Need huge Chief piston

Does anyone know of a source for extreme overbore Chief pistons, or unground blanks?

You might want to try

Egge Machine Co.
(800) 634-2645
fax (213) 693-1638

Egge Machine has always been good to me.

Cotten,
Website; http://www.egge.com with online form
Email; info@egge.com
don

I bought the last of Egge's stock a year and a half ago. They ground a set each of .070"s and .080"s for me, which used up all of their Robbins mold blanks.

They are out of Bonnies also, and have no expectations of casting any more, unless you order a thousand or so.

But I clumbsily chipped the skirt on one of the .080"s upon final assembly of a balanced motor.....!

(I am fortunate to have a patient customer.)

So I have been beating the bushes for another blank that is big enough, as a Lynite blank from Mr. Myles couldn't be cut by Egge big enough.
I would think you could index a workpiece to within a thou or two, but Egge needs .008" to .012" of extra meat to cam-grind the thrust faces.

I have had an encouraging response already, and hope to have another pair of Robbins blanks soon.

Thanks to all for the replies!
....Cotten

PS Question: Has anyone had experience with such gross overbores on a Chief?

I'm curious to know how it works as I have a .050 and a .070 cyl that I would like to use.

I believe, last year at Oley, I ran across .100 overs and/or semi finnished at one of the booths. I'll have to snag them up for ya. Slight possibility there might be somethin in the upper building of the Brit shop. I know we got new factory Injun pistons there.

HOOT

Thanks for the offer Hoot, but I think a pair are already heading my way. (This computer-thang is good for something after all!)

And Boog! It works like any other gross overbore: You have to use torqueplates

and probably stuff a hole back up in the counterweigh portion of the flywheel for balance.

I ran a stroked pan at .050" low compression on the rear against a .080" standard compression front for a while. The motor did not seem to mind, as even the plugs burned the same.......!?!

Boogs
I remember reading in a HD manual that running .020 difference between cylinders is acceptable.

HOOT

Thanks for the reply guys. I'll have to post the pictures of my torque plates for you Cotten. I think the top is 1.5 inch aluminum, and the bottom is a 1/2 grouond steel pattern plate. I'm in the process of building some pins to fit the holes in the top plate, and the holes in the heads, with the middle being a larger OD. I'm going to use them to hold the head to machine the combustion chamber for compensating for the 80" stroke. I think it will allow me to clamp them good and not damage the fins.
So if a guy wants to really ride his chief, how far over is safe? On the next one I have to build, (mine) I intend to go 84" with Kiwi's rods and I guess FHP cylinders. I have a bad habit of riding a bit hard. so I need to build in a little endurance. I sure would like to use those cylinders though.

The top plate in the picture above is magnesium printer's plate. It keeps the weight down for my back's sake, since I cannot get this gross assembly into my honing tank, and must do in on the floor in a drip pan I have made to hold it by the top plate. The bottom plate is some kind of aluminum billet. I found that the top plate gives very little distortion of the bore or valveseats at 55 ft/lbs.
But the bottom plate does this even at normal overbores, and much less torque (28 to 32 ft/lbs):

You can see the shadows where the Sunnen stone sweeps over depressions caused by the fastener torque. This is NOTHING compared to the distortion of Harley cylinders! (H-D's big spigots must give the fastener stress something to push against, plus I torque them at 40 ft/lbs.)

I'm still in trouble!
A VirtualIndian Lister graciously sent me a Robbins blank to get me out of
my bind over the skirt I chipped. But Egge told me they usually scrap six or
eight just to set their machines up!

Where else can I send a raw piston casting for machining?

Cotten, have you tried some of the auto perf. piston man. J.E, Ross, Wiseco, etc. on custom pistons. some of them will make custom pistons with a min. of 4. they're making alot of import 4 cyl. stuff and should have blanks close to the Indian Chief size or whatever. I have also started fusion sleeving Indian jugs now. So far so good, the stuff seems to work well.

Ross Performance Pistons is on the case! Updates to follow, if I am reminded..

cotten ..... give the boys at Venolia a shout , they'll do onezy and toozys .......no minimum last i knew of

[This message has been edited by meatball45e (edited 30 November 2001).]

Too late, the Ross pistons are being made. (I might break another one anyway!)