Just did a compression test.

[IZ1111]

I'm wondering what is the correct amount of compression in each cylender. I recently rebuild my 92 CV engine, but cant get it running.

Here is what I got:

4 = 68psi 8 = 88psi

3 = 85psi 7 = 94psi

2 = 67psi 6 = 76psi

1 = 84psi 5 = 74psi


I actualy removed and intalled the heads myself. Don't know if I applied enough torque.

[pollenjesus]

Originally Posted by IZ1111

I'm wondering what is the correct amount of compression in each cylender. I recently rebuild my 92 CV engine, but cant get it running.

Here is what I got:

4 = 68psi 8 = 88psi

3 = 85psi 7 = 94psi

2 = 67psi 6 = 76psi

1 = 84psi 5 = 74psi


I actualy removed and intalled the heads myself. Don't know if I applied enough torque.

Your compression numbers are way off. General rule is that compression should be be between 140-160 psi. Just a guess, but it sounds like the cam timing is off. Why did you rebuild in the first place? Were you having loss of power issues?

[450HP]

Originally Posted by pollenjesus

Your compression numbers are way off. General rule is that compression should be be between 140-160 psi. Just a guess, but it sounds like the cam timing is off.

Agreed... those numbers are way low... also they should all be pretty close to each to kind of "balance" the engine.

Scott

[IZ1111]

I removed the Heads so I could replace the Head Gaskets. The engine was burning coolant with white smoke coming out the tailpipe. I thought the head gaskets are worn.

I actualy unbolt the whole engine myself. Once I rebuild it back up. When I cranked it, I can only hear the starter turning the engine. But that was about it. I checked for spark, there was spark. I checked the fuel pressure, the fuel needed bleeding, so I bled it and the pressure is good. No I checked for compression and these are the numbers that came up.

I actualy looked around and found that any number above 100 is good. But couldn't find anything saying the correct amount that should be used for a Crown Vic. I'm going to try to use a torque wrench this time to tighten the heads. Maybe this will improve the compression.

Thanks for the advice.

[way2old]

The head bolts are torque to yield. Did you follow the exact torquing procedures? Also the head bolts should be replaced each time due to the stretching of bolt while torqueing.

[IZ1111]

I torqued the heads up. And didn't get much of an increase in compression. Maybe like 10 to 15 up in about each cylinder. So I tried adding a little bit of oil in each cylender (how Haynes suggest). And Boom! compression flew all the way up to 210psi in cylinder 1. Didn't have time to do the rest. But I'm not sure if having compression this high will cause any damage to the engine. But this means that my piston rings are worn . Oh well, I guess the pistons needed a lubrication/oil seal around them. I did have the oil drained and left the engine dry for weeks.

I hope this fixes my problem. I'll post an update if I do.

[IZ1111]

She's Alive!

But I discovered that I ripped the metal tube that connects the EGR to the right exhaust head when I disassembled the intake. So now I get smoke coming out one side of the engine.

I hope a replacement part can be bought at a store.

But still glad I got my car running again!