What heads for a supercharged 331

[95_red_gt]

I'm having trouble deciding what heads I want to go with, or even what specs I want for a supercharged 331 stroker I'm building. Can anyone give me some insight into what should go into this type of combo? What size valves I should use, 1.6 or 1.7, how much they should flow, etc. Thanks guys. Everyone's always been so helpful on here. Keep it up!

 

[revhead347]

I'm a big fan of Trick Flow heads. All the rest are basically the same, so just shop around for a good deal. Depends on how much power you want to make. I'd look for something that has a 2.02/1.60 combination, since piston to valve clearance shouldn't be an issue on a 331. The rockers have more to do with the cam selection. Most of the off the shelf cams are optimized for the stock ratio of 1.6:1. If you are going to get a custom cam, then the rocker ratio isn't really going to matter as long as you know what you are going to use before you have the cam ground.

Kurt

 

[Pops Fun]

I use Trickflow on my 347/Vortech motor.. My sons 331 with Vortech uses Trickflow also. Ported and polished... Anyway you can use any quality head IMHO... We are using Steeda 19 cams....

 

[95_red_gt]

I'm thinking of going with an e303 or f303 cam. Not too much lift. The F303's duration is just a little longer so i'm thinking of going with that. I want to run alot of boost (18ish) with about 8.5-9:1 compression.

 

[revhead347]

Skip the letter cams. They are old designs from the early 80s. Most people refer to them as "noise cams." They make a great sound, but don't to jack for power. As mentioned above, the Steeda 19 cam is an excellent blower cam. You won't give up any driveability, and it doesn't have much overlap. I recommend running the 19 cam with a 1.72 rocker for a little added lift to help the engine breath.

Kurt

 

[earleys94gt]

+1 on the Steeda 19 cam, even on my n/a 302 with e7's it pulled like a bastard.

If you are looking for pure power, a custom cam, though more expensive, would be worth looking into.

Trick Flow's are a good head chioce, as are Air Flow Research(AFR) heads.

 

[revhead347]

AFR is just reselling the same heads everyone else has been selling for 2 decades. If they are a good deal, go for it, but I always recommend shopping around. I've always found that out of the box heads weren't worth much, but Edelbrock is claiming their E-street heads are good on delivery. Worth looking into.

Kurt

 

[95_red_gt]

Thanks for the heads up on the cam. I've been out of the game for so long that I'm not sure what's going on!!

 

[HankyGT]

AFR is just reselling the same heads everyone else has been selling for 2 decades. If they are a good deal, go for it, but I always recommend shopping around. I've always found that out of the box heads weren't worth much, but Edelbrock is claiming their E-street heads are good on delivery. Worth looking into.

Kurt

The AFRs always seem to do the best in any sort of comparision and have excellent low lift #s. The trickflows have a unique valve angle design that allows for larger valves, which is nice; but it also limits you on piston choices aswell once you grow with them. Not to say they aren't decent but to call AFRs outdated in comparison is just well, crap

 

[95_red_gt]

I'm a big fan of Trick Flow heads. All the rest are basically the same, so just shop around for a good deal. Depends on how much power you want to make. I'd look for something that has a 2.02/1.60 combination, since piston to valve clearance shouldn't be an issue on a 331. The rockers have more to do with the cam selection. Most of the off the shelf cams are optimized for the stock ratio of 1.6:1. If you are going to get a custom cam, then the rocker ratio isn't really going to matter as long as you know what you are going to use before you have the cam ground.

Kurt

I'm hoping to make around 600 hp to the wheels. So would the same info apply?

 

[Adam95GT]

r's or hiports

 

[revhead347]

The AFRs always seem to do the best in any sort of comparision and have excellent low lift #s. The trickflows have a unique valve angle design that allows for larger valves, which is nice; but it also limits you on piston choices aswell once you grow with them. Not to say they aren't decent but to call AFRs outdated in comparison is just well, crap

