R32RennSport
Outlaw Amazonian
- Joined
- Nov 20, 2011
- Location
- Atascadero, CA
I'm gearing up to do sort of a do over on my B20 big bore (2130cc) engine. In doing so I've been eating up all the information on various engine builds from over the past few years, here and elsewhere. I've put together a list of wants and needs while trying to balance those against a reasonable budget. In a perfect world I send it out to be professionally assembled and would probably throw a stroker crank at it for good measure (I hear those engines are quite the kick in the pants).
Why am I going to put myself through all of this after just assembling this engine and putting approx. 5K miles on it in the last year? Well I discovered that when you do something for the first time you make a few mistakes, sound familiar to anyone? There is enough feedback after the past year to motivate me to do better job the second time around. It runs OK, but just OK, it doesn't feel like anything really special and it's had it's fair share of questionable issues.
The main issue on my first rodeo is I took everything for granted and didn't measure really much of anything. That leads me to not being able to explain why my fresh engine only makes 130ish psi on all cylinders because I never actually measured volume so I really don't know what my actual compression is. I was told it should be around 9.25:1, but the engine feels like a slightly stronger stock fresh B20, (which I recently had the opportunity to drive). Also, the camshaft degree-ing is suspect but again I did no measuring before hand (honestly didn't even know that that was thing until someone asked me). I tried to do it in car with a friend but it was over my head and we were both skeptical of the accuracy of the measurements we had.
I know for a fact the block was not zero decked and from what I gather this an important factor in getting proper squish. IPD big bore head gasket with advertised install height of .045. Pistons were used units with new Hasting .020 rings installed. I do have a new set of complete .030 Mahles on hand for the rebuild if needed. The head is an injected head from a '72/'73 with larger 38mm exhaust valves, stock intakes and mild port work. It looked thick, combustion chambers looked like decent volume, just surfaced but again I did not measure thickness. It has a KG10 camshaft installed and I haven't found anyone having issues with their camshafts. I have a pair of 45DCOEs with long runners and an infinite selection of tuning parts available to me as I'm a Redline Weber retailer at work.
So keeping in mind that I only have blended 91 octane California gasoline available to me what is the highest safe compression I should shoot for and is that compression going to be optimal for the KG10?
Looking for constructive suggestions and or advise.
Why am I going to put myself through all of this after just assembling this engine and putting approx. 5K miles on it in the last year? Well I discovered that when you do something for the first time you make a few mistakes, sound familiar to anyone? There is enough feedback after the past year to motivate me to do better job the second time around. It runs OK, but just OK, it doesn't feel like anything really special and it's had it's fair share of questionable issues.
The main issue on my first rodeo is I took everything for granted and didn't measure really much of anything. That leads me to not being able to explain why my fresh engine only makes 130ish psi on all cylinders because I never actually measured volume so I really don't know what my actual compression is. I was told it should be around 9.25:1, but the engine feels like a slightly stronger stock fresh B20, (which I recently had the opportunity to drive). Also, the camshaft degree-ing is suspect but again I did no measuring before hand (honestly didn't even know that that was thing until someone asked me). I tried to do it in car with a friend but it was over my head and we were both skeptical of the accuracy of the measurements we had.
I know for a fact the block was not zero decked and from what I gather this an important factor in getting proper squish. IPD big bore head gasket with advertised install height of .045. Pistons were used units with new Hasting .020 rings installed. I do have a new set of complete .030 Mahles on hand for the rebuild if needed. The head is an injected head from a '72/'73 with larger 38mm exhaust valves, stock intakes and mild port work. It looked thick, combustion chambers looked like decent volume, just surfaced but again I did not measure thickness. It has a KG10 camshaft installed and I haven't found anyone having issues with their camshafts. I have a pair of 45DCOEs with long runners and an infinite selection of tuning parts available to me as I'm a Redline Weber retailer at work.
So keeping in mind that I only have blended 91 octane California gasoline available to me what is the highest safe compression I should shoot for and is that compression going to be optimal for the KG10?
Looking for constructive suggestions and or advise.
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