65LSXNOVA

I know this is going to spark some back and forth but let's see how it's goes.
I'm considering selling my tfs 235 in favor of some ported 821 rec ports. Since I'm running a 416, is there anything to gain power wise?
I'd like to see proof either way.
Thanks

Tuskyz28

https://ls1tech.com/forums/generatio...or-builds.html

TrendSetter

you gotta share more details, we cant read your mind. is it going in a car, a boat, a dump truck?
boost? na? racing? cruising?

65LSXNOVA

it's in a car. Not sure why that matters unless you think rec ports make more power in a dump truck only....lol

65LSXNOVA

very good thread but that's very apples to oranges when trying to compare someone's combo from one side of the country to another.
I'm just wondering if anyone has tested using a good cathedral port head and swapping it to a rec port either oem or aftermarket and seen huge gain on a 400+ cube motor

TrendSetter

oh boy.
good luck.

65LSXNOVA

thanks

DualQuadDave

iTrader: (6)

To switch from a TFS to a ported stock LS3 head is backwards. If you want to go faster, either port/big valve the TFS heads or go LS7 architecture and pic a head. The only reason to run LS3 port is if you are already invested in it and don't want to change other things.

SlowTBSS

What do you make for power now? I personally would see about having the 235's ported like Dave said. can make great power with the cathedral port heads and keeping the port volume smaller will be much more enjoyable, for me anyways. I have a 235 head on a 402 right now.

65LSXNOVA

interesting......I just figured maybe I'm port limiting the engine as the tfs235 measured 229 cc along with only having the 2.08 intake valve. I do have some brand new ls3 intake valves here. I'm not sure if the trickflow head can take a 2.16 valve in its current intake seat.

65LSXNOVA

I don't have a clue....car isn't running right now as I've burnt a injector driver in the holley on my first test hit. It did go 102mph in the 1/8 th on 7 cylinders at 3100lb RW

bthomas

iTrader: (1)

I think it would be a mistake and going backwards as already said.
A 2.08 valve isn’t limiting that head. Tooley himself said they experimented with valve sizes when developing the tfs stuff and bigger didn’t gain.

having said that, I’m assuming that was a bigger valve on same csa port. Port the head some, then it’ll like a bigger valve. Not an ls3 valve, but likely a 2.10.

Tuskyz28

Mike C had ported LS3 heads/L76 intake on his 402ci WS6 Trans am and ditch them for TFS 235s. Back to Back testing at the track. Car went 10.80s to 10.55 in quarter and picked 4 mph at the track.

65LSXNOVA

what kind of control testing was done in order to make that comparison? Same track? Same or similar weather DA? Heads and intake only thing changed? If that was the only thing done and all the above was done to make it a even comparison that is truely awesome results.

DualQuadDave

iTrader: (6)

To give you a little guidance, think of it like this. All the LS3 heads have huge flow numbers, but few back those up with power production. Part of the issue is the big flow #'s happen at .700+ lift and hardly no one sets up the valvetrain to take advantage of that. Consequently, you have a low .600 lift intake lobe and a slow moving air stream in a too big port. You would think adding cI would fix the problem, but it doesn't. The AFR/TFS LS3 heads move the intake valve over and that helps a lot, but still not ideal. The Mast and Edelbrock canted LS3 heads are probably the best that port architecture will ever do. The LS7 was created for a reason, that raised runner/smaller port/better valve angle works. If you want to spend the $$$ once, just get the GPI Brodix LS7 mid bore heads and run it. That's the only real improvement you can buy over what got that's worth it. The WCCH Brodix and Higgins LS7 small bore heads work great, too, but more $$$.

helicoil

iTrader: (104)

I have had great success with the Mast 255 CNC Black Label LS3 ports (commonly overlooked LS3 head), although the rolled valve angle (11*) and small'er ports I believe are the reason they run well. On my 11.5:1 hydraulic roller 416" I have been 9.70's @ 3275# on pump gas.

low2001gmc

iTrader: (148)

I recall Pat G saying on a 4.0 bore, Cathedrals work better. On a 4.060, Rectangle Ports.

I think that would be because Rectangle Heads would shroud the valves on a 4.0 bore. 402 having 4.0 bore, I would think Cathedral 235s would be better. Always cheaper to go with what you got.

If not satisfied, then maybe try swapping, but don't sell 235s in case you go slower.

65LSXNOVA

I just wonder since i have brand new LS3 valves sitting here, if i turned them down to 2.10 or 2.12 if there is anything to be had power wise? Maybe not from added flow but maybe valvetrain stability.

02EBC5Z06

iTrader: (1)

I have turned down ls3 valves in my tfs 220s at 2.10".

The heads are also worked over heavily and basically a tfs245 and then some.

02EBC5Z06

iTrader: (1)

Only reason to use a stock worked ls3 head is if you are gonna spin some rpm and have a lot of lift.