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-   -   Pressurized crankcase - ring gap? (https://www.offshoreonly.com/forums/do-yourself-boating-budget/367172-pressurized-crankcase-ring-gap.html)

BillK 06-27-2020 07:28 PM

Second ring upside down will cause oil smoke but I dont think it should affect blowby that much.


Tahoe540 06-28-2020 09:55 AM

I appreciate the comments. Pulling engine today and checking my work.
One other problem I had when I first started it on the hose was the oil was milked.. I thought one of the head gaskets had leaked.
I found one of the exhaust manifolds had a crack and was the issue. I was given these by a friend and he had no idea. Could this of caused the new rings not to seat? It wa started a few times before I found it.
I flushed it with 3 oil changes and it is clear now.


Baja Rooster 06-29-2020 10:27 AM

How much time have you put on the engine? I’m just curious with no value to add to the problem.

I used the Brad Penn 30w break in oil and it worked great for me. Fwiw, I think I heard Brad Penn had been sold and the oil isn’t as good as it use to be. I haven’t verified that though.

https://www.speedsterowners.com/topi...-new-ownership

Tahoe540 06-30-2020 05:54 PM

I don't even have an hour. Probably 10-15 minutes on the hose a few times. Only twice on the lake 5 minutes and 7 minutes.

I have it apart and did a ball hone on it and installing new rings. Hopefully that will fix the issue. All the rings are oriented correct with the bevel up on the top ring and bevel down on the second ring.

I think the immediate milking of the oil caused the rings not to seat? Don't see any other problems.

Tahoe540 07-13-2020 12:35 PM

An update. I pulled the engine and took it apart. I installed new bearings and rings. I also honed the bores with a ball hone to make sure the rings had a chance to seat. The engine now has no crankcase pressure. I think since the motor was milked from startup the rings never seated correctly. All of the original rings were installed correct with no upside down rings. Always nice to find your problem.
https://cimg0.ibsrv.net/gimg/www.off...95405a27f0.jpg
Fresh hone

zz28zz 07-13-2020 06:04 PM

Interesting. Wonder if the instant milkshake caused the rings to overheat due to excessive friction making them loose their tension??
Anyone ever try to measure ring tension? Don't remember ever seeing it spec'ed.

How did the bearings look?

Tahoe540 07-13-2020 06:37 PM

The bearings looked OK but not perfect so I replaced them. I live 3 miles from Summit so getting parts is easy.

Smitty275 07-14-2020 11:15 PM

It could have been caused by glazed cylinder walls. Running a motor on a stand for longer than it takes to set timing and look for leaks is just not good for them. It takes load to build cylinder pressure. It takes cylinder pressure to seat rings. I've found that by putting an engine on a Dyno and getting it underload ASAP not only gives less crank case pressure they make more power. As soon as timing is set we run a computerised break-in that runs the engine to about 3000rpm and back to about 1200rpm at 60% load. You can do same thing in a boat. Run it on hose just long enough to set timing and look for leaks. Then launch and get underway and accelerate/decelerate repeatedly for about 15 minutes. You'll be surprised at how much better it'll run. Once break-in is done go over the valve train and double check the timing. Change oil and filter if you want. Then go run it full throttle and back to idle several times on about a 10second pull and get out of it as if you were making Dyno pulls. Then use it however you want.
If your near the Summit in Akron look up Chris Wright at Pro Car & Associates at 1100 Triplett Blvd. Tell him Smitty sent you.

Tahoe540 07-15-2020 09:37 AM

Thanks Smitty but I live in Reno so I go to the Sparks store. It is really easy to spend some money there when it is only 10 minutes from your house

CDShack 07-16-2020 03:37 PM

It's real easy to spend some money at Summit and Sparks with mail-order! haha!


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