2000 Volvo Penta 7.4 GI MPI compression

[bear_69cuda]

Happy New Year gang,

What is acceptable compression, and percentage of difference between each cylinder? I'm having compression test on the boat I'm looking at, and cannot locate this data...

Thanks in advance!

 

[Bondo]

Re: 2000 Volvo Penta 7.4 GI MPI compression

Ayuh,... More than 130psi, at no more than 15% between the highest, 'n lowest....

 

[Don S]

Re: 2000 Volvo Penta 7.4 GI MPI compression

I had a 98 7.4 Volvo MPI that had right at 15% difference (3 cylinders) and it ran horrible. Leakdown test also showed around 15% on those cylinders.
Did a valve job and it ran and idled perfect.
Probably wouldn't have noticed a running problem on a small block, but it showed up big time on the big block.

 

[bear_69cuda]

Re: 2000 Volvo Penta 7.4 GI MPI compression

Thanks Bond-o for the numbers!

And thanks for the tip on valve job Don!

I really appreciate you dudes!

 

[Don S]

Re: 2000 Volvo Penta 7.4 GI MPI compression

I wasn't trying to imply that a valve job could fix a particular problem, what i was trying to convey was the fact that 15% may not be a good number on that particular engine.

 

[proshadetree]

Re: 2000 Volvo Penta 7.4 GI MPI compression

bear_69cuda Did you find a cuddy project?

 

[bear_69cuda]

Re: 2000 Volvo Penta 7.4 GI MPI compression

I wasn't trying to imply that a valve job could fix a particular problem, what i was trying to convey was the fact that 15% may not be a good number on that particular engine.

10-4 boss thanks I understand....

 

[bear_69cuda]

Re: 2000 Volvo Penta 7.4 GI MPI compression

see PM

 

[bear_69cuda]

Re: 2000 Volvo Penta 7.4 GI MPI compression

Today I had my marine survey on the Cobalt 226 I'm looking at.

The compression numbers are as follows on the 7.4Gi.

#1 = 174
#2 = 168
#3 = 173
#4 = 171
#5 = 177
#6 = 170
#7 = 171
#8 = 175

No more than 5.0 % between cylinders lowest and highest. I think she's a good engine! Passed leak down also!

 

[Bondo]

Re: 2000 Volvo Penta 7.4 GI MPI compression

I think she's a good engine!

Ayuh,... Sounds like a Solid Runner,...

Take Good care of 'er.....