bigdog

Martyn. It could have been the fact that the first shop was not even attempting to align the rear suspension and they didn't seem to even want to mess with a De Dion set up. The only number I could see from the edge of the shop was the -.17 degrees thrust. One must also take into consideration that all the modern alignment machines in America are set up to use the VIN number (13-17 digits) as the basis for the spec. Mine being only 7-8 digits will stop their machines computer in it's tracks. I suspect that you are correct in that worn bushes is most likely the culprit with the nervous handling.

Took the 7 to it's Monday appointment with the alignment shop. All seems to be well. I printed out some of the informative posts from the thread for the techs perusal. The geometry shows as in spec. The tech (who is the owner as well) suggested that perhaps it could be the tires and their age, wear patterns. These A048's were sold in the UK so I'm not privy to reading nor even if there are date codes on them, I sure didn't see any. So I have no idea of their age. In all he had the car on the rack for an hour checking things out. He made note of how stout the frame looked. Even after checking the car out for an hour he sent me on my way with no fees due. I dread having to replace the 048's as it's impossible to find any sticky 14" tires in the USA anymore. That's a bridge I'll have to cross later. For now I'm just going to enjoy some twisty roads on Vancouver Island.

For those LSC members that are in the USA. just had this trailer made for my 7 last summer. But as I have bought a motor home. I need to upgrade to a trailer that can haul the 7 or our GLK SUV. The trailer was built by Express Custom in BC and is registered in Washington state (I'm in Walla Walla) The trailer is all marine grade aluminum, Has tandem axles with leaf springs, Is rated at 3,000 lbs (So that it doesn't need brakes) Has a 2" hitch. this trailer hauls really nicely and weighs only about 550-600 lbs (according to Express) I have not bothered to weigh it myself. I did upgrade the lights to LED units. This set up balances easily and so you can set the tongue weight to what you want. I set the 7's front wheel about 18-24" from the front edge of the deck and this gives me about 80-100 Lbs tongue weight. I have a clear title in hand. It does have US DOT certification. Here is a link to some photos. I would like $2,500 USD but would entertain offers as well. For an additional $18,500 USD I'll strap the seven to the trailer and deliver the both of them.

They had the proper bay and slip plates. But I was not sat in it. Of course the hunter computer had never heard of a Caterham.

Thanks one and all for the detailed info. The car was on a four wheel machine (hawkeye elite) and had loads of flashing led lights akin to a 70's disco. I was standing at the back of the bay and could only make out that the rear thrust angle was -.17 degrees. I will go back to the shop and try to pull up the files and look at all the numbers. We have a local community collage that teaches auto tech. So I might ask if they could let me put it on a lift to do a detailed inspection, measurements and take a few photos for this group. My front toe in was out of spec and the 7 was being really wondering all over and was what could be described as much more nervous than normal. This came to the fore after putting on the A048's for the summer. By the by, The A048's are pretty evenly worn across the tread 5MM inside, 6MM outside. The front toe is now set at 20" and feels much more settled. The tech had never seen a De Dion before but had heard of them and I'm quite sure there are very few shops over here that would stock or even know how to get shims for them (if that is what's needed) That's why I wanted a bit of education from the group so that I wouldn't be operating in the dark.

Had my 7 at the alignment shop and noted that the rear had a thrust angle of .17 Deg or a little over 10 arc minutes and showed as out of spec on the hunter machine. Of course the shop just scratched their head as a De Dion tube is a very rare thing in the USA. What should the thrust angle be? How does one go about adjusting the thrust angle? The net has precious little info. Thanks in advance

I do believe that I'm close Bob. But it's those last few percentiles that are hardest to over come. I think I inadvertently skewed my readings yesterday. As I had neglected to make sure the sync was spot on (The forward carb was one needles width slower) The just off idle reading at 1500 revs was much better after syncing at 12/1 down from 15/1 but the idle is still 11.5/1 so maybe a 50F4 (1.40 air bleed from the F8's 1.20 air bleed) might be in order. But as the 3000-4000 rev range still has shown 10/1 on a 115 main/160 air. I'll change over to a 180 air and see what that does. I also have to account for the fact that it has been extraordinarily hot lately. It was 45C last weekend. Walla Walla does remain in the 32-38 range for most of the summer. It will generally cool off in September. I'll post up the numbers as I continue experimenting. So that the collective supercomputer that is L7C can have it's input (which is always much appreciated)

