AFR 185's or 205's For 393 Stroker?

[wickedmach1]

Does the 393 really need the 205's for the added cubes? What are the pro's and con's for each. I am building a street engine for my 70 Mach. The car will see the strip ocassionally but will be on the street 95% of the time. I read AFR's article from Muscle Mustangs & Fast Fords December 2000 issue. The article is named "Cornucopia Of Carburetion" (airflowresearch.com/articles/article24). I see that the most successful combo from their test was AFR 185's, Vic Jr. intake, and a 750 carb. They did not mention the cam specs. Why would they have used the 185's over the 205's? I have been told and have read that the 205's are ideal for 393 stroker engines. My car will be for the street and will probably rev up to 6000 or 6500 RPM at the most. Will I need the added flow of the 205's? I will use the Vic Jr. intake which will help. Will the 185's be the bottle neck of air flow. Please help. Thanks.

 

[SadbutTrue]

You're gonna make a ton of power either way. Like I've said before... if 185s don't work, port the things. The pros and cons are probably exactly what you think they are... the 205s will make more power at the top end and sacrifice some bottom end, while being a good bit more expensive, and the 185s will be stronger in the low to mid range areas while falling a little short in the upper rpms.

If you use a Vic Jr., go ahead and use the 205s and a big cam. If you use a dual plane like a Stealth or Air Gap, stick with a slightly milder cam and the 185s (another way of saying this is either use the Vic, 205s, and huge cam and make peak power at 7k, or use the dual plane, the 185s, and smaller cam and make peak power at 6k). You don't need a Vic Jr. or 205s if 6000 is your intended peak hp, it will just kill your lowend torque.

 

[Fostang]

185's

 

[dolfan87]

I agree...185's on my engine as well. I did a port match to my air gap intake, and I don't plan on spinning mine any higher than 6 grand.

185's make more sense.

87

 

[1badII]

Go 205's. The Windsor strokers need to breath. My 418 is only going to be spun up to 63-6500 RPM, and I'm running 225's. My combo is fairly wild, though, hence the 225's over the 205's.

 

[Darkhorse845]

185's

 

[Denny Wiedman]

heads

i use the roush200 heads cast iron ported to flow [email protected] lift, mine is a 402w, vic jr manifold, 750Hp, custom comp hy roller 236-242-555-576-108, full manual c-4 with 10'' converter, this car 69mach1 just flat out moves, i was going to get bigger heads but it still a street car and some track maybe i or 2 times a month if that, torque and good mid range is all i need for now not 6500 rpms which ill never see unless i blow it up, street cars need torque to move, if you have good traction and good gears it will do the job. 185,s will be more then enough for street driving and some track time.

 

[wickedmach1]

I see that maybe the 185's will work for the street. I don't want to lose the bottom end. How will the 185's match with the Vic Jr. intake. Will the intake be oversized? Will port matching be a problem?

 

[wickedmach1]

I have been told by a few engine builders in the last couple of days that the AFR 185's would be better for a street driven 393 due to the smaller ports. Smaller ports equal higher velocity which make torque and the engine will respond quicker. They explained that if you cruise around town turning about 1500 RPM, that the engine won't like the 205's due to the ports being too large. They said the air will tend to stall and be lazy which makes drivability and engine response not as good as it could be. Again, the 70 Mach is for the street and I for sure want good throttle response. I understand that you may lose this response with the 205's but will gain on the upper RPM. I know I will use the lower end RPM most of the time since it will be driven on the street. Does anyone have an opinion or know enough about this to comment on this issue?

 

[Route666]

wickedmach1: What you've said is true, but what is needed is quantified information. How much low end do you lose? How much top end do you gain? Apply these to your engine's application (street cruiser or bruiser) and you'll have your decision.

AFR's site says 185s for 302-351 from 1500 to 6500 and 205s for 331 - 392 from 3500 to 8000. There doesn't seem to be a midway.

Dolfan's already got a 393 with 185s. His experience is what you should take note of most.

 

[Mosse]

There is this article which is about 302, comparing 165 cc and 185 cc AFR´, and even with only 302, 185 was better all aroung, meaning that no significant loss in low end could be revealed.

This means, I think, that 205, with 351 atroker isn´t over kill by any means, and it should wotk from the bottom. I know guy who changed his 393 AFR185´s to 225´s, and it still works great on the street... Too much power though, 550 RWHp... He is getting old? '

if money is no object, go with 205´s. though 185´s are much cheaper...

 

[10secgoal]

I used the 185's on my stock stroke 302. No lack of bottom end. Your really not going to see any problems with and little bigger head to go along with 90 extra cubes.

 

[jerry S]

I know guy who changed his 393 AFR185´s to 225´s, and it still works great on the street... Too much power though, 550 RWHp... He is getting old? '

550 rwhp from a 393? Is that after a 200 shot of nitrous or does he have forced induction?

 

[mustangdave]

My vote is 185's also. As stated they are good to 6500 r.p.m.'s on a 351W. A 393 would probably not be limited by the head until near 6000 r.p.m. and that depends on the cam and a million other things. It may just be me, but 351W blocks(stock) do not last as long if revved over 6000 r.p.m. anyway. It may have to do with their large main bearing surface. Unless racing, how often are you going to hit 6500 r.p.m.'s anyway?

 

[bnickel]

what you need to worry about on the street is the "area under the curve". on a street engine a smaller cam and smaller heads almost always make more power "under the curve" than larger heads and cams. the 185's will absolutely not be a bottleneck on the street for a 393w and the power and torque it makes will be more usable on the street. if you are running a standard trans you will probably have problems with 205's on the street anyway, an engine with big heads and cam needs more RPM to keep the intake charge velocity up and if the velocity gets too low the engine will lug and chug at low rpms, definitely not good for a street car, this will be less of a problem with the larger cubes but still a problem none the less.

in the long run you'll be much happier with the 185's. remember the old saying when you're building a street car when in doubt go small.

 

[dolfan87]

Man talk about bringing a thread back from the grave.

87

 

[10secgoal]

Haha, didn't even notice that.

 

[Mosse]

Yep, was doing a search on roush200 and it poped up... i guess somebody could tell us how it worked out?

"550 rwhp from a 393? Is that after a 200 shot of nitrous or does he have forced induction?"

Have to check that, wheter I remember wrong, the car has been in Ford Muscle. It had AFR 225´s, Super victor, 850 Mighty Demon, 286 XE solid roller. This engine rev´d until 8000 rpm...

Too bad it isn´t mine... Now he making it a bit milder.

 

[Max Power]

I run Performer RPMs on the street and I would think they are closest to the 185s. It's a torque monster with instant throttle response. 185s will be fine.