Easy Horsepower???

[ronzara]

I am looking to get 325-350 HP from my 1973 351W.

Call me skeptical, BUT........

Here's the claims:

1. Windage Tray: claims of +20HP
2. Roller Rockers: claims of +15-40HP
3. Underdrive Pulley: claims of +15-20HP
4. K&N air filter: claims of +10-15 HP

Are they trying to tell me........ Just by bolting on this stuff (Less then $300), I could go from a stock 225HP to between 285HP & 320HP ??????

If this is true, why would I spend $2500 for a set of aluminum heads, Cam, Intake, Lifter, Pushrod, Valve Springs, Valves, Retainer, Gaskets........ TO GET 75 MORE HORSEPOWER????

RZ

[427 S/O]

Oh please.............

[Excaliber]

Good point, and yes I'm VERY skeptical of such horse power claims in the "real world" by simply bolting this or that on.

I think these hp gains are not done in the real world. They are done in a labratory type environment. No doubt K&N filter will increase hp. But will it be 10 to 15 hp for the "average" application? Gimme a break! 10 to 15 hp over a poorly engineered factory setup MAYBE. Find a particularly offending vehicle with a lousy intake design. Put on the new K&N filter and measure the dfiference. OK test looks good, print the Ad! OR the hp gain could apply only at extreme rpm conditions to certain vehicles with OTHER modifications all ready in place. Same thing for windage tray. Zero impact unless your talking high rpm and in CERTAIN conditions with CERTAIN vehicles.

My opinion, and I could be wrong (nah, not possible):
Generally speaking ALL the above items are "good". Generally speaking NOT as good as the "Ad" states.

Ernie

[Whaler]

LOL
Don't forget to mention that ANYTHING with the additives... "Linkite" or "Teflon",
should provide large increases in HP and at the same time save on fuel!

My personal fave is when I hear of greater power when switching to a synthetic oil. "Less friction"

Seriously you have to also look at the HP to be gained when going away from a belt driven fan to an electric fan.

There are many little cumulative HP gains to be made. Just as there are numerous ways to chop weight in a car.

The lists go on.

Tim

[Harris]

Ron,
I agree with Ernie and the other posts. If you added everything on your list you might realize 30-35 horsepower, tops.

(I hope I didn't double post)

I once did almost the same thing to a 351C, plus a better cam and I came out with about 40 dyno horsepower.

Harris

[Hal Copple]

with good aftermarket heads, and a good intake and exhaust, i see no reason why you can't pull about 400 or so from a sturdy 351.

[Excaliber]

I agree with Hal on the heads, intake and exhaust mods.
Your post indicated 75 hp for similiar mods, a good conservative number! In contrast to the other bolt on goodies, 75 hp for THESE fundamental items seems on the "low" side.

Head, intake and exhaust is EXACTLY where the horses are found! Now, which ones and do they COMPLEMENT each other is the KEY! You do all that to a Ford EFI 302/351, for instance, and then expect the "stock" throttle body and injectors to "work" with the new mods, think again! Go with a 75 mm throttle body, 24 lb injectors, new mods and NOW were talking some serious HP gains. Got a carb? Same rule applies, might need to re-jet or get bigger.

How to find ALL the matching pieces to the puzzle is the trick!

Ernie

[Bannon]

In my experience Underdrive Pulleys are worth about 6-7 hp and an K&N filter is worth about 3 hp on a 215 hp 5.0 liter.

I did these mods plus a Flowmaster cat-back exhaust and timing advance on my 95 mustang GT and pulled 192hp at the rear wheels. I never measured before hand but given the typical 15-20% driveline loss the motor should have pulled between 172-182 hp at the wheels stock.

A K&N might be worth 15 Hp on a 700 hp motor if the alternative is a stock paper filter

In my experience you need to be careful with underdrive pulleys. If your cooling system is adequate to marginal, underdrive pulleys will get you into cooling trouble fast. My Mustang ran hot in the Texas Summers after putting on the underdrives.
My point is that some cheap horsepower gains are a tradeoff... A K&N might be worth 15 Hp on a 700 hp motor if the alternative is a stock paper filter. When I visited Bob Norwoods shop in Dallas Texas several years ago I was told yep, K&N's will gain you some power but you know what, they are a crappy "Filter".

I agree with the other folks here, to some extent you've got to pay to play. Go for the heads and intake/cam combo and you should at easily exceed the HP numbers you are looking for.