Just some quick readings from the new meter. I suppose that with the heat we are having I shouldn't be surprised that I'm a bit rich. Alt. 1000Ft ASL Temp, 100 dew point 44 baro 29.82 Our 1000 becomes 4000 density altitude. carb jets are 50F8, F16, 115 main, 180 air, 13MM float These are the readings from the air/fuel ratio meter. idle: 11-11.5/1 = rich Very light load @ 1500 revs 15-16/1 = lean steady throttle light load (cruising) 2500 revs: 12/1 = good Steady throttle cruising 4000 revs: 10/1 = very rich

Jonathan, Data logging on a smartphone would require me to have a smartphone. I'm a Luddite when it comes to cell phones. Although I do carry a pay as you go phone. After all, I do drive an old English car. :-) I was thinking along the lines of a semi-permanent mounting via a small alu surrogate dash panel with two small machine screws in the tunnel to fit key holes in the small panel, Thus the meter could be temp. removed to not interfere with a passengers leg and easily be put back in place.

As it's a direct all digital system. It is advertised as being one of the fastest out there. But of course the web site does not list a number. The analog output is 1/12 second. I'll endeavor to get the numbers. But in all honesty. I'm just trying to sort out my jetting for good road manners & not absolute max power. As for my dash photo. I'll send one along. But I have not installed the meter as of yet. I will most likely have to fabricate something that mounts under the dash and hangs down enough to read the meter or on the passenger side tunnel. There just doesn't seem to be enough room for a 52MM guage. The dash area to the far left has a bulk head/tubes and I fear I wouldn't be able to access the back side of that area.

Just installed an air/fuel ratio gauge here in my X-Flow 7 to try and sort out the jetting. Only one rolling road here in Walla Walla and it's not available till October. So I went the route of a poor mans dyno tune. I'll report on how it works out. Now to find a place to mount it. My dash panel is already full.

Having owned a carriage company at one time in my life. I was checking into the waterless coolant for my truck. Which used a 16 liter Caterpillar diesel engine. It was my understanding when the waterless coolant was first developed. The main intended use was in Diesels. As diesels do benefit from & are more efficient when operating at higher temps. So the WC would be very beneficial as it does not form steam bubbles next to the hot cylinder walls at higher temps. Said steam bubbles are a really bad thing. As the WC is so long lived, It would have been a definite plus in my case, As my truck would be driven about 120,000 miles per year. I don't imagine that a petrol engine would benefit much from a higher operating temp. Especially if one has a carbureted engine.

I was seriously considering a wideband sensor. here I even had a sensor bung welded to the pipe just after the collector, Then the silencer internals went wonky and no more bung. At least now I can hear my self think and the ringing has subsided.

Thanks for all the information Jim. Since my last post I did do a detailed look at the synchro flow numbers for each individual carb barrel and found that each carb had one barrel at 3 and the other was 2.5. I looked at the throttle plate position through the progression hole inspection cover and all were covering half of the first hole. So I adjusted the air bypass screw to balance them. That seemed to help a bit as all the carbs are now matched. I did as Mr. King suggested and dropped the main to a 115 and adjusted the floats to 13mm with a 6-7mm drop. As per the ignition, All I was told by my mechanic was that it was electronic & not points. He was replacing the valves so didn't do anything with the dizzy. I do not get a lot of popping on overrun from higher revs when I totally close the throttle. The popping (both from the carb and the exhaust) are at slower speeds around town at partial throttle. It gets worse when the engine is hot. Overall the car is much improved from when I first bought the it. Last week I logged 22MPG US or 26.5MPG imperial, which is nearly double from what I was getting prior to the valve job and new carbs. So things are looking up, But that last bit of tuning is proving elusive without the rolling road. Unfortunately I have yet to find a rolling road in my area that isn't booked up for the summer. I'm hoping to buy a trailer from Mr. David Saville Peck in BC (Caterham Canada@ super7cars.com) So I'll be able to travel to get some dyno tuning time. In the mean time, I can live with how the car is running.

Thank you Mr. King. I run the 7 sans bonnet on the next hot day & see if that makes a difference.