Hello from france, 5.7l V8 on boat...

Ok,

So when the seller give us this reference

http://www.dam-marine.com/omc/vilebrequin-avant-1988_14840.htm

And say "there is no importance for the direction of rotation"
The differentes options are :
- the crankshaft is just grinded and not polished. And we must polish it ourseleves.
- the seller is wrong ...
-?



I read read read and read again as much as i can :) this huge amount of litterature is really very interesting, with a high quality, and really help us to understand what happends,
but unfortunately we don't know what was done during the assembly of the reconditioned engine, it is difficult to have certainties, and we think the motor's seller is notreally reliable...
 

Maniacmechanic1

solid fixture here in the forum
Ok,

So when the seller give us this reference

http://www.dam-marine.com/omc/vilebrequin-avant-1988_14840.htm

And say "there is no importance for the direction of rotation"
The differentes options are :
- the crankshaft is just grinded and not polished. And we must polish it ourseleves.
- the seller is wrong ...
-?



I read read read and read again as much as i can :) this huge amount of litterature is really very interesting, with a high quality, and really help us to understand what happends,
but unfortunately we don't know what was done during the assembly of the reconditioned engine, it is difficult to have certainties, and we think the motor's seller is notreally reliable...
That Guy - Dude is wrong.
 
Hi,
Yesterday we finish to dissasemble the motor,
Camshaft looks good, i think it's a new one ( but the quality looks not very good... ) , almost all the hydraulics pushers looks new one apart 2 of thems, who looks very bad, they have been grinding, and they looks used.... ....
I think they can't be used like this in this motor, furthermore all the cam looks good and identical .... hydraulic pusher has a hollow of 0.02mm... ( see macrophoto of it... )
I took macrophoto ( yes i like macrophoto :D ) of the crankshaft on a part who don't scrub on the bearings ( on a side of No5 bearing ) and the surface looks bad for me... I think the crankshaft were not polished ? ... I found foundry default too... poor quality crankshaft and bad rebuilding ? ... And there is hits on the crankshaft... Like someone who hit with a hammer.... :/
I compare the original ( 20 years run motor ) camshaft and the new one, all looks identical ( cam shape, cam height, cam angle... .... )
On the original crankshaft, there is in addition to the size of the rectification(010), there is the mention "mr", do you know what it can match? Does it mean the crankshaft were reverse polished ?

I found this : http://www.correctcraftfan.com/foru...0&KW=bearings&PN=1&title=351w-crankshaft-help

Looks like my problem...
5 hours, little too tight bearings, no reverse polishing... .... ....

So, my provisional conclusion of failure is this combination of many things :
-No reverse polishing
-Maybe too tight clearance ( hard to be certain due to bad surface ... )
-Bad cleaning of crankshaft or block.

Are you agree with this conclusions ?

I took photos to refer all that i talk about here, i put them in a new folder : https://www.dropbox.com/sh/55gctl05w5od2i9/AADH0GSjuF3WhjDeirozhORDa?dl=0

Next step is the rebuilding of the motor ( by US, not by a "marine motor seller" :rolleyes: )
I will post news of the adventure ASAP...

Many thanks for help and for the amount of informations on the forum, otherwise it would be difficult to progress for us, it's hard to find quality and reliable informations here, in france.... This motors are not very widespread here.
 

Maniacmechanic1

solid fixture here in the forum
Hi,
Yesterday we finish to dissasemble the motor,
Camshaft looks good, i think it's a new one ( but the quality looks not very good... ) , almost all the hydraulics pushers looks new one apart 2 of thems, who looks very bad, they have been grinding, and they looks used.... ....
I think they can't be used like this in this motor, furthermore all the cam looks good and identical .... hydraulic pusher has a hollow of 0.02mm... ( see macrophoto of it... )
I took macrophoto ( yes i like macrophoto :D ) of the crankshafts on a part who don't scrub on the bearings ( on a side of No5 bearing ) and the surface looks bad for me... I think the crankshaft were not polished ? ... I found foundry default too... poor quality crankshaft and bad rebuilding ? ... And there is hits on the crankshaft... Like someone who hit with a hammer.... :/
I compare the original ( 20 years run motor ) camshaft and the new one, all looks identical ( cam shape, cam height, cam angle... .... )
On the original crankshaft, there is in addition to the size of the rectification(010), there is the mention "mr", do you know what it can match? Does it mean the crankshaft were reverse polished ?

I found this : http://www.correctcraftfan.com/foru...0&KW=bearings&PN=1&title=351w-crankshaft-help

Looks like my problem...
5 hours, little too tight bearings, no reverse polishing... .... ....

So, my provisional conclusion of failure is this combination of many things :
-No reverse polishing
-Maybe too tight clearance ( hard to be certain due to bad surface ... )
-Bad cleaning of crankshaft or block.

Are you agree with this conclusions ?

