Hey all - quick question for anyone who has done this yet - does anyone know what the cc's of the standard and Ralliart heads are (to determine static CR) - looking to remove a bit of material from the heads to increase CR in preference to fitting higher compression pistons.

I do know that on a V style engine, the 'crossover' manifold between the two heads needs to be shaved as well (or it won't fit).

Looking to remove enough without causing issues - aiming for 9.4-10.0:1 comp ratio.

Any help here would be appreciated.

The compression increase is good for (rule of thumb) 2% per point (ie. 9.0 - 9.4:1 = 8%).

Cheers
Heath Young

what motor do you have in there as the 6g72 N/A DOHC is 10:1, as is the SOHC that was put in the Diamante. The TT in the 3000gt was 8.5 and i 'think' the US wagon is 9:1.

So yeah, it'll be worth finding out just what you have already as like i said, you might be running a high compression as is and anything much bigger then 10:1 might cause probs.

He has a Magna AWD (3rd Generation Magna), so it is fitted with a 6G74 SOHC 24 valve. It has a factory CR of 9.0:1 :P

The only factory Magna to have a higher CR in the 3rg Generation is the Ralliart Magna witch had a CR of 9.4:1

The compression increase is good for (rule of thumb) 2% per point (ie. 9.0 - 9.4:1 = 8%).
You're talking increase in power?

<shameless plug>
My personal advice would be to talk to Dallas from Street Torque. He machined quite a bit off of my heads, and knows his way around them fairly well.
</shameless plug>

cthulhu - OK - I may be sending some heads his way soon.

Revdave - Yes, the 2% per point is increase in overall power output. Moving to 10:1 compression should net 15-20% more output power.

Only looking at about a 0.4 increase (to 9.4:1) as these are ralliart heads I am looking at an wish to reflash the computer to the Ralliart maps.

Cheers
Heath Young

I dont have anything at all against Dallas except that hes in the middle of nowhere. I wish there were people as competent/experienced as him on the east coast. Anybody know anywhere for this more techincal type of work?

Agreed.. it can be a bit of a pain.. but think of it this way - he's equidistant from everyone in the country lol

He'll do exchange heads and things though, but you still need to find a shop you trust to fit and tune.

Agreed.. it can be a bit of a pain.. but think of it this way - he's equidistant from everyone in the country lol

He'll do exchange heads and things though, but you still need to find a shop you trust to fit and tune.wasnt such a big issue for me tho :redface:

as brendan said - he's the centre of everywhere lol

Agreed.. it can be a bit of a pain.. but think of it this way - he's equidistant from everyone in the country lol

He'll do exchange heads and things though, but you still need to find a shop you trust to fit and tune.

Very true. Hard to find. :doh:

I dont have anything at all against Dallas except that hes in the middle of nowhere. I wish there were people as competent/experienced as him on the east coast. Anybody know anywhere for this more techincal type of work?


i hear what ur saying, but i also think if ppl go down to their local performance shops and have a chat with the owners they may be suprised,

perhaps look at nissansilvia.com's sponsors who do custom work, i enquired for something with my car and got very competitive quote back

:stoopid:

That's really what it comes down to - talking to the people who run the shop and building up a rapport with them, instead of just being some guy who comes in off the street looking for miracles. Of course it helps if you know their reputation too. Sometimes of course the owners just won't want to know you if you haven't got an import or something run-of-the-mill, but that's their loss.

It was easy with Street Torque not least because Booya spent so much time there and gave me the referral, but also cos Dallas is just a top bloke and is willing to spend time talking about what the options are.

:stoopid:

That's really what it comes down to - talking to the people who run the shop and building up a rapport with them, instead of just being some guy who comes in off the street looking for miracles. Of course it helps if you know their reputation too. Sometimes of course the owners just won't want to know you if you haven't got an import or something run-of-the-mill, but that's their loss.

It was easy with Street Torque not least because Booya spent so much time there and gave me the referral, but also cos Dallas is just a top bloke and is willing to spend time talking about what the options are.


Yeah we must all watchout for the sharks who promise ya heaps but take ya money and run and or rip you off very badly with there overinflated prices, hence why i do 99% of my own stuff. That way ive only got myself to blame :bowrofl:

Does Dallas have an email contact etc?

Cheers
Heath Young