Abdullah

iTrader: (2)

i think the AI TFS 208cc LS1 heads will perform better than my 215's because of better port design and usualy when any 2 different cathedral heads (or any kind of 2 heads of the same type) make the same rwhp the one with smaller runner usualy i'm saying usualy will make more torque due to higher port velocity.

SOMbitch

iTrader: (8)

There is a lot more than port velocity in the equation to making torque. Smaller does not necessarily mean better. Personally I would stick with the tried and true 215's.....

And what do you consider better about the port design other than a smaller runner on the AI's???

chrs1313

iTrader: (24)

what do you want for the 215s then...shoot me a price

Abdullah

iTrader: (2)

i will let you know after i try the AI 208cc heads. if i like the AI 208cc heads i will sell my 215's if i don't like the AI 208cc i will take the 208's off and install my 215's, sorry for that Chris.

Abdullah

iTrader: (2)

consider 2 heads the GM LS7 255cc heads and the TFS 235cc heads. the GM LS7 heads when ported will go to 265cc maybe even more. and the TFS 235cc when touched up will reach 237cc-239cc. now both heads will make close rwhp to each other but the TFS 235cc will definitely will make more torque. that is what poeple are seeing when using these 2 heads.

Paint_It_Black

iTrader: (1)

No, runner size is not a great indicator of torque.

what is the minimum cross sectional area? what is the maximum cross sectional area? where are they located? What is the average air velocity? any unusual local velocities? what size valve? how many cfm per square inch of curtain area? which head promotes better swirl?

If engines operated at a constant 28" of water depression, life would be a lot easier. Unfortunately cfm and runner size sell heads. Well, except to the people who really want to go fast..

Paint_It_Black

iTrader: (1)

you didn't ask me a question, thus, no reply..

Abdullah

iTrader: (2)

maybe you are correct but i don't know much about cross sectional area, swirl, average air velocity...etc but what i know that AI makes stout heads for sure and they know what they are doing. and i think all the things you said about cross sectional area, swirl, average air velocity.....etc AI considers them all and applies them to the max when designing and CNC'ing their own ports to their heads.

Pwebbz28

iTrader: (31)

Chirs at RayMac did the ls3 heads on my 408. With 750hp and 600tq NA I would say he knows WTF he is doing.

Abdullah

iTrader: (2)

also Chris Frank@RayMac racing engines did my TFS 215 LS1 heads, he touched them up to 218cc and i think they will perform very well but i want to see what the AI TFS 208cc LS1 heads can do.

Abdullah

iTrader: (2)

btw, what is the runner size on your LS3 heads and what are the cfm numbers? 750hp and 600tq are very good numbers that will equate to around 637rwhp/510rwtq. were your numbers on an engine dyno? looks like your engine is for race not for the street.

what is your car? and your mods?

Abdullah

iTrader: (2)

check out this thread :

https://ls1tech.com/forums/dynamomet...-494-rwhp.html

SOMbitch

iTrader: (8)

Abdullah

It sounds like your mind is made up so GREAT luck to you and I hope your setup performs like you want it too... AI does turn out some impressive stuff and I am sure it will haul ***. Let us know your results !!!

I just wanted to make the point that the smallest runner does not always make the best torque. PIB just states it much more eloquently and technical than I.....

Abdullah

iTrader: (2)

thanks.

you are correct smaller runner doesn't always mean more torque or more hp that what AI told me, they AI told me it is the port design that makes more torque and hp. but from what i saw from different heads through the years usualy i'm saying usualy smaller runner will make more torque and some times more hp (if i'm wrong then at least maybe for the street heads not for big race heads).