Hi To All, I am needing to knock down the ridges on a Holt engine. I have not been able to find anyone with a reamer to go to that bore size. any help or suggestions is appreciated. Jim.

You might have to take it to an automotive machine shop and have them use a boring bar to do it. We had the regular reamers at the Cat dealer and the largest ridge we had to bore was the D9 with a 6 1/4" bore.

I can tell you thae cast iron in the cylinders are going to be hard. How deep is the wear?
Mike

I have checked all the local machine shops and no one wants to mess with it. One guy suggested using a die grinder to take them down.
Mike, the wear varies from jug to jug, worst is about .030 and is not symetrical. Cylinders have .005 to .007 taper also. Jim.

You can do worse than a die grinder. That's not a hi-tech engine. Files or die grinders are used often in the big bore John Deere's. Make a plug or find a junk piston to clamp into the bore so that you ndon't wander down onto the ring travel area. Hold the grinder straight up so as not to bell the top of the bore. Raise the ridge only enough to clear the the ring travel. It's not necessary to go clear to the top and it increases the chance of accidently belling the bore, which increases the pressure on the top ring.

Boring bars cut a round bore. You need to cut to the existing surface of the bore, thus the trouble shops get into with boring ridges and the reason they don't want to try it.

Good luck,

Jack

Sounds like you need a sleeve job if they are worn .030" unless your just patching the engine just enough to run it.Sounds like the grinder would get rid of the ridge if that,s all your going to do to overhaul it.

Jack and SJ, Thanks for the tips. I am redoing this engine for show purposes only. I have redone the valves, except for the two which had the stems rewelded to the heads and have a set of replacement rings ready to install. The pistons have been removed, cleaned, and rod and wrist pins have been cleaned and refitted. I have very little machining experience, so the best possible repair is not always clear to me. Thanks for your help, Jim.

I recently finished building a 1914 Holt 30 and it had .015 wear. I honed the cylinders out .040 to clean to 5.650, spray welded the pistons and then ground them to fit and still getting available rings to work. Don't go after it with a die grinder, you will regret it. A ridge reamer would be impossible to use since you have a large combustion chamber. sleeving is an option (providing you can find someone to do it) but your best bet is to hone out the jugs and build up the pistons.
Mike

If you are going to run it for show then you can deglaze the cylinders and run the rings tyou have.
Mike