Purchased a used 357 windsor 1969 9.5" deck motor. It has old GT40 aluminum heads w/2.02 int, 1.60 exh, a ford motorsport b-303 cam, and unported GT40 upper and lower intake manifold w/ 70mm throttlebody. I want to get a new head/cam/intake package on it to hopefully wake it up a bit. Any suggestions?? The motor is naturally aspirated and will be for a while. I would like to put a turbo on it in a few years but don't have the $ to do so right now. Any insight would be GREATLY appreciated! Thanks. P.S. This will be a street motor, not a daily driver, but for street use!
WHAT'S A GREAT HEAD,CAM,INTAKE PACKAGE FOR 357?
- Thread starter rbonella
- Start date
squeak93
15 Year Member
U sure a 69 block is a 9.5 deck? I thought it was a 9.2.
Anyway. Ur choking the engine with those heads and cam.
Think 200 cc runners (afr's) and a trick flow 2 cam (or close to specs) Port the lower as its a good lower and go from there. 75mm t/b as well.
Anyway. Ur choking the engine with those heads and cam.
Think 200 cc runners (afr's) and a trick flow 2 cam (or close to specs) Port the lower as its a good lower and go from there. 75mm t/b as well.
69 is a 9.4 . . .
The heads wouldn't be too bad, if you had them ported. The cam and the intake are definitely holding you back. IMO, I would talk to a custom guy or if you really cheap out at least run a comp xe282 or the matching lunati (I think 51012).
If you want to keep the fi, get a short runner or a spyder (especially if you turbo down the road)
The heads wouldn't be too bad, if you had them ported. The cam and the intake are definitely holding you back. IMO, I would talk to a custom guy or if you really cheap out at least run a comp xe282 or the matching lunati (I think 51012).
If you want to keep the fi, get a short runner or a spyder (especially if you turbo down the road)
Where do you want to shift the motor?
Don't worry about the turbo combination down the road. Use a heads and intake package for a certain displacement and powerband, and it will still be appropriate in a boosted application. The cam *should* be swapped at that point, though.
I'm thinking you're looking to shift around 6000 RPM. I would go AFR or TFS 205cc head, though you could get away with AFR 185cc heads. At this RPM you could also get away with a long-runner intake like the RPM II, or Systemax II. With a higher rpm engine, I would lean heavily towards a short-runner boxed upper like the TFS-R and would not go smaller than a 200cc head.
Chris
Don't worry about the turbo combination down the road. Use a heads and intake package for a certain displacement and powerband, and it will still be appropriate in a boosted application. The cam *should* be swapped at that point, though.
I'm thinking you're looking to shift around 6000 RPM. I would go AFR or TFS 205cc head, though you could get away with AFR 185cc heads. At this RPM you could also get away with a long-runner intake like the RPM II, or Systemax II. With a higher rpm engine, I would lean heavily towards a short-runner boxed upper like the TFS-R and would not go smaller than a 200cc head.
Chris
I think 6000 rpm is about right for me. I like having plenty of torque right around 2000-3500 in the rpm range, I want nice street manners. The car will be a street car, but when I go to the drag strip, I want to be able to mop some dudes up! Also, the motor has Vanolia 10.5:1 pistons in it. With boost in the future, what heads (if possible) could lower my compression ratio, but still flow nicely so I don't have to worry about detonation issues with pump gas? Will I always be limited in boost with these pistons? SOme guys tell me to build the na motor and keep the compression right where it is, if and when I turbo it....deal with compression then. "the best foundation for a strong boosted motor is a strong na motor!" What are your feelings about that?
Since it's a street car, you're always going to be limited on the boost you can run on pump gas with those pistons. A combustion chamber volume increase can decrease the static compression ratio. A custom cam can also allow more boost by lowering the dynamic compression ratio. These things can only go so far. Most guys that build forced induction pump-gas engines from scratch aim for somewhere between 8:1 and 9:1 SCR. You can still boost a motor with higher compression, but you will not be able to go as far without running into detonation issues.
I can't answer the bolded cylinder head question because I don't know what size the combustion chamber is on the heads that are on your motor. You mentioned that you have "old GT40 aluminum heads w/ 2.02 int, 1.60 exh" To my knowledge there are 2 types of aluminum GT40 heads, GT40Xs, and GT40Ys. I'm not that familiar with the Ys, as I understand them to be aluminum equivalents of the iron counterparts - the GT40P (I'm sure someone will correct me if I'm wrong). However, the Xs are the next step up, and are probably the ones on your vehicle. The X303 head has a 64cc combustion chamber, and the X305 has a 58cc combustion chamber out of the box. Both come with 1.94" intake valves, not the 2.02" valves that you mentioned were on yours. If you have 2.02" valves, it's because some custom work has been done on your heads. If that's the case, that throws everything out of the window. The heads could also have been milled to reduce combustion chamber volume. So, your current combustion chamber volume, unless you already know it, is likely to be anywhere from 54cc to 64cc.
In any case, the only way to use heads to decrease your compression ratio (SCR) is by getting a set of heads with a larger combustion chamber volume than what is already on your car. I've made my recommendation for heads already. Using any of the many online compression ratio calculators you can determine how changing the combustion chamber volume will change your compression.
My feelings about the saying you mentioned is that it is an accurate statement as it applies to intake, and head selection. It is also accurate for compression if you're not detonation limited by the type of fuel you are using. However, it is not an accurate statement when applied to camshafts, or detonation limited compression ratio. You're going to make more power n/a with high compression, but boosted you'll make more by lowering compression and upping boost.
If I may, I would suggest keeping the short block you already have, and sticking with high compression heads. Eventually, should you choose to go forced induction, nitrous would be best suited for your engine.
Chris
Thanks Chris! I really appreciate the advice you've given me. I have some decisions to make. I don't want to make any stupid decisions that will cost me time and ultimately money. Thanks for the help!
I'd consider this set of heads and the intake too while you are at it.
It's not any magazine BS, i was there for it.
'86-'93 Mustang Cylinder Heads - 347 Engine Head Swap - 5.0 Mustang & Super Fords Magazine
It's not any magazine BS, i was there for it.
'86-'93 Mustang Cylinder Heads - 347 Engine Head Swap - 5.0 Mustang & Super Fords Magazine
That's the best way, bro. Just keep doing research until you're confident you have a good answer, and then execute that decision with no regrets. It sounds like you're on the right track
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