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Discussion Starter · #1 ·
Well I bought a vito's monoblock that has been drag ported, I was told it was on a 4 mill running a spacer plate with stock length rods. Problem is when I installed it on my stock rod 4 mill motor with a spacer plate the pistons were way below deck height so after some measurement I decided to make a .045 spacer plate which put my pistons at 0 deck height I then checked the squish and had .046. So far so good them I put my 9 inch degree wheel on and checked the port timing. With this setup the piston was passing down slightly past the transfer windows

Outer exhaust ports 200*
main exhaust 198*
main transfers 134*
boost intake transfer138*

I didn't think this was right so I took the .045 spacer out and checked them again leaving both of the .020 base gaskets in. I now have the pistons sticking out of the cylinder .045. Now the piston doesn't quite make it to the bottom of the transfer windows.

Outer exhaust ports 196*
main exhaust port194*
main transfers 126*
boost intake transfer 130*

This whole thing didn't make sense so I did some reserch on the pistons and found out that they are a vito's piston that from my understanding have been cut on top to increase port timing on motors with stockish port timing. So should I add a.020 shim to my base stackup from the second setup above and then cut the dome to get the squish right? Are these vito's pistons supposed to have some crazy amount of squish? I know I should just buy a new set of wiseco's but I am running out of time and cash.
 

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Your second set of numbers look to be where you want them and it doesn't matter if the window is covered with the piston on the transfers. Send your domes in and have a little more taken off to get the squish where you want it and your good to go. Shouldn't cost too much to have it done.

Backcountry on here can do it for you
 

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Discussion Starter · #3 ·
QUOTE (vwpartsman @ Mar 22 2009, 05:16 PM) index.php?act=findpost&pid=35381Your second set of numbers look to be where you want them and it doesn't matter if the window is covered with the piston on the transfers. Send your domes in and have a little more taken off to get the squish where you want it and your good to go. Shouldn't cost too much to have it done.

Backcountry on here can do it for you

I can but the domes myself, thats no problem. I guess what I am asking is where I should set my timing at, should the exhaust numbers be different from the outer ports versus the main?
 

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Standard disclaimer - if we all did it the same, you'd go to Wal Mart to get your stuff done.

Id prefer the latter set of numbers and modify them by bringing the transfer timing up to 128* and the main exhaust port up to 196-197*.

I wouldnt raise the cylinder anymore because of the high boost port timing.

Modify the domes and check the trapped volume at TDC to set the compression ratio.
 

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Discussion Starter · #5 ·
QUOTE (Backcountry @ Mar 23 2009, 08:05 AM) index.php?act=findpost&pid=35446Standard disclaimer - if we all did it the same, you'd go to Wal Mart to get your stuff done.

Id prefer the latter set of numbers and modify them by bringing the transfer timing up to 128* and the main exhaust port up to 196-197*.

I wouldnt raise the cylinder anymore because of the high boost port timing.

Modify the domes and check the trapped volume at TDC to set the compression ratio.

You said exactly what I wanted to hear, from what I have heard/read/seen those are the numbers I should be running.
 

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I've usually seen the outers lower than the main exh by a few degrees. I had a long rod stock stroke cub motor that I had to mess with a bunch as far as domes, gasket thickness etc. Try a few diff combos if you have the time and patience. Radar
 

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those pistons are not the vito's "super stockers" they dont have the cut out ont he exhaust side at least they dont look like it
 
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