Compression Test Results (not good)

Post by **Sluggo** » Thu Sep 21, 2006 4:45 pm

Finally found Bottomends Compression Tester. The results aren't good. The wierd thing is, I have pretty decent power. And these results are almost identical to my tests before the rebuild. I used new/rebuilt heads & rings but the same pistons & cylinders.

Here are the results:

#1 - 100
#2 - 110
#3 - Just over 80 (same weak cylinder as before the rebuild)
#4 - 105 (a little oily)

What do you think? New P&Cs?

Post by **Amskeptic** » Thu Sep 21, 2006 5:49 pm

Sluggo wrote: I have pretty decent power.
#1 - 100
#2 - 110
#3 - Just over 80 (same weak cylinder as before the rebuild)
#4 - 105 (a little oily)

What do you think?

Give the engine a chance to break-in, like 1,000 miles. Aftermarket rings take longer to break-in.
Monitor the low cylinder. Your readings are as indicative of basic engine assembly architecture as anything else.
Deck height, combustion chamber cc's, even variations in valve grinding can send your numbers on a romp through your anxiety centers.
You will establish a baseline shortly, and that is what you will compare to future readings.
Type 4 engines with the factory 7.3:1 are not compression reading champs on a good day. That is why the factory gives you from 85 to 135 psi.
Power, smoothness, cool running, if these criteria are met, get out and enjoy the drive.
Colin

Post by **Sluggo** » Thu Sep 21, 2006 6:14 pm

I was just looking up info on compression testing and discovered that I should have taken all the plugs out instead of just the one I was testing.

Decent Power, pretty smooth (except sometimes accelerating in 2nd), Head temps rarely go over 320 never over 350. Oil temp usually around 150-175.

chitwnvw · Post by **chitwnvw** » Thu Sep 21, 2006 8:57 pm

Gut reaction. Trust what you feel when you're driving. The no gauge theory. Especially, compression, you aren't hurting anything. Patience. I knew a guy once who ran windows 95 w/o a mouse. He told me to hold on, to let it happen, he was right. It all worked out.

CASEY79WESTFALIA · Post by **CASEY79WESTFALIA** » Mon Sep 25, 2006 5:28 pm

I would drive it and see if things improve. Make sure that your valves are all dead on before you check compression. I only have just under 80 miles on my new raby build and I am seeing 125 on every cylinder. Did you use dino or synthetic oil for break in?? If synthetic was used the rings will have a tough time setting up, may never get full compression with synthetic.

Post by **Sluggo** » Mon Sep 25, 2006 7:22 pm

CASEY79WESTFALIA wrote:I would drive it and see if things improve. Make sure that your valves are all dead on before you check compression. I only have just under 80 miles on my new raby build and I am seeing 125 on every cylinder. Did you use dino or synthetic oil for break in?? If synthetic was used the rings will have a tough time setting up, may never get full compression with synthetic.

I'll do it again after I drive a little more. Castrol GTX 20/50 dino all the way. Checked my valves just a few minutes ago and a couple were just slightly off. Took her for a little drive and felt a little more power. I've been driving just to put miles on her. I live where I work and just about everything I would want is within a few miles. Except a VW store of course. Gotta drive to Eagle Rock for that. My poor Corolla hasn't been started since I got the Bus running.

chitwnvw · Post by **chitwnvw** » Mon Sep 25, 2006 8:26 pm

Sluggo wrote: Except a VW store of course. Gotta drive to Eagle Rock for that. My poor Corolla hasn't been started since I got the Bus running.

Jealous, Beeatch! I have noticed that the Japanese cars are great but emotionally temperamental. Got a 91 Camry out back that will testify.

I would think on the west coast that you'd have stores all over the place. It frustrates me, I live in a metro area of 7million+ and no stores, a guy in Minneapolis, he's got a store around the corner! WTF!

Using the same 20/50.

I'd say be happy. You're driving around, it handles well, responds well, temps are good, there's not oodles of oil pouring out. The milage will come...

chitwnvw · Post by **chitwnvw** » Mon Oct 02, 2006 8:43 pm

I'd really be happy now if I could be driving around...

hambone · Post by **hambone** » Wed Oct 04, 2006 12:44 pm

It'll be frozen solid and salty in a couple months, so don't sweat it. A winter project is FUN, doncha know? I rebuilt an engine in the basement one winter when I lived at Rockwell and Augusta, loads of fun. Kept me sane. SANE!

Post by **Sluggo** » Wed Oct 04, 2006 1:19 pm

chitwnvw wrote:
Sluggo wrote: Except a VW store of course. Gotta drive to Eagle Rock for that. My poor Corolla hasn't been started since I got the Bus running.
I would think on the west coast that you'd have stores all over the place. It frustrates me, I live in a metro area of 7million+ and no stores, a guy in Minneapolis, he's got a store around the corner! WTF!

I'd say be happy. You're driving around, it handles well, responds well, temps are good, there's not oodles of oil pouring out. The milage will come...

Just Bob Costa. He can be a bit pricey sometimes. But sometimes he just goes out back and yanks the part off another bus and gives it to ya. There's a place out in Hawthorne that good for cams & carbs & stuff. But the performance places here in L.A. that sell VW stuff are just selling overpriced crap (mostly EMPI) and the employees might as well be working at Autobone.

It handles okay right now. I have to replace the Ball Joints, Tie Rods & Assemblies, Center Pin Bushings, Steering Damper, front Shocks, adjust the Steering Box and possibly have to adjust the Toe & Camber after the Tie Rods are installed. Bottomend & I will have a full weekend. The back end is nice & tight though. New Spring Plate Bushings & Old School Konis thanks to Colin.

hambone · Post by **hambone** » Wed Oct 04, 2006 1:43 pm

The good news is once you get everything German-like it'll stay that way for some time. Sounds like that poor bus was neglected for a while, I hate that. Like seeing a sick cat. But it feels great to get things running right again, helping it's Karma and all.

DurocShark · Post by **DurocShark** » Mon Oct 09, 2006 5:29 am

Sluggo wrote: Just Bob Costa. He can be a bit pricey sometimes. But sometimes he just goes out back and yanks the part off another bus and gives it to ya. There's a place out in Hawthorne that good for cams & carbs & stuff. But the performance places here in L.A. that sell VW stuff are just selling overpriced crap (mostly EMPI) and the employees might as well be working at Autobone.

Take a drive down to HB one day. I like the guys at VeeDub. http://www.vwparts.net/

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Compression Test Results (not good)

Compression Test Results (not good)

Re: Compression Test Results (not good)