replacing rod and main bearings
replacing rod and main bearings Okay guy i bought a used 383 shortblock with 500 miles on it.
And i will be replacing the pistons with forged ones and i also want to replace the main and rod bearings.
I know i will need to hone the cylinders before i install the pistons. But will i need any machine work before i replace the main and rod bearings?
also is there a writeup on how to replace the bearings. my stepdad was a mechanic for over 10 years but its been awhile since he did this. and would like a point of reference.
and i would like to NOT have the shop do as much as possible because their prices are outrages around here.
thanks guys.
And i will be replacing the pistons with forged ones and i also want to replace the main and rod bearings.
I know i will need to hone the cylinders before i install the pistons. But will i need any machine work before i replace the main and rod bearings?
also is there a writeup on how to replace the bearings. my stepdad was a mechanic for over 10 years but its been awhile since he did this. and would like a point of reference.
and i would like to NOT have the shop do as much as possible because their prices are outrages around here.
thanks guys.
yea i know it will have to be rebalanced but other than that i would really like to not have a shop do anymore of the work.
also anyone know what the bearing clearances need to be for a 383 it has a forged eagle crank.
also anyone know what the bearing clearances need to be for a 383 it has a forged eagle crank.
Call eagle and why not just have a shop do that? all you are doing is a re balance Piston and rings. They have to remove the bearings anyway, just have them resize them.
You can have the shop Polish the journals on the crank and have them check to see I'd it needs to be align honed. Alsop be sure to check the cam bearings. They get beat on alot installing and removing the cam.
I normally like the bearing clearance between .002 and .003. I like to stay closer to .002 for a daily driver, and .003 for a race motor.
I normally like the bearing clearance between .002 and .003. I like to stay closer to .002 for a daily driver, and .003 for a race motor.
why are you rebuilding an engine with 500 miles on it??? Unless you're gonna spray/boost the engine why worry about new pistons? A little more of an idea why you are going through the hassle would help. So would knowing how the engine was put together originally. If it was blueprinted then there are exact tolerances already planned for it. Therefore you would basically be building the shortblock from scratch with used parts. Let an engine shop handle it of you want the best results. JMO.
why are you rebuilding an engine with 500 miles on it??? Unless you're gonna spray/boost the engine why worry about new pistons? A little more of an idea why you are going through the hassle would help. So would knowing how the engine was put together originally. If it was blueprinted then there are exact tolerances already planned for it. Therefore you would basically be building the shortblock from scratch with used parts. Let an engine shop handle it of you want the best results. JMO.
Yes i am planning on spraying this motor. thats the reason for the new pistons. and i know it only has 500 miles on it but for my own piece of mind i want to change out the bearings.
I will find out if it was blueprinted as well.
and the reason i dont want to go to a shop is for one. Im my area they are WAY overpriced. and second NOBODY wants to touch the LT1 motor they all say to sell it and buy an ls1.
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yea...so plan on having the rotating assembly balanced, then have the crank polished. From there you can get new bearings for the crank, rods and cam. Check the ones coming out of the engine for indication of over/undersize (should have a +/- .010etc). Purchase corresponding bearings for replacement, then assemble. If you're clearence is more then .0025" you'll have severe issues. it should be between there and .0015". As for the shops, tell them the rotating assembly is no different than any other SBC....they should have plenty of experience with them if they're worth anything.
That should get you started.
That should get you started.
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Verdad Gallardo Yes i am planning on spraying this motor. thats the reason for the new pistons. and i know it only has 500 miles on it but for my own piece of mind i want to change out the bearings.
I will find out if it was blueprinted as well.
and the reason i dont want to go to a shop is for one. Im my area they are WAY overpriced. and second NOBODY wants to touch the LT1 motor they all say to sell it and buy an ls1.
I will find out if it was blueprinted as well.
and the reason i dont want to go to a shop is for one. Im my area they are WAY overpriced. and second NOBODY wants to touch the LT1 motor they all say to sell it and buy an ls1.
Okay well if i do go to a shop what do you guys think is a reasonable price.
for installing a new set of pistons on my rods
installing new bearings
polishing the crank
And balancing thw whole thing
for installing a new set of pistons on my rods
installing new bearings
polishing the crank
And balancing thw whole thing
depends on location and what shops charge. I know around me there are some top shops that build all sorts of motors....including ProMod and really top end motors.....they also charge top dollar so it may be different than where you are. Shop around and see what the local shops are charging, just tell them it's a 2 bolt main SBC...leave out the LT1 otherwise you get the stupid comments. G/L, and if nothing else get ahold of Corey at Clayton....he may be able to work something out for you at a decent price....
yea...so plan on having the rotating assembly balanced, then have the crank polished. From there you can get new bearings for the crank, rods and cam. Check the ones coming out of the engine for indication of over/undersize (should have a +/- .010etc). Purchase corresponding bearings for replacement, then assemble. If you're clearence is more then .0025" you'll have severe issues. it should be between there and .0015". As for the shops, tell them the rotating assembly is no different than any other SBC....they should have plenty of experience with them if they're worth anything.
That should get you started.
That should get you started.
as for going above .0025 and having major issues this is not true at all.....im runnin .0028 on my mains and .0031 on my rods with no issues at all spinning 8K plus on the regular and street driving
not true at all........it all depends on application....... .0015 is actually too tight........general rule of thumb is .001 per 1 inch of pin diameter.....crank mains in a performace motor are ususally good between .0024 and .0026 as a general rule of thumb.......also the rods are usuall around the same in the .0025 area you can go down to a .002 but i'd stay around that...........rod journals are 2.100 inches so .0021 is the rule of thumb.......
as for going above .0025 and having major issues this is not true at all.....im runnin .0028 on my mains and .0031 on my rods with no issues at all spinning 8K plus on the regular and street driving
as for going above .0025 and having major issues this is not true at all.....im runnin .0028 on my mains and .0031 on my rods with no issues at all spinning 8K plus on the regular and street driving
Okay i will call around and see what everyone says.
the motor is 4 bolt mains tho. will that make any difference?
anyone know any shops in or around vegas that do good work at a decent price?
the motor is 4 bolt mains tho. will that make any difference?
anyone know any shops in or around vegas that do good work at a decent price?
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Joined: Apr 2007
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From: Kempner, TX
not true at all........it all depends on application....... .0015 is actually too tight........general rule of thumb is .001 per 1 inch of pin diameter.....crank mains in a performace motor are ususally good between .0024 and .0026 as a general rule of thumb.......also the rods are usuall around the same in the .0025 area you can go down to a .002 but i'd stay around that...........rod journals are 2.100 inches so .0021 is the rule of thumb.......
as for going above .0025 and having major issues this is not true at all.....im runnin .0028 on my mains and .0031 on my rods with no issues at all spinning 8K plus on the regular and street driving
as for going above .0025 and having major issues this is not true at all.....im runnin .0028 on my mains and .0031 on my rods with no issues at all spinning 8K plus on the regular and street driving
How do you treat the #5 main?
Jake
Yep, that's my way of thinking, too. Your numbers are almost 'dead on' with what I like to see (an insignicant difference of only .0001") When I looked up GM's specs for the 96 LT1 I was shocked at how tight they can be and STILL meet factory spec.
How do you treat the #5 main?
Jake
How do you treat the #5 main?
Jake
