Volvo Owners Club Forum - View Single Post

Juular · Jan 19th, 2024, 20:41

The engine in my car is a B18B with twin SU carbs and high compression head. While rebuilding (more accurately, refreshing) it I noticed that it had a D grind cam installed which I simply reused.

Since balancing, tuning and timing, the engine pulls exceptionally well through the low - mid range. However I've noticed that if I try to rev out the engine, say past 4500-5000rpm, it starts pinking.

In normal driving it does not pink at all and the dizzy seems to be functioning perfectly, advancing up to around 30 degrees at 3000rpm.

Mix seems good for normal driving and plugs look a nice sandy colour.

I have no idea what needles are currently in the carbs but am I right in thinking that the needles should have been changed to match the cam? I suspect it may be too lean at higher rpm.

What needles should I be using for this setup?

Jan 19th, 2024, 20:41	#1
Juular Senior Member Last Online: Today 13:28 Join Date: Sep 2020 Location: Falkirk	B18 needles for a D grind cam The engine in my car is a B18B with twin SU carbs and high compression head. While rebuilding (more accurately, refreshing) it I noticed that it had a D grind cam installed which I simply reused. Since balancing, tuning and timing, the engine pulls exceptionally well through the low - mid range. However I've noticed that if I try to rev out the engine, say past 4500-5000rpm, it starts pinking. In normal driving it does not pink at all and the dizzy seems to be functioning perfectly, advancing up to around 30 degrees at 3000rpm. Mix seems good for normal driving and plugs look a nice sandy colour. I have no idea what needles are currently in the carbs but am I right in thinking that the needles should have been changed to match the cam? I suspect it may be too lean at higher rpm. What needles should I be using for this setup?