anyone have a link to a head flow comparison chart?
- Thread starter 2000xp8
- Start date
houstonstangguy
Founding Member
maverick0716
Founding Member
sn9550
Founding Member
Michael Yount
Mustang Master
I was gonna pm/email you the chart that sn9550 put up. Take it with a grain of salt. Flow benches are just like dynos - subject to the vagueries of the conditions tested under, how hard they are 'pulled' on (25 in, 28 in, etc.) and the operator running the test. That means the same head can be tested on 2 different benches under different ambient conditions by different operators and come up with 2 entirely different sets of numbers. It also makes a huge difference the types of connections/manifolds that are used to hook the ports up to the machine. The data in the tables were pooled from a variety of different sources - consequently, it can be really misleading to compare them directly - as I did when I first saw the data. At best the data is useful to give you an rough idea of how heads flow at different lift levels. If you're using it to decide which head you want, you should augment the info with some input from those who have the heads you're thinking about. If you're using the data for modeling for a custom cam - remember, garbage in/garbage out. For a daily driver/street car - it's probably close enough. For a serious racer, you probably ought to have the heads you actually get flow tested and use that data.
Well my idea is to find a set of used heads since i'm on a budget with this project, so i'm not real picky with what set, but i figured a chart would give me an idea what's worth and how much.
I would prefer AFR's but they are going to cost me too much at the moment.
Next i figured edelbrocks or gt40x but the resale value on them seems pretty high too. Then you have the gt40y which seem to be significantly cheaper, and i know i don't need new rockers either, but i don't really find too much info on them.
I'd also like a head that if at a later date i'd like to have redone for more power the potential is there.
BTW, thanks for the chart. And if they were all tested on the same bench for that chart shouldn't it be pretty accurate?
I would prefer AFR's but they are going to cost me too much at the moment.
Next i figured edelbrocks or gt40x but the resale value on them seems pretty high too. Then you have the gt40y which seem to be significantly cheaper, and i know i don't need new rockers either, but i don't really find too much info on them.
I'd also like a head that if at a later date i'd like to have redone for more power the potential is there.
BTW, thanks for the chart. And if they were all tested on the same bench for that chart shouldn't it be pretty accurate?
houstonstangguy
Founding Member
sorry that chart wasn't quite what you were looking for.
what kind of cash do you have to spend?? when it comes to used parts you can usually find them all for pretty good prices on the different forums. Honestly though, you should probably plan for the right head now, even if that means saving up a little longer to get them. you dont want to get a set of heads merely because it is all you could afford or you will most definitely be buying new ones again later.
plan the application, ask questions and then buy the heads. I got my tfs heads with the rockers and pushrods and arp head bolts for just under 1000 if i remember correctly last november on corral classifieds. afr's and tfs were my first two choices and I knew that going in, but I couldnt really pass up the deal when i found them, so i jumped right on them.
i am sure you realize all of that though, but i wouldnt really waste my money on the lower end set of heads especially once you realize that later when you port them you will have already spent more on them than they are worth and wont be able to recover most of that back.
what kind of cash do you have to spend?? when it comes to used parts you can usually find them all for pretty good prices on the different forums. Honestly though, you should probably plan for the right head now, even if that means saving up a little longer to get them. you dont want to get a set of heads merely because it is all you could afford or you will most definitely be buying new ones again later.
plan the application, ask questions and then buy the heads. I got my tfs heads with the rockers and pushrods and arp head bolts for just under 1000 if i remember correctly last november on corral classifieds. afr's and tfs were my first two choices and I knew that going in, but I couldnt really pass up the deal when i found them, so i jumped right on them.
i am sure you realize all of that though, but i wouldnt really waste my money on the lower end set of heads especially once you realize that later when you port them you will have already spent more on them than they are worth and wont be able to recover most of that back.
Well, i'd like something aluminum and i'm going to try to stay around $750 or so, which IMO is reasonable since most brand new heads cost around 1100. So taking a 1/4 off the price for a used pair seems fair.
But that doesnt' really seem to be the prices on ebay, everything goes up past $900.
The afr's probably won't happen, i want the HP faster than a new set of them will allow in my budget.
Now and then a set of gt40x's show up locally for around my price but you have to be at the right place at the right time. These are the ones i really want.
