Synchro909
Well-known member
I have 2 A engines that I have put together for touring and I'm very happy with them. I also have a Diamond B block with which I am not so happy. All three engines have a 5.5:1 head and a downdraft Stromberg carburettor from a Holden. The two A engines also have a slightly modified cam - the B has an original B camshaft - the only difference.
I have always thought the B engine was not doing as well as it should and it is thirsty. For quite a while I thought the fact that the car (1928Tudor) with a heavy sedan body and a 3.54 diff ratio was why. I have just spent 4 hours behind the wheel of this car which gave me the chance to do some thinking on the matter. Here's what I arrived at.
There are the three Cs to make an engine go - Carb, Cam and Compression. Since all engines have the same Carbs and same Compression, the difference must be the cam. I understand that the B cam is better than the A but it may not be as good as the one I had done locally for the A engines(I don't know the figures - just that is is a good thing!).
These diamond B blocks were built for Industrial/ Agricultural purposes so I wonder if because they are more likely to be running at fairly constant RPM, the cam timing might be different from a car engine.Is anyone able to confirm or refute that?
Looks like I might have one of my spare A cams ground the same as the others and put that in. Yet another job! UGGHHH!
I have always thought the B engine was not doing as well as it should and it is thirsty. For quite a while I thought the fact that the car (1928Tudor) with a heavy sedan body and a 3.54 diff ratio was why. I have just spent 4 hours behind the wheel of this car which gave me the chance to do some thinking on the matter. Here's what I arrived at.
There are the three Cs to make an engine go - Carb, Cam and Compression. Since all engines have the same Carbs and same Compression, the difference must be the cam. I understand that the B cam is better than the A but it may not be as good as the one I had done locally for the A engines(I don't know the figures - just that is is a good thing!).
These diamond B blocks were built for Industrial/ Agricultural purposes so I wonder if because they are more likely to be running at fairly constant RPM, the cam timing might be different from a car engine.Is anyone able to confirm or refute that?
Looks like I might have one of my spare A cams ground the same as the others and put that in. Yet another job! UGGHHH!
..I'd check tune,vac leaks and float level before tearing into it. Then if it did,Id do as Brent suggests and center on the timing gear. Anything is possible with your cam till your measure it,but Id make sure everything else is correct before I jump in there.