How much compression should a 3.2 be making?

[SHeepsclOthing]

Im looking to see how much compression I should be making with a stock 3.2. Im getting about 140-150psi on a dry test. I have no clue what I should be seeing. 150psi sounds pretty good to me though.

 

[NWGRN94MTX]

If I remember right, about 210.

 

[The Dude]

You do know to pull all the plugs before testing? Just a friendly reminder.

 

[twr]

You do know to pull all the plugs before testing? Just a friendly reminder.

And block open the throttle plate (WOT)

 

[Yamaha V6]

I remove the intake completely - allows open intake ports & remove the plugs in the same bank (do all 6, saves time etc).

Typically seeing 190-210 on most cars w/ 75k-150k, in decent shape. Big thing is the difference between cylinders, if you have a large variation between high & low, you have an issue.

 

[SHeepsclOthing]

I know all the tips and tricks and such. That test was a last ditch effort before I went to work and it was with the plugs in (I was aware it would effect readings...did not have time to remove them). It was at WOT.

 

[SHeepsclOthing]

Found time to do the test right today. Same results though. 160psi in all cylinders which is good in a sense because they are all even but they are still too low. I really didnt want to tear down the whole motor because of price of gaskets alone. Its insane paying 300 for head gaskets but you gotta do what you gotta do.

 

[Yamaha V6]

Run it. Perhaps see what numbers you're making on a dyno, and if it's excessively low, ok. Otherwise, if it runs well, drive it.

 

[SHOtimer]

Found time to do the test right today. Same results though. 160psi in all cylinders which is good in a sense because they are all even but they are still too low. I really didnt want to tear down the whole motor because of price of gaskets alone. Its insane paying 300 for head gaskets but you gotta do what you gotta do.

I bought my head gasktes from RCM for just $100, IIRC.

Doug

 

[Yamaha V6]

Doug, I don't know what his current pricing is, but FWIW, NAPA & a bunch of the other gasket mfg's finally figured out there was a discrepancy in the HG pricing, and the costs went through the roof a couple of months ago.

 

[SHOtimer]

I just checked the RCM page and he still has 3.2 HG's at $100 and 3.0 HG's at $70. Those prices are just for the HG's not the whole upper set.

Doug

 

[SHeepsclOthing]

Run it. Perhaps see what numbers you're making on a dyno, and if it's excessively low, ok. Otherwise, if it runs well, drive it.

I would if I had the time or patience. Im very limited on time and this will be my daily driver so I can take my other DD off the road and some more work on it. This has to get running before snow falls.

Its quite a relief knowing that I can get gaskets for less than 300.

 

[The Dude]

if you wanna save money just put some thicker oil in there. Your good to go.

 

[SHeepsclOthing]

Something else Id like to mention is that this engine was dead nuts cold. With the engine at opperating temps, it should be higher.

 

[Off Road SHO]

Something else Id like to mention is that this engine was dead nuts cold. With the engine at opperating temps, it should be higher.

Yes that would give the pistons a chance to expand to operating size and the oil a chance to seal the ring to cylinder wall gap.

How accurate is your guage? Can it be "zero'd" and if so was it? My buggy engine had lousy compression on my guage but great compression on my neighbors'.

Tom