what does it take to rev a 302 to 10K???
 

Ok, I am having a dissagrement with a guy at school. He says you can get a 302 to wrap 10K for about 5K if you do the work. I say this it BS.

So my question is....What would it take and how much would it cost to get a 302 to rev realiably up to 10,000rpms?

I think it would eat 5k up. Maybe not alot over but it would be closei think. First off good heads, no great heads. Extremely light rotating assembly - billet crank, aluminum rods and forged pistons. Must have a good cam( no idea on specs for that bad boy) I seen one 306 turn 9500 and it was a screaming little bit*&. It was wound about as tight as I'd want to wind one. It had all of the above, a girdle, and was built to the "T" if you will. No idea how much was invested though. I'd say it could be done for 5K if you had access to the machines to do the block yourself. A larger bore nad shorter stroke would also come into play. Makes torque and can be turned higher. Still wouldn't be easy to turn 10k.

Brad

It would take a miracle, after blowing about 4k on the bottom end, you would need another 3-4 k, probaly, "just guessing" to strenghten the valvtrain, hydralic lifters would be out of the question, as the hydraulic cam would probaly melt, and the oiling system would have to be a nascar like design, however that would work? the guys in the hot street classes see 9k rpms i believe, and im willing to bet they sink over 10-20 k in a motor, but im no expert, lemme know if you can build a monster like that for 5k, i would love to see how many times it would actually see 10k rpms, maybe one pass:rolleyes:

this is how
 

get a 302 cc crotch rocket :D thats the only way i can think of for 5k hehe....get em boys

I doubt it would take just 5000 grand. I think maybe for 10,000 an engine could be made to the right tolerances, but 5000 just doesn't seem like enough. People that have a sbf running 9000+ rpms have thousand in their engines. I know a guy that has over 25,000 in his engine to get it to turn those rpms. Hope this helps.

-Billy

On horse power TV they had a 283 on there that would rev 10,000 rpms....That is the only V-8 that I know for a fact revs 10,000 rpms in a street car.

You maybe could build a 302 that could rev 10,000rpms for 5,000 bucks, I dont think that you would hit 10 grand very many times before you need a tow truck though.

Technicaly he is right if you knew how to do all the work yourself you could build a 10,000 rpm 302 for 5,000 bucks. No way it would be reliable though.

You would need some VERY lightweight and NEAR PERFECT machining and tolerances as well as very little imbalance to be able to rev a 302 that high "reliably". I suppose you could invest in a rotary valve cylinder head and get a well put together bottom end for around $5000 for just the main parts, but you'd have to machine and balance everything yourself. Chances are unless you get parts for free, you'd go over the 5,000 dollar budget pretty quick. There's alot of inertia and rotating mass forces going on at 10,000 rpm. I can't see it being done for $5,000. Now 8,000 rpm possibly, but not 10,000

Pretty much everybody that runs in Hot Street and I believe a few Pro-5.0 guys spin their motors PAST 10k rpm. I remember reading about a Hot Street Racer named Sam LaManna that shifted his car at about 10,500 rpm. :eek:
I'm not sure what his setup was, but any engine component that moved would have to be the lightest on the market. Also, most of the hot street motors are 360-400 inch small-blocks, have C/R's around 15:1 or more,and heads that flow close to 400cfm.
So it is definitely possible, if you want to spend the big bucks and change valve springs every month.

Boss 302 engine.
lightweight pistons
aluminum rods
crank work
serious timing set
ported boss 302 heads
mondo springs, lightened valvetrain
wicked cam

I'd be willing to be that setup could see 10k. Probably over $5000 to build.

are you talking reliably for a long period of time?


If your talking about kissing 10k for a couple seconds, then

Big carb
Single plane intake
Big headers
big compression

solid roller, small valves, heavy springs.

stock recipocating assy.


I've got a brand X motor that was low compression and basically the same as above. its seen 9,000 rpm + numerous times, a few seconds at the time.

A purpose built block, pneumatic valvetrain, titanium everywhere....you see where I'm going

Call Cosworth...there's run 14,500 rpm.

My friend paid 5 k, for a built and installed 347 that he shifts at 7k, and it pulls all the way to 7 and makes power probaly higher, it's forged pistons, crank, 10:1, stage 3 tricks, sometimes open headers, vic jr intk,

just think, a little more compression, solid roller, and some invinsible head gasket and race gas, i could see how it could go 9500.

