torn b/w iron gt-40s or afr165!

Foxfan88 · May 15, 2006

AGH i cant decide, i want to go alum then i consider gt-40s will help alot and cost less.

But i want to have a step up, be different, my friend has a HCI with ported Pheads i duno i just feel like goin aluminum....

plans for the engine are B-cam and cobra intake. I think the gt-40s would be a perfect match for them. but i also want to go aluminum, to save weight and make more power. but the alum heads seem like they migh be overkill for the B-cam.

The gt-40s will be much cheaper also.

i dont know, i cant decide.

Goals are a 12 sec street car.

post your advice!

Grn92LX · May 15, 2006

Go with the gt40's if all you want is a 12 second street car. The 165's are nice but why would you use a B cam with them? You can get used gt40's for around $400. New afr's are over $1300. The price difference isn't worth it for this particular combo.

JUst do valve springs in the 40's and have them clean up milled.

DMAN302 · May 15, 2006

Go with the Gt40's and a nice port job from Tmoss..with the money saved over aluminum perhaps look at a better cam.

bentley429 · May 15, 2006

Grn92LX said:
Go with the gt40's if all you want is a 12 second street car. The 165's are nice but why would you use a B cam with them? You can get used gt40's for around $400. New afr's are over $1300. The price difference isn't worth it for this particular combo.

JUst do valve springs in the 40's and have them clean up milled.

This seems like some good advise FoxFan, if you were running a different cam, had the extra $$ and wanted abit faster car it would be a different story. But for your setup i looks like GT40s would be a good choice, I have also heard good things about the Thumper E7s . Another idea is to put the gt40's on and for that little extra run a 75 or 100 shot, used kits go for $400 easy. Good luck!

stang8urimport · May 15, 2006

You really can't compare GT-40s to AFRs... They're in a different league... If you want 30-40 hp gain, get the GT-40s... you want 90+ HP gain (with the right combo), go with the AFRs.

dragnazz5.0 · May 15, 2006

yeah, id go with the gt40s and possibly talk to thumper about getting a set of ported ones. but if you decided on the afrs dont put a b cam in it. atleast go with an anderson cam or a trickflow cam

Roland69 · May 15, 2006

The 40's will kick the SOTP gauge up a few notches and are good to help you get in the 12's

maverick0716 · May 15, 2006

Another good thing about aluminum heads that I don't think anyone has mentioned is weight savings. You would save 50 lbs. off the front end (where it's needed most) if you go aluminum. In this case however, the other guys are right.....if you keep the b cam then you might as well get Gt-40's which are also a very good head.

rd · May 15, 2006

The iron GT40's should get you into the 12's without two much trouble. I have 2 sets of them and there is probably a lot more potential in my main setup, if I ever get to tuning.

All that said, I decided to go to AFR's. Sometime this summer I should have them on there. They should also carry next years stroker also.

Tonys96Cobra · May 15, 2006

For what you want out of it, go iron! You can always spray it or s/c it later if you need more.

Foxfan88 · May 15, 2006

i've also heard that iron heads are better for a supercharger, at least for a mild build up, since the alum head will dissapate heat more, the engine will emit more heat and heat up the supercharger and the incoming air.

the iron head will contain the heat and will give off less.

are all the gt-40 heads the same, like are the actual 93 cobra heads the same as say a lightning head or the early explorer head?? i've heard some have the 1/2" bolt holes.

also looking at some flowcharts i got to wondering, how well will a FULLY PORTED TO THE MAX set of gt-40s flow? say as good as the 165s or performer heads??

stang8urimport · May 15, 2006

Foxfan88 said:
i've also heard that iron heads are better for a supercharger, at least for a mild build up, since the alum head will dissapate heat more, the engine will emit more heat and heat up the supercharger and the incoming air.

the iron head will contain the heat and will give off less.

:SNSign:

Foxfan88 · May 15, 2006

PoopDawg said:
:SNSign:

uhhh...makes sense to me, if an alum heads gives off more heat and makes the engine bay hotter, making the blower hotter wouldnt that just hurt it? i mean it wouldnt be horrible but in theory?

Roland69 · May 16, 2006

a set of iron 40's worked would be a good gain. Your theory makes sence to me but the air would be moving around so much that you would hardly tell the difference in temp's.

DMAN302 · May 16, 2006

Foxfan88 said:
uhhh...makes sense to me, if an alum heads gives off more heat and makes the engine bay hotter, making the blower hotter wouldnt that just hurt it? i mean it wouldnt be horrible but in theory?

Your thinking about it the wrong way..you want the heat to disapate. Your thinking, like the sun does, the heat from the heads will radiate out and heat up the components in the engine bay...not the case. The 'supercharger' would experience no ill effects from aluminum cylinder heads...in truth they would be an advantage in making power with any engine addition.

