what is the most HP you can get out of a naturally aspirated, non-stroked 351W?

[69 Mach I]

I am wondering if I can get to 500 hp at the fly. I am bored .060 over. I am running 11:1 compression on forged flat top pistons, Edelbrock RPM performers, and long tube headers. I have a Holley 4150 series 4bbl 650 cfm with vac. secondaries. The cam has the following specs: ADV duartion: INT 297 EXH 308 LIFT INT 538 EXH 534 DURATION @ .50 INT 236 EXH 242 108 Centerline. THe car dynoed at a peak 351rwhp (438 at the fly estimated) using the crappy old ignition and points distributor. However, it really wasn't in peak tune for that dyno run. I am adding a hot ignition (MSD 6AL and a MSD Pro-billet distributor) and hope to pick up 10 hp with that. From here, would it be possible to pick up another 50 hp? Would porting the heads net me anything worthwhile? What about a serp. conversion?

[Woodz428]

You should be able to squeeze 500 HP from a 351W. I'm not sure whether it can be done with the build you have.Heas porting will gain some. You didn't really give much info about the build (any blueprinting?,balancing?) other than specs.

[TerrysSPF]

There's always a way to get more HP out of an engine. It's called $$$$$$$$$$ !!!

Why do you want to stay away from stroking? That would definately get you 500HP. Other than that, try sending your heads, intake, and cam profile sheet into Keith Craft. His head work is second to none.

[CowtownCobra]

Stroking is your best bang for the buck. My KC stroker engine makes about 540 hp, and that is with a milder cam because I want the best streetability. Keith will build you a windsor based engine that makes 650 hp if you want.

[69 Mach I]

I know that speed is just a question of money. I am over budget already and still have to put in a new interior and repaint. Stroking will cost me more than I want to go because I just put new rods and pistons in there at a materials cost of $1000. I would have to toss that investment if I were to stroke. If I put a hair dryer on, I still have to toss the $620 I spent on the pistons becasue the CR is too high to blow. And to top it all off, I am in Europe where things cost 2x what they cost in the US. So I am looking to see if I cannot squeeze 50 hp out of my application in some other way that complements my existing componentry. Bigger carb? Port the heads? EFI? Something else?

[CowtownCobra]

Don't know where NL is, but as long as it isn't france, then it must be nice

Sounds like you need a good set of heads. That is the secret to horsepower. You need a LOWER compression ratio if you put a blower on it, probably about 8 to 1. I'm no fan of power adders, I think hp should be made the old fashion way. A good set of free flowing heads, no restrictons in the intake or exhaust, and with about a 10.5 to 1 CR (dished pistons) you should have a real nice motor that runs on 93 octane. If you are willing to run it on exotic fuel then up the CR to 12 to 1 (flat top or domed pistons) and 500+ hp is no problem at all.

[MidOHasp]

Port the heads.

Everything else sounds about right for 475-500 HP.

Stroking it would add 50, but if you just put new rotating assy. in it, then I agree...don't stroke it.

NL=Netherlands

[69 Mach I]

Originally posted by MidOHasp


Port the heads.

Everything else sounds about right for 475-500 HP.

Stroking it would add 50, but if you just put new rotating assy. in it, then I agree...don't stroke it.

NL=Netherlands

What would porting the heads net me in terms of peak hp? Would I sacrifice any low end torque? thanks to all y'alls for the advice so fars.

[CowtownCobra]

Be careful now, Mach I, what kind of heads do you have? Are they the stock iron windsor heads? If so you may do better to get new set of ported aluminum heads. Something like an AFR 185, or a set from Keith Craft. Too bad about your import duties...

[69 Mach I]

Originally posted by CowtownCobra


Be careful now, Mach I, what kind of heads do you have?

Edelbrock Performer RPM alum heads.

[NZCOBRA]

My 351 is a little different , dart 195s , crower pro comp level 4 ,15359. only has 9.4:1 , rpm intake, 830 DP , full MSD , ARP Pro series rod bolts , Aluminium flywheel with steel insert I think it ended up at about 5.9 kg . Im sure your engine goes real good , When I first assembled my motor I used a 164 tooth 11kg steel flywheel (bad choice ) Then I tried a 157 at about 7.9 kg , these last two flywheels really make the engine come alive , my engine only dynoed at 335 rwhp or so with the 11kg . But now with the 5.9 kg it is a really fun car to thrash through the gears, loves to rev to 7000+and is not short on torque at 1000, what I am trying to say is, if 500 hp is what you need for acceleration ,but you don't really want to strip it down or spend a heap more money , A faster reving engine is much the same , mine will rev to 7000 in top gear (150) .Going to the next level will cost , get some use out of your motor

[MidOHasp]

Mach 1...

Not sure if you are still following this thread, but I've been away for a couple weeks.

Porting and polishing your heads shouldn't hurt bottom end torque. I like to oversimplify how heads affect HP and TQ.

Air speed going into the combustion chambers helps torque.

Air volume going into the cc's helps HP.

Porting and polishing should help both.

Larger heads will help volume, and hurt velocity all else being equal. Net: More HP, less bottom end TQ...needs to rev higher.

HTH

[powerpagers]

STROKE & PORT, GO FOR IT !!!!