View Full Version : Compression

06-07-2005, 12:08 PM
I have a 1988 Prostar 190 with a 351 and i was wondering if anyone knew what the compression should be on each cylinder. Thanks.

east tx skier
06-07-2005, 12:31 PM
Welcome. The general number in the manual is 8.5:1 I believe. Sounds like you may be looking for something more specific.

You get over to Texas much?

06-07-2005, 12:58 PM
In a perfect world they will all be 150lbs. In the real world if they are all above 125 AND the lowest is no more than about 15% below the highest then the compression is fine. It's best to do the test with the engine warm, remove all the sparkplugs, block the throttle wide open and make sure the battery is fully charged. If you're going to do this kind of test I would also suggest a vacuum test as well. That will tell you how well everything is working. If your engine has the same exhaust manifolds as mine then you will probably have to remove them to get the compression tester in. They only have four bolts holding them on, but watch out, they weigh a ton.

Good luck. Hopefully it's all good.


06-07-2005, 01:38 PM
thanks just got done and they are all good. i have been havin some problems once the engine heats up it starts to bog down a bit. but to the texas question, i have been out to lake of the pines a few times. beautiful lake.

east tx skier
06-07-2005, 02:15 PM
Never been there, but hear it's a great place to go.

06-07-2005, 02:25 PM
88mastercraft, you need to join the Bossier City Pro(zach) tour with Farmer and I!!!! And you can help me move next week.... You could get an invite for a Greeson weekend and some now famous sauce, bar-b-que sauce I will add.....

We need a replacement for the Wildman, who is on injured reserve! :(