teger

I've heard of all sorts of different combinations with the different blocks/pistons/heads.
I've got a 1.8 Sir VTEC Integra (JDM). I'm trying to get the CR up from 10.6 to at least 11.0. But the main thing is the head.
I've got access to a JDM 1st gen B16A head. I've heard that they flow better than the B18C heads. Will I loose compression when converting to the B16A head? What kind of compretion will I get if I use The existing B18C Block, with JDM B16A head and pistons.

If anyone has any experiance with these kind of setups (B16A head for better flow and diferent pistons), I'd be very interested in hearing what you've found works.

Also. If i'm going to use a B16A head. Is a CTR intake manifold going to be able to flow enough for the B18C or should I use an ITR Intake Mani.

thanks guys/gals


[Modified by teger, 3:51 PM 4/6/2002]

qtiger

B16 head will lower your compression significantly.


Depending on the lift of your cams, the b16 head may or may not flow more air. However, once you get into the realm of the port & polish, the b16 will definately flow more.

Pat McGroin

just port and polish the gsr head, why does every one want to swap a b16 head into a b18c. come on wake up and smell the coffee

teger

So is there a difference between the CTR and ITR manifolds

rainmanEK

not to much of difference between ctr and itr manifolds, mill the b16 head!

bigblockEG

From what I understand, the b16 head will drop the cr on a usdm b18c1 down to 8.8. This is prime for boost though, I dont know if that helps..

AzG35

By putting a B16A head on a B18C block you will lose approx .6 CR. So on the JDM motor, it will drop to 10:1 or so. If you put in PR3 pistons, it will bring the CR up to 11.1:1. This is the combo I am running right now. Works pretty well. The B16A head does flow better than the GSR head, in the top end and low end. The GSR is better for midrange output.

If you want to calculate the CR's yourself, try this website http://www.bojangs.com/calculator/

The CTR and ITR manifold are the same. A CTR motor is a destroked ITR motor. The only difference in the intake part is the throttle body, the CTR is 60mm and the ITR is 62mm.

With this combo I put down 182hp and 134tq with all honda internal parts. B16A head(mild port/polish), B18C1 block w/PR3 pistons, ITR cams, IM, valvesprings/retainers.

Katman

1) I suggest you keep your JDM B18C head & block as is.

2) To get up to 11.1 all you need, is a set of US ITR pistons or you can go with either JDM ITR, or PR3/P30 B16A pistons which will put you over 11.0 (around 11.5)

3) you can leave your current engine setup & run a thinner headgasket if you don't want to spend $$ on ripping your block apart for some pistons. A mugen gakset should get you right under 11.1.

4) like AZsi said, ITR & CTR manifolds are exactly the same, but they're made for B16A/B17A/ITR/CTR heads only. It will not bolt up to a B18C head....you'll have to go Skunk2 manifold which is a spitting image of type-R manifold but made to fit a GSR head.

5) the gsr head is hated upon too much it's a good head which you don't have to mill to get high compression using a combo of stock OEM parts...

bojangs

a b16 head will not yield a static .6 difference than a gsr in the same application.. more like .2.. that's assuming both heads are equal (no milling or combustion chamber work)

why change heads anyways?? p72's are great heads! like jdm dasilva and kat, i'm confused why everyone is out to trade in their p72 for a pr3.. whateva.. to each his own i guess.


[Modified by bojangs, 8:00 PM 4/8/2002]

g's integ

I'm doing the same thing. The reason why i do it is because b16 heads are cheaper and i can slap a itr mani w/o a problem. But not hating b18c head at all. If I had the funds I'll get it but for now, it's the best i could do.
In regards to the swap of p28, p72 are a little costly for 300 these days and p28 are around $200-280.
Some of us are tryin spare a buck.

Katman

hah! what!?
Ok, you're losing your mind.....or I'm about to lose mine...
Dude, you already have a P72/GSR head, all you need to do is buy a Skunk2 manifold for it and you'll basically convert your top end (head) to that of Type-R, almost, minus the valvetrain parts & cams. If you do this you don't have to buy a B16A head at all! that's where you 'spare a buck'.

g's integ

Don't you remember my setup KATMAN? I'm sorry, i forgot to add that I bought only the gs-r block, not the head. I got a great deal for the longblock for $400. And the b16 head was givin to me. The point that i'm makin is in myself or other people situation where your limited in funds and you wanna go close to GS-R or maybe type R status. This is an option to go. But I do agree about what Katman on if you the whole engine top to bottom gs-r. Why would you swap heads?
ya get me....

Kataku2K3

Yea the B16 head will drop your compression roughly .22 so you basically have the same compression as a 500 series B16. A lot of people don't like the GSR head and manifold because it doesn't flow as well as the B16, but I do. If you port/polish the head and take out the secondary runners and the IAB solenoid you have a trick GSR manifold. That's all you really need to do. I would think that keepin the compression up would be better than getting more flow. If you do the B16 head mill it a little or get some CTR pistons, hehe!

teger

I've all ready done some work to the stock GSR intake manifold; mild porting, polishing, removal of secondary runner valves (this makes the runners 2.5cm shorter and much fatter), Port matched the plenum to the runners, and did all of the coolant bypasses. I also added a Honda heatshield gasket. I reason I've got definite gains as I can keep up with my friends prelude, where before these MOD's, he used to pull away from me.
By the sounds of things I think I'll keep my current head. maybe do some porting, polishing at a latter date. Some JDM Type R pistons sound like a pretty good mod. they promise to raise compression on a stock JDM teg from 10.6 to 11.1
Would it hurt if I added a Mugen head gasket to raise compression more? And by adding a thin head gasket/ITR pistons is it likely I would start having problems with Valves hitting the pistons if I decided to add some Jun/Toda Stage3 cams at a latter date?

bojangs

nope, you should be fine running a one layer gasket with those pistons.. itr slugs have pretty generous valve reliefs.. one suggestion.. instead of spending all that dough on a mugen gasket just mod a honda gasket instead (use the bottom layer if you're wanting to go with a one layer gasket) and use some copper spray to help it seal.. torque the head in 5 increments (instead of 3) and up the torque specs a few pounds..

SPORT INJECTION

Just wondering how you guys learned all this stuff? Hands on.....reading.....? I'm amazed from reading all these posts in the "tech" forum. I really need to stay in here and learn things instead of participating in dumb use-less topics.
-Dave

AzG35

Doing it is the best way to learn

bojangs

BOTH!! sure you can read alot but if you've never done it then you're truly speaking out of your ***.. i know plenty of people that are "board smart" but if you give them a wrench they'll ask which direction is "tighten and loosen"..

nothing can replace hands-on experience..

teger

thanks guys for all the comments made
I'm pretty confident with the desition ive made on what i'm going to do.
thanks again