Thread: L67 Engine Swap and Cam Decisions.

Ended up getting another set they said it would cost more to get them fixed so I exhanged them they had a fresh pair right there left mine as a core total 220 but hopefully that is it for this engine to run good.
Once I am done and works well start the vs cam.

Now referring to the VS can build should I keep the stock heads how they are or get them ported and freshened up as well?

Originally Posted by OrangeL67

VS cams love ported heads.

Is there a such thing as too much overport for the vs cam?

Originally Posted by OrangeL67

Not really. The VS cam holds boost, so heads will make a big difference in blower effeciency with a VS cam. Then lift can be added by way of rockers. This was a build I always wanted to do. I think some crazy horses can be made without revving terribly high.

So my IS4 heads would be great with the setup?
This is my actual first cam build so what kind of rockers can I add to it? I've heard adding rockers to a cam doesn't make much of a difference.
I think my Gtx has 1.8 SLP rockers so I can use those if it can be done with this cam.
i just want to know what all should I do to get started on it or have things getting done or bought.

IS4 heads + XPZ = 380whp on 93 octane.

You need RPM and lift to make use of the heads, the extra duration of a xp/xpz makes more power on any head. The only cam that "throws away" power is the IS3/IS4/NIC cam due to its high cyl cleaning overlap... its a tradeoff for low octane fuel.

1.8 rockers may not lose horsepower, but they will not help over stock rockers. 1.7s will increase valve float, and reduce lift over stock, dyno proven loss of at least 5% horsepower.

Originally Posted by darkhorizon

IS4 heads + XPZ = 380whp on 93 octane.

You need RPM and lift to make use of the heads, the extra duration of a xp/xpz makes more power on any head. The only cam that "throws away" power is the IS3/IS4/NIC cam due to its high cyl cleaning overlap... its a tradeoff for low octane fuel.

1.8 rockers may not lose horsepower, but they will not help over stock rockers. 1.7s will increase valve float, and reduce lift over stock, dyno proven loss of at least 5% horsepower.

So VS cam and IS4 and 1.8 not a good idea? Will be using my xpz on my Gtx this is for my 40th vs cam build.

1.8 rockers work as good as stock, maybe. I put 1.8s on a NIC and saw no gains, and the customer wanted the 1.8's because he was planning on putting some custom heads with some crazy huge springs on eventually, and wanted to break the idea in. Bonus was we didnt see any major issues with float up to 6300, but we were only running ~9psi of boost.

A VS cam with 1.8s would for sure make no more, and possibly less power due to valvefloat issues over stock.

I would never see a reason not to run a xpz if you were putting a cam in. Cutting down valve guide seal seats costs ~$50 and thats all you need to put the best performing cam out there in a 3800.

Originally Posted by darkhorizon

1.8 rockers work as good as stock, maybe. I put 1.8s on a NIC and saw no gains, and the customer wanted the 1.8's because he was planning on putting some custom heads with some crazy huge springs on eventually, and wanted to break the idea in. Bonus was we didnt see any major issues with float up to 6300, but we were only running ~9psi of boost.

A VS cam with 1.8s would for sure make no more, and possibly less power due to valvefloat issues over stock.

I would never see a reason not to run a xpz if you were putting a cam in. Cutting down valve guide seal seats costs ~$50 and thats all you need to put the best performing cam out there in a 3800.

Dont have enough money for a Trans to support a build like that. I have both vs and xpz already but since the vs is a nice street friendly cam I am goin with that on my dd and xpz on my Gtx will also be driven on the street but not as much or maybe close to it.
So once I have enough funds meaning sell the Gtp I can get a good Trans for the Gtx and xpz build.

When did a xpz become a "not street friendly" cam?

Originally Posted by darkhorizon

When did a xpz become a "not street friendly" cam?

Not saying it isn't, that's why I have both cams and they both will be daily just one more then the other. I just don't have enough funds to do supporting tranny mods for the xpz build besides the guy that I bought the Gtx from claims it is stroked so I have to tear it apart to verify if it is or isn't and what has been done internally to that motor.

pulling the oil pan is all you need to do. if the crank looks stock, you can check the rods to see how they look. You can stroke a stock crank with custom rods.. if that was the case, you would want to launch that motor into the sun or just run it NA for maximium troll.

Originally Posted by darkhorizon

pulling the oil pan is all you need to do. if the crank looks stock, you can check the rods to see how they look. You can stroke a stock crank with custom rods.. if that was the case, you would want to launch that motor into the sun or just run it NA for maximium troll.

Well from what he told me he said it had JE pistons I believe. The motor runs but seems like it needs a tune. It is a Florida car has some pretty good mods at it sits but want to know what I am dealing with engine wise on the internals before I just start to cam the motor.

major cooling problems, and a headgasket failure are about all you can get from this.

Originally Posted by darkhorizon

major cooling problems, and a headgasket failure are about all you can get from this.

Agreed if they are on backwards as in flipped over you might have some issues since the back side of the gasket has the metal ring sitting on the block. If you got the right side or left side mixed up on the spots they were suppose to Go like mine pictured I'm sure you will be ok. Idk if all that made sense.

Originally Posted by BlackGT97

From it being backwards like ^^^ or upside down?

You can't put these gaskets upside down at all if somehow you did or managed to irk how you did since nothing will line up.