Adding AFR185's to FMS392

[Mark Brye]

I have read a bunch of posts about adding AFR 185 Heads to the 392 and how they make so much more power. I read the MM&FF article and a couple others. I emailed Keith Kraft and asked them about adding these heads and they said there should be no piston to valve clearance issues. But I read a post on here that someone had bent a push rod.
Is there enough room for these heads? If I have to flycut the pistons then I will just leave the heads that are on there now.

Thanks

[DavidNJ]

How wild is the cam in that 392? Are those heads big enough?

[cleandan]

It depends on what your engine is exactly as compared to what "they" said would fit.
If your 392 is running uncut flat tops with zero deck and your current heads have smallish valves then yes, you will have clearance issues with the AFR's.
If you are running a street atyle comp ratio, say 9:1, with valve reliefs in the pistons to fit larger valves then you may have no fitment issues.
The real story comes from trying them on your motor, or at least one head for clearance fit trial. This IS a bit of a pain, but you will know for certain if you do a clay mold clearance test.
If you know your deck, your piston part numbers and if anything custom was done to them, your current valve size, and the lift/duration of your cam, and how it was installed (advances/retarded) you can get a very close approximation, but nothing beats clay clearance trials.

[ERA-FIA]

Mark, I installed AFR 205's on a FMS 392 (is that what you have) and there was more valve clearance than I expected. The valve pockets were large enough for the intake (2.08") vlave.

[Mark Brye]

Yes, I have the FMS 392 with the stock GT40X heads. I am not sure what all the specs of the motor are. I know that the X heads have 1.94x1.60 valves in them. I am not sure what pistons or cam Ford puts into the FMS Stroker. Mine is a 2006 build of the motor I think, so it would have the newer forged pistons.
I would never had thought that the AFR205's would have fit. Guess I will look into those instead of the AFR185's.

[ERA-FIA]

Mark, I did have an earlier version prior to the forged pistons, so you should still check the valve pocket size currently in use.

[ERA Chas]

...and if the pistons are installed backwards.

[jeffko]

185 are still the best match to the FMS crate engines. 205's move a lot of air and you will need the necessary parts to compliment them.

[Mark Brye]

I sent an email off to AFR to ask them about installing the 185's onto my 392. They responded but did not give me any insight. I was talking to our local Ford Guru and he was showing me the difference between an X head and the new FMS Z head. The Z head has exhaust ports that are so big that I do not know if my Backdraft header will even cover the entire port. Also on the Z head, the spark plug sits a little higher in the head which looks like it will interfear with the headers flange at the head making it imposible to install sparkplugs.
I now have these questions about the AFR heads also. I really do not want to buy new headers along with stud mounted rockers and the possibility of flycutting the pistons. I just want to bolt on and go!

[jrr]

Mark
If headers are a concern, the first question you need to ask is exhaust port location. There are some really great heads available but a lot of them have raised exhaust ports. For my little configuration, this is a major reconstruction of headers. Make sure you ask and have the flexibility to move up with your set up.
AFR 185s, Edelbrock Performers and TF Twisted Wedge's [most of them] are stock location ex ports. The FMS Z and AFRs are not.
Jack

[jeffko]

Mark, I just installed a set of new BDR headers on my 205s without any problem at all.

I recall several guys on here that have 185s on engines from 302 to 393. The 205 is a smaller combustion chamber, raising compression, and the intake valves are bigger. I used -12cc probe pistons in my build for clearance and to keep my compression under 11:1.

[Dennis Kelley]

AFR 165 and 185 exhaust ports are not raised. The only difference is the intake volume and the valve size. The exhaust ports on both heads are the same. They are made to bolt to standard ford exhaust headers. No custom headers need with these heads.

later Dennis

[Mark Brye]

Well, I ordered the 185's with 58cc chambers. I took the car to the local DynoJet to get a baseline. It sure didnt make what I expected granted I had done no tuning to the car as I received it from Backdraft. I don't even want to post the numbers but I figure this will be a help to someone somehow.
302HP and 323tq. Horsepower flattened out at 5300rpm. My air fuel ratio was between 10-11 so its WAY rich as delivered by backdraft. We checked the timing and it was at 8 initial. So either I have a really bad 392 or I am loosing about 70 due to a super bad tune. Will let everyone know what my new numbers are in a week or so after the head swap. Dyno sure is the ultimate ego deflater!

