McBreadhead

Anthony, Point taken - it does sound a bit like a bit of a goose chase but that is not how I planned it! I originally wanted a 7 specialist to do all the work which he did to the point of getting the engine running (it was a sealed unit using carbs, Lucas competition ignition and dizzie, and 4 into 1 Caterham exhaust from my current car), but he couldn't get a rolling road slot booked for weeks. So in desperation I took it elsewhere and they naturally had no history with the car but did as best they could. It was there they said the Emerald EC3 wasn't communicating with their set up which to me sounds like a fairly crucial component to include/match. The carbs are same size and type as on the engine I bought (and which I still have), although they ran 32mm chokes. However these were relatively worn out compared to mine, hence I swapped them over. Not sure if the EC3 is fully mapped 3D item but as I have a dizzie I assume not. As you see I'm not that technically literate, and as I don't have a garage or tools I'm a bit helpless, hence I need to know where to focus my efforts on commissioning appropriate 3rd party experts. I guess at this point I'm unsure of who to go back to, compounded by awkward logistics of getting car to either. If I can iron out certain possibilities it will make the task easier I hope. Car based in South Bucks or South Hants. Appreciate your help so far....

Petrolhead, thanks for advice - I was thinking 32 or 34mm chokes. Will this deteriorate fuel consumption further tho? Yes A6 is pretty wild and I'm happy to accept some loss of tractability but it's as if a Ford Fiesta would out accelerate me under 2,500 rpm!!! I also recall being driven with this engine in another car in May and it pulled cleanly all the way, admittedly using 32mm chokes. Wonder why the engine is stalling so much? Is this the ECU not working properly or timing too advanced?

BRG with yellow stripe and clams on roundabout in Midhurst, Friday evening July 7th around 7.30 pm. You were coming east from Petersfield, I was in green Jag saloon coming from north giving you thumbs up.

It's an Emerald EC3 from memory - is this significant? It has Roger King's stamp upon it and has a 3 pin port for analysis/download purposes.

Recently upgraded my std crossflow to a 1760cc unit with forged pistons, stage 4 race head, Cosworth A6 cam, running on twin 40 DCOEs with (only) 30mm chokes. This is supposed to put out 160bhp but I had it rolling road (carb) tuned last month and it only managed 134bhp. I know you can't compare rolling roads but this discrepancy seems excessive. Roughly how much power would be liberated increasing the choke sizes? Furthermore the fuel consumption seems poor at around 20mpg for a steady 75mph cruise around 4,000 rpm. Took car onto track this weekend and it bogs down badly under 2,500rpm plus constantly stalling on overun. People have suggested timing is way too advanced. Obvious route is to take it back to rolling road and get them to sort but unsure of where I stand in terms of should I be made to pay for extra work or should they do it for free? Would/should they be able to sort timing issues? To compound matters, the engine installation (engine was a sealed unit) has been performed by a collection of professionals which means I do not have 'continuity' of service making responsibility difficult to apportion. Should the rolling road be able to sort the ignition problem (preferred for continuity) or am I better off taking to Caterham specialist? They did originally mention they had difficulty getting their system to communicate with the ECU so I wonder if they have had to make too coarse an assumption with a setting somewhere. The iginition is a Lucas competition unit fitted by Roger King and should be worth 5-10bhp more than std Caterham unit. Lots of possibilities I know, but I need to start isolating things in a logical fashion. Any ideas and/or suggestions how I should attack this? Your help much appreciated o wise wuns.

If you have the standard boot cover it will fit over the new style FIA bar (the one with the X cross bracing) as the tube dia just fits the cover's cut outs. If you were upgrading from the std Caterham rollbar to the old style FIA bar, you had to change the boot cover too as the tube dia was significantly larger.

Went to a tractor and farm machinery stockists and found 2 jubilee clips, 120 - 165mm, for £2.00 ea. Now I know the 7 is described as agricultural............

Ah yes twas us. BRG with yellow nose. First spotted in 6 years!!! Came back to do the B3078 and B3081 which we 'found' a couple of weeks ago on our return from Compton Abbas. Wonderful roads. How did car sound as I'm always conscious it's loud? Were you in the 7 duo on Saturday 24th June heading towards Shaftesbury, one orange the other green, about 5pm as we zoomed in opposite direction going to Verwood?

