454 bored 1/4 inch over- Is it Possible???? [Archive] - Chevelle Tech

: 454 bored 1/4 inch over- Is it Possible????


Horsepower69
Mar 7th, 00, 6:53 PM
If someone was to bore a 454 chevy 1/4 of an inch over and put cylinder sleeves, would the engine run properly or will there be future problems with this?? Roughly how much horsepower and torque can you gain if you bore 1/4 inch over??


Thanks
Pete

RatPowr
Mar 7th, 00, 7:18 PM
Isnt 1/4 inch over .25 over? Thats not possible. I think the max SOME BBC's can take is .125 or .100 over...no way your gonna get .25 out of a production 454 block. Bowtie and merlins are another story.

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66 Nitrous Fed Big-Block Chevelle Houston, TX ACES#3321 "There is no Replacement for Displacement"

Gene Chas
Mar 7th, 00, 7:32 PM
Gotta get a 4.5" block or do some real expensive sleeving. GenV 4.5" block not hugely expensive.

DZAUTO
Mar 7th, 00, 8:07 PM
Just reading the title scared the heck out of me! What is the stock bore of a 502? It has siamesed cyls.

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Tom Parsons

street_racer_502
Mar 7th, 00, 8:23 PM
The stock bore size of a 502 is 4.47. The 509 Merlin is 4.5. I don't know how much you can overbore these engines though.

JWagner
Mar 7th, 00, 9:26 PM
There is no problem in boring this .25 inches over. What you have left after this is another question. Why put in the sleeves? They just take up more room that could be cubic inches?? The real question is how much distance is there between pistons? Sleeves are for repairs of distresed blocks that are on their last legs. If you were to bore out your 454 and put in sleeves, what size would you sleeve it to?

IgnitionMan
Mar 7th, 00, 10:49 PM
Well, think about the 4.470 bore block, and the 4.500 Merlin. They are sound enough to go .030 over for rebuild safely, giving the 4.500 and 4.530 bores respectively.

Still, I'd sonic check any big block before any boring took place, just for peace of mind.

Original question was on 454, answer is to sonic check the production 454 block, but unless it is one of the engines above, I don't think I'd even try it.

Now, ZL1 aluminum 427 blocks will handle lots more bore, with the proper sleeving, than most would consider prudent and safe, just have to use the right sleeves and machinist. Touchy, but worth it, and safe, if you make a good job of it.

[This message has been edited by IgnitionMan (edited 03-07-2000).]

Morris
Mar 8th, 00, 3:24 PM
I may be wrong but I'm under the impression that any production ,cast iron block can safely go .100 and still be streetable.1/4 inch would be out of the question.

Fred Ont canada
Mar 9th, 00, 3:42 PM
JWagner left off the "0" thats .250. The sleeves would be .250 over inside so you bore the block to fit the OD of the sleeve.Thats if it were possible...FRED

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Wally
Mar 9th, 00, 5:40 PM
JWagner

Sleeves are not just for repairs. There are all sorts of engines that use sleeves as a replaceable resource. Lots of diesels use sleeves, and all the KB fuel blocks. It is much easier and cheaper to knock a sleeve out between rounds then to repair a block. I the big equipment world, the rebuild the motor in the unit, replacing the sleeves if necessary.

If you bore a normal 454 .250 over, there would be nothing but air left. I have sonic tested lots of these blocks, ou are lucky to find one that is .200 between cylinders.



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Wally
Gold #67
67 Malibu "Small Block" second owner
90 SS454
71 Malibu "Small Block"
93 torch red vette(crashed)Bad day at Blackrock! 6 grand in damage!

mike reeh
Mar 10th, 00, 1:29 AM
How does sonic testing work and what, exactly, does it test?

-mike

Wally
Mar 10th, 00, 3:13 PM
Sonic testing test for thickness of the cast iron. It is very nice for detecting core shifted blocks.

It has a standard that you use to calibrate the machine, then you apply lite oil to the probe and place it on the wall of the cylinder, it has a digital display that reads the thickness. When you do a block, you do readings at 4 places in the bore at three levels. I have had 454 that were to thin to bore .060, testing is a good idea for a serious big buck motor.

Not every shop has a tester, the 2 grand price tag is hard to swallow.

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Wally
Gold #67
67 Malibu "Small Block" second owner
90 SS454
71 Malibu "Small Block"
93 torch red vette(crashed)Bad day at Blackrock! 6 grand in damage!