question about a 74 351m
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I'm wondering why you want to go to .060 overbore instead of .030. The extra 5 cid from the extra .030 overbore isn't going to be noticed and all you'll end up with is thiner cylinder walls. This is jmo, of course. Everyone has different ideas. What do others think?
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From: Paragould Ar
my brother built up a 351m a few years back and went with a .060 overbore and it didnt have a single problem. Guy that machining it says it will be perfectly safe aswell. I say why not? If a .060 is equivalant to 10 ci's that would put me at a 412. And in terms of saying if i ever have to go back into the motor, i look at it like this. 351m/400 blocks are a dime a dozen.
Posting Guru
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so has he done any 400s? these are not usually race engines so he probably has no idea on a 400
You may get away with it , but you still have to check your cylinder walls..
Also the extra CID wont help much your power but could create a chronical overheater...
Anyways its still your choice...
You may get away with it , but you still have to check your cylinder walls..
Also the extra CID wont help much your power but could create a chronical overheater...
Anyways its still your choice...
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From: Paragould Ar
He has a 74 gran torino elite with a 400 so im sure he knows his way around it.
CID's make power, im not saying it will be a night and day differance.
With a good 4 core rad dual efans and the right termostat temps wont be a problem at all. like i said my brother has a 351 that was bored .060 over and its running the factory rad and tstat with no heating problems, so im not gonna worry much.
CID's make power, im not saying it will be a night and day differance.
With a good 4 core rad dual efans and the right termostat temps wont be a problem at all. like i said my brother has a 351 that was bored .060 over and its running the factory rad and tstat with no heating problems, so im not gonna worry much.
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I'm sure there's a good chance you won't have a problem. I think I read somewhere if you want go more than .030 the cylinders should be sonic checked before hand. I was just curious your reasoning and like you said there are plenty of these engines out there.
Laughing Gas
Joined: Jan 2006
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From: New-brunswick,Canada
He has a 74 gran torino elite with a 400 so im sure he knows his way around it.
CID's make power, im not saying it will be a night and day differance.
With a good 4 core rad dual efans and the right termostat temps wont be a problem at all. like i said my brother has a 351 that was bored .060 over and its running the factory rad and tstat with no heating problems, so im not gonna worry much.
CID's make power, im not saying it will be a night and day differance.
With a good 4 core rad dual efans and the right termostat temps wont be a problem at all. like i said my brother has a 351 that was bored .060 over and its running the factory rad and tstat with no heating problems, so im not gonna worry much.
Posting Guru
Joined: Jul 2007
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You could always leave it to luck....
The 351M/400 engines have "thin wall" castings and can not be safely over-bored beyond .040" -- Okay. Don't let this scare you away from "M" block engines. Ford did this to save weight. An "M" block engine is good for one or two complete rebuilds before you have to sleeve the block. All this means is that you can't over bore an "M" engine much beyond .040". As an example, when I had my engine rebuilt, the shop found that the #1 piston's wrist pin came loose and scored the block. A .030" over bore would not clean this cylinder up, so they had to put a sleeve in it. Big deal. It cost me $75.00 to fix it.
source:
Rumors & Myths
The 351M/400 engines have "thin wall" castings and can not be safely over-bored beyond .040" -- Okay. Don't let this scare you away from "M" block engines. Ford did this to save weight. An "M" block engine is good for one or two complete rebuilds before you have to sleeve the block. All this means is that you can't over bore an "M" engine much beyond .040". As an example, when I had my engine rebuilt, the shop found that the #1 piston's wrist pin came loose and scored the block. A .030" over bore would not clean this cylinder up, so they had to put a sleeve in it. Big deal. It cost me $75.00 to fix it.
source:
Rumors & Myths
Mountain Pass
Joined: Jun 2006
Posts: 160
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From: Alaska
You would come out better stroking the motor and gettingj some more power from having you heads worked. .60 overbore is definitely pushing it to the outer limits. Check out some of the stroker kits out there.
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