i read some wear that taking 50 thou off your head should give you 9-1 compression it was a search i did on google and i am wondering how much you can plain the head on a 225 bfore you start running the risk of the valves hitting the pistons

i'll see if i can find that article again so some of you can read over it

_________________
MOPAR OR NO CAR
1985 Ram
1975 Coronet
1998 Dakota

Stock motor stock cam .100 off head and .100 off block
I used to run that all the time. you can even get away with a bigger cam without hitting.

Will

ok thanks will that is good to know

_________________
MOPAR OR NO CAR
1985 Ram
1975 Coronet
1998 Dakota

I took .115 off the head and used .o6o over wolverine pistons and got 9.1:1 compression oh forgot the ford valves not sure if that helped or hurt anything but makes for better breathing.

Erick

it is good to know that there is anouther slanter so close to home.
that makes at least 5 of us around here!

Will

ok i'm trying to figure out how i can get a 9-1 compression ratio with stock valves and pistons and have heard the stock compression ratio is 8.4-1 for the slant now i don't know if this is accurate but if so how come eric f. took 115 thou off and only has 9.1-1 compression i'm only thinking of removing 50 or 60 thou myself

_________________
MOPAR OR NO CAR
1985 Ram
1975 Coronet
1998 Dakota

so what is the stock compression ratio for the sixes mine is old enuf to not have a hydrolic setup in it but new enuf that i don't have the plug seals either so my guess would be 80 but that could be wrong

_________________
MOPAR OR NO CAR
1985 Ram
1975 Coronet
1998 Dakota

Stock comp is rated at 8.4:1, but the deck height and head chamber vol are almost always bigger than the specs, so stock is usually around 8.0:1. 0.090" off a typical stock motor (block or head or combination) will take you to around 9:1. Measure your specs above, then you can compute it and figure how much to remove.

Lou

_________________
Home of Slant6-powered fun machines since 1988

alright so taking 0.060" off the head won't give me the 9-1 i was hoping it might i don't want to take much more off it even though i can it is going to be a daily driver and i don't want to make it less durable the it would be stock

_________________
MOPAR OR NO CAR
1985 Ram
1975 Coronet
1998 Dakota

You're safe taking more than that off the head if you want. The head on a /6 is unusually thick. The head was designed to mount on a aluminum block (60-62?) which had no top deck. Because of this, the head had to be more rigid. In later re-designs, they never removed the extra metal. So, that's why everyone says it's safe to remove 0.100 from the head...

Supposedly there's that much extra metal in the iron block as well. Probably had to do with expansion & contraction coefficients needing to be the same.

_________________
My truck is a Frankenstein creation
Built from the dead carcasses of others
And brought BACK TO LIFE!

yea but i still want to be able to run on regular fuel which around here is only 87 to 89 octane depending on where you get it

_________________
MOPAR OR NO CAR
1985 Ram
1975 Coronet
1998 Dakota

I did this up when working on my engine
http://www.slantsix.org/forum/viewtopic ... ompression or search for 'compression' by author 'Al T'

_________________
Cheers!
Al T

thanks for the link it's rather intresting

_________________
MOPAR OR NO CAR
1985 Ram
1975 Coronet
1998 Dakota