Gathering Info for Caterham 1600 GT Tuning Project

[bcrain]

After a 34 year absence, I picked up a 1988 Caterham  to replace the long gone 1962 series II. We are going to fine tune and re-jet the DCOE 40 Webers for operation a mile high (Albuquerque, New Mexico, USA).

Before we do that, I have to reset the valve clearances and find the timing marks. I have some original information, but it is not comprehensive.

Can anyone tell me:
1 - if I am to set the valves hot or cold
2 - if I should make any clearance modifications for roller rockers (original sales sheet says in-.010" or .25 mm and ex-.022" or .56 mm - previous owner says in-.010-.012" and ex-.018-.022")
3 - Any information on the locations and specifications for the timing marks would be greatly appreciated as well.

This car has the South African block - 831C6015R34. I believe it still has the original head, but it was ported and the roller rockers added, some time in the past. That may have been when the Webers were added.

Right now, it is slow and overly rich, but if I open it up on a longer road, the spark plugs look pretty good.

[Duckpit]

I have a 1600GT on my 68 Lotus, but with Weber 32DFM.

If it is same as UK 1600 GT Timing mark is on bottom pulley a small groove on outer rim, probably groove full of muck now so go to TDC and then run finger nail across & should find it, The marks on the block about 1-2 pm above the pulley.

Tappets adjusted when hot.

Have you got the idle adjusted properly ?

Nick

[bcrain]

Thanks for the info. I assume 1-2 pm is on the clock.

They were terrible when I got it. But are in good rough tune now. I'm working with an expert.

[elie boone]

Valves are set cold, for the GT engine in =0,25mm out =0,55mm hotter camshaft do differ from these valve clearances