Beefed up 302 putting out how much HP?

lineslinger · #1 (**permalink**) 10-27-2006, 10:15 AM

I've got a buddy (really, I do) who has just "re engined" his 68' Mustang fastback with a bored and stroked 302. I am still waiting for him to send me a copy of the build sheet so I do not have any specifics yet. Now he is not an engine guy and asked me my opinion of the performance claimed.
The builder claims the car is putting out over 450 hp at the WHEELS with an early production 302 block bored out (don't know how much), polished and ported Edlbk. heads and a demon carb, an Edlbk intake manifold., headers, with an under car exauhst. I don't have any info on the cam yet.
This sounded like a lot of hp to me for this set up. The builder claims pump premium is fine while also claiming the car is an easily managed street machine.
When I get some more specifics I will post them but I really am skeptical of the horsepower claims.....opinions??
Mark

blykins · #2 (**permalink**) 10-27-2006, 10:42 AM

Sounds awfully high Mark. I would think maybe 450hp at the FLYWHEEL from a really warm 347ci....

DAVID GAGNARD · #3 (**permalink**) 10-27-2006, 10:51 AM

Wishful thinking!!!!!!!!!!!!!!!

Compare his motor specs to my RACE motor specs.

1972 Ford 302 Block, bored .030
331 cu. in. stroker, 4340 forged steel crank,forged H-beam rods, forged Diamond dome pistons, 13.65 to 1 compression......
Ported/polished, and other work, Edel. RPM performer heads
Solid roller cam, lift= .586, dur.=288
Edel. Victor intake, port matched to the heads
Slightly reworked Demon carb.
MSD igniton,distributor,plug wires
Double roller timing chain
and a few other odds and ends...........

Motor runs on 110 octane leaded gas.....the motor is actually tame enough to run on the street, if you could afford the 7 bucks a gallon 110 gas, It would not last long on premium pump gas.......

Made 472 hp @ 6400 rpms on the dyno
Made 430 ft. lbs. torque @ 5500 rpms

Recenlty at a Mustang Club car show I was attending they had some guys there with a portable chasis dyno, I tried, but we could not get my car on it, my car is a road race car and really low to the ground......as we were getting ready to try to get it on the dyno the operater was asking about my car/motor specs, he thought I should make about 400 hp at the wheels with my combo, tops............

Not saying your buddies motor is not what it's claimed to be, but he had better have some serouis stuff in it to make that kind of power at the wheels..........450 hp at the wheels would equate to at least 525 hp or more likely 550 hp at the crank!!!!!!!!!!!!!!!!!!

David

Woodz428 · #4 (**permalink**) 10-27-2006, 11:31 AM

There seems to be a big incentive for some engine builders to exaggerate their HP claims. That's why dyno comparisons only have some validity. I think there are a few tricks that you can use to get a dyno to read higher than reality. There is also the different style and mfg. Dynos as well. I think he is a little optimistic. However, if it blows up in a really short time...I guess it could be accurate.

Mister · #5 (**permalink**) 10-27-2006, 12:27 PM

I have a fairly healthy 331, almost 11 to 1, AFR 185's, custom hydraulic roller, Air gap, 650 Demon etc. It made 449 hp at 6,000rpm at the flywheel. I think it would take some serious work, and dollars, to get....what....maybe another 20% out of it. And then I wonder how streetable it would be?
Mike

KevinM · #6 (**permalink**) 10-27-2006, 12:53 PM

Are the Edelbrock heads Performer RPMs or Victor Jrs? If it is performer RPMs there is NO WAY it is making 450 HP at the wheels.

I am reminded that during the late 60's there were 3 kinds of horsepower quoted: At the tires, At the flywheel, and At the brochure. This sounds a lot like the latter.

With a 347 with ported Victor Jr heads, Intake, and a bottom end and cam capable of safely turning 7,500 RPM, it would be possible, but you would have to be pretty hardcore to call that a street engine.

