400 Cylinder Walls Breaking ???

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PROSTOCKTOM

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I am waiting to inquire about anyone the breaking cylinder walls on 400 blocks while drag racing. The main reason I ask is that it seems like more guys are building B blocks than RB blocks today. I would prefer that only those that broke post replies. Hear say I am not interested in.

My friend John Armenoff (If you're in Indiana you know who he is) raced 470" B blocks in the 80's and early 90's before switching to RB blocks. He ran them in Colts and later Daytona's.
In the 80's he was racing at least 3 times a week and running 5.90-6.00 1/8th mile times in the early days and running 5.50's later on in the Daytona. The engines saw 7,000-7,200 rpms. Aluminum rods, lightweight pistons, and a roller cam with 282 degrees duration @ .050" He told me he went through 16 blocks during the time he raced them and finally switched to RB blocks and never broke one of them after that. I just keep seeing all these B block builds, but never hear of any broken blocks. What say you that have real world experience?

Thank,
Tom
 
I don't have any knowledge of breakage, but my former racing partner decided to build the 400 blocks when the 440 block prices started climbing. He had a killer 470 in his 65 Satellite street car that ran like a scalded dog. I don't remember what the internals were, I do remember it was a solid flat tappet motor & it ran on pump gas.
 
We have had a few serious cylinder problems with the 400 Blocks

We now run exclusively the 400 Cold weather early blocks out of medium
duty trucks. Easiest way to tell is the early casting # PLUS casting number is TWICE
as large on the side of block.

Google John Irving Drag Racer

To see our 400 Roadrunner = Fastest Stock 400 in NHRA Drag Racing
 
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We have had a few cylinder problems with the 400 Blocks

We now run exclusively the 400 Cold weather early blocks out of medium
duty trucks. Easiest way to tell is the early casting # PLUS casting number is TWICE
as large on the side of block.
Now that's interesting. One I've never heard.
 
We have had a few cylinder problems with the 400 Blocks

We now run exclusively the 400 Cold weather early blocks out of medium
duty trucks. Easiest way to tell is the early casting # PLUS casting number is TWICE
as large on the side of block.

Medium Duty 400 Blocks???
What part number/s where those?
Are large of a bore size are you running?
I would like to see a photo of the block sides.

Thanks,
Tom
 
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Guys if you would PLEASE stay on topic. I appreciate your enthusiasm, but if you haven't raced one to the point of breaking the cylinder walls please refrain from posting on this topic. I only want real world information.

Thanks,
Tom
 
I have a parts book for mid 70s trucks.
Light to heavy duty .... I will have to reaearch this . Very interesting .
 
My buddy says the cure for that is a main girdle. That way it takes the twist out of the mains which can/has cracked/split the block and cylinder walls. Aluminum main caps absorb the load better also. Kim
 
built a low deck 470 motor for my dart. first go around used 516 big valve heads ported by me. ran 6.40s with no issues. first freshen up scored a set of victor heads cnc by hughes. put a small roler in it .660 lift . first pass 6.24 was very happy. started upping shift points and kept going faster. with 516 heads 6200 was fastest. tried 6400 then 6600 at 6800 got 6.13. was hoping to see a 5.99 or better with 7000 or 7200 shift. next weekend car slowed over a tenth, trouble shoot and yep #8 split cylinder wall. sleeved that cylinder and put it back together. have not raced since. know john very well, motor was based on his combo. was leary of putting too much power through it for the very reasons stated. john was pulling mains out, i split a cylinder, go figure.
 
A regular old 400 block @4.375" bore:

IMG_20220515_122125.jpg


IMG_20220516_141909.jpg


IMG_20220516_144457.jpg
 
400;s had different rod/stroke ratios, maybe more side loading? It WAS the largest bore offered.
 
400;s had different rod/stroke ratios, maybe more side loading? It WAS the largest bore offered.

Some of it has to do with luck and a lot of it has to do with the person that Sonic checks the block and how thorough they are during the process. I did not check this block and there is definitely a thin spot on number 5.
 
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