455 oil mod recommendations

[boatermike]

gonna take a good hard look at all the whoop la la but i think a rev limiter is probably the most effective device for keeping this motor alive. hopefully the money for this fantasy starts arriving soon........

[thompy]

that and adding drainage pipes at the back of the heads to the pan

[455maveric]

How about just adding a pump to suck the oil out of the top end and pump it back into the pan . i would think a single stage pump would work and i bet they could be found on Ebay cheap enough

[Tom@JBP]

We have built dozens of these motors over the years and I actually worked for Olds when these motors were originally produced ;) .I have always had good luck with using a large capacity pan (8 to 10 qts) , and a "modified" standard volume pump along with a few other standard Olds internal "mods" picked up from Mondellos years back. If driven/used conservativley these motors make good power and will last a long time Tom

[boatermike]

so back in 74 when my boat was new it must have had some degree of reliability. why cant a stock rebuild be reliable? why is the original speed and reliability so hard to achieve now? i wonder how many olds motors have met there demise courtesy of user error or rebuilder error?

[Hamjet]

The Olds engine is happy hauling around a 2 ton motorhome or car at 2500 RPM.

They also had inherent design flaws regarding their oiling set up.

In a marine application the engine works 4 times as hard and the small oil return holes in the heads, narrow big end bearings and tendencies to blow head gaskets and valley pan gaskets due to over pressurising the cooling system are some flaws that can be rectified.

IMO I will take an Olds over any other V8, just to be different. Done correctly they will last forever.

Boatermike, did you receive my mail?

JM

[Road Trip]

I need in on this post for the gasket comment above. I have a fresh built 455 w/ Edelbrock heads and apparently correct oil set-up, but I'm getting water in the oil. If its from over-pressure on the cooling system, what gasket is the most likely failure?

Thanks.

[thompy]

intake then head , whats your water pressure?

[Road Trip]

Don't know; It was rigged up with no gauge by the previous owner. I didn't think anything of it because my last jet boat had a 460 and no water in the oil. I don't even know if that boat had a valve to restrict pressure to the engine, but it was never an issue so I remained ignorant of the risk until now.

[Last Mohican]

Don't know; It was rigged up with no gauge by the previous owner. I didn't think anything of it because my last jet boat had a 460 and no water in the oil. I don't even know if that boat had a valve to restrict pressure to the engine, but it was never an issue so I remained ignorant of the risk until now.

Does it have headers or log exhaust? If logs, is the water plumbed to the logs first then the motor?

[Road Trip]

It has log manifolds with Rewarder O/T pipes. I believe the water goes to the manifolds first, then the motor but I'll double check tonight

[Hamjet]

I need in on this post for the gasket comment above. I have a fresh built 455 w/ Edelbrock heads and apparently correct oil set-up, but I'm getting water in the oil. If its from over-pressure on the cooling system, what gasket is the most likely failure?

Thanks.

RT,

The most likely spot is the OEM valley pan gasket. If you are running chebby style intake manifold gaskets it is most likely automotive headgaskets that is the problem. On the Olds they are designed to handle pressures of between 22 - 25 Psi.

Automotive gaskets also tend to have normal steel rings around the cylinder, where as the marine gaskets have a SS ring. Remember you are running a raw water cooling system without any antifreeze. Corrosion is a factor.

Invest in some good Felpro Marine gaskets, but make sure that the coolent holes in the marine gasket is the same size as the ones on the block and head.(Just found out you have to check) Might make a difference of up 20 degrees F.

HJ

[Last Mohican]

It has log manifolds with Rewarder O/T pipes. I believe the water goes to the manifolds first, then the motor but I'll double check tonight

Typically with log exhaust you will not have a pressure problem. The logs are restrictive enough to reduce the pressure before it hits the block.

[Last Mohican]

gonna take a good hard look at all the whoop la la but i think a rev limiter is probably the most effective device for keeping this motor alive. hopefully the money for this fantasy starts arriving soon........

If you don't already have it Tim's article is here.

http://www.classiccustomboats.com/phpbb2/viewtopic.php?f=5&t=146