bodhi

Why do people say that you can't run STG III heads on a stock cube motor and make it work? I just spoke with Brent @ TEA and he has told me of some very interesting results with this setup. I have been on a quest lately to find the best "value" head. meaning the best performance for the money.
It appears that for $2600 I can have a 6.0L cut down .050" with a STG III port, with 2.08/1.60 ferrea valves. This sounds incredible to me. anyone have any reasons why it WON'T work?
There shouldn't be any PTV clearance issues since I plan on a G5X2 style cam with a little less lift.

LEO

iTrader: (3)

Yes - go for it!

1999_SS_M6

Personally, I'm against the idea for reasons of port volume. Quite frankly, there is a finite amount of air volume that a 346ci motor can fill an intake port with, and when you begin to stretch that figure, low end torque suffers.

If you are building a max-effort engine with a power band above 7000 RPM, then maybe... but if the engine is in your daily driver, or in basically a street car, there's no way I would go that route in my own vehicle.

SScam68

iTrader: (20)

So what is the limiting port volume?

They come with 200cc stock and 210-215 ported, how much does a "stage III" add over a "stage II".

If I recall from posted flow sheets the difference in flow is only a bit more CFM. I believe "Stage III" heads have more to do with valve sizes and chamber shape. Correct me if I am wrong.

"Stage XX" heads are also relative. It be best to call up Brent again and ask or have him chime in here.

Krazy98Z28

iTrader: (12)

i think the 2.08 intake valves are too much for a N/A 346 but if u were to go the force induction route it wouldnt hurt you.

BurnOut

iTrader: (1)

I think that while the S3 heads will flow more on a bench-top fixture, they may lose flow (compared to an S2 head) into a stock LS1 bore (due to valve shrouding).

I have no personal experience with this on LSx motors, but have seen it happen on traditional SBC's.

Something to consider.

bodhi

All of these things make sense, and Brent admitted all of the factors were against it working. However, he was involved with a stock cube 346 with these heads and it performed excellently. This piqued his interest and is wanting to do more testing or so he said.
I'll see if I can't get him to post up concerning this and shed a little light on what exactly happened and how it could be reproduced.

TEA Brent

Hey guys. I have been thinking over all the reasons not to try this, but think of all the people who said that port volume was to big to start with or cams in 224 duration being to big. These engines are proving all sorts of old ideas wrong. In this situation we won't use a 2.08 but a 2.055 valve because it is a stock bottom end. The stage 3 head flows considerable more than a 2. 330 int and 280 exhaust. I really think that this combo is going to make good power. Powerband will be determined by the style camshaft he will use. I can't say for sure because it is not proven like most of our other packages, but I think this will soon be proven.

bodhi

I am hoping by the end of summer to have these heads with a 232/232-.588"/.588"-110 cam. This should help keep the usable power below 6600rpm. If all goes well, I'll know in a few months.
Anyone have any ideas or thoughts to add? Anything we are missing?
With my gear, a 27" slick and this setup, I should be able to run a 10 sec ET.

BurnOut

iTrader: (1)

Hey, don't get me wrong... if it works, it works; all theories aside. It'll definitely be interesting to see the results.

LS1derfull

You cant have too much airflow, only too little airspeed if ports need too much rpm for good cylinder filling. This will make motor doggy overall. I dont know if Ls1 head valve bowls really support anything bigger than 2.05" because of casting limitations. 15* valve angle eliminates most cylinder shrouding with stock bore. You cant really overcam LS1, it keeps building power the more you cam it.
It would be interesting to see results on this...

SNAXS

Ditto, I would really like to see the results of this setup, possibly a very successful combo if u ask me....I wouldnt mind trying it..