best ways to get to 300-400hp?

Alarus · Feb 5, 2006

i think i was told that i had the larger 8 in, is there a small and a large and whats the diff?

LUCAFU1 · Feb 5, 2006

look at the front of the third member under the d/s. if the two bottom nuts can be removed with a socket then its a 8", if you need a wrench its a 9". There are two 9" rear ends, a big bearing and small bearing, you need to measure the the distance between the bolts up and down, left to right on the housing ends to find out which is which.

180 Out · Feb 5, 2006

Alarus said:
what is the power to waight % between the 460-302/351

According to Ford data, a 460 weighs 644 lbs and a 351W weighs about 518 lbs.

Power to weight depends on the level of the build up. At a relatively mild 1.0 hp/ci, the 460 returns 0.71 hp/lb, and the 351 is 0.67 hp/lb. At 1.5 hp/ci, a 460 does 1.07 hp/lb, and the 351 does 1.02. (Actually, the 528 hp Windsor is making NO power, because the block just split. )

But the more meaningful number is that the 1.5 hp/ci 460 is making 690 hp, while the 351 is making 528. That 162 hp is more than enough to handle the 126 lb difference in weight.

Alarus · Feb 5, 2006

ok in stupid please, i dont get on till 5 hrs past my bed time so im always drained, what your trying to say is that the 460 will make more than enuf power to out performe the 351 even with all the extra waight? (i kinda figured that, but the main question i guess im trying to ask is would it be worth it to have a 460,351 or a 302?

________________________________________________________________________________________________OK now , what kind of power would i be looking at with a stock 302, then add heads, cam, good coil and electronic points? would i be up to around 300?, before i do any of this im gonna try to take it to the track (witch means i have to get a new battery hold down thingy, and new tray)then do a before and after time slip thing

Edbert · Feb 5, 2006

Hack said:
I remember last year there was a guy on here that had destroyed several (was it 5?) 8 inch rears. They were all built up with good parts too, IIRC.

I wish I could remember what he was doing, how much hp, etc. but I think it was hard street driving. Maybe he will find this thread.

Yup, I recall that as well. It wasn't all on the street though, at least one of them blew at the track.

Remember, power does not break drivetrain components, traction does

Of course the more power you have the more likely to blow up you'll be, I was making a point though that heavy launches with slicks and a well set-up traction system can blow an 8" rear with less than 300rwhp. But for mild street driving on skinny radials they can live for a long time behind 450rwhp. The problem is who has 450rwhp and never romps on it or takes it to the track?

Just consider that the 8" needs to be stronger than the traction your tires have and you "should" be okay.

Edbert · Feb 5, 2006

Alarus said:
ok in stupid please

I do not want to appear condescending here, I am trying to help and provide what you asked for...

What 180 Out was saying is that the power output of ANY engine can vary considerably. In stock form most of these motors make about 2/3rds of a horsepower per cubic inch. A typically strong but modest, inexpensive, reliable and acheivable goal for a motor is a 1 to 1 ratio, meaning the 460 would make ...ready?...460hp and the 351 would make....ummmm....351hp.

So using the performance build of 1 to 1 the extra 109hp would just about cancel out the extra weight performance-wise. The bigger motor's advantage is coolness factor, the smaller one's advantage is handling (for normal street there's little difference) and fuel economy.

The reason the 460 was mentioned though was that you could get the 400hp from it with less expense than it would take to get it from a 351W, and MUCH less than it would take to get 400hp from the 302. So for those comparions we aren't talking about them all having that 1 to 1 ratio.

Hack · Feb 5, 2006

Edbert said:
I do not want to appear condescending here, I am trying to help and provide what you asked for...

What 180 Out was saying is that the power output of ANY engine can vary considerably. In stock form most of these motors make about 2/3rds of a horsepower per cubic inch. A typically strong but modest, inexpensive, reliable and acheivable goal for a motor is a 1 to 1 ratio, meaning the 460 would make ...ready?...460hp and the 351 would make....ummmm....351hp.

So using the performance build of 1 to 1 the extra 109hp would just about cancel out the extra weight performance-wise. The bigger motor's advantage is coolness factor, the smaller one's advantage is handling (for normal street there's little difference) and fuel economy.

