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  1. Version 1.0.0

    1 download

    Various Caterham measurements by model.
  2. The mystery of the main bolts is solved. The OEM items were suddenly hard to get due to supply chain issues. Rather than delay my short block build any further, Esslinger opted to use a different OEM bolt from an Ecoboost that shares the same critical dimensions. The one difference is head height. For the Ecoboost application, Ford uses a taller head that is drilled and tapped to receive a small fastener. Esslinger now has the OEM main bolts on hand which measure under 8mm high and should fit without issue. Once those arrive, I'll swap them out and get on with the build. -John
  3. I can't add much to what Kitcat wrote above. Interior space should be the same as the early Lotus as these were near exact replicas (and hence the reason there was litigation). The only things I'd add is that as with any se7en that age, try to look closely at the frame to make sure there are no surprises. Westfield still uses the A-series engine in the Westfield XI, so there is always a chance that some parts you may need are still produced for that implementation. Of course, Murphy's Law states they will only still produce the parts you don't need, but that's for another thread. BTW a great resource for Westfields is the WSCC forum. Huge knowledge base and likely some good pre-lit information there. -John
  4. I'd argue the industry standard in the US is pounds/hp, whereas bhp/metric ton seems to be the popular measure in the UK for both manufacturers and publications. I suppose that might not be clear to everyone reading the US Caterham site, but it shouldn't be surprising given that site also uses KG rather than pounds, KPH rather than MPH, and marginally higher PS (aka metric horsepower) rather than HP. Then there is the use of the words hood to describe the soft top and bonnet to describe the hood. It's all so confusing -John
  5. Caterham's current convention for the model names is to double the claimed bhp and round slightly when desired. It's no longer intended to represent an accurate bhp/ton. 620R = 310bhp 420R = 210bhp 360R = 180bhp 170R = 84 bhp -John
  6. I'd call the shop and ask what percent loss they normally see on stock engines that come through their shop. If they do any volume, they should have a guestimate based on experience and that will give you an idea if the number is wildly off or in the ballpark. The thing that surprised me is the big torque dip around 5k. Assuming that's not exaggerated by scaling issues, does anyone know if that is normal in the 420 without roller barrels? Looking at the curve for my old engine that has the same cams as the 420 but Jenvey throttle bodies and a different exhaust (4-2-1 with very long secondaries), it's pretty flat with the torque peak much higher in the rpm range. -John
  7. I just got off the phone with Peter at Raceline. He confirmed the ARP main studs aren't needed and as Andy notes, do require a little fettling to fit the dry sump pan. However, because Ford won't sell the OEM main bolts in the UK, he only has experience with the Mazda equivalents they use instead. While we spoke, he measured the height of the head on a spare bolt sitting on his bench; it's only ~10.5mm high, so much shorter than what I have and fits without any clearance issue. I'll call Esslinger later this morning once they open. -John
  8. Andy, was that the Raceline dry sump? I'm looking forward to seeing how this works out too -John
  9. Locking this thread since it is a duplicate of the one located here. If you wish to post a comment, please go to the original thread to avoid splitting the discussion. Thanks, John
  10. First step after mounting the block on the engine stand was assembling the dry sump. In lieu of instructions, Raceline sent several photos to help me figure out which part goes where and confirmed the torque settings in my wet sump assembly manual still apply. After cleaning the sump, the various parts -- of which there were surprisingly many -- were attached and it was ready to dry fit to the block to ensure there were no issues. Guess what? Yep, issues. Esslinger advised me to save my money and stick with OEM Main bolts as the ARPs aren't needed unless it's a boosted Duratec making more than 500hp. Typically, I prefer to waste money and overbuild things, but this time I decided to be fiscally responsible and take their advice. Bad choice. It turns out the heads of the OEM bolts are really tall (>15mm), and although they would present no issue for a wet sump, they foul the dry sump pan as seen in the photo. I'll call Raceline and Esslinger in the morning to figure out the underlying issue and how to address. My suspicion is ARP main studs are much shorter and I'll need to swap them in. I suppose the other possibility is Raceline sent me the wrong dry sump pan. They do call out a specific version for the 2.5L, but I have no idea if that is for marketing purposes or if there really are design tweaks. -John
  11. Time for another engine build thread! For my incoming 420R, I'm swapping the 2.0L Duratec for a 2.4L version based on a short block from Esslinger Engineering who has a ton of experience building race and hot street Duratecs. Unlike my last engine build, where I started with an existing engine, stripped it down, then upgraded everything, this time I'm assembling the engine from scratch. Some aspects, such as having Esslinger supply one of their special sauce short blocks rather than me playing general contractor with the machine shop and various suppliers, should be easier. Other aspects, like trying to use cryptic online parts sites to figure out all the little parts and fasteners needed to assemble a ready to-to-fire engine has been…well, less easy. The short block is the heart of this engine. Esslinger starts with a new 2.5L block from Ford, then performs a laundry list of machining operations and upgrades before adding a 2.3L forged crank with balance shaft delete, 12:1 pistons custom manufactured to their spec (shorter height with marginally larger bore (+ 0.078mm) and stout 0.886" wrist pins) and longer H-Beam rods to improve rod ratio. The entire rotating assembly, including the flywheel and pressure plate, is fully balanced, and the crank pulley is keyed. The end result is a 2344cc engine vs. 2269cc for the stock 2.3L and 2488cc for the 2.5L. Engine Bore Stroke Bore/Stroke Capacity 2.0L 87.5mm 83.1mm 1.054 1999cc 2.3L 87.5mm 94mm 0.931 2261cc 2.5L 89mm 100mm 0.890 2488cc 2.4L 89.078mm 94mm 0.948 2344cc For the top end, I've purchased a new 2.5L head from Ford and sent it off for porting using starting specs provided by Raceline. Cams, stiffer valve springs and Titanium retainers are also from Esslinger. After much deliberation, I settled on their non-VVT Stage 4. These are an asymmetric setup with different profiles for the intake and exhaust: Intake: 0.460" (11.68mm) lift & 246deg duration @ 0.050" Exhaust: 0.429" (10.9mm) lift & 235deg duration @ 0.050" Air intake is handled by Jenvey 50mm Direct-to Head Throttle Bodies, and exhaust (for now) is stock 420R. Dry sump is from Raceline who also supply the light flywheel, clutch, and a bunch of other parts necessary to prep the engine for a Seven. With a properly sized exhaust, the engine should make ~270hp, but even with the smaller-than-optimal 420R exhaust, output should fall into the 250-260hp range. -John
  12. @Astro Bob drop me a PM if you decide you want to make the change. It's an easy backend edit. -John
  13. Version 1.0.0


    Service Instruction Manual covering the Standard 10 rear axle and brakes found on the Lotus Se7en S2.
  14. Comparing it to the 1/2-20 in the photo, it looks like it could be 1/2-28 which is a UNEF size. Do you have a thread pitch tool for that thread size you could compare? Perhaps a 1/4-28? -John
  15. Hi John, welcome and congratulations! What's the spec of the car? Any pics yet? Cheers, John
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