decking block..questions

[Old Guy with 87 GT]

i have plans in the works to mill the deck on my moterblock to further the compression ratio ......i,m not going to crazy toleraces i'm only milling to a safe tolerance with a few exra thousants in case i ever have to resurface my block agian ,i forget the actuall number but i'm going to bring my pistons as close to 0 deck as can

wanted to get opinions and see if anybody has had any bad experiences doing this

the combo going into it = speedpro forged pistons(flat tops with 4 reliefes) , plasma moly rings ,clevite bearings, stock crank and rods (with arp rod bolts) e-cam ,ported/milled e7ets......see sig for everything else

i'm also getting it internally balenced ,bored 0.030 over , getting lower intake matched , checking valve clearance and adding a head stud kit

any opinions would be valued .........
also any guesses at what compression ratio i'll come up with ?(heads have 020 milled off em )

[Old Guy with 87 GT]

back up to the top

where's all our motor gurus at

[NotchJohnson]

courtesy of PKRWUD:

http://www.ricehatersclub.com/vbulle...=&threadid=349

[sn95gt19]

do you plan on milling the heads, or just 0 decking the block?

the chart above will work if your just milling some off the heads to raise the compression.

0 decking the block really isnt going to raise your compression, you just do that so you have the same distance on both sides from the center of the crank.

[Old Guy with 87 GT]

i did get the block 0 decked ,but also talked to my builder about milling my deck to bring the piston up closer to the head

according to him there was a varyience from one side to another ,witch was equalized ,.....but from what i gathered he did take the deck down a tiny bit to bring the pistons up higher ,not sure the exact clearences ,i'll find out exactly how close the clearance is tuesday ,think he said he'd mill it to 080 to the top

as for my heads i milled them 020 last spring so they should be around 60.8 cc chambers

the differences that i'm not sure about would be ....it's a 306 now and my pistons are closer now ,and the new pistons don't have that tiny little dish in em like the stock ones

i'll find out tomorrow the clearance to the top of the deck

notch thanks for the link .....i saw that link before but when milling the block it changes the equation cause there is a wider valume being removed (the chamber isn't as wide as the piston top)
thanks for the replies

[NotchJohnson]

Yeah I knew that number wouldnt be exactly right since you are decking the block, but I figured it would give you some idea.

[Old Guy with 87 GT]

Originally posted by NotchJohnson
Yeah I knew that number wouldnt be exactly right since you are decking the block, but I figured it would give you some idea.

judging from the chamber equition i should be around 9.5 to one .........educated guess

the difference in bore will change the eqution a bit just in the chambers

but ......having the different pistons ,i'm not sure how much higher in the bore the new ones are as compared to the old ones .....plus i noticed on the stock pistons there was a tiny dish ....the new ones are a striat flat top

from what i gather the deck can't really be milled alot closer since you have to maintain a safe distance and i didn't want the piston above the deck (i've heard of guys bringing the piston up to the gasket thickness.....didn't want to go that close),

i'm not sure the exact numbers (pretty novice at this stuff ) ....but i told him to mill the block as close as you can to the pistons ......whitch should change the compression even if its only like thousants of an inch