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Discussion Starter #1
doesn't this piss u off u take your engine to get rebuilt and your wrist pins feeze up and all rod bearing r fryed after only 45mins of run time. had good oil presser any ideals what would cause the the wrist pins to lock up like that u cant even move the pistons on the rod.and its not like it only did it to one but it did it 2 all of them.
 

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jetboataholic
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doesn't this piss u off u take your engine to get rebuilt and your wrist pins feeze up and all rod bearing r fryed after only 45mins of run time. had good oil presser any ideals what would cause the the wrist pins to lock up like that u cant even move the pistons on the rod.and its not like it only did it to one but it did it 2 all of them.
Damn, that sucks. Looks like you'll be looking for a new machine shop.
 

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One part at a time...
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Im gonna say wrong clearances on the bearings and the heat from that caused the wrist pins to seize as well? Someone else with more knowledge might know better but thats my guess. Ask your shop if they have heard of plastigage.
 

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Pinfit was to tight. Either not done correctly or not done at all. Did you assemble the engine or the shop? If the shop did it, have you showed them? What was their response? Sorry for your problem! Hope you get is resolved.
 

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Mic (measure) any remaining "good spots" on the crank journals and then look at the bearing size designations on the main and rod shells ,just curious ,got lots of Ideas but would be interested in more info prior to speculating, What pan what O'pump ,what oil ?? the more info the better Tom

Heres a web site to look at pretty good examples , you be the judge ..
http://www.thirskauto.net/BearingPics.html
 

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Discussion Starter #7
ya showed ? i wont say any names wright now see if hes going to fix the problem for free. he said he heats up the rod then press the pin.he was trying tell me the oil was contaminated i can see over a long time but 45mins of run time guys kind of arrogant and trying to put the blame on us.ah [email protected]#% it i don't what to see any one els have the same problem it was A&d engines in Whittier.
 

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Half a bubble off
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Wow! I am by no means an expert (or even a novice) but I would look over everything closely for heat issues too. I've seen discolored mains from heat generated by stuff worse than that (yah, I know these are the rods, but I would assume the same worries apply).

Regardless, good luck and I'm certain there are many here that are willing to talk you off the ledge........john
 

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What was your oil pressure like? Either no oil pressure at all or way to tight of clearances and I am betting on the second. That sucks, hope the shop stands up and takes care of it.
 

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OK.....

You say you had good oil pressure. What was it?.........What do the main bearings look like. Was the carb/fuel pump flooding liquid gas into the engine?.....Do you have a water temp gauge? and where is it picking up the temp?........How badly are the piston skirts gauled? Usually press pin pistons come with the matching wrist pins already in the pistons, but it is always a good idea to give them the shake test. With your fingers over one side, and your thumbs over the other, shake the piston. The pins should move from fingers to thumbs with very little resistance.........Some light oil should be used for this purpose. Also, when installing pistons, invert the entire piston in a coffee can of oil, below the pin boss and let the oil work its way into the piston from all sides. I don't know if you assembled it or the shop, If it was the shop it would seem to me they should have caught tight clearances, or a not so straight crank binding in the main saddles.....MP

PS I went back and looked at your pics blown up and there was some serious clearance issues. It could also be the jet pump pushing the crank off center, and/or actually having the splined shaft bottomed out in the slide yolk I had a jet motor tear up the mains in 5 minutes, and the rod bearings survived. Never found out why, but finally wrote it off to pump/crank C/line error........
 

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Show your "builder' the pics and the "bearing failure examples", honestly looks like lack of lube to me (that could be multple things) . If he assembled the motor and "prelubed it" he should have the opportunity to look at it and provide you his honest opinion as to exactly what he feels caused the failure (in writing) ,probably everyones curious to know what he gives as a reason ? . Give him the opportunity to help if he will he deserves the benefit of the doubt ... Tom
 

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Engine junkie
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Damn that thing is cooked!
What about oil filter, is it remote, and if so where the lines run in reverse possibly?
The piston pins are seized due to no oil splash off the rods and metal contamination in the oil.
 

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It appears from the pictures that the offset in main bearing tangs would prevent the bearing from being installed improperly.
A problem like this usualy starts in one place and travels down the system. From the looks of the main bearings it started there, either from oil starvation, WAY too tight of clearances or lack of lubrication. You can see a few grooves in the mains from some trash but it may have happened after the damaged started. With good oil flow and proper clearance you can still run a few peices through there and get away with it so I am assuming it wasn't just from a dirty build so it is still pointing at a lack of lube or a SERIOUSE clearance problem (were the main caps installed in the proper positions??).
I would bet that the piston pin problem is from this lack of lubrication, or it was WAY improperly clearanced also (or both). It would be tough for the problem to start at the pins as a properly running engine would destroy the piston long before it took out all the bearings due to a pin/pins locking up. If everything else was good and the pin siezed it would have yanked the pin right out of the boss or broke the pistons into pieces.

To me all of this points to an oiling system problem or machining/assembly error starting at the main line.
 

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Yah, I guess I was a little tired :)coffee when I posted that about the upside down bearing thing, post edited.
Main caps on wrong, a definite looks see there.

One other thought however is a remote mounted filter that did not have a bypass, and collapsed, or just a bad collapsed filter period.
 

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jetboataholic
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What engine did these come out of? What size? Was it just a mild build? Or is this a race type setup? Did you have a blower, turbos, or nitrous or something like that?
 

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Discussion Starter #16
just a mild build 468 10.1,i usually don't like talking bad about someone but when the engine shop said it was my fault kind of maid me a Little mad.he tried to say it was the heads we used or oil was contaminated i can see over a long time but come on after 45 mins of run time come on. i just think he cant take the blame if it was his fault but come on man up.
thanks for all the advise.
 

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E-7 Sheepdog (ret)
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Im gonna say wrong clearances on the bearings and the heat from that caused the wrist pins to seize as well? Someone else with more knowledge might know better but thats my guess. Ask your shop if they have heard of plastigage.
Yep. IMO pin clearances too small, mains too.

Go to the wider 1/2 of the factory clearances on a marine motor and it will live a LOT happier life.
.0025 to .003" main bearings
.0025 rod bearings (recomended span .002 to .0025)
.0007 to .0008" wrist pins (same in rod for full floaters).
These are the larger 1/2 of the factory High-Perf specs.

I'm suspecting yours was very close to absolute minimums.
 

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just a mild build 468 10.1,i usually don't like talking bad about someone but when the engine shop said it was my fault kind of maid me a Little mad.he tried to say it was the heads we used or oil was contaminated i can see over a long time but come on after 45 mins of run time come on. i just think he cant take the blame if it was his fault but come on man up.
thanks for all the advise.
small claims court or better business bureaul would be my first to calls
 
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