JohnCh

Just did a little digging and it appears the 310 uses the stock Ford intake with a MAF sensor, so it looks like the MAP is definitely intended as a barometric sensor. -John

I'm not sure how the Sigma is set up in the 310. An ECU can be setup to use a MAP sensor as you indicate, and what I referenced earlier with air density within the intake. However, if you are running a Throttle Position Sensor, which many people do, you can then use a MAP sensor as a barometric sensor to identify the ambient air density -- i.e. altitude. The ECU then compares this reading to sea level and adjusts the fueling table based on a look up table. This is helpful if you tour and go through mountain passes -- or if you live in the mountains and head down to the seashore. I B Sevener is using the MAP sensor (or at least the pictured MAP sensor) in that capacity. If it were determining the air density within the intake to establish A/F based on amount of air passing through the throttle, then the vacuum port would need to be attached to the intake. -John

Dave, is the MAP sensor used as a barometric sensor to adjust for elevation changes, or is it in lieu of a Throttle Position Sensor to feed intake air density information to the ECU for A/F ratios? I B Sevener's setup is the former and why it can be left open to atmosphere. -John

See this thread on BlatChat. It has the settings for a stock Supersprint (post #2) and feedback from folks on issues they've chased and what jetting worked best. -John

Someone here may know the correct jetting for the Supersprint spec engine. If not, I'd try BlatChat for that info. Someone in your car's past may have tried to "improve" things by playing around with chokes, various jets, or emulsion tubes, and screwed things up. I've even heard from someone who discovered a random PO had changed the emulsion tube in just one carb, creating a mismatch. Always good to know if your starting point is correct. -John

I've had three cars with DCOEs, including a Crossflow similar to yours (1700cc, Kent 234 cam). None of them had the issue you describe. The closest was a built Alfa that used new casting DCOEs with progression holes that didn't work well with the engine, and would go through a rich/lean/rich cycle when cruising around 3000rpm. Have you already verified the basic settings are correct? Float height, various jets and emulsion tubes? Have you synchronized the carbs? Checked for air leaks when they attach to the manifold? Confirmed timing is correct? Occam's Razor doesn't seem to apply to DCOEs, so even if you find several of these things out of whack, you could still need a rebuild. -John

If the JPG files are under 2mb, please send me a PM and I'll see if I can figure out what's going on. Thanks, John

Welcome Brittex! I don't have any experience with wireless buttons (I'm using a wired approach), but FREEwheel is very popular in Westfield circles in the UK. If you are only considering wireless to accommodate the quick release feature, another option is this quick release from Spa Technique which can be configured with either 8 or 12 pins to support steering wheel buttons. -John

It's hard not to love the sound of a crossflow driven in anger! Thanks for sharing. -John

To celebrate the engine breaking the 500 mile barrier today, the break-in oil was swapped for 5w-40 synthetic per SBD's recommendation. This appears to have solved my low oil pressure issue at hot idle. During the subsequent test drive, I made a brief foray into higher rpm, hitting 6500 rpm in second, and using *maybe* 3/4 throttle. The engine feels like it's getting into its zone over 5000 rpm, which is what I was after. Although the plan is to leave the safe, starter ignition map alone until the car gets on the dyno in a couple of weeks, I may do a little data logging in the morning and make inroads on the fueling map at heavier throttle. -John

Thanks for the tip Sean! Just ordered a can from Amazon and will try it on my seats when it arrives. After 15 years, the Mogs are looking a little tired. -John

See Croc's definitive thread here. I'm using a DJI Osmo Action Camera w/Cynova 3.5mm mic adapter, Audio-Technica Pro 24 CM microphone w/ Movo WS1 Furry Microphone Windscreen (aka dead cat), and Manfrotto Super Clamp all per Mike's recommendations. My setup also uses a mini ball head, tripod mount adapter for GoPro/Osmo, and an extension cable for the mic which is taped inside the tub below my left elbow. There is a lot of driveline noise in the background thanks to a complete absence of carpet, cushy seats, or anything else to absorb those frequencies, but I'm still experimenting. -John