Kevin

Todd Spence · #7 (**permalink**) 10-27-2006, 01:26 PM

My previous car had a new 392 crate motor that ford claims 430 hp. When dyno'd it made 326 to the rear wheels. My next motor was a 1965 427 so that claimed 500 hp motor. It made 374 to the rear wheels. I just had a KC 482 Genesis put in my car. It made 596 hp motor. We haven't had it on the dyno yet but I would be happy with 475 at the rear wheels. It takes a very strong engine to put 450 to the rear wheels.

lineslinger · #8 (**permalink**) 10-29-2006, 02:34 PM

Thank you for the opinions and observations....pretty much along the line of what I had been thinking.
My pal is skeptical as well so next week we are headed to the dyno. Once I get the build sheet I will try to post both it and the dyno results, should be interesting.
Mark

Dennis Kelley · #9 (**permalink**) 10-29-2006, 07:02 PM

450 rwhp is BIG for a stroked 302. Wishful thinking and still streetable. Maybe with a 150 shot of N2O.

later

dennis

Dwight · #10 (**permalink**) 10-29-2006, 07:25 PM

I have a 5.0 EFI with the Holley systemax II stuff. I have all the stuff they recomend plus some. Holley claims 350 flywheel. I had my Cobra dyno'ed 3 times and the best is 305 rear wheel hp. I'm building a 354 and will use the Holley stuff, 36 lbs injectors, plus a custom chip. I hope I can get close to 370 rear wheel. I HOPE! Parts have to be matched and everything tuned just right. I should have the motor installed by Dec and maybe dyno'ed by Jan. I can keep up with a 107 ci ( 100 hp & 100 tq ) Big Dog chopper but can't pass him. Maybe next spring.

Dwight

See yall in June at London

J Persons · #11 (**permalink**) 11-01-2006, 08:53 PM

If you want to compare RWHP to flywheel HP numbers, multiply the RWHP X .12 for a live axle, and X .15 for a IRS. That will get you pretty close.

lnfletcher · #12 (**permalink**) 11-02-2006, 01:12 PM

Quote:

Originally Posted by J Persons

If you want to compare RWHP to flywheel HP numbers, multiply the RWHP X .12 for a live axle, and X .15 for a IRS. That will get you pretty close.

HuH?

Excaliber · #13 (**permalink**) 11-02-2006, 01:14 PM

300 (horse) X .12 = 36

Subtract 36 from 300 and you get 264 RWHP. Probably more like 20% for IRS (oops, .20, or 240 RWHP).

450 at the WHEELS? Whoa, that is one BAD A$$ small block (or so says the brochure).

lineslinger · #14 (**permalink**) 11-02-2006, 03:02 PM

No brochure Ernie, just a builders claim.
Now get a load of this....he had the car out this past weekend and after a quick ride I told him he is putting out MAYBE 400hp at the flywheel which made sense to both of us.
During a little tire screeching coming off of a red light the gear box went down. I scolded my buddy for "goosing" his new motor too much and explained to him about break in etc. and he asked me if this new engine might have caused the transmission problem. My answer to him was that with the engine/tranny combo he has no way should the gear box give up. At first we thought it was the clutch but upon further inspection it turns out to be an internal problem within the transmission.
Its a Tremec 600 (sound like a familiar thread?)

The builder of the car made a two hour drive down here to pick it up and now has it back in his shop.....I can't wait to found out how this one comes out.

Excaliber · #15 (**permalink**) 11-02-2006, 04:38 PM

Tremec 600 you say?

the plot thickens...

footnfan · #16 (**permalink**) 11-02-2006, 06:25 PM

I about a year or so ago rebuilt the engine in 6S2166, primarily a road race GT350....nicely appointed interior etc. It had a way too high strung 302 stroker that required 110 octane gas at all times.

I bought new Canfield heads, lowered the compression, and gave the engine to Orlando Mustang .....and pro engine shop in Orlando ( CRE machine) to make more streetable. I did request engine dyno sheets prior to taking delivery of the engine...and I had the pleasure of filming the action. It is a true R FMS block with mostly off the shelf bits.

