Hi
I calculated that a .20 mill of 806 heads is about 5 mm taken off the bottom head surface wich is about half a centemeter ... is this correct and what will the chamber cc be after milling? (and how about .15-.10-.25 while your at it )

I have a 98 with a tr224 with 7.400 with that much of milling what will the compression be (with stock gaskets) and will I have to change to a shorter pushrod (7.350 or 7.375) just guess and help me I know a pushrod lenth checker but that`s not a practical method here (the only available are 7.400 and when the engine is opened can`t wait for more than a week for this to come).

thanks and if you provide the formulas and/or examples for other users help in searches then thanks even more.

 

.020 mill you knock off about 3-4 cc's of chamber volume, which is 60-61cc on a 806 head IIRC.

 

i thought 806 heads were 69cc's to start... not 64cc to start...

and i thought the 241 heads were 67cc's... and you mill .007 to take off 1cc.. so .021 to get to 64cc's on a 241 head...

is this not right?

 

That may be true, im not sure, I do know they are 5.3L heads and my 5.3's were 64cc's.

 

806's are 5.3 heads? ive never seen a or head of a 5.3 head having casting # 806.. as far as i know the 806 heads were only used on 98 Fbody's and have a 69cc chamber.. the 853's were on the 99-00 cars.. and the 01-02 cars got the 241 67cc heads..

only head i know of with stock 64cc's is the 243 LS6 heads...


anyone else please confirm or set this straight?

 

On my stock LS1 heads and my TR224, the 7.40 seemed to work fine.

When I had the 228R installed under AFR 205s milled -0.020, I should have changed to 7.425 rod lengths. I did picked up some valve train noise between the cams.

 

yeah just ignore me, im really confused today.

 

yeah the 806 are 98 ls1 heads (wich is on my 98 car) 67.8 or 68 cc chambers as I`ve read here .... damn .20 mill and it`ll knock off only 3-4 cc? that`ll make it 64 only as a stock ls6...

1 inche is about 2.5 cm = 25 mm , .20 inche =5 mm ...
this is how I calculated (could be wrong) so is it a .020 something else other than inches?

I thought that since with stock afr and stock cam it`s 7.400with an aftermarket cam might go a little longer ..... but milled heads and aftermarket cam and longer than 7.400?

thanks for the replyies still waiting for more light on the subject.

 

do it this way... for every .007 you take off about 1cc ... so .028 off will take you down 4cc's to 63.8cc if thats what you want...