7100 RPM too much ? - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

barman5 · 04-07-2006, 03:09

Im concerned that my std bottom end is going to fly apart...
Ive got a 302 60" over std heads rods and bolts, Ive put an Elderbrock performer, 650 Double pumper and a bert jones cam (i had to shim under the rockers to get it to run) It doesnt idle under 1800 rpm and ive had the rev limimiter 5500 but on my last run i had a rush of shit to the brain and upped it to 7100 and it loved it never missed a beat. oh yeah its in a datsun sunny burnout car with a C4 and a GTR bango diff 2.78 ratio. It spins in top and holds top on the donut pad, Should i lash out and put ARP rod bolts ?

jas24zzk · 04-07-2006, 09:17

Mate,
if you have the money to run a burnout car....who cares if it goes bang....half your points com from crowd cheers!

and if they are catching red hot pistons they WILL cheer!

The fact you are 60 thou over is a bigger concern to me!.. 7100 its pittance! have seen 351 clevo's pull strong to the limiter @ 8500 and myself owned a 186 that spat 226kw at 11400.

RPM will only kill if your parent materials are substandard (also factor in build quality)

Jas

madmelon · 04-11-2006, 05:03

Think of it like this- 302W is a rather short stroke motor. Shorter stroke= higher allowable revs. I think your stroke is 3in, (about 76mm) where ford mondeo V6 has 79mm (and shared with jaguar AJv6 and astonn martin V12) and they can go as high as 7400 in the aston V12, 7000 in the Jag motor and i'm not sure in the mondeo.
The big thing is how long it stays at those revs. Being a burn out car I'd imagine it would be up there often and for a lengthy time. While i have no experience with windsors (or any motor really) I'd be leaning towards strengtherning the bottom end.
It's all about fatigue- and the life of the fatigued component goes down exponentially when revs go up.
Eg- doubling of strain in a piece of steel can reduce it's life from 5,000,000 cycles to 20,000 cycles before failure. PM if you want more info.

ebxr8240 · 04-29-2006, 05:53

The block is the weak link...
Keep it under 6500...

garth04 · 04-29-2006, 06:06

You really need to dyno the vehicle and find the rpm where its torque peaks, thats where you need to keep the motor running at for your burnouts.

Freshmeat · 04-29-2006, 06:50

I've known 302s to hold 7,000 RPMs all day with only a valvetrain swap. The ".060 over bothers me, too, but just be sure to bring it back down every now and then to make sure it'll have a chance to rest. Also, make sure you have a kick ass cooling system and you really shouldn't have a problem.

AXR88U · 05-06-2006, 16:38

Have you seen the standard bottom end on those ?
At the bare minimum I would get some decent rod bolts for the 7100 that you are pulling.

Freshmeat · 05-06-2006, 18:28

Considering people spin 'em up to 6,500 without any mods, the 7100 isn't bad. ARP rod bolts would be a good idea, for reliability, but the bottom end should hold just fine as long as it's getting sufficient oil (high volume pump, perhaps?)

jas24zzk · 05-07-2006, 05:13

On Madmelons comments...
i will stand corrected...... but i thought the 302 was a square engine... bore size = stroke...same as a 186 holden red. 4"x 4"

My understanding is, over square.....Long stroke, short bore = torque! and undersquare, Large bore, short stroke = High RPM, low torque high horsepower.

Cheers
Jas

AXR88U · 05-07-2006, 15:43

You've got them arse about face.
Over square is a larger bore than stroke.
302 has 4" X 3" (bore/stroke).