Broke a valve.
 

As some of you know I hade a little car trouble. Well I got the head off and the problem was I broke a valve. It put a couple of dents in the piston but did not seem to do anymore damage than that.

Do you think the piston will be ok or will I have to replace it?

The dent is about 1/8" deep (about the depth of the fly cuts in the piston) and about a 1/4" wide.

The heads appear to be fine but I will have them checked to be sure.


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James Cox
nochevy@hotmail.com
1991 Mustang LX
12.565 @109.38mph 1.764 60ft

I'd just de-burr the spot on the piston to make sure you don't get a hot spot, they're pretty tough (yours are forged, right?).



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GT-40 heads (ported, polished, + milled), B303 cam, 1.7rr's, JE pistons, Offy intake, Carter AFB 625cfm carb, Flowtech 1 5/8" shortys, Flowtech X-pipe, MAC Flowpath exhaust, MAC pulleys, 373's, subframes, Eibachs+Tokicos, B&M ripper, FMS Clutch, Zoom Quadrant+cable, 17" CSA Ultra rims, 235/45ZR17 Yokohama AVS S4's, MSD 6A ignition+coil, FMS 9mm wires, Carbed, Naturally Aspirated, and Nasty!

Yes they are forged.
How much do you think it would cost to replace the pistons with some better ones with a higher compression and maybe lighter weight?

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James Cox
nochevy@hotmail.com
1991 Mustang LX
12.565 @109.38mph 1.764 60ft

And do you think it would be worth the time and money?

How much difference do you think it would make?

The motor has about 100,000 miles on it.

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James Cox
nochevy@hotmail.com
1991 Mustang LX
12.565 @109.38mph 1.764 60ft

With that many miles you probably wouldn't want to do just a piston and ring change, you'd want to measure the wear on the block and probably have it bored and fitted with oversize pistons. I would wait until the short-block needs a rebuild, you'll need to do the bearings to change pistons and rings.

How much do you think all that will cost and will it make a difference in performance?

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James Cox
nochevy@hotmail.com
1991 Mustang LX
12.565 @109.38mph 1.764 60ft

Interesting way to do it....

For good aftermarket forged pistons-$500, $80 for rings, $60 for gaskets, etc. Then whatever your favorite machine shop charges for boring.
I'll cost about $800-$900 (total)and a streetable bump in compression (<11:1) will get you maybe 25hp.

Thanks for the help red82gt.

I don't know what I am going to do yet, I may use this as an excuse to get me a 351w installed; but I may be without a car for a while as this is my daily driver.

Can someone tell me why the headers I have on my 302 won't work on the 351w?


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James Cox
nochevy@hotmail.com
1991 Mustang LX
12.565 @109.38mph 1.764 60ft

I think the main problem is the alignment of the H-pipe since the headers sit higher up, I think it doesn't clear the transmission or something.