Factors for low end power gain/loss

[IllestGalant]

sorry for the confusion, but just regroup and read through it slow and really think about it.

[jiul]

OK, Jip, I got the part about porting exhaust to "match" the size of the intake.
LOL

And the next question, is , when you send heads to a shop to be ported how big do you thell them to make the exhaust ports? Is there a standard number that evryone uses?

[Kain]

<div class='quotetop'>QUOTE(jiul)</div><div class='quotemain'>OK, Jip, I got the part about porting exhaust to "match" the size of the intake.
LOL

And the next question, is , when you send heads to a shop to be ported how big Â*do you thell them to make the exhaust ports? Â*Is there a standard number that evryone uses?</div>

A good machine shop knows how much material to remove. They can only take out so much before it will compromise structural integrity of the piece. Like, the old V8 heads of the '60's had like 1"+ thick walls on their ports. You could remove like half of that, nearly doubling the size of your intake and exhaust ports. However, new technology has caused auto manufacturers to decrease the extraneous wall size, leaving less for a machine shop to work with. Though, on the Galant head I think you can go about 30% larger fairly safely. But, again the machine shop will know about how far they can go before they risk craking the head.

[jiul]

JIP, got it, I was just wondering if there was a standard ammount that is proven to work best witha stock 2G exhaust manifold, but I guess its best to just port out as much as safely possible.

Also is there a difference between turbo and n/t dohc heads or are they the same?

[Kain]

<div class='quotetop'>QUOTE(jiul)</div><div class='quotemain'>
Also is there a difference between turbo and n/t dohc heads or are they the same?</div>

I Don't know about the 1G (well, the 1.8L is very diffrent from the turbo, but I don't know between the 2.0Ls) But the 2g there's a HUGE diffrence between the N/T and turbo motors. They are entirely un-interchangable.

[JiP]

I have a 1g Turbo head. Thats the most popular one thrown up on ebay. I never seen any other head 2g, NA's so I dont know what they look like.

And you notice Jiul always uses the wrong persons name when he thanks someone lol.

<div class='quotetop'>QUOTE</div><div class='quotemain'>jiul wrote: Â*
JIP, got it, Â*
</div>

It was Kain not Jip! :laughing:

[jiul]

I saw 1G heads on a site, but the guy says that they're from a NA engine.
He actually claims that it is a plus because of less wear and tear.
I want to buy them but I want to make sure that they are the same as the turbo heads.


Oh yeah and to cover all bases : THANKS ALL ( even jip)

[seth98esT]

the only thing different between a turbo head and nt head is the cams and lifters...isnt that correct?

[JiP]

What could the differences possibly be? a smaller intake? Less agressive cams? springs not as beefed up? I would think a turbo model head would always be better to use since it is made to take the abuse of a turbod engine. But I could be wrong..

[krazienluv10]

bringing this back up... soo which is better, swapping the head or just porting it???

[seth98esT]

if your going to go turbo, its easier to tune with a DOHC head