A destroked 302 could turn 10,500. It would take alot of money. Coupe your talking a 2500 rpm difference, there is a huge difference between 7,000, and 9,500. Not saying it couldn't be done, if you wanted any kind of longevity it would take the big bucks $$$, My 383 will turn 7500, for how long? I personally don't want to find out. Peak hp is around 6500 at the moment with the current cam set-up. :)

yea i know, but Im just saying it was installed, ready to run for that price, so built and installed yourself, i guess it could be done for around 5-8 k, how reliable is the big question? might be spending 5k every time you rebuild, which would probaly be frequent, and the poor tranny would have to be a piece of $$ work too.

Wouldn't cost much of anything to destroke a 302. Just get a 289 crank.

There is a formula based on piston speed (and thus, stroke length), that determines an engines theoretical top speeds. It sheds some interesting light onto which engines would be better for high rpm modification. For example, all things being equal, a Chevy 327 has a max potential of 11,077 rpms, while a Pontiac 326's max is only 9600 rpms. Why is it that the Chevy has a max potential that is nearly 1500 rpm higher than that of another GM engine of virtually the same size? The stroke. The Pontiac 326 crank has a stroke that is 1/2" longer than the Chevy 327.

Using this formula and late 1980's parts, and classifying the engine as Stock (stock), Heavy Duty (stronger, factory parts), Built (mid budget aftermarket parts and machine work), and Race Only (the best parts and machine work available), the following are the theoretical limits for Ford engines:

Engine / Stroke / Stock / Heavy Duty / Built / Race Only

Small Block

289 ci / 2.870" / 7,317 rpms / 8,362 / 10,452 / 12,544

302 ci / 3.000" / 7,000 rpms / 8,000 / 10,000 / 12,000

351 ci / 3.500" / 6,000 rpms / 6,857 / 8,571 / 10,286

400 ci / 3.750" / 5,600 rpms / 6,400 / 8,000 / 9,600

Big Block

390 ci / 3.780" / 5,556 rpms / 6,349 / 7,937 / 9,524

427 ci / 3.780" / 5,556 rpms / 6,349 / 7,937 / 9,524

428 ci / 3.980" / 5,276 rpms / 6,030 / 7,538 / 9,045

429 ci / 3.590" / 5,850 rpms / 6,685 / 8,357 / 10,028

460 ci / 3.850" / 5,455 rpms / 6,234 / 7,792 / 9,351

Now, keep in mind that these numbers reflect the rpms at which the engine will hold together. For the actual max rpms, other factors need to be considered. This, however, is an excellent starting point for referencing an engines potential.

Take care,
-Chris

What exactly is this formula??? You said there was a formula, but you only gave us the results. I only ask because I'm an engineering student and would like to have a basic concept on this.

Piston speed, which is the speed at which the piston travels between BDC and TDC in each stroke, is the determining factor. A piston makes two full strokes, one up and one down, during each crankshaft revolution. Therefore, the mean piston speed in inches per minute would be two times the stroke in inches, times the crankshaft revolutions per minute (rpm). The result is divided by 12 to convert it to feet per minute (fpm). The formula is:

Piston Speed in fpm = 2 x stroke in inches x rpm / 12.

By dividing the numerator and the denominator by 2, you can simplify that to:

Piston Speed in fpm = stroke in inches x rpm / 6.

With todays technologies, the following Piston Speeds are the widely accepted limits for the classes I listed:

Stock: 3500 fpm
Heavy Duty: 4000 fpm
Built: 5000 fpm
Race Only: 6000 fpm

To determine the rev limits, the formula is:

RPM = piston speed in fpm x 6 / stroke in inches.

Thus, to determine an engines maximum potential rpm, based on piston speed, divide the following by an engines stroke:

Stock: 21,000
H.D.: 24,000
Built: 30,000
Race: 36,000

This becomes interesting when you really stop and think about it. In a Ford 302 spinning at 7000 rpms, the piston travels from a dead stop to nearly 40 mph, and back to a dead stop, in only 3 inches!!!

(to convert fpm to mph, multiply the fpm by .0113628)

Did that help?

Take care,
-Chris

Thanks for the formula. I can now rest easy as an engineer.

:D

Take care,
-Chris