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Old 08-17-2009, 10:49 PM
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mopower04 mopower04 is offline
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Exclamation 5.9magnum crank??

so i picked up my 5.9 magnum for my 96 ram. took off the oil pan and found the no. 6 rod had spun the bearing and its paperthin... so my ? is can i have the crank ground to whatever to clean it up, replace all bearings, have just the one rod R&R'd and put it all back together? or do i rip it all down, have the block hot tanked and cleaned and do all the rods, re-ring it and all new gaskets etc? kinda lookin for a $2000 limit on this not performance just want to replace my 5.2 with alittle more oomph!
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Old 08-18-2009, 01:18 AM
dodger1 dodger1 is offline
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Are you gonna do the re and re? (free labour) Or are you gonna pay someone? (not so free labour) I'm thinking that if you do the labour, you might get away with a proper rebuild for your budget. Can't see doing a band-aid fix if a bearing spun, i.m.h.o.
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Old 08-18-2009, 02:57 AM
cudabob496 cudabob496 is offline
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Any helpful info here?

Tech Question
jason zalewski, prince albert, SK, canada, 1978 dodge monaco 360

I was wondering if it is possible to offset grind a 360 crank down to a 2 inch rod journal. If so can it be done on a cast crank as well as a forged? My plan would be to use a 4 inch stroke crank,offset grind it .125 inch to achieve a 4.25 stroke, use a 6.3 inch rod,1.09 comp height piston,at .060 overbore will come to 440 cube small block..will this combo work?

In a word: No. You have some math problems, for starters: If you offset grind a 2.125" journal to 2.00" you've only increased the stroke by 0.0625", theoretical maximum..

Then there's the cyl. wall thickness problem. The factory recommends 0.040" max. O/S for a reason. Any extra HP you'd get from the small displacement increase from, say, 0.020" to 0.060" bore diameter would be much more than offset by wall flex, which equals blowby.

Then there's the piston question. Sounds like yours will be hockey pucks. If the engine will be drag race only, you'd get by. For street durability, though, I'd rate this engine combo about a 3 on a 10 scale.

The cast crank needs all the iron it comes with!

Rick
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Old 08-18-2009, 05:41 PM
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Ray Bell Ray Bell is offline
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Theoretical maximum stroke increase is the difference between the original pin size and the reduced size...

While you only move the pin half that distance, it rewards you by increasing how far the piston travels in both directions... hence the total gouged off the crank is the total extra stroke.

If a nice radius can be left each side of the pins the strength might not be compromised so much.

Agree on wall thickness... you can't go too far with modern thin castings.
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Old 08-18-2009, 10:26 PM
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Arrow ....

well that article didnt really help. i plan on keeping it a stock rebuild. and yes i will be doing the work myself. would have it anyother way! other than the machine work of course.
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Old 08-18-2009, 11:42 PM
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You're on the right track there, young fella...

I've been working on my own cars, everything except sometimes exhaust systems and machining like that. Nothing like knowing what you have under you, is there?
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