Spark Plug recommendation Options

[Eddie914]

What spark plugs should we use in a 2.7 with 40 IDA Webers, stock ignition, and Bursch headers and exhaust?

Thanks in advance

Eddie

'71 914/6 2.7

[Eddie914]

JP ...

Question: What compression/pistons ya gots?

Answer: Some/six



Question: Cam?

Answer: two


The previous owner performed the conversion years ago with a 1977 2.7 motor he purchased complete with the Webers from a salvage yard. He was note sure of the specs.

I have yet to do a compression test or pull the valve covers to look for part numbers on the cams. I suspect that if it still has it's stock pistons (8.5:1 IIRC) compression should be about 170psi. I have run everything from regular unleaded to premium unleaded and have never noticed any predetonation (as if I could over the Weber induction music).

It revs freely and and seems to have a very even powerband right up to the rev limiter at 6500rpm. The engine seems to load up a bit under 3,000 rpm under light throttle application. The smooth idle does not seem to indicate aggressive cams. Above 3,000 it runs beautifully. I'm guessing the carbs need a rebuild and the plugs are fouled. I've cleaned the idle jets three or four times since we got the car in January to cure the backfiring. We have run all of the old gas out of the tank now and the idle has cleared up but it's not very happy under 3,000 rpm.

A borescope would be a handy tool to check out the piston crowns ... unfortunately I don't happen to have one.

Thanks again.

Eddie(IMG:http://home.comcast.net/~mark_seiferth/Ed_060.jpg)