455 break down from over heating question

« **on:** August 03, 2014, 02:06:49 PM »

So from my last post.. our rebuilt motor with about an hour on it broke down. Looks like over heating was the cause of rod knock. I did some research on how an olds 455 should be plumbed. I noticed the diagram is different from mine. Could this be the cause of motor failure? Here are some pics

« **Reply #1 on:** August 03, 2014, 02:08:23 PM »

Btw it has gleenwood exhaust

« **Reply #2 on:** August 03, 2014, 06:25:58 PM »

Can anyone tell me how water travels up up hill against gravity and exhaust pressure? I truly and confused, Any pics of how logs work internally? I'll google iti guess

« **Reply #3 on:** August 03, 2014, 10:35:39 PM »

from the pics you posted, it appears to be plumbed correctly, although that is different than the diagram. Heres why- Some logs have BOTH in and out flow connections on the front, However, yours enter at the rear and flow to the front, and from there should go to the water pump block off plate. After the water comes out the t-stat housing, it goes to the snails.

The snails are only water jacketed about 3/4 of the way, and this is where the water and exhaust combine to go through the exhaust hoses, at about 3 o'clock.

Over heating by itself doesn't cause a rod knock, but getting water into the oil like from a blown head gasket would. Or there is multiple problems.

Good luck
Dan'l

« **Reply #4 on:** August 04, 2014, 05:14:59 PM »

No water in the oil and thanks for the info

« **Reply #5 on:** August 04, 2014, 09:44:27 PM »

When you got a rod knock did you look at the oil pressure??? What was it??? I have the distinction of spinning all the rod bearings . Oil pressure went down to just about 5.

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« **Reply #6 on:** August 04, 2014, 10:01:27 PM »

Was at 50 when I heard a noise that's when I parked it.knowing it was a new motor I was nonstop watching the gauges We then walked it out to deeper water to turn it on and check the oil pressure. It would be low like 0-5 but then raised when given some gas. When we left to head to the launch ramp the noise got worse but pressure and temp where normal then it got real bad and ideled across the lake and back to the ramp. When the noise happend motor was at about 2500 cause I was coming into a 5mph zone. It didn't knock at idle untell almost have way to the ramp

« **Reply #7 on:** August 04, 2014, 10:16:24 PM »

Have you drained the oil yet ???and looked at it?? If you have a rod knock there will be a lot of evidence in the oil!

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« **Reply #8 on:** August 04, 2014, 10:27:02 PM »

I haven't but will for sure tomorrow and post pics of what comes out. Appreciate the help guys

« **Reply #9 on:** August 06, 2014, 03:00:38 PM »

Okay drained the oil and clean no metal flakes in it and poped the valve covers off to just see it there was a bad rocker everything was nice and tight no breaks.

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« **Reply #10 on:** August 06, 2014, 09:45:59 PM »

Well now?? You need to find that knock. You may have to pull the motor flip it over pull the pan and check bearings .

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« **Reply #11 on:** August 06, 2014, 09:53:24 PM »

Something is amiss....

Can you go through the events that started all this again? I don't know what "other thread" you are talking about.

sorry... Didn't want to have to go back and forth, rather keep it all on this one..

I know...........PITA

« **Reply #12 on:** August 07, 2014, 01:47:30 PM »

Long story short this was the 2nd time out less than an hour on the rebuilt motor. Temp was at 210 at idle then dropped to 150-170 when running even at very low speeds. Ran good both days a week part. Then after the 3rd run around pyramid then what I typed above happened and no idea why. Just going to have to pl the motor with some help that's been offered by moarpower since I don't have the space or tools to do that at my house.

« **Reply #13 on:** August 07, 2014, 03:48:29 PM »

You might have sucked a valve. Olds are so delicate when it come to water flow/temp oil flow/return. Set your olds at just a tad cooler but your pretty close to where it needs to be. If you open it to much you risk water cracking the head around the valves. Do you have a 10qt pan or opened up your oil drains in the heads? Log exhaust is simple regardless of motor log style. Basically water in to log then out(2 different fitting mounts water in water out), then to front of block( where a water pump would be if car/plate with 2 hookups) then out of top manifold to snails....your logs are double walled.