2000xp8 · May 16, 2006

Don't waste your time or money on gt40's. Or the b cam. Especially if you are considering afr's. If this was more like ported e7's vs gt40 irons, i'd say do whatever, but it's obvious you are going to want more power.

You'll be back in no time for more power.

You don't "need" afrs to make a very potent combo, you can get a set of used gt40x, edel rpm, or Twisted wedges. Probably around $900 or less.

Gaskets, pushrods and other misc parts add up, so you don't want to do this twice.

Headwork on a $400 set of gt40 irons, would likely add up to the cost of buying aluminum heads.

eric88gt · May 16, 2006

I'm gonna be one of the very few here to say go ahead and run the b-cam if you can get one cheap. I've been running 165's and a b-cam with a cobra intake for a 3 years now. Still speed density, with stock injectors and fuel pump, it's best is a 12.51@109.9mph. That was with a 1.78 sixty foot. Just because it's old and cheap does not mean it doesn't work, it may not be perfect, but it's not as bad as people make it out to be.

352Ford2 · May 16, 2006

2000xp8 said:
Don't waste your time or money on gt40's. Or the b cam. Especially if you are considering afr's. If this was more like ported e7's vs gt40 irons, i'd say do whatever, but it's obvious you are going to want more power.

You'll be back in no time for more power.

You don't "need" afrs to make a very potent combo, you can get a set of used gt40x, edel rpm, or Twisted wedges. Probably around $900 or less.

Gaskets, pushrods and other misc parts add up, so you don't want to do this twice.

Headwork on a $400 set of gt40 irons, would likely add up to the cost of buying aluminum heads.

I have a 350 bucks into my gt-40 heads total including purches price (fully ported by me, new springs, retainers, locks, couple valves, valve job, etc) Just have to be smart with what you buy, try to avoid something that doesn't need to much machine work and do the porting and as much of the work as you can yourself.

not a bad bang for your buck

thermal proberties of iron and al. AL disapates heat much beter than irons heads (you welders out there will agree) whitch is good and bad. As we all know from Thermodynamics heat is energy and when it leaves the combustion chamber it is lost HP. IF everything is equal an identical iron headed engine will make more power, but in this world we are limited by many things. The biggest things are fuel and the fact that most al heads are designed better than their iron conterparts. The fact that al heads bleed out heat alow you to run more cr, boost, etc, without problems with pre-igition on a given octane/specific gravity of fuel.

maverick0716 · May 16, 2006

eric88gt said:
I'm gonna be one of the very few here to say go ahead and run the b-cam if you can get one cheap. I've been running 165's and a b-cam with a cobra intake for a 3 years now. Still speed density, with stock injectors and fuel pump, it's best is a 12.51@109.9mph. That was with a 1.78 sixty foot. Just because it's old and cheap does not mean it doesn't work, it may not be perfect, but it's not as bad as people make it out to be.

Those 1.72 rockers help that cam a lot though. If someone was going with a B-Cam, I would only recommend 1.7's (or 1.72s) with it......screw 1.6 rockers.

Foxfan88 · May 16, 2006

i have 1.7s, should put the lift at about .512 not sure tho

torn b/w iron gt-40s or afr165!

Foxfan88

My Grandpa has great wood.

Grn92LX

Fidanza Man!

DMAN302

My mom says thanks for the pearl necklace.

bentley429

Banned

stang8urimport

Autozone Junkie

dragnazz5.0

My "0" key d0esn't w0rk, s0 I have t0 use the zer0

Roland69

Sergeant Tangnet

maverick0716

rd

Tonys96Cobra

professional deer "mounter"

Foxfan88

My Grandpa has great wood.

stang8urimport

Autozone Junkie

Foxfan88

My Grandpa has great wood.

Roland69

Sergeant Tangnet

DMAN302

My mom says thanks for the pearl necklace.

2000xp8

eric88gt

352Ford2

New Member

maverick0716

Foxfan88

My Grandpa has great wood.

Similar threads

torn b/w iron gt-40s or afr165!

My Grandpa has great wood.

Fidanza Man!

My mom says thanks for the pearl necklace.

Banned

Autozone Junkie

My "0" key d0esn't w0rk, s0 I have t0 use the zer0

Sergeant Tangnet

professional deer "mounter"

My Grandpa has great wood.

Autozone Junkie

My Grandpa has great wood.

Sergeant Tangnet

My mom says thanks for the pearl necklace.

New Member

My Grandpa has great wood.

Similar threads

Privacy & Transparency

Privacy & Transparency