I took photos to refer all that i talk about here, i put them in a new folder : https://www.dropbox.com/sh/55gctl05w5od2i9/AADH0GSjuF3WhjDeirozhORDa?dl=0

Next step is the rebuilding of the motor ( by US, not by a "marine motor seller" :rolleyes: )
I will post news of the adventure ASAP...

Many thanks for help and for the amount of informations on the forum, otherwise it would be difficult to progress for us, it's hard to find quality and reliable informations here, in france.... This motors are not very widespread here.
MR .010 Means the Crankshaft is ground .010" under on the Mains and Rod Journals both.
It's an accepted practice in non race engine rebuilding industry to straighten crankshaft and they are often bent in Small Block Chevys.
Put in a Hydraulic press and straighten.
While force is applied its Struck hard with a 5 lb hammer at a strategic area chosen.
Such as the outer counter weights.
Forces the Molecular structure back to shape and hold there.
Scary stuff but it works.
Not wanted at all in race engine.
Boat engine I don't like either but some thinks it's Ok.

New Forged crankshaft be best.
Premium new Camshaft and lifters too.
I like tight clearances but a boat engine needs to be a bit looser like Grumpy said.
It's a fine line....too loose and blows up right away.

I would use Straight 30 weight oil or 20w50 Racing oil.
 

Maniacmechanic1

solid fixture here in the forum
Big Blocks are way stronger.
Rare to have a bent crank in Big Block Chevy.
Never happens in a Pontiac V8.
Both cranks huge super strong.
 
Hello !
I'm not dead :D
We gave the crankshaft to a "specialist machinist", and he returnd the crankshaft with a perfect "potatoes" shape... Facetting, 0.05 out of round, ...
I did 200km yesterday to bring crankshaft to a other machinist... I just have to pray that he works better...
We buy all to rebuilt motor... hydraulic pushers, crank/cam bearings, all caps, all seals, moly lube, additives .... Just wait for the crankshaft...

I hope i'll be back soon and can say " the crankshaft is perfect, i can begin rebuildt " ...
 

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
most of the damage in the photos
https://www.dropbox.com/sh/55gctl05w5od2i9/AADH0GSjuF3WhjDeirozhORDa?dl=0

looks like its the result of fine (micro) debris circulating in the oil,
(common if the oil passages in the block are not properly cleaned after engine bearing failure)
and less than quality crank journal polishing

14653.jpg

55798-01-200.jpg

nozzle.gif

read the links it should help
http://garage.grumpysperformance.com/index.php?threads/types-of-crankshaft-steel.204/#post-239

http://garage.grumpysperformance.com/index.php?threads/can-i-get-it-polished.9214/#post-33116

http://garage.grumpysperformance.co...shaft-journal-surface-finnish.2728/#post-9886

http://garage.grumpysperformance.com/index.php?threads/thrust-bearing-wear.619/#post-37676

http://garage.grumpysperformance.co...uring-crank-bearing-journals.5478/#post-16429

http://garage.grumpysperformance.co...ing-oil-feed-holes-in-cranks.4419/#post-11637

http://garage.grumpysperformance.co...ank-durring-short-blk-assembly.852/#post-1311
 

Unforgiven

solid fixture here in the forum
Have your dealer check out this place .... They can help with your marine related items.
https://www.marysvillemarine.com/
Top notch company.... My wife has been there for 30 years.
They do not deal with the public though, ONLY dealers.

I agree that your damage was caused by tight tolerances and debri in the oil. The crankshaft being ground the opposite direction
would have contributed to that I believe.
Example: If you were BRAZIN enough to stroke an alligater from front to back, it would be smooth. Now if you stroked that same alligater from back to front, you would find your hand catching on the scales..
 
Thanks for replys,
I'm agree, my conclusion of bearing failure is bad cleaning/too tight clearance too....
Notice that we bought fully assembly rebuilt motors...
We have planned to clean all oil passages and holes in block, crankshaft ... ... high pressure hot water cleaner seems ok for you ?
Thanks
 
Hello,
crankshaft is still at the machinist... Waiting...
We clean and clean and clean all holes, feed lines .... ....

I have few questions:

On our pistons, the small hole is facing to the flywheel... For us , the marks should to the timing side ? Are they wrong mount ? Must we turn all pistons ? Although our motor is reverse rotation ?

I read many things on camshaft bearings, but i have doubt. On many pics, I see oil bearing facing down ( facing crankshaft bearings ), but I read :

"Its generally a very poor idea to locate the oil feed hole at the bottom or 6 ),CLOCK as thats where the oil wedge needs to be the strongest and where the oil feed will be most restricted due to thousands of pounds of valve spring loads on the cam core, trying to seal off the oil feed hole, placing the bearing oil feed hole at between 12 o,clock and 2 o,clock provides the largest possible clearance and oil flow rate plus allows the full 180 degrees of the bearings lower surface to support the cam journal "

So can you confirm me that 2/3/4/5 cam bearings are facing feed hole on the feed line (between pushers feed lines ) ( 12 clock, according motor up at 12 clock .... ) and 1 cam bearing with holes at 10 and 2 clock.

Thanks again
 
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