The tw's would be good, but unless i find a deal on them with the 1.7rr's i'd just have to spend another $150-200 bucks on them. If that's the way i did i might as well just save up for a new pair.
I'll check the classifieds on other boards (there's not a classified here right?) but i have some issues sending someone $700 bucks with no protection. At least on ebay you can check their feedback, and leave poor feedback if they screw you.
But that doesnt' really seem to be the prices on ebay, everything goes up past $900.
The afr's probably won't happen, i want the HP faster than a new set of them will allow in my budget.
Now and then a set of gt40x's show up locally for around my price but you have to be at the right place at the right time. These are the ones i really want.
The tw's would be good, but unless i find a deal on them with the 1.7rr's i'd just have to spend another $150-200 bucks on them. If that's the way i did i might as well just save up for a new pair.
I'll check the classifieds on other boards (there's not a classified here right?) but i have some issues sending someone $700 bucks with no protection. At least on ebay you can check their feedback, and leave poor feedback if they screw you.
houstonstangguy
Founding Member
2000xp8 said:
honestly, most people I know with tfs heads run 1.6 rockers which is what tfs recommends. with 1.6's you will still have to check the ptv clearances though.
stangnet had classifieds although since they changed the site i havent used it too much. I would use corral.net/classfieds because they have a feedback thing there, and most people will either do COD or paypal, otherwise I wouldnt deal with them. On big parts, i am usually skeptical about sending out money orders too. paypal and cod protect you both.
You should be able to find the gt40x heads for the price you are looking for, and I wouldn't go with the y's unless they were fully ported. A guy about 50 miles from me was selling some ported y's for 750 in november, so those are still in your budget. you can also find the 1.7 cobra rockers for 100 pretty much all the time on that forum as well. it is a very good forum for used parts. honestly i bought alot of my stuff off of there, just check feedbacks before dealing with someone.
email me and I can talk to you some more and help you look on there since I am very familiar with that site.
[email protected]
Joe
Michael Yount
Mustang Master
2000xp - the numbers on the chart didn't all come from the same flow test/set up - I mentioned it in my previous post. They came from multiple sources, different tests, different magazines, etc. For your price range, the Y's are probably what you're gonna find. Keep in mind, they are pretty much an aluminum version of the GT40 or GT40P from a flow perspective. And they only come in the 64cc chamber which will relegate you to a relatively low compression ratio unless you change pistons or mill them. They can flow pretty well with porting work -- but if serious naturally aspirated HP is what you're after, you'd probably be better off saving a few more bucks and going with some of the heads that already flow better.
Well, you very well maybe right about waiting. I guess a couple of weeks can't hurt.
What heads box stock with my combo will produce 300 at the wheels?
I've seen gt40x's do it, just not sure the cam in the car.
the tfs i hear good things but i don't want to buy new rockers.
I also hear good things about the edelbrocks.
Are these my choices?
What heads box stock with my combo will produce 300 at the wheels?
I've seen gt40x's do it, just not sure the cam in the car.
the tfs i hear good things but i don't want to buy new rockers.
I also hear good things about the edelbrocks.
Are these my choices?
Michael Yount
Mustang Master
If you want 300 at the wheels, you'll be hard pressed to get there with the Y's. The X's maybe. If you look at sigs/combos that do that, most of them have AFR's, TFS, Holley, Edelbrock - etc.
Well, i was just saying that if i spend a little more i want a little more.
I figured with the y's i may be able to get about 280-285 which i can live with if i spend about 600-700 on the heads.
There's a new set of Y's on ebay, only been bolted down, BIN $699.
But if i drop $1000, i'd like 300rwhp.
I figured with the y's i may be able to get about 280-285 which i can live with if i spend about 600-700 on the heads.
There's a new set of Y's on ebay, only been bolted down, BIN $699.
But if i drop $1000, i'd like 300rwhp.
cardudeusa
Founding Member
I love my edelbrocks. Havent been to the track yet, because I have a cracked windshield. I should have done a cam when I did the heads, because there isn't as much power down low. Once I get up to 4,500 rpms it pulls like crazy though. I also have stock rear gears for now. It pulls easily until 6,500, I havent taken it any farther. I also kept stock pushrods and rockers. I opted for the 1.90 intake valves so I wouldn't have to worry about the pistons and valves making friends.
cardudeusa
Founding Member
