Compression test results. Your suggestions needed!

[shoot_my_boat]

Hey,<br /><br />I just performed a compression test on my boat's engine. The engine is a 1972 Ford 302ci. 5.0L 200HP model number AQ190A. The compression test results are listed below.<br /><br />Cyl. 1 - 144<br />Cyl. 2 - 125<br />Cyl. 3 - 072 - Leak down test results - 130<br />Cyl. 4 - 138<br />Cyl. 5 - 142<br />Cyl. 6 - 152<br />Cyl. 7 - 068 - Leak down test results - 151<br />Cyl. 8 - 139<br />(I'm just getting this engine put back together so the test was done on a cold engine. Would being a hot engine change the 2 low cyl.'s? I plan on running another comp. test once it's all put back together.)<br />As you can see I have 2 weak cyl. likely to be caused by bad piston rings. My questions are if I run the boat in it's current condition will there be any more damage to the engine. How much power do you think I am loseing? This is a long shot but any possible quick fixes? Is it possible to replace the rings with the engine still in the boat by taking off the heads?<br /><br />Thanks for any suggestions!

 

[Trent]

Re: Compression test results. Your suggestions needed!

Not trying to second guess you but, Explain what you mean by leak down test. Some people dont understand it. You putting it on TDC and putting air into the cylinder and checking...right? Or are you squirting oil in the cylinder and then doing a compression check?

 

[clanton]

Re: Compression test results. Your suggestions needed!

On the leakdown, where is the air comming out, crankcase, intake, exhaust, water jacket? I would guess valves. If you dont want to pull the head, put a can of OMC engine tuner thru engine, follow instruction on can.

 

[shoot_my_boat]

Re: Compression test results. Your suggestions needed!

Thanks for the replies!<br /><br />Sorry for the confusion, but I did a wet compression test for the bad cylinders. I guess I heard that called a leakdown test and assumed thats what is was called.

 

[Bondo]

Re: Compression test results. Your suggestions needed!

In a 72 302, Run it till she Pukes......<br />Then get a Rebuilt 351 to take it's place.....<br /><br />You Can't rebuild a motor IN the boat.... If your going to go through the time,+ Expence of a rebuild, Get a 351.....

 

[Rick Byers]

Re: Compression test results. Your suggestions needed!

The increase in compression during wet test indicates the rings worn on those 2 cylinders run it till it quits then replace with 351. Rick

 

[shoot_my_boat]

Re: Compression test results. Your suggestions needed!

Thanks for the replies!<br /><br />How long do you think it will last? What will it happen when it finally goes? The 302 barely fits in the engine bay legnth ways. Will a 351 fit? Any idea what a 351 would cost? Does is work with my volvo penta 270?<br /><br />Sorry for all the questions & thanks!

 

[Bondo]

Re: Compression test results. Your suggestions needed!

It Could last 10 years......<br />Or it might last 10 minutes.....<br />a 351 is pretty much the same exact size as the 302..... Maybe an inch taller.... You'll be able to reuse Everthing that's bolted to your engine now....

 

[chris in va]

Re: Compression test results. Your suggestions needed!

How did ya get 200hp from your 5.0? Mine only nets 190...and it's a 94.

 

[Fouled Plug]

Re: Compression test results. Your suggestions needed!

No way to replace the rings by pulling heads. If you don't have a kicker motor, get one. That way when she conks you can make it home! You're certainly losing some performance with the low #'s, but if you don't want to pull it out for R&R just run it till it don't go. No way to tell when that will be, unfortunately.

 

[shoot_my_boat]

Re: Compression test results. Your suggestions needed!

Thanks for the info.<br /><br />Hey chris in va, on my valve cover it says 200HP. Ford actually rates it at 210HP for the year of the engine.