408 stroker only 210 HP. HELP please.

[Rhauf]

Well, let me first start by saying that im a bit new here.. i've been registered since 2001 or so, but only sometimes lurked and i haven't posted any untill now. i tried posting this earlier today but i dont think it went through, so if this is a double post, forgive me. anyway, i have this new build which has been giving me some trouble, so i thought i'd ask and see if you guys have any insight on it.

It's a 351W roller block, stroker crank, forged pistons at 10.0:1 compression. edelbrock RPM heads (170cc, 2.02 intake) crane hyd roller cam 224/232 @0/50, 560/540 lift, 114lsa, roller rockers, dual 2.5 inch exhaust, edelbrock 750cfm carb, and mallory distributor.

its a new build and it has about 600 miles on it now, so i took it to be dyno tuned, and it showed up as running lean, and only making 210 rwhp. drivetrain is a c-6 w/ a 9" rear. i upgraded the fuel pump to a 110gph 8psi mechanical (from the stock mechanical) and regapped the spark plugs and it's running a little better now (perhaps the lean condition was caused by low fuel pressure?) i havnt dynoed it again, but i dont expect it has gained more than 50 more horsepower. still well below the 400 rwhp that i was hoping for when i built it. any body have any ideas, what is a realistic expectation for horsepower from a build like this?

thanks for reading

[gtnby2]

" drivetrain is a c-6 w/ a 9" rear. "

Here is roughly a 60HP loss....C-6's are a hp hog!!! If you want to make a night and day difference in your car, switch to a C-4 or a built AOD. I tourched my AOD and got a brand new c-6 for 75 bucks so I couldn't pass it up and my car dyno'd @ 157hp with a built 306 after getting the AOD rebuilt, a 2200 stall and NO other mods on the same dyno it went up to 275. Do you have a stall? If you drive the car, a 2400 to 2800 would be ideal, if it's drag only you can go up to 3500 or so. A 408 with your setup should easily be in the upper 300's on HP and over in torque so a stall rated at 2400 would spool up to 2800 easily if you just crammed it but move around town at 2400 or less and act like a stocker.

[Rhauf]

Originally Posted by gtnby2

" drivetrain is a c-6 w/ a 9" rear. "

Here is roughly a 60HP loss....C-6's are a hp hog!!! If you want to make a night and day difference in your car, switch to a C-4 or a built AOD. I tourched my AOD and got a brand new c-6 for 75 bucks so I couldn't pass it up and my car dyno'd @ 157hp with a built 306 after getting the AOD rebuilt, a 2200 stall and NO other mods on the same dyno it went up to 275. Do you have a stall? If you drive the car, a 2400 to 2800 would be ideal, if it's drag only you can go up to 3500 or so. A 408 with your setup should easily be in the upper 300's on HP and over in torque so a stall rated at 2400 would spool up to 2800 easily if you just crammed it but move around town at 2400 or less and act like a stocker.

I have a hughes 2400 RPM converter, the engine is actually not in my mustang it's in my bronco.. but the guys over at the bronco board didn't have any ideas so i tried you guys since there is alot more mustang hotrodding than bronco hotrodding, and i have a couple mustangs, too (yea im the usual ford nut) so your saying you gained over 100 rwhp JUST by dumping the c-6? i know ive heard they are big and heavy, but damn!! do you think having the c-6 rebuilt would help? it's never been rebuilt and has a million miles, but i didnt think that would cause drag in it.

ive also been reading some other threads (just now) is my cam big enough? i'm starting to think my cam and head choices are just too small for a 408

[gtnby2]

yeah no sh^T 100hp. I thought the dyno was screwed up but it all checked out and man did it make a difference seat of the pants!!!185's should be fine, and the cam should not be to far off either assuming the timing is set. i.ve got a friend that runs a carbed 408 and he's in the low 5's in the 1/8...I'll talk to hime tomarrow and get back to ya on his setup...K?

[Rhauf]

Originally Posted by gtnby2

yeah no sh^T 100hp. I thought the dyno was screwed up but it all checked out and man did it make a difference seat of the pants!!!185's should be fine, and the cam should not be to far off either assuming the timing is set. i.ve got a friend that runs a carbed 408 and he's in the low 5's in the 1/8...I'll talk to hime tomarrow and get back to ya on his setup...K?

Awesome, I'd be interested to know how his is set up, as well. thanks

[Rhauf]

Anyone else have any thoughts here? or do all agree that my transmisisn is the culprit?

[Rhauf]

anybody else have any thoughts? nobody?

[gtnby2]

Hey, my friend sez to check the cam timing to make sure the cam isn't retarded, the cam is a little small but ok, and the heads are not the best but you should still be in the 350hp range at the wheels with the components you have easily. Also he suggested about 32 to 34 degrees of total timing for the best results. He has a set of Trick flow twisted wedge heads that have been stage 3 ported and polished, a 5 angle valve job, shaved to produce 12 to 1 compression, a 750 demon carb and a solid roller cam with over a 650 lift. Sorry he wouldn't give me specifics, hes pretty tight lipped about what he runs cause he runs at the local Drag strip alot and he don't want to let the cat out of the bag for the compitition!! hope this helps...let me know if ya make any head way!!!

[Dark_5.0]

I built a 393 stroker that made 367RWHP and it was pretty mild.

The heads and especially the cam are damn small for a 408 but I would still expect around 350RWHP with that much cubic inch.

What size primaries on the headers? What size exhaust?