Stage II HP gains?

[Big Paul]

If I use the Stage II heads and intake manifold, with a good cam, how much HP can I gain from a 4.1L N/A?

 

[GNSCOTT]

Do you mean using a stright carbeurated Busch motor?? If so they were 525hp at the crank i beleive.

 

[RealFastV6]

Big Paul, you dont mean putting Stage 2 heads/intake on a regular production 4.1L motor do you?

In that case, its not really possible.

 

[Big Paul]

Yes I meant putting them on a stock 4.1, how come it isn't possible?

Do I have to use the Stage II block? Is that why?

 

[mygrain]

I was gonna do the same thing in a sand rail that my friends and I are building. I figured out that a stock block would never take the kind of RPMs that would be necessary to make STG2 parts work. It just wouldnt last. I'm now using a 283 (made it into a 302) with LT1 heads and nitrous. This is a much cheaper and easier route. I have maybe $500 including the machine work in this engine minus the nitrous plate.

 

[TurboCrazy]

Stg II heads on a prod. 4.1

Big Paul,

Yes, it can be made to work. You just have to be willing to do alot of work
on the production block!! A minimum of 2" of Hard Blok in the water jackets.
Devcon titanium epoxy the lifter valley, and a "have to" is 2 center steel main
caps. I would recommend a girdle, also. This would make it live (for a while),
With the RPM's and horsepower potential. It would be less $$ than a Stg II,
but a limited life grenade, if run hard. Going to a stage I-II block might be good
money spent in the end. The mods to a production block that I have listed above,
should make it capable of handling approximately 575 hp and about 7500rpm.
But not for extened periods of time(extended WOT blasts).

 

[Intercooler]

Stop the press! So what your guys are saying here is that Stage 2 aluminum heads will bolt right on a production block with a N/A intake setup and the required hardware? What the hell is anyone wasting time on GN-1's for?

 

[mygrain]

The heads have differant dimensions than a GN1's or 8445's. Custom headers arent cheap for these turbo cars.

 

[ChrisCairns]

Originally posted by Intercooler
Stop the press! So what your guys are saying here is that Stage 2 aluminum heads will bolt right on a production block with a N/A intake setup and the required hardware? What the hell is anyone wasting time on GN-1's for?

No. Well, they'll bolt on...just using 8 of the 14 head bolts. But the cam won't work. It would have to be changed.

Production heads have a different valve setup than S2 heads...production heads have, from memory ...exhaust, intake, intake, exhaust, intake, exhaust.

Stage 2 heads are exhaust, intake, exhaust, intake, exhaust, intake. Again from memory, but you get the idea.

Just another roadblock...I'm sure there are more.

 

[TurboCrazy]

Hey, somebody looking at the big picture! Chris, basically you are correct.
It CAN be made to work, and HAS been done before on a production block.
(not by me) It all depends on $$ and what and how much your willing to do
to have stage heads on a production .