I cant find any 351m pistons. Does any body know what brands there are? What happened to the 8.6 to 1 compression piston?

 

I already posted this but I think Ebay is a good cheap source.

Ebay seller
This auction is over but they it's typical of the prices that can be found on Ebay.

http://cgi.ebay.com/ebaymotors/ws/e...&category=33623

This guy has a lot of piston auctions, so you may want to ask if he has any more for a 351M.
He has a set of .060" over 351M pistons on auction now, but I don't think you want to go that big.

 

Summit racing carries them. They also have a high compression forged piston.

 

How about high compression ones for the 400? does summit have them? if so whats the part #

 

http://store.summitracing.com/
This was all I found.

STL-451P30
$8.39Vendor: Sterling Pistons
Product Line: Sterling/Federal Mogul Cast Pistons
Material: Cast Aluminum
Finish: Machined
Pistons for everyday use.
Ford/Lincoln/Mercury: 351M, .030 in. oversize, 4.030 in. bore, 3.50 in. stroke, 6.580 in. rod length, .088 in. dish, cast piston
For budget or stock style rebuilds, it’s hard to beat the value of cast pistons. These high quality cast pistons are made from high quality aluminum alloys and feature a carefully controlled casting process, heat-treating, and CNC-machining. And because they’re designed and manufactured to exceed OEM specs, they’ll provide improved reliability, performance, and a long service life.

STL-427P30
$9.39Vendor: Sterling Pistons
Product Line: Sterling/Federal Mogul Cast Pistons
Material: Cast Aluminum
Finish: Machined
Pistons for everyday use.
Ford/Lincoln/Mercury: 400M, .030 in. oversize, 4.030 in. bore, 4.00 in. stroke, 6.580 in. rod length, .145 in. dish, cast piston
For budget or stock style rebuilds, it’s hard to beat the value of cast pistons. These high quality cast pistons are made from high quality aluminum alloys and feature a carefully controlled casting process, heat-treating, and CNC-machining. And because they’re designed and manufactured to exceed OEM specs, they’ll provide improved reliability, performance, and a long service life.

 

No high compression pistons for the 400 through summit. Most people run the 351C pistons and quench heads to raise compression..

 

Maybe there is no tooling to do it easily, but why couldn't you have the 351C piston pin bores enlarged to a 400 size pin diameter?

 

The piston pin boss area is subjected to some really high stress levels. Modifying it is usually a last resort and most won't even consider it.

 

For the 400-

Ertel 1282P

Cast flat top, good for 350-450 HP engines. These come with pins.

~9.0:1 compression with a standard 10/10 decking on the heads and block.

Order desk: 1-800-443-1905

Ertel is the parent company for Ohio Piston and Nylen.

Build your 351 to 400 specs by getting a 400 crank.

 

Maybe that explains why it is not done. Obviously a lot would depend on the level of performance, the amount of size increase needed and the brand of pistons used. I thought ACL made pistons with a substantial pin boss.

I was always more worried about the bronze bushings. Most applications enlarge the rod, why isn't the rod weakened?
2nd dumb idea is reducing the 400 wrist pin to a 351C diameter while leaving the center part alone.
3rd dumb idea is making a steel sleeve for the 351C pin than can be heat shrunk in place.

Obviously for the budget conscious, these are not high performance suggestions.

 

Rods are made of steel which is a LOT stronger than aluminum.

You should be looking at converting your 351M to a 400 with a crankshaft.

There is a long tech article available here that you can read all about the performance options for the 400 family.

High Performance Options for the 351M/400 Engine by Dave Resch

 

Dave R has a new 400 site that is completely updated.
http://home.earthlink.net/~bubbaf250/

Forged steel is stronger than cast aluminum? Duh, of the month. That must be why the pin boss is 3X bigger.

 

Turning the ends of the wristpin down would be a neat idea except for the fact that you couldn't install them. I've seen steel tubing used to reduce the pin bores but galling of the pin is the usual result due to the lack of lubrication; that why the bushings are bronze. There are probably some forged pistons out there for the 351C that have enough meat in the pin boss to be bored out for the 400 pin but resizing the pin bore of the rod to .912" reduces reciprocating weight and stress. Lightweight taper-wall pins are available in .912" to reduce the weight even further.

 

"Turning the ends of the wristpin down would be a neat idea except for the fact that you couldn't install them."
I guess not. Good think I labled it, dumb idea.

The steel sleeve should still be do-able. I have a spare set of 400 rods, maybe I'll look into making a set. Galling and lubrication are not an issue on stock pins, they are pressed into the rods and don't move.

 

You asked a Duh question... You got a Duh answer. -hehe