I know I've been preaching this for awhile, but oh well. Almost all the cylinder head companies (with the exception of Trick Flow) buy their bare castings from Canfield. I think AFR makes their own castings, but it's just a copy of the Canfield design. That's why you see an unbelievable number of cylinder heads from different companies for SBFs. There are a few variations of cylinder heads available, all based on old Canfield designs. There are a few variations. There are the heads with the stock port locations, and valve angles. This is basically Edelbrock RPMs, AFR 165s etc, you get the point. Then you get into the raised port heads (newer AFR 185s and such based on the old Trick Flow Hi-ports). Then there are heads with a slightly different valve angle, usually no more than 17 degrees which flow a little better. If you look at the flow bench numbers on comparable heads from different manufacturers, you'll see that comparable heads almost always flow the same. It's all about how they package the heads. Different valve sizes, CNC finish, etc. These are the things you should look into when buying a head. It's kind of like the pizza special of the week. See who is running the best deal and buy it. I'm honestly biased against AFR. They came into the Ford cylinder head game late. Almost like the Chinese. Offering you the same thing at a lower price to try and drive out the competition. There were plenty of cylinder heads available, we didn't need a Chevy head manufacturer to come in and offer all kinds of heads that were already available. That just drives down the quality of everyone else. Trick Flow has the only original design for Ford heads, which is patented. I give them credit for that.

Kurt

 

[revhead347]

I'm hoping to make around 600 hp to the wheels. So would the same info apply?

I hope you aren't trying to do this with a stock block.

Kurt

 

[revhead347]

Here is the link to the old Stan Weiss Cylinder Head Flow data base. The flow data on similiar heads from different manufacturers is unbelievably............similiar.

Stan Weiss' - Cylinder Head Flow Data at 28 Inches of Water

Kurt

 

[nmcgrawj]

wow.

AFR is compared to chinese driving down price?


And i always thought AFR's were in the "more expensive" category....although i havent shopped around in 2 years now. Have things changed?

 

[revhead347]

Yeah, I've got an unrealistic bias I realize. But AFR came into the game about 10 years ago. They started offering heads with more standard stuff. They started out including more stuff, like CNC porting and a better valve job from the box which yielded better performance numbers. AFR was a very succesful manufacturer for aftermarket Chevy heads. They wanted to get into the Ford market, and at first they were considered a bargain. After establishing their reputation over the last decade, they have no raised their prices, and become the more expensive option. Edelbrock has copies this business strategy with their new E-street heads, offering an out of the box ready head for a reasonable price. Way back in the late 90s, aftermarket heads were considered worthless out of the box. It was considered necessary to clean up the port work, and get the valve job finished up on aftermarket heads. It's something that most 5.0 enthusiasts aren't aware of, because they haven't been in the 5.0 market for 15 years like I have.

Again, I would like point out that it's all marketing strategy. All the manufacturers are offering basically the same heads at different stages.

Kurt

 

[95_red_gt]

I hope you aren't trying to do this with a stock block.

Kurt

Not stock internals obviously, but the bare stock block I had planned on re-using. Not without a trip to the machine shop to have checked and cleaned up of course.

Not a good idea?

 

[Pops Fun]

Hi
the stock block is only good for around 500 hp. Last year I cracked a stock block making about 520rwhp. It lasted 4 years at that hp. I put a dart shp block in this time $1600 plus shipping.
My understanding of the problem is that stock blocks only use 2 mains and aftermarket use 4 mains.
Wish I had done the dart when mine was built the first time... parts only get more expensive..

 

[revhead347]

600hp at the wheels on a stock block is really pushing it. That much power on a stock will probably crack it. There are a few people who have done it, but not with any sort of reliability. Most of them did it with high end turbocharger kits, and didn't rev the engine up much. If you really have your heart set on making 600 to the wheels, then you really need to step up to an aftermarket block, which is going to run you a little over $2K just for the block. If you are willing to settle for about 500 to the wheels, then you can get away with a stock block. There is another member here, Pops Fun, who used to have a 500rwhp stock block engine. He is now running an aftermarket block. His stock block motor blew a piston, but the block itself didn't crack. I believe Pops Fun had a stock block 347 with AFR 185s and an S-trim. Given that you want to run a blower, don't go crazy spending money super duper heads. You should be able to make that kind of power with a blower, and a mid range Aluminum head. Something like an AFR 185 or Twisted Wedge, or the mid range RHS head. I think the RHS is the most affordable. As long as it has a 2.02" intake and 1.60" exhaust it should suit your needs.

Kurt

 

[revhead347]

And right as I was typing that up, Pops beats me to the punch. I have about 500rwhp on my stock block, but I do it with nitrous which is totally different from a blower. I also spray it very infrequently.

Kurt