Max Horse Power for Ford 302 block

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ENGINEX
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Max Horse Power for Ford 302 block

Postby ENGINEX » Tue Jan 01, 2013 10:44 pm

How much HP can a Ford 302 block take in a mild road race ap. ?
11 to 1
solid cam
standard stoke 3.00
Windsor 2.02/1.60 heads
RPM limit 7k

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Re: Max Horse Power for Ford 302 block

Postby MadBill » Tue Jan 01, 2013 10:55 pm

We've run a dry sump 306 SBF road racer with an original 1970 Boss 302 block for 4 years; 2 making 500 HP @ 7300 RPM with Crower crank and rods, Wiseco pistons & 11:1 CR and 2 with it freshened via 12.5:1 TFS 185 CNC heads and a solid Jones roller to 625 @ 8,000. We just pulled it down and (almost*) everything looks perfect. *Rocker studs showed some fretting distress, as did the damper bore. The univeral opinion is we've been deep in the Red Zone since day one. [-o<
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Re: Max Horse Power for Ford 302 block

Postby dfree383 » Wed Jan 02, 2013 1:43 am

450-500 is about it for a regular 2 boult block with any reliability IMO, Drag guys get away with more for awhile.

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Re: Max Horse Power for Ford 302 block

Postby Walter R. Malik » Wed Jan 02, 2013 11:21 am

This will depend upon a lot of other influences.
Keeping it out of ANY detonation, getting the horsepower through high RPM instead of brute torque and NA horsepower instead of "pressurized" power will raise the amount of horsepower which the block will be tolerate.
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Re: Max Horse Power for Ford 302 block

Postby Erland Cox » Wed Jan 02, 2013 11:40 am

One of my customers broke a 289 block with approximately 430 hp.
It separated above the mains and it has not been detonated.
It was run in road racing and lasted for 2 years.
It is a copy of a Daytona Cobra with IDA 48:s and tri-y:s so it has a lot of torque.

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Re: Max Horse Power for Ford 302 block

Postby fishman » Wed Jan 02, 2013 12:01 pm

425hp then u need a girdle
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Re: Max Horse Power for Ford 302 block

Postby avengerengines » Wed Jan 02, 2013 12:10 pm

fishman wrote:425hp then u need a girdle


I've seen them break when they had a girdle. I don't think it helps much if any. I have some 347's making a little over 500 hp. That makes me nervous. I wouldn't be comfortable going over that.
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Re: Max Horse Power for Ford 302 block

Postby fishman » Wed Jan 02, 2013 12:15 pm

avengerengines wrote:
fishman wrote:425hp then u need a girdle


I've seen them break when they had a girdle. I don't think it helps much if any. I have some 347's making a little over 500 hp. That makes me nervous. I wouldn't be comfortable going over that.
Bob



I think it depends on whose girlde you buy as everything in this world can be better or worse then others and i think if u buy one that u can mount your windage tray on will be worse then one without
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Re: Max Horse Power for Ford 302 block

Postby MadBill » Wed Jan 02, 2013 12:21 pm

What's the feeling re stud size? Do the increased clamping loads of 1/2" ones (especially inners) matter more than the loss of web material due to the larger threads?
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Re: Max Horse Power for Ford 302 block

Postby bmcdaniel » Wed Jan 02, 2013 12:23 pm

The girdle will only help to keep the rotating assembly from falling on the ground when the block splits. The '78 and earlier blocks have more web material in them than the later roller cam blocks and can be good for 500 hp or so. The roller cam blocks, cross your fingers at about 450 hp. As mentioned, detonation can break them sooner.

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Re: Max Horse Power for Ford 302 block

Postby rustang » Wed Jan 02, 2013 12:30 pm

One thing I've often pondered about the split blocks is how much the motor mounts come into play. If you use solid motor mounts, and you have chassis flex, all of a sudden you're trying to transmit chassis forces thru the block.

So then if you look at the attachment points of the motor mount, and where the forces go thru the block (between the cam tunnel and main journal), that sucker's like a big ole wishbone waiting to be split in half.

Again, I don't know if this has any bearing at all in why they break, but I don't think it would take a lot of force at the motor mounts to split it...combine that with detonation...

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Re: Max Horse Power for Ford 302 block

Postby k-star » Wed Jan 02, 2013 12:51 pm

The blocks that I have seen break, and where they brake, the girdle is useless.

I seen an early non-roller block come un-hooked on the dyno. That engine made around 400hp.

Seen a late model roller block based 347 break. That one made maybe 450 hp.

Neither was detonated.

Seen other 302 based engine make 500hp, with no issues.

It's a guessing (or waiting) game with these bocks.

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Re: Max Horse Power for Ford 302 block

Postby JohnsnsFord2@aol.com » Wed Jan 02, 2013 1:06 pm

Low Rpm and 0 balance of the motor helps to keep these blocks to last!!!
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Re: Max Horse Power for Ford 302 block

Postby avengerengines » Wed Jan 02, 2013 1:25 pm

fishman wrote:
avengerengines wrote:
fishman wrote:425hp then u need a girdle


I've seen them break when they had a girdle. I don't think it helps much if any. I have some 347's making a little over 500 hp. That makes me nervous. I wouldn't be comfortable going over that.
Bob



I think it depends on whose girlde you buy as everything in this world can be better or worse then others and i think if u buy one that u can mount your windage tray on will be worse then one without



The cracks start above the crank. How will a girdle stop that?

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Re: Max Horse Power for Ford 302 block

Postby MadBill » Wed Jan 02, 2013 1:41 pm

Some girdles angle out and up and are sandwiched at their edges between the pan and the block, anchored by the pan bolts..
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