« **Reply #14 on:** August 07, 2014, 04:00:06 PM »

I should have posted a pic after I removed the covers. Yes the drains are opened up on the left and right side plus was told one other oil mod. I don't have any paper work on what was done I'm an idiot for not making him give me something. That's on me so lesson learned. I know the pan is much larger than what was on before. Sure it's atleast 10 filled most of the 15 gallon oil pan I have. I just need to fix it and sell the motor I don't want to deal with such a finicky motor. From air scoop to tips if I can get them out. Should have done a Chevy like so many people told me to

« **Reply #15 on:** August 07, 2014, 05:10:55 PM »

I'd just fix what is wrong and keep it. Why only to sell it and put a chevy in it???

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« **Reply #16 on:** August 07, 2014, 05:19:48 PM »

I hear nothing but bad about them and I thought we covered the oil issue but bam. Re used the old pistons but was told they would be fine and some work was done to them. I just want to get it fixed. Just have to be patient but it sure is hard once you get hooked

« **Reply #17 on:** August 07, 2014, 05:52:09 PM »

Quote from: Handi-Crack on August 07, 2014, 05:19:48 PM

I hear nothing but bad about them and I thought we covered the oil issue but bam. Re used the old pistons but was told they would be fine and some work was done to them. I just want to get it fixed. Just have to be patient but it sure is hard once you get hooked

I am going to just be bold and sound like a total dick right now.

YOUR PROBLEMS ARE NOT OLDSMOBILE RELATED...... Your shit would still be broken even if you had a 540 Donovan in it.

K. I feel better now.

GT

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« **Reply #18 on:** August 07, 2014, 06:06:20 PM »

What carb were you running? Running lean could have caused you to heat the valves up and stretched them out, creating bent valves....

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« **Reply #19 on:** August 07, 2014, 06:20:51 PM »

Quote from: GT Jets on August 07, 2014, 05:52:09 PM

I am going to just be bold and sound like a total dick right now.

YOUR PROBLEMS ARE NOT OLDSMOBILE RELATED...... Your shit would still be broken even if you had a 540 Donovan in it.

K. I feel better now.

GT

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Sound like the guy who built it. Sorry I'm not some jet boat guru but I do know how to drive a boat and read Gauges.

And if you think I'm the problem feel free to explain just curious

« **Reply #20 on:** August 07, 2014, 06:22:07 PM »

Was running an edelbrock 750.

« **Reply #21 on:** August 07, 2014, 06:50:09 PM »

What was the jetting?

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« **Reply #22 on:** August 07, 2014, 06:56:07 PM »

No clue was never given the info and I can see why GT said what he did. Trying to learn and have a ton to read up on

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« **Reply #23 on:** August 07, 2014, 07:08:31 PM »

Quote from: Handi-Crack on August 07, 2014, 06:20:51 PM

Sound like the guy who built it. Sorry I'm not some jet boat guru but I do know how to drive a boat and read Gauges.

And if you think I'm the problem feel free to explain just curious

Not coming straight out and blaming you... However, every time I see someone having NORMAL failures due to improper set ups and it happens to be an Olds, that is the first thing that gets blamed.

Do you guys have any idea how many Oldsmobile jets there are out there still running since the early seventies? It would be very easy for me to say several thousand of them. I personally know of at least 10.

Your carburetor has automotive jetting, those things do not work at all on a jet boat motor without a shit ton of work. They're horrible. Anybody who says theirs works great either has been very lucky, have no idea what they are talking about, or spent some serious time tweaking it.

Running a marine engine at 210°F, for even a few minutes, is begging for a catastrophic failure, does not matter what engine make it is. This thing should have ran at 150°F max and cruised at less than 130°F without any drama whatsoever.

If the plumbing is not correct and working the way it is supposed to, you will blow it up, again, does not matter if it is a $40,000 race engine.

Basically, and why I am telling you this, is you would have had all the same issues if you had built a Chevy. Figure out where the problem is/was before you switch flavors thinking all your problems are going to magically go away, I assure you, they wont.

Don't take any offense, not my intention, just don't blame a 40 year old engine. A 454 Chevy has more similarities than it does differences to an Oldsmobile, they were made in the same building.

Rant over...

GT

« **Reply #24 on:** August 07, 2014, 07:18:35 PM »

Quote from: Handi-Crack on August 07, 2014, 06:56:07 PM

No clue was never given the info and I can see why GT said what he did. Trying to learn and have a ton to read up on

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Again, I was not hammering you personally, not how I roll. All I was trying to convey is that your problems are not brand specific.

Do you have a spark plug from this dealio? Can you post a picture of it?

GT

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