think i have a cracked block

[jeffbriggs18]

1972 glastron swinger v-177 with AQ130C and 270 outdrive, done oil change, points condensor, cap, head gasket, exhaust manifold and gasket, adjusted the valves and distributor, cleaned the carbs. got the boat sounding good and running at about 35 MPH at about 5000 RPM. took it out for a few hours after headgasket replacment, everything looked and sounded good, got home checked the oil and it looked good and right level. took it out 2 days later and an hour into it we were burning about half quart every hour or so and the oil turned a dark grey color and had alot of white slimy gunky smoke coming out the breather tube. took it home and after sitting for a little bit, the oil went back to looking like oil. took it out again and this time the oil would be over filled and turning grey and bubbly, still with a lot of smoke. so the oil only turns gray when we run it and it burns up a good amount of oil. when doing the headgasket we noticed the 3rd cylinder wall had like a qouge in the side of it which we thought was a score from the pistons rings. when we started it up for the first time we noticed 1 of the soft plugs had com eout slightly and we had to put it back in. we got this boat and trailor for under $200 so we expected it to need work. the engine sounds and revs up good, i know the rings r shot because we only got 120 to 130 compression in the cylinders, but i am wondering if the block is cracked and if so where we can find a replacment engine decently priced or what engines can bolt up to a 270 outdrive. Any help will be appreciated

 

[sqbtr]

Re: think i have a cracked block

Check the oil cooler

 

[6meter]

Re: think i have a cracked block

If water was getting into the oil, the oil would turn almost white and won't look like regular oil any time soon. What is a soft plug? 120-130lbs compression seems acceptable.

 

[jtmarten]

Re: think i have a cracked block

If by soft plug you mean freeze plug, sounds like you've got a head gasket problem pressurizing the cooling system. Or a cracked head near an exhaust valve since it sounds like you're loading up the oil with exhaust/carbon. May be a cracked guide, not sure if the exhaust guides on the B20's are in contact with the cooling system or not.
120-130lbs might be ok if the 10lb diff isn't adjacent cylinders.

 

[jeffbriggs18]

Re: think i have a cracked block

What am i checking for at the oil cooler? compression for this engine is suppose to be 170- 180 PSi in all 4 cylinders, so compression is low, soft plugs are round peices of metal pressed into the side of an engine block so if the block freezes it will push out the soft plugs instead of cracking the block. any one know where i can find a replacment engine? is their a way to check for a cracked head or cracked valve train parts?

 

[jtmarten]

Re: think i have a cracked block

Depends on how you performed the compression test. If you did it cold, with the carb closed, you'll get low numbers. You should be performing a compression test with the engine warm, and the carb wide open.

 

[jtmarten]

Re: think i have a cracked block

What am i checking for at the oil cooler? compression for this engine is suppose to be 170- 180 PSi in all 4 cylinders, so compression is low, soft plugs are round peices of metal pressed into the side of an engine block so if the block freezes it will push out the soft plugs instead of cracking the block. any one know where i can find a replacment engine? is their a way to check for a cracked head or cracked valve train parts?

Your oil cooler should be OK, doesn't sound like you're loading up the oil with water, and the oil cooler is one place that can happen.

 

[jeffbriggs18]

Re: think i have a cracked block

If weather permits i will run a second compression test tonight after running it for about 10 min at idle. so they dark gray oil sounds like the smoke thats filling up the crankcase is just mixing with the oil? what would cause so much smoke in the crankcase, i mean it just pours out the breather tube. Bad valve train? i like to do all the work myself i do have 7 years experience in the automotive field, but never had to check a valve train, whats the procedure for fining out what aspect of the valve train is bad causing all the smoke?

 

[jtmarten]

Re: think i have a cracked block

I'm guessing 1 cyl will have very little compression.
Does the smoke thats pouring out the breather smell like exhaust?
You may have to do a leak down test as well to determine which cyl is leaking compression.
Could also be a broken ring, or lots and lots of blowby from the cyl with the gouge.

