Deck height
#1
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Deck height
I just put in new flat top mahle pistons in my gen 6 454. I checked a couple cylinders and got a deck height of +/- .040
I am going to be using new 781 heads,
Bob m says im going to have low compression around 8.19 he says a stock 330 has around 8.75
My ? is how could i have lost compression by not changing anything but new pistons from old stock ones?
What are my alternatives? Shave heads down? and is that risky?
and 2nd option shave heads and use smaller head gasket?
Thanks
I am going to be using new 781 heads,
Bob m says im going to have low compression around 8.19 he says a stock 330 has around 8.75
My ? is how could i have lost compression by not changing anything but new pistons from old stock ones?
What are my alternatives? Shave heads down? and is that risky?
and 2nd option shave heads and use smaller head gasket?
Thanks
#4
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I just put in new flat top mahle pistons in my gen 6 454. I checked a couple cylinders and got a deck height of +/- .040
I am going to be using new 781 heads,
Bob m says im going to have low compression around 8.19 he says a stock 330 has around 8.75
My ? is how could i have lost compression by not changing anything but new pistons from old stock ones?
What are my alternatives? Shave heads down? and is that risky?
and 2nd option shave heads and use smaller head gasket?
Thanks
I am going to be using new 781 heads,
Bob m says im going to have low compression around 8.19 he says a stock 330 has around 8.75
My ? is how could i have lost compression by not changing anything but new pistons from old stock ones?
What are my alternatives? Shave heads down? and is that risky?
and 2nd option shave heads and use smaller head gasket?
Thanks
Last edited by jeffswav; 03-05-2011 at 03:06 PM.
#6
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Maybe I dont understand what you mean, but how can you have + - .040 ? The pistons are either down the hole or sticking up past the deck. If you have both , something is seriously wrong here. In either case, 040 is a good number to have.
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the motor was a 330 bravo motor, with flat top pistons......the engine builder who bored out the motor and ordered pistons.. He didnt give me a option on ordering dome but the stock were flat......
I said +/- meaning give or take a couple thousandths.. no pistons are protruding the deck all below the deck .040...
Maybe the magnum motor had domed pistons, but mine had stock flat pistons and we just bored it .04
fml!!
I said +/- meaning give or take a couple thousandths.. no pistons are protruding the deck all below the deck .040...
Maybe the magnum motor had domed pistons, but mine had stock flat pistons and we just bored it .04
fml!!
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Now the 820's have a 113cc chamber, thats what I have. I had a little milled off, now they cc at 110.
What heads came with the engine?
Last edited by jeffswav; 03-05-2011 at 03:03 PM.