It was a little more than that. One of the wires in the injector harness connector wasn't fully seated. You could see the rubber seal sticking out the back. With the plastic cover inside the connector removed, and that pin fully seated, we noticed it was still a couple of mm shorter than the five other pins. Now whether that's an issue with the connector itself, or that pin is physically shorter, is an open question. Regardless, it now makes the connection and consistently fires the injector on #1. If there isn't an occasional electrical issue, it can't be British :jester: -John

I keep my tools in a tool roll attached via velcro straps to the top of the passenger footbox in front of the scuttle. The exposure to heat and dirt under the bonnet is irrelevant -- they're tools -- and they don't take up valuable boot space when touring. The shape of available real estate in that area is a little different in a Caterham, but it's workable. -John

Um, that day/night mirror is in a Westfield. And we can get very soft. I even have a locking boot with a separate key to keep things safe from valets! -John

Not a GoPro. My video consultant (i.e. Croc) put me into a DJI Osmo Action Camera, and Audio Technique microphone. -John

The situation today is one reason I love se7ens so much; the community. Mike's on East Coast, probably having a mid-afternoon bourbon, Bruce is on the West Coast finishing another coffee (mandatory here in the PNW), but between the 4 of us, we got the car running and were able to salvage the drive. Greg's car is beautifully finished and painted in the fastest color Short, but fun drive today! -John

Proof Pokey's car can move under its own power! -John

Met up with Pokey today for a short blat. The rolling pylons were particularly bad, although strangely only of the motorized variety. Typically this route is full of bio-powered pylons whose idea of sharing the road is to ride 3-abreast in the lane and force you to either risk a fairly blind pass, or settle in for a 25mph drive. As we approached the base of a particularly fun uphill section before the turnaround point, the Blat gods smiled upon us and the traffic finally parted. Woo hoo! With over 400 miles on the engine, I'm starting to use a little more throttle and revs. -John

Usually it's jets and air correctors that change for altitude, not the chokes. But the chokes are frequently changed when going to more aggressive cams. -John

Swindon is still around. A bit of a longshot, but they might have some information on the various tunes they can share. Another option is to see if anyone on the c20xe Facebook page you mentioned on BaT know carb settings for stock cams and the various Swindon stages. I bet the chokes go up in size with each HP increase and that's an easy thing to check. e.g. if a stock vx engine uses 34mm chokes and yours are 38mm, then you know your engine is flowing a lot more air....or someone really screwed up the carbs -John

I connected with AP Racing to help me identify clutch condition. Below are the specifics they provided (note: this is for a Duratec). Looking this information over again, I notice they state the clutch is rated for 7000 rpm. I previously used 7500 rpm redline with no issues, and plan to increase that 500+ rpm with the new engine. Guess I'll see if that creates a problem: From the numbers provided I can tell you that the driven plate is an AP Racing component CP5352-5 Ø215mm, spring centre, organic friction linings, Ø1.02x23T spline. Rimmed retainer plate for increased strength to spring windows Increase damper springs strength to accept 250lbft torque High Mu friction linings (0.3mu) to increase torque. Rated to 7,000 rpm New clamp thickness = 7.11mm Minimum worn thickness = 5.6mm Pressure plate # LC03JR 003B is just the cover pressing # used in a number of clutch assembly builds including standard service units produced by Raicam here in the UK. We both use this same Ford pattern pressing, but APR produce the uprated / high clamp / high torque units. APR Part # CP5905-500 (RED paint code on spring fingers) Rated to 220lbft -John

Well, that would explain things. Yikes! I'm using an AP Racing clutch and pressure plate, and a Raceline steel flywheel. I believe Caterham and SBD also use AP Racing clutch components, but I'm sure someone here can refute if that's incorrect. My clutch was out as part of the rebuild, and after 32k street miles, there was plenty of meat left on the disc, and both the pressure plate and flywheel mating surfaces were in great shape with no obvious burn marks or wear. -John

This is what I've used: Neoprene Weather Stripping -John

Vintage green is definitely a little lighter than BRG, but the photos in that BaT listing were either processed or lit to make the color pop as much as possible. These pictures on Caterham's site are more representative of the shade. Still a little lighter than BRG, but not as big a delta. https://www.caterhamcars.com/en/in-stock/model?id=7487 -John