The reason the 460 was mentioned though was that you could get the 400hp from it with less expense than it would take to get it from a 351W, and MUCH less than it would take to get 400hp from the 302. So for those comparions we aren't talking about them all having that 1 to 1 ratio.

Very well said. Another thing to consider is that horsepower = torque at about 5200 rpm. Below that, torque is > hp. Why do we care? Because a street driven engine spends most of its life below 5200 rpm, peak hp isn't the most important thing when considering whether a street motor will seem powerful.

A NA 302 at 400 horsepower will be spinning FAST - it just doesn't have the displacement to make that much power at a low rpm. That's hard on every part of the engine, and you don't feel that power when you ease out the clutch at 1,000 rpm and push down on the pedal. In fact, the changes you make to get 400 hp up top in a NA 302 are likely to decrease the torque you feel at 1,000 rpm.

A NA 460 at 400 horsepower will be working at a much lower rpm. The torque generated is higher. So when you ease out the clutch at 1,000 rpm and step on it HANG ON! I do think of a 460 as somewhat over the top for a street driven car, but I imagine it's fun.

Alarus · Feb 6, 2006

im sorry about that its just that sometimes i dont do too good understading one persons way of saying it, if i hear/read 2 or more its easer to understand, that and i dont get on till about 11:00 at night, or 8 in the morning, and i dont go to sleep till about 2-3 in the morning, and ilike my sleep,

What about 300 hp, thats what im mainly looking for, i was just kinda wondering how much harder it would be to get to 400 and what it would take/how hard it would be...NOW...how much better would it feel with 300 hp, i was told that i prob only have 150(and is that fly or wheels)but anyway, back to a question i asked before, what would just heads and a cam do?(together and seperate)

Also id like to just say THANK YOU ALL VERY MUCH FOR ALL THE HELP YOU HAVE GIVEN ME!!!

Regardless i think im gonna keep my engine and just do heads, cam, hedders, and ignition stuff im just wondering what kind of gains i would feel, right now i feel perty good when i stomp on it and it chirps when it goes into 2nd, but how much more power would it have with all of the above and would i be able to feel a big diff. when i floor it?

jerry S · Feb 6, 2006

never mind

LMan · Feb 6, 2006

Alarus said:
ok in stupid please, i dont get on till 5 hrs past my bed time so im always drained, what your trying to say is that the 460 will make more than enuf power to out performe the 351 even with all the extra waight? (i kinda figured that, but the main question i guess im trying to ask is would it be worth it to have a 460,351 or a 302?

________________________________________________________________________________________________OK now , what kind of power would i be looking at with a stock 302, then add heads, cam, good coil and electronic points? would i be up to around 300?, before i do any of this im gonna try to take it to the track (witch means i have to get a new battery hold down thingy, and new tray)then do a before and after time slip thing

Are you old enough to drive?

180 Out · Feb 6, 2006

Alarus said:
What your trying to say is that the 460 will make more than enuf power to out performe the 351 even with all the extra waight?

If you play around with the formula for converting trap speed to horsepower (rwhp = (trap speed/234)^3 x weight), you find that in the 105 to 110 mph range (which is where most 12 second cars trap), about ten pounds is equal to one rear wheel horsepower. That is, a 12 second car trapping at 110 mph which adds one horsepower and ten pounds will still have the same trap speed.

So the 644 lb 460 only needs to put out about 13 more horsepower than the 518 lb 351W, in order to make up for the additional 126 lbs and trap at the same mph as the 351W. 13 more horsepower out of 109 more cubic inches is a given. In fact, at a real world streetable 1 hp per cubic inch level of build, you'll be making 109 more horsepower. That's enough for the 460 to handle 1000 extra pounds, and still trap at the same mph as the 351.

THAT'S why they say there's no replacement for displacement.