If it's not too cheeky of me to ask how much did it cost? For comparison I went to Southern Carbs in SW London and it set me back £180 incl Vat. But fuel consumption is appalling (around 100m a tank) and it 'only' managed 134bhp at the crank for a 1760 crossflow with stage 4 race head, Cosworth A6 cam and forged pistons. Admittedly running twin 40 DCOEs on 30mm chokes (as opposed to 32 or 34mm) but that's because it's for road use and sized to aid driveability and to improve fuel consumption I thought. Nick

The jubilee clips that secure the exhaust heat deflector to the baffled enclosure have rusted through and Halfords only do lengths to 120mm. I'm guessing the next size is 150mm which should just about do it but where do I get them from? Thanks, Nick

Wonder what using 32mm chokes would do then - anyone prepared to put a finger in the air?

After much to-ing and fro-ing between various specialists (and copious assistance from Blatchat *thumbup* ) I finally have my new cross flow up and running with good oil pressure (PRV spring in oil pump uprated to stiffer type plus new sender). Had it rolling road tuned when ambient temp about 30 deg C but she 'only' managed 134bhp at the crank. The engine is quite lairy with an A6 Cosworth profile cam, stage 4 race head and forged pistons displacing 1760cc. Running on twin 40DCOEs with 30mm chokes to aid driveability as it's a road car. RR speculated that high ambient temps could result in power down by as much as 15% which translates to a theoretical 158bhp which is bang on where it should be. Is this assumption correct/reasonable? Or has use of 30mm chokes restricted power by a significant amount?

GN or GV06 KVM? yellow CSR or SV. Looked the biz as you were on Rocks Lane crossing over Lower Richmond Road. Where you based?

We were headed towards Ringwood in a green with yellow nose while you were Shaftesbury bound. You were two cars - one orange the other a yellow nose????? - and one waved and the other tooted and flashed. *thumbup* We turned round to try to catch you then got to the junction and stalled and died, straddled across the junction. Then I forced my partner out at gunpoint to push barefoot. 😳 Haven't had so much fun in years - what a brilliant car 😬

Nick, A lot of 😬 thanks. Yes got your email, plus YHM. Nick

Anyone care to translate? 1760 crossflow with Stage 4 race head, A6 Cosworth cam, forged pistons. I guess just under 160bhp at the crank - how much do I allow for losses?

It wasn't a LOCAL car for local roads then? Malcolm - how did you do at Curborough?

Blue with cycle wings on A217 going south to M25 yesterday rushhour around 6.30pm. Driver wearing base ball cap. Me in old Jag giving you the and a wee bit envious.

John, I may well have a Lumenition box and dizzie once the 7Workshop have sorted my engine transplant. The car and bits will be based in Gerrards Cross hopefully from June 2nd which may be convenient to view? Nick

Andy, Thanks, think I will stick with me current one and suck and see. But I will get it polished to make it gleam nicely. Nick

Alan, I bought mine ready built from a fellow blatchatter and avoided the ground up rebuild. If you can find someone who is moving one on with the work already done this will work out hugely cheaper. If you get someone to build it from scratch you are looking at £3k plus. Chris Wheeler at the 7 workshop in Herts can do it but there must be others around. Re the silencer I would go Raceco rather than Techcraft as from what I've heard the welding is superior. It's also pretty good on noise for track days too. Nick

I am in the process of swapping my 135bhp crossflow for an upgraded 160bhp unit. The car currently has a standard Caterham 4 into 1 primary exhaust system with the Caterham silencer and side exit rear. My understanding is that the primaries are tuned to the harmonics of the 135bhp, namely with 3 tubes of 31" and 1 tube of 27" or thereabouts. Question is with the new powerplant will the harmonics require primaries of different lengths to extract the max power? Or will the difference be negligible?

Apparently the new style FIA roll bar can replace the standard Caterham 'up and over with twin rear stays' job (which I curently have on my '96 cross flow de dion) with no requirement to replace the boot cover. The previous FIA bar was of much larger diameter necessitating the cover change as part of the package. However Caterham have them on back order - anyone got a spare incl petty strut? Nick

Will be taking an engine down to Chris Wheeler on Sat afternoon so should have a bit of space in our half cab pick up. Call me on 07970 276 292 if interested, Regards, Nick

Plan to visit Curborough on way up to Wrexham from Worcester Park, leaving London at 9am. We have a half cab pickup with space if anyone can get items to Worcs Pk before the off. Could be a call for wet tyres methinks. Call me on 07970 276 292. Nick