pistons for DJXC

RLH · January 21, 2004, 03:02:50 AM

Does anyone know where I could find pistons for a DJXC for a resonable cost? I found one set for $900.00. Seems a bit high to me. I would think some one would make pistons for this engine. Same with bearings. Under sizes are all most impossible to find. Any ideas?

Randy

Blake Malkamaki · January 21, 2004, 04:36:01 AM

You don't give your location in your bio. Where are you located? There's a guy near me near Albion, Pa. who has an OC-12 in really bad shape that I'm sure you could get very reasonably. I know it has an injector pump on it and probably has good pistons in it. Tracks and related parts are very bad.

The guy also has a BG dozer for sale.

Let me know if you're interested and I'll try to find his number.

RLH · January 21, 2004, 02:49:41 PM

I am in Frederick Md. If you give me his # I will call.

Thanks,
Randy

Blake Malkamaki · January 22, 2004, 02:16:31 AM

Randy, check your U2U messages.

RLH · January 24, 2004, 03:24:26 AM

Well, I found everything I need to rebuild my engine except for the pistons. Jerry Biro has a lot of hercules parts. Jerry recomended that I weld up the broken ring lands and remachine new ring grooves. And that is what I am doing. I have one piston done and it turned out nice. We will see how well it holds up once I get it together. It is going to be a wile though, since I just about took the whole machine. Started out I was just going to fix the engine, and then guess what hapened? Now it is sitting there in pieces, tracks are off, wheels, sprockets and upper and lower track wheel off and in pieces, transmission cover off. Everyone thinks Iam crazy!

Robert Barbour · January 25, 2004, 08:55:18 PM

Good luck with welding up the pistons! I have had 2 RXC's and one DRXC appart and all had aluminum pistons marked Zollner Heavy Duty Heat Treated. The only heat treatment I know of for aluminum is for the precipation harding alloys. For these alloys the parts are cast, cooled then reheated to about 3/4 of the melting point and held there for several hours then slowly cooled. Ingredients in the alloy precipitate out at the grain boundries and this hardens the alloy. Welding will destroy the hardening in the area around the weld and the weld metal will be soft too. I would not expect it to stand up like the original.

Blake Malkamaki · January 25, 2004, 10:09:51 PM

I wonder if there is any kind of cross reference for pistons? If you could find some with the same bore, height from wrist pin to top and similar number of rings. Maybe you could make them work. There might even be a common engine that uses similar pistons.

I do know from trial and error that John Deer M valves will work in a Cat 10; and that 255 V-8 Mack valves will work in a 1930 28-50 Hart Parr tractor.

John Schwiebert · January 26, 2004, 12:40:59 AM

Blake I agree. I did a 12-24 Hartt Parr and it has used Mack stelite valves and rotators in the head. I would like to see dimension on some of the old Hercules pistons. I knew a guy a couple of years ago who was a consultant and former Zollner employee. Maybe he is still around and can come up with dimensions. I can get pistons made off shore but I need to take 600 for a minimum order

Robert Barbour · January 26, 2004, 02:40:22 AM

You would want to use a piston from a diesel, most gas ones would be to light. You might try and find some from the old cat D2 from 38 to 47,( 3j and 5 j serial numbers) they had the same 3 3/4 bore, about 19,000 were made so should not be that hard to find. Good luck

RLH · January 26, 2004, 06:13:02 PM

Does anyone know what the hardness of the pistons should be? I am using a R5356HQ welding rod, witch is suposed to be a harder aloy.

Randy

John Schwiebert · January 27, 2004, 01:38:23 AM

I would like to know the size of the wrist pin and the distance from the top of the pin to the top of the piston. I would guess the piston is a flat top. Thanks.

RLH · January 27, 2004, 12:47:43 PM

The piston pin height is 3.062, top ring is down .680 to clear notch in sleeve, over all lenth is 4.785, 3.750 bore.

Randy

Robert Barbour · January 28, 2004, 03:39:16 AM

I looked up some stuff on aluminum alloys. Alloy 5356 is weld filler metal alloy and is not used for anything else. Couln't find anything on hardenss for it but for comparison alloy 1100 prue aluminum has a yield of 8ksi, 5356 as welded 15ksi and most heatable alloys about 30ksi. So 5356 is quite soft. also it does not harden by heat treatment only by strain (work)hardening. Some things I have seen done to save pistons with worn grooves. Machine out the groove over size and add the thin scraper section of an oil ring along with the compression ring. Second Machine out the groove oversize and have a thicker compression ring ground down to size on a surface grinder to fit. Good luck!

Blake Malkamaki · January 28, 2004, 04:18:17 AM

Niagara Piston Ring Works http://www.niagarapistonringworks.com/ in Corry, Pennsylvania makes all kinds of custom piston rings in all sizes. And they do piston repairs.

I had them make tow 10" diameter rings 3/4" wide for my Rumely steam engine several years ago. Very reasonable and fast.

I've asked them to advertise on the site here, as I think it would gain them some business, but so far no response.