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Discussion Starter · #1 ·
My friend just rebuilt a 1988 454 block using 78 heads. It ran for awhile, say maybe 10 miles total. Chewed the holy crap out of the cam lobes and the lifters (i mean really bad!!) He thought it was a defective cam or lifters. Put a matched set in it and after 20 minutes same thing, lifters mushroomed so bad they had to come out the bottom. Its not a radical cam and its got oil pressure. Anyone have a similar problem? Could it have anything to do with the newer block with the older heads? Any help is appreciated.

Thanks,
Ryan
 

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it could have something to do with mixing early and late model stuff.....the heads might have a different degree on the valvetrain and putting to much pressure on the cam......

also check to see if the cam is too far in the block...that happened to my small block when i put it together with a fawkin gear drive....what a pos..the lifters wher hitting the lobes next to the correct ones......
 

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Is your buddy using plenty of cam lube during the twenty minute break in as the cam instructions say?? if not that could be the problem. Or he could be using too much spring pressure during the break in.
 

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Discussion Starter · #4 ·
he just asked if he needs to fill his whole motor with assembly lube lol. Yes he is using the proper break in porcedure, hes familiar with engine rebuilds so im thinking its something deeper than the break in.
 

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must be an obstruction somewhere in the oil passages. Tear down the block and clean every passage by hand with bottle brushes and warm soapy water.
 

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Just a thought but what about pushrod length?Maybee with the older heads the length is wrong.Also I believe these use different length rod for intake and exhaust.They didn't get switch or replaced with the wrong ones did they?Worth a look.Blazin <IMG SRC="smilies/biggrin.gif" border="0">
 

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Originally posted by Reddwarf:
<STRONG>must be an obstruction somewhere in the oil passages. Tear down the block and clean every passage by hand with bottle brushes and warm soapy water.</STRONG>
First thing that I would do is what Reddwarf said to do. Next thing to do is when braking in the engine you should use Valoline Racing Oil because it has a high sulfur content to it. The sulfur is a great lubricate but the new oils have only half as much as the Valoline Racing oil. The new engines don't need the sulfur in it because they have roller cams and lifters. Also when you brake the cam in you should use EOS lub. They sell it at the Chevy Dealers.
 

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Push rods are what I was going to ask to. The push rods maybe too long. block decked, heads surface done, and mixing years. Get a mock up push rods one for the intake and exhaust for number one cycinder. and find the rod length you need for the set up. Good luck
 

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how many cam lobes are you guys loosing? a friend of mine in high school went through 2 cams before we figured out that the lifter bores were binding. had them honed and never had a problem again. it's worth checking anyways.
i'd still disassemble the whole thing and check the entire lube circuit before anything else.
good luck! <IMG SRC="smilies/bounce2.gif" border="0"> <IMG SRC="smilies/bounce2.gif" border="0"> <IMG SRC="smilies/bounce2.gif" border="0">
 

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I was not thinking how about coil bind in the valve springs or the retainers are bottoming out on the valve guide. This will take a cam out in no time.
 

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what valve springs are you running?
my BBC book claims with any cam other than stock you have to change the springs.
perhaps you are bottoming the springs, or going the other way with excessive pressure during break-in.
 

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Discussion Starter · #12 ·
I am passing all this along to him. Im not 100% (95%)positive but the cam lobes are oiled from runoff in the lifter valley, and if the lifter valley doesnt have oil then the lifters dont either and he could tell if they were dry. As far as the lifter bores sticking, the 100% correct pushrods, and valvesprings i'll ask him and let you guys know.

Thank You,
Ryan
 
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