JohnCh

As someone who obsesses about trade-offs from various cam profile options, that's just not fair. I'm looking to forward to hearing the results from both changes. Thanks, John

Sounds like a nice little Christmas project! What power levels are you targetting with these mods? Thanks, John

Someone clearly doesn't have too many meetings today -John

Now that my order has reached the stage where it's locked with Caterham, I thought I'd post an update before the engine build thread begins (hopefully) later this month. The spec has evolved just a bit from my initial plan. Changes and decisions include: Heated carbon fiber seats. Yes, on the surface, heated seats may seem incongruous with a Caterham but they weigh a lot less than a heater and should take the edge off on Fall drives. Also, the heat helps my back should the Tillets prove less comfortable for me than the Westfield's MOGs. No Track suspension upgrade. A big concern for this car is the ability to put down power on less than ideal pavement; I don't want to get sideways on a narrow back road when passing a rolling pylon. After a lot of research, I've decided to go aftermarket with shocks and springs and have ordered a set of CORE dampers from Meteor Motorsport. The fronts have a digressive valve with linear springs while the rears are normally valved but with progressive springs. Simon believes this combination will give the best performance. Stock 3.92 rear diff rather than the longer 3.64. Bruce wasn't convinced Caterham would honor the diff swap request and given I'm unsure on the shape of the torque curve on the new engine, staying stock for now seemed like the better bet. If the traction control doesn’t work well, then swapping to the 3.64 may be on the winter upgrade list next year. Or I'll finally need to make progress on exhibiting self control (who am I kidding?) I've decided to stick with the Emerald K6+ native Traction Control rather than use the Race TCS system. Although I have more confidence in the latter working better, I might as well start with the no-cost option. Emerald is building the custom ECU loom now. Jenvey 50mm DTHTB vs the larger 52mm. Dyno tests from Raceline and Esslinger show the smaller set flow more than enough for my power targets and should have a slight edge on idle and low-mid range given the increased air velocity. As for velocity stacks, there are only two choices in this size: 40mm and 93mm. I'd prefer to use a cold air box and not cut the bonnet, so I'm starting with the shorter set but reserve the right to make dramatic changes here based on dyno results and how I feel about the torque curve after driving the car. Longer is definitely better for all but the top of the rev range, but I'm not yet sure I'll need improvements down low. I've opted for the Esslinger Stage 4 cams over the Raceline RDL 270. They should more than meet my power target and I do like they are an asymmetric setup vs the symmetric for the Racelines (interestingly, their more aggressive RDL 300 cams are asymmetrical.) The downside to this choice is COVID supply chain issues. When I placed the order in mid-July I was told they were out-of-stock and would take 4-5 weeks to ship. Five months later and I still don't have an ETA on when Esslinger's cam grinder will have the blanks for my set. It's beyond frustrating. Parts continue to arrive and fill my layout bench. The next big shipment should be the short block which I'm hoping will ship by the end of next week. -John

@Bonjo2glad the results weren't worse, but sorry your injuries are that severe. I hope your recovery goes smoothly and you are creating havoc again in the garage soon. -John

Interesting @Lightguy, my key learning is that I should have studied Mechanical Engineering It's fascinating how much he has made this car his own. Really admire the craftsmanship and thought process behind it all. -John

Build thread is available on GRM. https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/brunton-stalker-m-spec-bmw-n52/149440/page1/ -John

Here you go. In return, please track him down and entice him to start a thread here about the car https://www.caranddriver.com/features/a38224306/gm-engineer-alex-macdonald-fabricates-sports-car/ -John

Esslinger is building a short block for me at the moment. I know they are busy and can be difficult to reach, so my advice is to be persistent. BTW if you haven't already done so, it's a good idea to pull the plugs and look for signs of detonation. Clean plugs won't mean there isn't a problem, but if they sparkle at least you'll definitively know compression ratio is an issue for street fuel. -John

Congrats on the BaT win @Whit! It sounds like a lot of car for money -- pretty surprised it sold quite that cheaply. 12.75:1 is really high for that engine on street gas. Did the previous owner indicate he was running race gas or an octane booster? -John

I'd start with the easy stuff. Do a visual check on the caster washers to see if a previous owner set that up with a lot of negative caster. Also closely examine the various ball joint rubber boots for tears. Next, with the front end jacked up, grab a front wheel and move it back and forth to get a sense for what the friction feels like with the system intact. Movement should be pretty smooth. Next remove the steering shaft from the rack. Rotate the steering wheel and confirm there isn't friction in that assembly and it rotates smoothly. Now try moving the wheels again and reconfirm smoothness. If something doesn't feel right there, reattach the steering shaft, remove the tie rod ends from the uprights and check steering rack and both wheel assemblies to see where the problem resides. Positive caster creates more self-centering and increases steering effort. Negative caster, just the opposite. Given your symptoms are heavy steering (positive caster) and lack of self centering (negative caster) I suspect stiction in the ball joints, steering rack, or steering shaft assemblies is at least part of the problem. One caveat to all this is that what you consider heavy, others may consider normal. However, given you've owned a Seven before, it does sound like something is amiss. -John