Also got car weighed. 2540 with 1/4 tank of juice

[Humbucker]

That's not so bad for a baseline. That engine makes about 430 at the flywheel on average BEST CASE scenerio. That would equal about 325-335 or so HP at the wheels. I'd say the tune is a little off and that would account for the difference in RWHP from what you should expect.

With my new heads and intake, my RWHP hit 422. I feel pretty sure that with the new heads and a proper tune, you'll be somewhere in the neighborhood.

Here's something else... I made 8 more HP with my air filter on than when it was off. We made three pulls to verify this. It's the same air filter housing that Hal Copple uses. I forget the brand, but it' sfrom a Nascar shop in NC. It allows me to use a 3" x 14" K&N filter. Too small a filter with certainly rob some power, and with our compartment constrictions, we need to take all we can get.

[rlearp]

Originally Posted by Humbucker

made three pulls to verify this. It's the same air filter housing that Hal Copple uses. I forget the brand, but it' sfrom a Nascar shop in NC. It allows me to use a 3" x 14" K&N filter. Too small a filter with certainly rob some power, and with our compartment constrictions, we need to take all we can get.

Hi Jake,

Any way to get a make on the housing? I'm looking for a housing, and while I don't care about every last hp, I wouldn't mind having something a little different from a Mr. Gasket chrome job, or some of the standard stuff from Summitt etc.

Thanks,
Ron

[Streetwize]

Strokers like a lot of air at higher RPM, on a 392" motor I wouldn't personally run a port any smaller than 205-215CC, even if it only flowed the same air on the bench as a 185 (granted more efficient port per CC of Area) a long stroke motor will like the bigger port at high RPM better, ESPECIALLY in a light car like a Cobra that doesn't want or need a lot of low end velocity to get it moving. Remember a flowbench only measures air, at a 12.5:1 A/F ratio 7 percent of what flows through the port is atomized (but still solid) fuel, if the velocity gets too high the fuel falls out of suspension and will ride the walls and then the walls become even more of a restriction to flow and the BSFC goes down.

A comparison of 170 vs 205CC intake port Trick Flow heads on a 347" SBF made 50 more HP, granted the 205's are cnc ported and flow more but the 205 ports are obviosly not too big for even 347 cubes in terms of torque/hp.

http://trickflow.com/product/fordcyl...cnctwisted.asp

[69 Mach I]

Originally Posted by Mark Brye

Well, I ordered the 185's with 58cc chambers. I took the car to the local DynoJet to get a baseline. It sure didnt make what I expected granted I had done no tuning to the car as I received it from Backdraft. I don't even want to post the numbers but I figure this will be a help to someone somehow.
302HP and 323tq. Horsepower flattened out at 5300rpm. My air fuel ratio was between 10-11 so its WAY rich as delivered by backdraft. We checked the timing and it was at 8 initial. So either I have a really bad 392 or I am loosing about 70 due to a super bad tune. Will let everyone know what my new numbers are in a week or so after the head swap. Dyno sure is the ultimate ego deflater!

Also got car weighed. 2540 with 1/4 tank of juice

what transmission do you have?

What cam is in there?

[Mark Brye]

Hi everyone,

I have received alot of emails asking for an update on my head swap dyno results. I have been on travel for the last couple of weeks and the dyno shop I used had recently relocated so there dyno had been down. I hope to get the car dyno'd soon now that they have the dyno up and running again. I will post the results once I have the car tuned.
On a side note, I can say that these heads have made a big improvement. I can sure feel it in the seat of the pants. I can't wait to see what a tune does!

[Mark Brye]

Made it back to the dyno today. Original numbers with Xhead 302hp,323tq as delivered from BDR. This had 10-11 air fuel ratio. After only the head swap to AFR185's and no tune, numbers increased to 383hp, 375tq. The air fuel ration leaned out to the 11-12 range. After making about 10 pulls, and playing with timing and jets, I am at 415hp, 415tq.
One thing we did notice, is that my fuel pump is getting near its limits. It has a Carter Electric pump with a gold top. I have tried to find information on it but have not found it anywhere to see what its capacity is.

[tbirdz12]

Nice gain. 37% more HP