I also question whether 126 more pounds is enough to make a really big difference in handling. Granted, that big block planted right on top of the front wheels, and with a lot of the weight high up in the heads and intake, are not good things. But I have a '65 289 fastback Mustang and a '70 351C Cougar, and both of these cars just plow and plow and plow when cornering. Another 126 pounds could hardly make them plow any worse. If anything, the 460 would help the chassis rotate with power oversteer, which my mild engines can't do. Therefore a 460 might actually shave a few seconds on the road course.

Alarus · Feb 7, 2006

LMan said:
Are you old enough to drive?

are you serious, im a cupple months away form 19..."I" bought my car, "I" am on the title...do you think im i kid just becuse ifeel i shoud be asleep at a serten time becuse i have a job where i work all day? becuse im stupid in the car world, or is it becuse i cant spell worth a crap?......im here to learn all i can, and give what imput iknow, so far i have learned ALOT from everyone here and i thank you all...is it really nessesery to call me a kid?

Edbert · Feb 7, 2006

Alarus said:
is it really nessesery to call me a kid?

Don't let folks get to you dude, be the duck.

Besides, nothing wrong with being a kid in the first place, although I still feel 25 it has been a long time since I was called a kid, I have a kid older than you, and I only WISH & DREAM that he was willing to work full time and buy a car rather than mooch off his mom's biological urges.

Don't feel bad about asking stupid questions. In my opinion there are only stupid answers and those too stupid to ask in the first place.

jbuening · Feb 7, 2006

My advice would be to go to the local junk yard, get a 1994 or later 5.8L truck motor (351w), and buy a 393/408 stroker kit with a decent cam and AFR 185 heads. The truck motor won't cost you much, it is already a roller cam motor (definite plus), and you can slap an intake and carb on it. No need for nitrous or a supercharger, but you still have close to or over 400rwhp. Stroker kits start a little over $1k, heads will run $1300 or cheaper if you can get a used set off ebay, and the cam/lifters will be around $200. I've seen guys pick up the truck motor complete for around $200. Some machine work will be needed for the rods to clear the block (stroker only).

Then after that, you'll still want more power and you still have room for poweradders. Just don't neglect your trans/rear with the addition of all this power.

LMan · Feb 7, 2006

OK, no offense intended. I was having such a difficult time reading/deciphering your posts that genuine doubt came to my mind.

Carry on with your regularly scheduled program...

HistoricMustang · Feb 7, 2006

Alarus said:
are you serious, im a cupple months away form 19..."I" bought my car, "I" am on the title...do you think im i kid just becuse ifeel i shoud be asleep at a serten time becuse i have a job where i work all day? becuse im stupid in the car world, or is it becuse i cant spell worth a crap?......im here to learn all i can, and give what imput iknow, so far i have learned ALOT from everyone here and i thank you all...is it really nessesery to call me a kid?

Old LMan has been going round and round for too long. He tends to get a little dizzy so pay him no mind!

HistoricMustang
www.historicmustang.com

He did this stuff too much:

www.historicmustang.com/pearsonhenrywaveby.html

Alarus · Feb 8, 2006

jbuening said:
My advice would be to go to the local junk yard, get a 1994 or later 5.8L truck motor (351w), and buy a 393/408 stroker kit with a decent cam and AFR 185 heads. The truck motor won't cost you much, it is already a roller cam motor (definite plus), and you can slap an intake and carb on it. No need for nitrous or a supercharger, but you still have close to or over 400rwhp. Stroker kits start a little over $1k, heads will run $1300 or cheaper if you can get a used set off ebay, and the cam/lifters will be around $200. I've seen guys pick up the truck motor complete for around $200. Some machine work will be needed for the rods to clear the block (stroker only).

Then after that, you'll still want more power and you still have room for poweradders. Just don't neglect your trans/rear with the addition of all this power.

that dosnt sound too bad, i might be looking into that, just get all the kits, (stroker kit, heads, cam, and full engine gasket kit) and start from scratch, put it together on my time away from work, and then take a weekend to drop the engine in the old girl...Note that this is all still the planning stage, im gonna have a wedding to help payfor come aug26th

Also im sorry about blowing up lastnight, i just had a little bid of a long day...anyway i apologize, no hard feelings , and i understand what was being said, i am confuzing sometimes

best ways to get to 300-400hp?

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