I second the recommendation for those Esco jack stands. They don't damage the undersurface, are very stable, and as shown in the photos can raise the car quite a bit. -John

Agree with this! Adding to the irrelevency, I'd pull the valve cover and look over the cams for any markings to determine what's in there. Even more irrelevency if this is a Will Sours engine; I purchased a used 2.3L head from him in 2006/2007 timeframe that was supposed to have stock cams. I later discovered it actually had custom ground Web Cams. Providing that company with the number stamped on them revealed they were ground to specs that seemed to mirror those of the Kent DTEC20. Not sure if this was standard fare for Will (but interesting nonetheless to me ) -John

Back then, couldn't you order a Caterham from a US dealer without the engine and install what you wanted? I believe @scannon did this when he went with a turbo Miata engine for his build. 2003 is when the Duratec started landing in a few cars (I ordered my conversion parts from Raceline in late 2003 from their initial production run) so not out of the realm of possibility that it's the original engine. -John

SBD has very good setup and rebuild instructions for their ITBs here. Might be a good thing to look over given the rough running. Obviously a lot of other reasons could be responsible for that behavior, but always good to start with the basics like balancing the intakes, setting correct fuel pressure and initial throttle plate angle, and ensuring no air leaks. -John

Um...because you know just enough about Duratecs to be dangerous? @UlfarE I'm curious about the car's history. You mention above the engine has covered over 20k miles, and the Hillbank ad states the car had just under 500 miles. When did Hillbank sell the car and was it to the person from whom you purchased it? Any indication of the original owner's name in the paperwork? -John

Ah, I missed the gallery on the Hillbank site. Definitely ITG filter (no slots). Those ITBs look very similar to the SBD units from that era. If so, that's a good sign. It might have been done right. -John

I can vouch for that That looks like a Pipercross air filter. The ITG is similar, but the bottom of the air filter attaches differently and doesn't have the two tabs that go through slots in the backing plate. Do you know what the car is running for an ECU? What about Throttle Bodies, or does that picture above mean you have the Webcon Alpha engine setup? -John

I've always had good luck with Magnecor on my cars, including my old Crossflow-powered Westfield. They have standard setups available for most engines, but are also happy to adjust lengths and boots to accommodate a specific need. -John

I just visited WSCC and see you already started a thread there, but they got a picture and we didn't! Granted it's just a photo of a giant box in a truck, but still... -John

Hi Dan, Congrats on the arrival! Westfields are pretty rare in North America compared to the UK so not sure we have any active members with the Miata-based car, but there are a few of us with the standard Westfield who might be able to help with aspects along the way. Definitely start a build thread. Also, the WSCC forum (Westfield Club in the UK) is huge, with a lot of helpful folks, so if aren't a member there, I suggest joining. Cheers, John

Thanks Andy, I appreciate the offer, but given the differences it's may not be worth your effort. I would still need to measure specific reference points on a new build to see how your engine placement differs so I could adjust the air filter backing plate to bonnet cut out measurements. If I'm doing that, it's not much more effort to run string from scuttle to nosecone to mimic the bonnet location and take measurements from the head to the strings. If no one else has any information, I may try that approach ( @Pokeywarning: there may be an incoming request to stop by your garage again with a tape measure). If that is still inconclusive or proves too difficult given the location of the stock 420R intake, then I'll take you up on your kind offer and let you know which reference points are most helpful. Thanks, John

@The Fuselage great story! If you decide to sell, I'm sure it would quickly find a good home, but perhaps you should think about it for another year. Just to be certain -John

Thanks, I've been watching that thread, but no one is actually providing data except for the Caterham RB setup which is a lot shorter than the Jenveys. I have more confidence in this group to actually answer the question -John

Is anyone running Jenvey TBs on a Duratec in an SV without a hole in the bonnet? If so, how long are the air horns in your setup and how deep is the filter? Given I'll be running a 620R nosecone, the intercooler ducting can be repurposed as a cold air feed for an under bonnet air filter, so I may opt to initially go that route and forgo cutting the bonnet until after I can compare air horn lengths on the dyno. However, I have no idea what will actually fit, or if something appropriately sized is even available for the 50mm TBs (apparently options are limited for the bigger Jenveys.) Thanks, John