67BELRO
Well-Known Member
New guy on the block. Can you look at the front of a block for a core shift.
Opinion on minimum cylinder wall thickness
- Thread starter theman440
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I wouldn't know what to look for, but I would suspect checking cylinder wall thickness is a definite indicator?
I learn a lot in this forum with guys who go racing and many who have been for a long time.
My local engine builder that built our modded Pontiac 421 Tri-power told me about the BCR girdle and I checked it out.
You can get a rough idea by looking where the galley plugs and other holes are drilled from the factory. Look at the casting bosses. Is every hole drilled to the same side of each boss? Or are they centered. Still tells you nothing about where the sand cores were placed inside.
Doug
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DeuceCoupe
Member
I would be nervous about the .076 and .080 non-thrust at that power level.
I once had a 400M Ford that ran about 200,000 miles with .045" non-thrust in some places - amazing. But that was at only 260hp or so. Built the engine to about 350hp, now at .040" min non-thrust, it lasted another 1000 miles up in cool WA weather, but wall split as soon as I got on it in 90F+ CA weather. THEN I measured. Same as comments above - lifetime depends on power level, and always do a sonic. I would add that lifetime also depends on how hot the engine gets. Looks like you are in a hot climate, and at 700hp I guess I'd worry about a non-thrust split. Usually not catastrophic, I nursed mine 80 miles to get it fixed, but it still made a mess and the block was now worthless.
I once had a 400M Ford that ran about 200,000 miles with .045" non-thrust in some places - amazing. But that was at only 260hp or so. Built the engine to about 350hp, now at .040" min non-thrust, it lasted another 1000 miles up in cool WA weather, but wall split as soon as I got on it in 90F+ CA weather. THEN I measured. Same as comments above - lifetime depends on power level, and always do a sonic. I would add that lifetime also depends on how hot the engine gets. Looks like you are in a hot climate, and at 700hp I guess I'd worry about a non-thrust split. Usually not catastrophic, I nursed mine 80 miles to get it fixed, but it still made a mess and the block was now worthless.
theman440
Well-Known Member
Yea, I'm not gonna use this block . . .
moper
Well-Known Member
Sleeve the two holes and move on with the build. Procuring another block, cleaning, and retesting will cost more than the two sleeves.
Though the MP block would be more desirable why do you think sleeves wouldn't fix it? Many different size sleeves available.. 060" over won't bother anything
Doug
Though the MP block would be more desirable why do you think sleeves wouldn't fix it? Many different size sleeves available.. 060" over won't bother anything
Doug
theman440
Well-Known Member
Though the MP block would be more desirable why do you think sleeves wouldn't fix it? Many different size sleeves available.. 060" over won't bother anything
Doug[/QUOTE]
How is a sleave going to get me a 4.38 bore with adequate cylinder wall thickness?
Doug[/QUOTE]
How is a sleave going to get me a 4.38 bore with adequate cylinder wall thickness?
How is a sleave going to get me a 4.38 bore with adequate cylinder wall thickness?[/QUOTE]
Get a sleeve designed to accommodate a 4.380 bore. You wouldn't use a 4.25 bore sleeve. They come in many sizes.
Doug
moper
Well-Known Member
You use a sleeve to get the minimum thickness to where you want it. Or just to replace the cast iron with a better material... There's a reason NHRA didn't let racers sleeve all 8 holes - because they are stronger than stock walls. Like dvw said - get the right sleeve and do what you want. Or go find more blocks, and sonic test them. BTW - most of the MP blocks you will find are terrible. They should be sonic tested too. Especially if it was never run. Some really poorly cast ones were sold, but they were never used and you find them for sale now. Don't pay big coin for any MP block until you see the sonic test results - even the Siamese bore versions.
IQ52
Well-Known Member
Get a sleeve designed to accommodate a 4.380 bore. You wouldn't use a 4.25 bore sleeve. They come in many sizes.
Doug[/QUOTE]
How thick a sleeve would you recommend, where would you get this, and have you ever done this?
IQ52
Well-Known Member
Food for thought. How well will this sleeve seal out the water when it removes most of the existing cylinder wall? How much does this distort the adjacent bore? If I sleeve two next to each other, how much material is left between the bores at the deck? How close am I to the bolt holes and water holes?
https://www.lasleeve.com/tech/all-purpose-sleeves
https://www.lasleeve.com/tech/all-purpose-sleeves
How thick a sleeve would you recommend, where would you get this, and have you ever done this?[/QUOTE]
I see no reason a std 4.375'x .125" sleeve with locktite wouldn't get the job done. Have a Hemi running round with one for years, no issue.
Doug
theman440
Well-Known Member
Well, I've decided against the Mopar block - too much of a risk (distance, price, possible shipping damage ETC) I purchased another std bore block from a friend who is a Stock Eliminator racer - says he had it sonic checked and it can go .060. I'm going to have sonic'd again, "Trust but verify" - Ronald Reagan.
theman440
Well-Known Member
Here are the results from another block I bought from a friend - this one is much better, I had Bob Mazzolini sonic this one. I've decided to go 30 over - Any opinions on if a partial block fill would be beneficial?
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