3.0 compression check tell me I have hope

[thejeep007]

Re: 3.0 compression check tell me I have hope

I am with the dirty budget post haha. Got a used head from a friend for. Hundred. If that doesn't do it he said take the whole thing. Maybe some winter fun either way. This isn't a race boat guys, low compression from worn cylinder will get me fishing and always have enough beers to wait for a tow

 

[aerobat]

Re: 3.0 compression check tell me I have hope

put the head in and go for fish , beer and girls. report how the engine runs.

i checked the compression for a friend on a tired 170aq grandpa in a birchwood 22 footer. 2 cylinders are 50 psi and the rest below 90. guess what - the grandpa puts the boat on glide and the girls onboard have fun. beer included.

happy boating...

 

[thejeep007]

Re: 3.0 compression check tell me I have hope

Should know tomorrow evening. Hope a few of you guys areppulling for me...

 

[Cptkid570]

Re: 3.0 compression check tell me I have hope

Let us know the result. I see 3.0 motors on craigslist all the time. If you like the boat, I've seen remanufactured 3.0 longblocks for $1500 at remanufactured.com (I don't know anything about them, I just saw on another post one time that they sold reman 3.0s).

 

[thejeep007]

Re: 3.0 compression check tell me I have hope

Put the other head on still nothing in number 4. Guess I'll be Rollin on 3 cylinders till I get that other engine.... Anything I should check before buttoning it up or just no seal on piston....

 

[aerobat]

Re: 3.0 compression check tell me I have hope

ouch... so i was too optimistic for you ... but when you say "nothing" you mean still zero ?

can you post a close up picture of the number 4 piston ? it does not seem blown from the other pictures, low(er) compression is one thing, but how you get zero ? broken compression ring ?

 

[thejeep007]

Re: 3.0 compression check tell me I have hope

Posted close ups earlier. Can't get em up again

 

[thejeep007]

Re: 3.0 compression check tell me I have hope



Number 4

 

[Don S]

Re: 3.0 compression check tell me I have hope

Have you checked other cylinders to see if they have compression? Would sure be bad to have checked only number 4 and find the gauge died after checking #3 the first time.

 

[thejeep007]

Re: 3.0 compression check tell me I have hope

Rechecked number 2 have 60 can get a used motor that the head came off, just need to pull it and swap some parts over like timing cover. So could be worse. Just frustrating as hell throwing the rest together and goin out tomorrow. Think all the damage is done... Fixing the riser leak though... Any mor input appreciated. Thanks for laying off the I told you so

 

[Don S]

Re: 3.0 compression check tell me I have hope

Why are you putting it back together, one cylinder with 0 compression and the others in the 60 and 70 range ???????

That engine is junk.

 

[roseran]

Re: 3.0 compression check tell me I have hope

your hydraulic lifter is stuck and won't let the valve close.

 

[thejeep007]

Re: 3.0 compression check tell me I have hope

Lifters are seating properly. Got the new to me motor and just pulled the one from the boat. Should be at a driveway start level by Monday. With the motor out is there anything you guys can think to do now that can save me aggravation in the future? Oh ya when I pulled the head off this time with different head different manifold had water on top of the piston.... A crack in the cylinder I can't see?

 

[fishrdan]

Re: 3.0 compression check tell me I have hope

From post #24, first page (couldn't get pics to post in my reply...........)


Where is the water in the mainfold's intake runners coming from?

I'd dry the manifold off and fill the waterjacket with acetone, to see if there is an internal leak in the manifold. Cracked manifold letting water into intake runners?

 

[Cptkid570]

Re: 3.0 compression check tell me I have hope

while the engine is out, I would check the timing chain cover (timing gears on this engine if I remember right).. anyway, that cover has tendencies to rust out and it is easier to change while the engine is out of the boat.

 

[thejeep007]

Re: 3.0 compression check tell me I have hope

Ya the timing cover on the motor I pulled is goin on the new to me motor. Replaced it last year. Can'twait to to drill and tap aanother crank to get the pulley back on too. I used a different manifold with the different head. Why use acetone to check it? Can't complain about pulling the 3.0. Did notice the pinion seal leaking gear oil into the bellow but will hit that once I have a functioning motor.....

 

[ajax5240]

Re: 3.0 compression check tell me I have hope

Bent valve stem? Or rusted in place during compression test. Like Don said, too bad you pulled the head as the results from a cylinder leakage test would have saved you a lot of detective work. Put the valves in the head, turn it upside down so the combustion chamber faces up. Pour water in the combustion chamber and see if water leaks past either of the valves. Obviously you need a spark plug in too.

With no catastrophic failure from your pictures I would wager that a mistake was made in your reading of cyl 4. Even a bent valve and a small hole in a piston will give you a little compression. Either your helper had their finger on the pressure relief button or you didn't crank it a full cycle to build compression.

How do the cylinder walls look in the #4 hole?

 

[thejeep007]

Re: 3.0 compression check tell me I have hope

Looks like the compression culprit...

 

[ricohman]

Re: 3.0 compression check tell me I have hope

That vertical gouge looks like a busted compression ring.
At the minimum you need to re-ring and have that head rebuilt. The used motor out of a rotten boat is a good idea.

Yup.

 

[fishrdan]

Re: 3.0 compression check tell me I have hope

Why use acetone to check it?

Acetone has less surface tension than water and will seep through finer cracks than water.