B'klyn9C1

Guys,

I read in the Sept. 2009 issue Chevy High Performance, in the Q&A section, that the current Fast Burn heads from GMPP are really an as cast version of the CNC-ported LT4 cylinder heads.

So much better are the Fast Burns to the LT4?

Do you think that they would be a good part of a LT1/LT4 build after a conversion to reverse cooling??

Puck

iTrader: (17)

I think it would be a waste.

If you are considering converting SBC heads to reverse flow for an LTX, they better be some sick big runner RHS, SB2.2, Brodix, or other high performance race heads to sit on top a nasty solid roller stroker.

For anything else, there are already plenty of options that would be better ways to spend your money .

GIZMO

iTrader: (8)

Despite what you will read on here, the LT4 heads actually perform pretty well when compared to stock LT1 heads. Ported they will make big HP.

Michigan Skip

Puck

iTrader: (17)

I would have the stockers you already ported before I spent the money on buying and then converting fastburn heads. If you already had LT4 heads, then all the better to port...but neither are worth buying over your stockers.

If you were starting from a clean slate and could get LT4s for a good price somehow then it would be a good route to take, but if you already have LT1 heads then even LT4s wouldn't really justify the cost...never mind spending the money to buy then converting mild heads like the fastburns.

GIZMO

iTrader: (8)

I agree that it is not worth the effort to convert Fastburn heads, but only because the LT4s already fit and won't take much to make similar power.


Wouldn't that depend on the OP's budget and performance goals?


What experience do you have with this? The Fastburns are awsome right out of the box. Lots of low ten second IHRA Stock Eliminator cars are running this head.

B'klyn9C1

The reason I asked this is that they alledgedly took the LT4 heads further ported them, tested them and digitized them and then used that tooling model as the new as cast Fast Burn heads with conventional SBC water passages.

I was wondering if GMPP really made substantial improvements to LT4.

If those improvements are real??

What are the effects on performance as compared to the LT4??

Can those improvements be gotten by other means??

Puck

iTrader: (17)

The OP is not making a stock eliminator caprice...now that I think about it last I read I think he was actually thinking of an LSX swap.

The fast burns are good heads out of the box and if you are starting from scratch on a SBC, I just think they are not good enough for an LTX to purchase and then convert them, when ported stockers would reach the same performance for cheaper. They flow what, around 265cfm or so? Then you have to deal with the SBC oriented big chambers that would lower CR...I just do not think it would be worth the hassle for an LTX. He would be looking at around 2 grand to get them working on his LTX, and for that he could do a lot better.

I'm sure there are also a lot of SE cars running 10s on stock LTX heads too, but that doesnt mean they are good for street cars .

GIZMO

iTrader: (8)

If you want to compare flow numbers the answer would be yes.


Yes.


Again, yes. But converting Fastburns is a bad idea when compared to porting, LT4, and most of the aftermarket heads. It all goes back to the question of goals and budget.

GIZMO

iTrader: (8)

I'm not sure why you posted that. My Stock Eliminator reference was in regards to performance potential.


What does that have to do with this thread?


Agreed (again).


What does that have to do with anything?