I recently purchased a D1SC Procharger and have stock 241 heads on my stock bottom end 2000 Z28. I had originally planed only doing a H/C/I setup and since decided to go FI. I was (?) going to get Advanced Induction to do my head work and custom cam. I talked with Phil today (AI) and told him what I got and my new plans and asked him about my LS6 243 sodium filled valve heads I had sitting around waiting to go to them and if he thought they would be a good head for FI. I have been told to stay with my stock 241's or maybe go to a 6.0 head along with an LS6 intake. Just want to get opinions on what heads I should use on my stock bottom end 346. I emailed Phil this:

Phil,
Looks like it's back to the drawing board for us. I bought a ATI D1SC
Procharger today for my car. With the stock bottom end I hear I should
be able to push 6-8# of boost safely. Now I need to know do you work
with forced induction H/C setups and if so how are your results ?
Assuming everything is good on your end do you think my 243's will be
the right head for my new combo and work just fine ? I also guess we
will have to spec out a blower cam now so I'm going to leave all this
up to you and get a lot more out of my motor. One thing about it now, high
compression won't be needed like before when we were talking about the
old setup and the whole fly cutting thing. Keep in mind I still want to
push it and go as radical as I can with this thing (within reason).
Thanks and let me know what you think!

Phil wrote back:

Mike,
That is no problem. Regarding "what works," SC engines can be
likened to NA engines w/ a more favorable pressure ratio. While engines are
often limited to the capacity of the head unit, an efficient head helps FI
engines manage more output on a given fuel. For instance, a stock headed
setup may manage 480rwhp at 8psi, whereas a well done head will often make
more power at a lower manifold pressure. Often, a head will retain
approximately the same percentage gain in a FI application, which can
translate into more than the typical ~4Xrwhp when the manifold pressure is
increased.
In this instance, the added chamber volume will be helpful in that
we can get the compression down to ~9.9-10.0:1. I've no concerns about
running a 243 in FI applications. I'd consider an aftermarket stainless
exhaust valve, and possibly intake valve, but provided you don't fly too
close to the sun in regard to power/egt/detonation they should survive.
It would be worth considering a supplemental injection system
(water/alcohol/meth/etc), not for the power potential but for the headroom
it affords. We should have enough room to run some of our larger grinds as
well, which will make for a pretty outrageous street setup. A note, I'll be
heading out of town without cell/inet access from the 3rd-9th. There will
still be someone around however, so we'll be able to collect shipments/mail
etc. Have a nice holiday if we do not speak prior!

-Phil


I wrote him back:

Phil,
I was talking with the guy who sold me the Procharger and he mentioned
that he did not like the idea of running the 243 heads I have because
they will give to much compression. He suggested either staying with my
stock 241's already on the car and not touching them and just doing a
really nice cam along with changing the valve springs to handle
everything along with getting rid of my stock LS1 intake and getting an
LS6 intake and letting it be. Of course doing fuel pump, harness, 60#
injectors etc. He also mentioned using a 6.0 head and working it over
for the FI setup but not really needed with my stock bottom end motor.
Might be better to wait to do heads for my nest FI motor (stroked 6.0
and built bottom end). What do you think about these ideas ?

Phil responded:

Mike,
Beware who you take advice from is about all that can be said. Our
243 will lower your compression with 69-70cc chambers, not raise it.
Furthermore, they will have significantly more p2v available than any stock
241/243, allowing us to get into the more performance oriented grinds.
Beyond that, low compression is less than ideal for most FI apps,
and especially those making moderate (under 1khp) power. Cylinder pressure
is power, and compression is essentially free cylinder pressure. There is a
reason our race engine builders, from the little 4cyls to the 8XXcid promods
all request heads that will produce 12-16:1 static compression. The
enthusiasts who think low CR is desirable are simply behind the curve.
These are usually the same guys who suddenly decide head efficiency doesn't
matter when you have a more favorable pressure ratio w/ blower/turbo.
9.5-10:1 is an ideal range to be in for a street setup w/ a small blower if
you are looking for better than average results.
Eventually, you may crack a ring land & the car will typically start
smoking a while before anything actually comes apart. Almost invariably
this happens because of detonation or pre-ignition. That is precisely why
being able to make the power at lower manifold pressure w/ a more efficient
top-end helps. A better head will help lower inlet temps and timing
requirement, which are the two main areas that improve both power and safety
margin. Hope that helps, Mike!

