TALL DECK 427
- Thread starter KINGDADDY
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LOL I KNOW ,I KNOW YOU SEE MY BUDDY GOT SUCKERED INTO THIS TALL DECK MOTOR AND SEEMS TO THINK YOU CAN DO IT, BUT I SAY THE DECK WONT BE THICK ENOUGH .SO I POSTED IT HERE .A LOT MORE PEOPLE THAT KNOW.HES THE SAME GENT THAT PUT A SUPER BIG CAM IN A 427 WITH STOCK VALVE TRAIN AND HEADS,PUSHED THE PUSH RODS THROUGH THE LIFTERS,,,,,,,BUT I WILL BET THERE IS OTHERS THAT WOULD BE INTERESTED IN KNOWING
I'm sure it could be done yes, but then after its milled down there will be some issues. Don't know about the particular engine someone else could help out here, but I would look for issues with intake manifold fitment, distributor, and water/cooling effects that would have on the engine. Who knows if someone worked at it enough it could be better than a stock 427.
It seems to me a longer rod could be used to gain stability at rpms. Honda guys do this a lot and there are many pros and cons.
One thing to consider about the tall deck - with a stroker crank and longer rods is going to give a huge stroke vs bore advantage to other engines of its size. Meaning with some aftermarket heads, 4v or hemi/heart/peanut style whatever, you're going to have a more central burn in a smaller bore vs displacement. = better spark/burn distribution and more compression allowed. The catch is a longer stroke engine would be working against detonation resistance by spending slightly more time at TDC so the engine will be slightly weaker at peak torque when components may be stressed
...more rambling. It could be said that the stall at TDC vs a shorter rod and heavier rotational mass would make for more torque at a lower rpm, but if it makes a difference in the real world I dunno.
It seems to me a longer rod could be used to gain stability at rpms. Honda guys do this a lot and there are many pros and cons.
One thing to consider about the tall deck - with a stroker crank and longer rods is going to give a huge stroke vs bore advantage to other engines of its size. Meaning with some aftermarket heads, 4v or hemi/heart/peanut style whatever, you're going to have a more central burn in a smaller bore vs displacement. = better spark/burn distribution and more compression allowed. The catch is a longer stroke engine would be working against detonation resistance by spending slightly more time at TDC so the engine will be slightly weaker at peak torque when components may be stressed
...more rambling. It could be said that the stall at TDC vs a shorter rod and heavier rotational mass would make for more torque at a lower rpm, but if it makes a difference in the real world I dunno.
Only if the tall deck block has about 1" thick deck to start with.KINGDADDY said:
BBC deck height=9.8"
Tall deck height=10.2"
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Difference= .400"
Sorry, sarcasm is hard to type :lol: . The answer to your question is no, you can't mill a tall deck by .400". The deck would end up being too thin (if there was any left at all). You would be left with a very weak and unstable deck surface. I went looking for factory deck thickness specs and couldn't find them, but the Dart Big M spec was .625" (many sources just listed "adequate for all applications"). It would be easy enough to verify this. Just measure the thickness of the deck at the water jacket openings.
There's really no reason to modify it anyway. There are performance parts available for tall deck blocks. If you don't like the idea of a tall deck -- just don't use it.
There's really no reason to modify it anyway. There are performance parts available for tall deck blocks. If you don't like the idea of a tall deck -- just don't use it.
DRIVEN said:Sorry, sarcasm is hard to type :lol: . The answer to your question is no, you can't mill a tall deck by .400". The deck would end up being too thin (if there was any left at all). You would be left with a very weak and unstable deck surface. I went looking for factory deck thickness specs and couldn't find them, but the Dart Big M spec was .625" (many sources just listed "adequate for all applications"). It would be easy enough to verify this. Just measure the thickness of the deck at the water jacket openings.
There's really no reason to modify it anyway. There are performance parts available for tall deck blocks. If you don't like the idea of a tall deck -- just don't use it.
I was reading it was around .600" as well. with some serious block modification he could use it I suppose, if the water jackets could be made stronger from the inside possibly some sort of cementing. Anything can be done but who knows what stress it could take. I think we're all agreed it'd never justify the cost.
I've read the tall decks are stronger when using a stroker crank, whats different about the block or is it just the use of longer rods helps stability?
Honestly, I'm not much of a big block guru. My understanding is that all tall decks were intended for HD/commercial use. That being the case, I would assume the castings are at least as strong as the passenger counterparts (low deck). Longer rods reduce side thrust on the cylinder. I don't know that there would be any strength difference with a stroker crank alone.
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