Compression test...what to expect?

[Phast SVX]

What can i expect to pay for a compression check at my local suby dealer? And does anybody know what the STock compression for the EG33 is, along with the service limit? I havnt heard of a whole lot of 3.3's having trouble, but my engine has 170k+ miles on it, and want to check up on it before i decided to give it the wet bottle... It feels fairly strong but I would like to be sure before, not to send it to that premature of a death!........Thanks alot!
Phil

[huck369]

I have no ideal what they'll charge you, but they have to pull the plugs to run a compression check, so I'd buy some new plugs for the to put back in, as the labor shouldn't change.

[GreenMarine]

You know that the compression ratio is 10:1 right? well there is 14.7psi for each one of those 10. so just take 14.7 and multiply that by 10 and you should get 147psi. Now don't hold me to it, but I believe that that is right..... that is the highest that it should be, stock. but I'm not shure if you sub tract 14.7 for sealevel being relative zero...... oh well it is either 147psi or 132.3psi

[Stevebsy]

....and he opened the book called service manual sections 2&3 and read:

Chapter 2-2:4a

1. After warming up the engine, turn off the ignition switch
2. Make sure the battery is fully charged
3. Remove all the spark plugs
4. Disconnect connectors from the fuel injectors
5. Fully open the throttle valve
6. Check the starter motor for proper operation
7. Connect the gauge in the spark plug hole
8. Crank the engine by means of the starter motor, and read the maximum value on the gauge when the pointer is steady
9. Perform at least 2 measurements per cylinder and make sure the values are correct

Values:
200-300 RPM and fully open throttle
Standard: 171-206 psi
Limit: 142 psi
Difference between cylinders: 28 psi

Saying thus, he closed the big book

[GreenMarine]

Thank you for enlightening me I just mede an educated guess at what it was... oops, I'll not do it again master

[svx_commuter]

Originally posted by Stevebsy
....and he opened the book called service manual sections 2&3 and read:

Chapter 2-2:4a

1. After warming up the engine, turn off the ignition switch
2. Make sure the battery is fully charged
3. Remove all the spark plugs

Any idea how to run the car warm it up and then get the plugs out within oh say 10 minutes so that the engine will still be warm?

Save your money on this test. If your are getting at least 22 MPG and don't use more than a qt of oil in 500 miles and can still run 0-60 in about 8 sec's the piston rings are fine.

Try doing a vacuum manifold test first. This can tell you a lot about the rings and is easy to do.

[Phast SVX]

Im not really worried, more or less wanting to know the condition of our Engines after 170k miles. People rant and rave all day about forged this, forged that, but how do the parts that keep things all in working order sufice the test of time?
phil


Steve thanks a lot for the comp #'s. Taht is really odd how low the service limit is for a 10:1 car. Oh well. Ilread ran a vacuum test, all is well and there really was not much pressure as most hoses are new. A leak down test will be my last safetly precuation before the bottle, and i will be putting new ngk's in at the same time.
phil
P.S.....The 0-60 is well under 8 seconds

[svx_commuter]

This engine has hand picked pistons matched to the cylinders with a design clearance of about .0006 inches. Someone else with a SM can check. Mine is at home. Three size grades of pistons are use A< B< C. The size in each cylinder is stamped on the top of the engine.

My engine that I broke and then took out and removed the from had 153k miles on it. Theoriginal honing marks are still there in the bores and the psitons still look very snug. I just do not know if the rings wore much.

[Phast SVX]

What exactly did you break on the engine and how? Crank problems? That seems to be the only thing i can dredge upwhen looking for engine failure
phil


PS Could you maybe get into a little bit more detail on the sze grades of pistons and how that is beneficial. Im dont know a whole lot in terms of the mechanics of our engines, or standard cumbustion engines in detail. maybe you could point me to a good book or good website on the subject?
phil

[svx_commuter]

Originally posted by Phast SVX
What exactly did you break on the engine and how? Crank problems? That seems to be the only thing i can dredge upwhen looking for engine failure
phil


PS Could you maybe get into a little bit more detail on the sze grades of pistons and how that is beneficial. Im dont know a whole lot in terms of the mechanics of our engines, or standard cumbustion engines in detail. maybe you could point me to a good book or good website on the subject?
phil

Oh I went flying with the SVX awhile ago When it came down it slammed into the ground and the exhaust headers/pipes smashed the pavement. Turns out I bent the block on both sides at that time and developed a head gasket after 14 months or so. It is an expensive way to have fun.

I am sure your local library has books that may help.

[Phast SVX]

I just ordered a book after spending some time spending some time researching a good one for a good price. That realy sucks, were you off roading? I have yet had the balls to take mine off the tarmac and mess around, though it seems very enticing.
phil

[wawazat??]

Originally posted by svx_commuter


Oh I went flying with the SVX awhile ago When it came down it slammed into the ground and the exhaust headers/pipes smashed the pavement. Turns out I bent the block on both sides at that time and developed a head gasket after 14 months or so. It is an expensive way to have fun.

So have you determined an outcome for your flexible EG33 John .

I'm still interested in in for..... research

Todd