Crack in engine at the valley
03-06-2023, 05:09 PM
#91
Rennlist Member
Hello Fred,
I just want to give you an update about the cracked engine. Engine is still holding with the Belzona. Only minor loss (500cc within 6 months) of coolant .
And I measured also the compression on each cylinder :
1: 10,3 bar (149 Psi)
2: 10,2 bar (148 Psi)
3: 10,4 bar (150 Psi)
4: 10,2 bar (148 Psi)
5: 10,5 bar (152 Psi)
6: 10,2 bar (148 Psi)
7: 10,5 bar (152 Psi)
8: 10 bar (145 Psi)
Porsche compression specs for my M28.12 engine is 10:1 .So all great numbers which means my engine is in good condition.
For the moment I did not have the time to replace the engine by the spare engine I bought...
I just want to give you an update about the cracked engine. Engine is still holding with the Belzona. Only minor loss (500cc within 6 months) of coolant .
And I measured also the compression on each cylinder :
1: 10,3 bar (149 Psi)
2: 10,2 bar (148 Psi)
3: 10,4 bar (150 Psi)
4: 10,2 bar (148 Psi)
5: 10,5 bar (152 Psi)
6: 10,2 bar (148 Psi)
7: 10,5 bar (152 Psi)
8: 10 bar (145 Psi)
Porsche compression specs for my M28.12 engine is 10:1 .So all great numbers which means my engine is in good condition.
For the moment I did not have the time to replace the engine by the spare engine I bought...
Was thinking about you only the other day!
Whatever way you look at it the Belzona has achieved the primary goal and providing you have a recovery policy to get you home in the event of an issue just keep running as is until such time as you are either forced to change out the motor or want to do it for the sake of it.
The spread of compression values is perfect. The actual cranking compression pressure tends to be controlled by the cam design so if you have the peakier S cam or whatever it is called I might expect that to produce the kind of numbers you are seeing but doubtless someone can confirm that. Similarly advancing the cam timing favours low end torque and that will increase cranking compression pressure but retarding it will do the opposite. Whether this can be done with your engine setup I know not.
At the end of the day all that really matters is whether you are happy with the way it drives.
