrub and additional tie wrapping where needed. I added a piece of flexible conduit to the exposed wires that run to the alternator and crankshaft sensor across the bottom of the timing cover:

I will try to remember to do a recording, John. At initial startup I have to totally focused on keeping it at 2500 to 3000RPM for the first 20mins to accomplish the cam and ring break-in. With the fuel map being an estimation scaled from the old R400 map I had fine tuned, it may be a bit of a struggle, but no time can be spent on adjustments until that key break-in phase has been completed and an oil change done. Still have to fettle the throttle body fitment, likely construct a new throttle cable, check all sensor readings and wait for a suitably warm day to roll the car on to the driveway to do the startup. After the initial startup, a basic set of adjustments will be done, followed by 500km of varied road use with break-in oil while logging parameters to tune the fuel map. After that a second oil change to 5w50 synthetic before a rolling road session to fine tune the fuel and ignition maps.

Spent a few hours this evening checking the timing and fine tuning the verniers to get it to within 0.5 degrees of the spec: The engine is now ready for transfer to the engine crane and hopefully fitting back into the car next weekend:

Although I decided that I was too tired to fine tune the cam timing today, I now have the engine in a state that I can put it back on the engine crane to fit the flywheel and clutch and put it back in the car. I started off with the bits and pieces to fit the cams: Lots of assembly lube used on all surfaces that will be last to get oil pressure on engine start: With the cams in, the verniers are bolted on: Re-checking the valve clearances, I was lucky to get all inlet valves exactly at 0.25mm and the exhaust valves are all reasonable at between 0.25 and 0.28mm (0.25mm was the aiming point, but with the issue of bucket tappet availability, I elected to err on the high side with the exhaust valves): Valve # Tappet # Used Tappet Thickness (mm) Final Clearance (mm) Inlet 1 282 3.282 0.25 2 282 3.282 0.25 3 302 3.302 0.25 4 362 3.362 0.25 5 442 3.442 0.25 6 502 3.502 0.25 7 382 3.382 0.25 8 502 3.502 0.25 Exhaust 1 422 3.422 0.25 2 442 3.442 0.25 3 462 3.462 0.28 4 502 3.502 0.26 5 442 3.442 0.26 6 382 3.382 0.27 7 462 3.462 0.27 8 442 3.442 0.28 The timing bar is placed in the cam slots to lock them in the TDC position to set the basic timing with the teeth on the vernier pulleys chosen to put the clamping bolts close to the centre of the slots: The crankshaft TDC timing stop was also screwed into the side of the block in place of the blanking plug and the crankshaft is rotated against it, to match the cam positions that the timing bar has set: Before fitting the timing chain, the oil pump sprocket is fitted. Instead of using the special tool to hold the sprocket, an 8mm diameter rod can be used to stop the pulley rotating by holding against a bolt head on the pump body: The timing chain tensioner stop is now set by using a screw driver in a slot I had cut in the end of the stop, and adjusting until there is 10mm of slack in the chain between the vernier pulleys (all slack removed elsewhere by pushing down hard on the chain between the pulleys and working with the tensioner piston and spring removed): Once the piston and spring is back in the tensioner, the slack is moved back into the chain tensioner arm run by pushing hard on the bottom of the arm. The gap from the stop to the tensioner arm can then be checked with a wire style feeler gauge and confirmed to be 1mm when using a used chain, as suggested by SBD: The timing chain is now correctly tensioned and ready for the timing cover to be installed: After the normal faffing about with black RTV and the normal spreading it everywhere, followed by cleaning it off my iPad screen, the timing cover is bolted in place and the crankshaft bolt is tightened up. The bolt is initially torqued to 100Nm, then rotated an additional 90 degrees. Using my largest torque wrench that clicked at the maximum 360Nm when I had about 50 degrees of rotation on the bolt, I estimate it required 450Nm to reach the required 90 degrees. The special crankshaft pulley holding tool made the job easier than expected, as I could pull the tool and torque wrench towards the breaker bar and socket with much better stability than just trying to turn one lever: The timing cover height above the head is checked. At 0.13mm, it should seal fine with the small spot of RTV that is used on the join under the cam cover seal: I bought a standard Ford crankshaft sensor alignment tool, but it needed some fettling to fit the sensor used by Caterham, with the rear legs needing widening and the tooth width at 4.5mm compared with the 3mm the tool initially had: The tool was then used to centre a tooth on the sensor with the engine at TDC:

From the most true-to-life TV programme about IT, ever:

Looks like the hacksaw mod is appropriate as it says "Pedal Bracket - Later Cars -------- Ford 100E 2471 with one side removed". Assume the use of a clutch cable required that to be done, as opposed to being used for a slave cylinder mount.

Now I have a complete set of tappets to install. Should have most of a day to work on the engine this weekend, perhaps will reach the point that it is ready to go back in the car:

Hi Nick, my Yuasa GYZ3HL 32Ah AGM battery is 164mm wide and 122mm deep at the base, with a height of 175mm. I did make a different battery tray than the original Caterham one, but I probably could have forced the Yuasa battery into the old tray, as the dimensions were within a few mm of the Banner battery: