3.0 sc timing uk model
 

Hi
can anyone confirm the correct timing in degrees per rpm for a 1980 3.0 sc 180bhp ROW (uk) car ?
is it 25 deg at 4000 rpm or 15-20 deg at 3000 rpm and 19-25 deg at 6000 rpm ?

Its an 8.5 compression engine, I would like either of the first 2 suggestions with about 30 degrees @ 6K. In the states, we have vacuum advance for the last 5 or so degrees.
Bruce

The specs for your engine, 930/09, are 5 BTDC @ 900 rpm and 23-29 BTDC @ 6000 rpm, both with vacuum disconnected. The specs you quote are a mix of later specs for ROW and US models, also with vacuum disconnected.

Didn't we go over this last week?

JR

Hi
the figures i quoted at 3000 and 6000 rpm are from the 'haynes' manual for a 1980 car which i have just obtained, where as other people have suggested other figures ie 25 deg at 4000 rpm etc, i just wanted to be sure as i suspect the car has too much advance?


I have just realised that when i checked the timing at 3000rpm i read 20 degrees on the strobe dial but i was lining up the '5' pulley mark up with the fan mark. I should have used 'Z1' so in effect i have 25 degrees of advance at 3000rpm instead of 20 degrees? What effect would extra advance have on performance ?

I will also be checking the throttle bushings over the weekend as advised.

The max advance spec for your engine is 29 BTDC @ 6000 rpm, vacuum disconnected, are you above this ?

Hi
i would say yes but i will recheck over the weekend. I measured 20 deg + 5 deg (due to using the wrong pulley mark) at 3000 rpm. When i previously measured at 6000rpm i had forgotten to remove the vac pipe and got 30 deg + the same 5 deg (35 deg) but i guess removing he vac pipe will reduce this ?

Don't guess, measure. If your timing was too advanced, you would get pinging under WOT. Have your lovely assistant Tabitha mash the throttle pedal with her foot and see it you can open the throttle further with your hand on the throttle body. If you are getting full throttle and the ignition is advancing, do a compression test and test the AFR under load. If these are all in spec, that's all you can expect.

As you advised the timing is 5 deg at tickover, which is where it is set.

I had someone floor the throttle (engine off) but couldn't open the throttle any more from the engine bay, so the linkage seems ok.

There seems to be a backfire at 1700 rpm, Co incorrectly set ?

If i test the compression what psi should a good engine be (1980 SC) ?
many thanks

80SC euro is a 8.7 CR I would look for 150 to 160# compression
Bruce