Good Luck,

JB

[bmalone]

Rarely, if ever can you expect to bolt four different types of things on an engine and EACH one is going to provide X additional HP. It doesn't work that way. In order to realize horsepower gains, the components must work TOGETHER to complement the whole--and the types of changes should complement what the engine is built for--torque, high rpm power, etc.

AN IC engine is a like an air pump--the more mixture that can flow through it--the more HP. That's why cam (determines how far and long the valves open), and head work--or more efficient heads (more flow again) will result in more HP. And adding cubic inches.

[Excaliber]

wait a minute,,,,isn't "easy horse power" an oxymoron?

Ernie

[ronzara]

Thanks guys,....
My point was:
I wish all these adds that try to get you to buy a specific "bolt on" item due to claimed (read: EXAGGERATED) HP gains would be more realistic.

In fact I just got a new Comp Cams Duel Energy Cam Kit (.500 lift) , Lifters, push Rods, Springs,..... looking for an Edelbrock Performer Manifold (unless otherwise advised)...... Thought this would be the best rough to work with my stock converter (C4 trans).

I have a 1973 351W with 1970 4v heads and manifold. I read the valves are 185cc intake and 155cc exhaust with a 60cc Combustion Chamber. ....... I was figuring on porting the exhaust and shaving them .10 to get compression up.
It has a vacuum advance distributor w/stock coil. Stock Water Pump.
Road Demon 625 which should easlily handle the upgrades.... It's leaned out as far as it will go now.

I'd like some imput on what else to do to get to my power goal (without taking out a 2nd morgage).
RZ

[dkjos]

Ron,
This combination was good for 351 HP at 5300 RPM on the dyno:
351W .030 over (pre '74)
Ford GT40P heads
Comp Xtreme Energy Cam(XE 274H)
Edelbrock Performer Intake
Edelbrock 600 CFM Carb

The GT40P heads are inexpensive and were recommended over re-working the stock heads. CR is 9.5:1

The Performer manifold will limit your RPM range compared to the Performer RPM, but I wasn't looking for a high revver.

[ronzara]

dkjos,
Thats a good amount of HP.

Only problem I've heard about the "P" heads is it needs specific header flange???

Do your gt-40p heads have a 64cc Combustion chamber?

I also like the performer Intake. I am not looking for high RPM's. I am looking for Torque and good crusing.
I have found a set of heads..... see my newer Post Questions about SVO ALUMINUM HEAD APPLICATION.
thanks.
RZ

[flipper35]

Hot Rod TV dynoed a car (about 400hp) with regular oil (engine,tranny,diff) and then with Royal Purple and gained 22 or 27 hp at the rear tires. Also saw dyno results from a C-5 vette getting 4hp by switching to Red-Line Shock-Proof diff lube over another synthetic lube.

I wish I could add a Tornado, Prolong, and all these other things. With all the products out there we should all be able to get about 900hp.

[DAVID GAGNARD]

Ron;

I think your goal of 325-350 hp is very acceptable with the combo you are talking about.... I have a similar combo on my car although I have never had it dynoed....I have used the desktop dyno on engines that have been dynoed and the results are real close....

I can not remember the company,but they flowed tested a bunch of heads from the early 289's to 351's to the newer aluminum heads..... They found that the early model heads like you have that have been ported and polished will flow almost the exact same numbers as the Edelbrock Aluminum heads out of the box. Granted you can take the aluminum heads further,but the old iron heads are still pretty good if you can rework them.... I would use a good Edelbrock Performer RPM manifold rather than the stock manifold though....My cam specs are about the same as yours and my heads have been ported-polished-gasket matched,I use the Edelbrock Performer RPM amnifold with a Holley 600 vac sec. carb and this motor runs great and get 23 mpg on the highway with a 5-speed tremec..

I would go with an MSD distributor (see my thread about MSD+K&N=gas mileage) as I find the Duraspark distibutor has too much "slack" in it and the MSD unit can be set on each end for your advance.....

350 hp from your combo is very realistic and will make a very reliable motor that you should get plenty trouble free miles out of....

David

[dkjos]

Ron,
The GT40P heads have a different spark plug location, so they do require a specific header or some hammer work. I'm not totally sure, but I believe 64CC is right for the chamber volume

As far as the manifold goes, I would have probably used the RPM, but my car doesn't have a hood scoop so I opted for the Performer, which is a little lower. I expect the performance difference would just be a shift upward in the power band and perhaps a little extra HP. I'd rather have the grunt at lower RPM's and this combo gave 390 FT/LB plus from 2500 to 4400 RPM.