Final result....552.1 Hp at 7100 RPM and max torque was 447.7 at 5300. It is a little lumpy...rough..off idle, but it is one heck of a ride. Great 302, light weight, but a bit peaky....but it sounds like a CART car revving up. It has yet to meet a fart can car that it likes!!!

I crave finding medallion wearing corvette drivers.......ok, I just won't go there. It is a great car to drive for fun. Next event, Florida SAAC event at Daytona in a week or so.

All the best

DC

Excaliber · #17 (**permalink**) 11-02-2006, 06:44 PM

I was just reading the latest issue of "Hot Rod" (yeah, I still like that rag, been reading it since I was a kid).

Anyway, they noted that typical 'well built' modified modern engines put out about 1.4 horse power per cubic inch, on average. Considering that for MANY MANY years 1 horse power per cubic inch was sort of a holy grail thing we've sure come a long way!

You can get 400 horse (flywheel) from a 302 running STOCK pistons and lower end components by simply bolting on readily available cost effective modern parts. Heads, intake, cam, EFI components etc. NO power adder needed, THAT is quite impressive. Want to get wild? Yeah I can see 500 plus out of a stroked and mild bore 302. Not that common, but 'can do'!

Assuming a typical 'build up' for a 302 brings it to 347 cubes X 1.4 = 485 horse. The KEY is knowing what parts work together well, it's the total PACKAGE that determines the final output. Mess with the recipe, even just a little, and you could LOOSE (or GAIN) a lot. Tricky stuff getting it right.

Sounds like Orlando Mustang has the recipe 'dialed in'.

Philm · #18 (**permalink**) 11-15-2006, 06:04 AM

I have a small block built arround a Dart 302 block with the 4.125 bore. Forged stroker crank, rods and pistons. Solid roller cam, 8 throttle body injection etc. The engine runs well on 98% octane pump gas.

I have had it on the dyno today and it produced 410 RWHP at 6500 rpm and the torque flatlined at 350 footpounds very quickly. It was still making power but I didnot want or need to push it any harder.

The engine has soild components but nothing exotic. I assembled the engine myself but the engine design was left to a pro builder with many years of testing and proving.

The combination of parts, compression ratio, cam specs or if you like the "recipe" was worked out before any part was bought or machined and we never strayed from that.

AS you have said it is the conbination of parts that makes good power.

Phil

J Persons · #19 (**permalink**) 11-15-2006, 08:04 AM

Quote:

Originally Posted by Philm

I have a small block built arround a Dart 302 block with the 4.125 bore. Forged stroker crank, rods and pistons. Solid roller cam, 8 throttle body injection etc. The engine runs well on 98% octane pump gas.

I have had it on the dyno today and it produced 410 RWHP at 6500 rpm and the torque flatlined at 350 footpounds very quickly.

Phil, could you share the details of your engine? Heads, stroke length, compression? I'm planning a large bore stroker small block, based on the new Boss 302 block, whenever it becomes available. My current 331 did 372 RWHP @6100 with 9.25 compression, and on 87 octane pump gas. Torque was 340 ft/lbs @5100RPM. This is with a Holley 650 DP carb.

jmarsey · #20 (**permalink**) 11-15-2006, 08:43 AM

Ok, since we're talking about the potential of one of the best engines Ford ever designed, if not thee best, I'll chime in too.

My Boss inspired 302 is a 302-R block, 331 stroker, 10.5:1, solid roller, neutral-balanced, Yates Heads, Roush intake, 750/4150 Holley which now has 2200 street miles including 3 days on a road course. Currently the main jets are #75 square and likes 30 degrees. Funny thing is, there is maybe another 100hp with a bigger cam, higher compression, and more rpm, if you were looking for max hp.

Last time it was dyno'd it made 580hp @ 7,000 and 460ft @ 4800. It will cruise all day at 2300 rpm. It has good mid range power, insane top end and starts on the first crank every time. I wouldn't say it was easy to drive around town but that’s all part of the fun. Oh yeah, it runs great on pump gas. Show the colors!

Talk soon, John