392 stroker - need power ideas

Jimbocobra · #1 (**permalink**) 07-24-2009, 08:27 AM

I have a Ford 392 with 430hp/450tq out of the box. Great engine, strong everywhere and reliable and only about 3200 miles on it, but everyone always wants more power and after reading a bit on this, there is still a lot of power potential in this engine.

I have researched and am planning on going with AFR 205 heads (+50hp to +75hp) and a new cam (+30hp) and new side pipes with 3+ inch tube (+15hp or more) since the stock BDR pipes could use better breathing (although they look great and sound cool). That should be good for at least 100 additional hp at the flywheel, bring it to about 530hp.

I don't want to go above 6000 RPM and want to keep the compression low (currently 9.7:1) maybe go 10:1. I do not want to sacrafice reliablity or streetability and want to run on 93 octane. I have a holly 750 CFM carb, MSD ingnition... Anything body got any ideas?

392cobra · #2 (**permalink**) 07-24-2009, 08:35 AM

Back when I had the same engine I got to looking into different heads too.

I believe there is a problem with bigger valves and the reliefs in the pistons.They needed flycut.

Something to be sure of going in. This was a 2002 FMS 392 crate,things may be different now.

blykins · #3 (**permalink**) 07-24-2009, 08:59 AM

Definitely go with the AFR heads. That will be a good improvement.

IMO, if you stay with a hydraulic roller then you don't really wanna go over 6000 anyway. I can help you spec a new HR cam that will help with the heads.

onefastmustang · #4 (**permalink**) 07-24-2009, 10:25 AM

Be very careful with flycutting pistons.. I had done that on my 392 and during a drag race I blew the top of two pistons off. I had the machinist take .025 off which may have been too much or maybe they were just cheap pistons. Luckily there was no damage to the motor and I rebuilt it with some really nice SRP pistons. Of course at $800 my wife didn't think they were all that nice. LOL

Jimbocobra · #5 (**permalink**) 07-24-2009, 11:46 AM

I called AFR, they recommended the AFR 205 (part number 1450) with the 8019 spring and I won't have any valve float. They recommended the Comp Cam Xtreme Energy part #35-426-8. The AFR rep pulled the specs on my "dish" pistons and said they were 64cc, so the recommended set up would give me a 10.3:1 compression ratio. He is confident of at least 525hp with this set up after doing some math.

They want me to check two things 1) the rocker arm geomitry/pushrod length and 2) piston and valve clearance so I don't ruin the engine. I have no idea on how to begin doing that. If I check into this ahead of time, I should not need to cut anything. Hopefully, whoever I do this with will know exactly what I need to do.

vector1 · #6 (**permalink**) 07-24-2009, 12:14 PM

i would use the 185's, the 4" bore won't be able to use the larger valve anyway, this way you won't have to worry about the p-v clearance and save a little cash, i don't think the 205's would gain much over the 185's imo at the rpm your looking at.

here is a discussion where i was comtemplating my options.

http://speedtalk.com/forum/viewtopic...239&highlight=

there is a cam recommendation in there also.

you'll have to check rocker geometry no matter what you use. i would go to an rpm air gap with a small open spacer if you can fit one. carb is the minimum but useable, if you go to the dual plane you will pull more vacuum and can use a bigger carb if you come across one. if you don't have lightweight flywheel/clutch that should be on the list. last, don't kill everything with a small air cleaner.

with all the above you will definitely have a different animal but i think you have the right ideas.