-Phil


What do you guys make of this ? Does it sound like 243's will work and be the best heads for my new project or are we way off here ? Thanks for any help!

 

Please understand I'm not trying to put Phil out there in any way IF anything he said might not be completely accurate. I trust him whole hardily but I also respect what the guy says that I bought the blower from. I have invested so much money in my setup and also more to come and I just want to make sure it gets done right the first time around and want to hear other people's opinions on the subject.

 

i am running prc stg 2.5 ls6s in my d1sc setup. But i ordered my long block with 9.3-1 compression..every engine tuner or builder has there own opinion on what works my advice to you is listen to one person you trust and go for it..good luck..

 

With the bottom end being stock, I'd just throw a cam in there with your stock heads along with an LS6 intake, and bolt the blower on. It will make all the power you want with the stock bottom end. Bob

 

I agree.....


Save your money for some thicker aftermarket castings (AFR, TFS, RHS) when you build the motor.

 

ya man, being a stock bottom end id just put a blower friendly cam in and leave the heads alone. stock head blower cam and a d1 will make more power than the stock bottom will take for too long. i just wait and save and get some good head when/if u rebuild. what kind of power u wanting to make?

 

600-650 rwhp is the goal. I think I'm going to use BruteSpeed's blower cam if you guys think that's what I should run. Bob do you have any sound clips or anything ?

Then there are the other things I have to get for the build. I just bought an LS6 intake today from Philip at HPE. As far as I know I still need:

piping (don't know where to get this)
BOV (don't know what kind to get)
FMIC (Ebay) (?)
J bracket (don't know where to get this)
Walbro fuel pump or dual pumps (?) & Racetronix harness (Nitro Dave)
60# injectors (don't know where to get them)
Methanol Injection (don't know where to get it)

I don't know what else I need, I head something about a bracket for like $700 that is supposed to take pressure off the blower or something and is highly recommended. Also as far as pulley's and belt rib things I have no clue.

If you guys can help me with this stuff I would really appreciate it so I can get my build underway.

 

I am using the EPP blower cam (aka Brutespeed). It sounds really good for being on a 115LSA. You will be good to go with that cam and just the blower. Id save your money and invest it into your fuel system. All of the little things will start to add up in a hurry!! I am using Aster's (goes by Aster on here) bracket. It is a really nice piece. You just have to swap to the LS2 water pump for pulley clearance. Are you looking to build a forged motor later on down the road?

 

Hey LS1redZ...I finally got 370 done. 235/243 115lsa .620ish lift on both sides.

 

Thanks man and I will look into that bracket and the LS2 water pump.
Yeah down the road I am. For now I just want a nice setup for my 346 stock bottom end.

 

+1 for keeping it stock. Don't waste the money on redoing the 243's.

 

For the piping I would do a universal 3" kit from eBay. I would purchase some T-Bolt clamps though.

As for the BOV, I would use a Race Part Solutions 50mm, they are cheap and work great.

The FMIC is a tricky one, I would at least shoot for a Treadstone unit.

Go with a Aster bracket in preparation for more power.

The pumps all depend on your power. I personally would overbuild the fuel system, and run dual pumps. Also, you can get the injectors from Brutespeed.

Go with an Alky Control meth kit.

 

Good advice right there.

 

I agree.

 

Guys, this thread is from 2010 lol...

 

Ha! Good call... Oops. Not sure how I brought this one back from the dead...

 

Its the little details that get me...