SBC 350 Compression Test Question

[DLOVE]

Hello,

A friend of mine completed a compression test on my original sbc 350 in my 71 K5. The test was done without running the engine first as its already pulled out of the blazer. He thinks these test results should be fine, but while I have it pulled out I am on the fence if I should have it re-built or just swap for an LS. My plan was to keep the original engine and add the Holley EFI. Any thoughts or input?

Thanks!

 

[Bent77]

#5 has a serious problem

Holley makes several EFI units. They are not all the same, or even comparable

 

[Wes Harden]

could be valves. nice set of performance heads could solve. do a leak down test this will tell you exactly where the compression is leaking.

 

[DLOVE]

#5 has a serious problem

Holley makes several EFI units. They are not all the same, or even comparable

I was going to go with the Holley Sniper 550-511K.

 

[Bent77]

I was going to go with the Holley Sniper 550-511K.

I’d do a lot of research before you buy

 

[venevidivicci]

They make an air chuck that screws into the spark plug hole. That way you can pressurize the cylinder and tell if it is blow by in the rings or in the valves. Another thing you can do is a wet test. Spray or add a little oil to the # 5 Cylinder and do it again. if your pressure increases it has blow by in the rings. if it stays low its probably in the valves.

 

[BoondocK5]

If it was me, and I had to buy the tools again, I'd buy a compression test kit, with a leak down feature.
I've used the leak down tester, way more than I've used a compression tester.
Yes, compression is an issue, but, I usually have to figure out where the suppossed compression is going.

 

[DLOVE]

They make an air chuck that screws into the spark plug hole. That way you can pressurize the cylinder and tell if it is blow by in the rings or in the valves. Another thing you can do is a wet test. Spray or add a little oil to the # 5 Cylinder and do it again. if your pressure increases it has blow by in the rings. if it stays low its probably in the valves.

Thanks!

 

[Wes Harden]

Need an adjustable regulator or set your compressor to @ 30psi. If you use to much pressure the piston will move and open a valve, invalidating your test.

 

[ford555]

Edelbrock Pro-Flo 4 EFI

 

[Kain]

THIS^^