 

[jeffbriggs18]

Re: think i have a cracked block

i will smell the smoke next time i run it and give u the accurate compression readings, how do u perform a leakdown test? i assume build up pressure and get a guage that will go down if it leaks out? no easy fix if the smoke is caused by blowby becaus eof the damaged cylinder wall is their? maybe put a sleeve in? If the oil is turning dark gray from carbon/exhaust is it ok to run it? we have gone out twice for about 8 hours each trip(with fishing and eating breaks) and she always sounds like shes running good, valves get a little noisy but can attribute that to being so old.

 

[jeffbriggs18]

Re: think i have a cracked block

Ran it last night, got it up to 165? F and ran a compression test, cylinders 1,2 &4 were all around 118-120 PSI but the 3rd cylinder was only about 100 PSi.the smoke coming out of the breather smelled like burning oil. i have attached some pictures, the oil on the stick is what it looks like after running it, the valves are suppose to be a brown color but they are gray and the sludge on the cap and the breather tube was not their 4 runs ago(allthough we did get alot of water in the oil when we popped the head off, but we did an oil change, maybe we didnt get all the water residue out?). We are definitly planning on a full rebuild this winter, new rings, bore hone or bore the cylinder, new valves and springs, distributor , ect.... just want to use it this summer, so as long as its just exhaust turning the oil into crap, should be good to run?

 

[sqbtr]

Re: think i have a cracked block

Sure looks overfull with water in it to me.

 

[jtmarten]

Re: think i have a cracked block

Water. You have a crack/failed gasket somewhere.

 

[Gary H NC]

Re: think i have a cracked block

Water for sure.....cracked block would be my guess.
The core plug that was pushed out should be a sign....

Yes,They are called core plugs,not freeze plugs or soft plugs and they are not there to save the block from cracking from freeze damage...

 

[Alpheus]

Re: think i have a cracked block

Yes,They are called core plugs,not freeze plugs or soft plugs and they are not there to save the block from cracking from freeze damage...

WORD.

That is a very common misconception...

 

[jeffbriggs18]

Re: think i have a cracked block

sorry if i used the wrong term, in 2 years of auto mechanics tought by a master technician who tought us they were refferd to as soft plugs, what arethey their for then? we ran it the first few times fine, then blew the headgasket, changed it and ran it and all of a sudden we got water in the oil, we used the posts to properly allign the gasket. does it seem right to be running fine, changethe head gasket and all of a sudden have a cracked block? what engines can bolt up to a volvo penta 270 outdrive and any good places to find them? would like to put a 6 cylinder in it for waterskiing.

 

[jimmyebay]

Re: think i have a cracked block

believe the "soft plugs" are from castiing the block. way to get the sand removed from the inside after casting.

 

[sqbtr]

Re: think i have a cracked block

I would definately check the oil cooler located right behind the oil filter. If it pushed a casting plug out they probably didn't drain the cooler either.

Loosen the cooler drain and see if any oil comes out. You might even get lucky and find bad o-rings.

 

[FillupD]

Re: think i have a cracked block

I have the same motor and my dip stick and cap look just like that. I too have replaced a head gasket looking for water intrusion.
I have replaced the o-rings in the cooler with o-rings from a hydraulic shop in town but I am still getting water intrusion.

I have a post trying to get info on how to set up the cooler for testing. It seems it would be tricky because it has two rubber grommets and the oil filter opening ? Anyway, if I get mine tested I'll let you know what I find out.

Your oil cooler is easy to remove if you want to look at yours and make sure tubes are not plugged and o-rings are OK.
You need a 1 1/8" socket for the nut behind your oil filter. There is a bracket that holds the copper tube in place and the screw is under the bracket close to the alternator, it is a little tricky to get that one in and out but not too bad.

 

[jeffbriggs18]

Re: think i have a cracked block

I changed the oil in it again, drain the oil cooler and no oil came out, so that system should be fine. after running it for 10 min when i shut it off i noticed that their are 2 little holes in the water pump cover, and a decent # of drips were coming out, i know that its suppose to allow water out instead of it getting into the bearings, but i heard it shouldn't really drip more than once every now and then, could my water pump be leaking into my block? how would i test that?