General block boring question

Patsdeere · Nov 19, 2009

I am getting a JD block bored over sized and am putting aluminum pistons in. Somebody mentioned that I make sure it is bored correctly for aluminum pistons. For my knowledge, what differences are there between blocks bored for aluminum pistons and cast pistons?

Thanks.

Anonymous-0 · Nov 19, 2009

where are you located, might know a shop or two to recommend.

Anonymous-0 · Nov 19, 2009

Different expansion characteristics of the two kinds of pistons mean that the aluminum piston needs more clearance when measured cold.

Patsdeere · Nov 19, 2009

Thanks, but I found a shop. They aren't easy to come by when you are boring 45 over 5.5. I can only imagine the look on their face when I call and ask if they can bore a block at 5.5. There is usually silence on the their end and they ask me if I am sure that it is that size. =)

Gene Davis(Ga.) · Nov 19, 2009

I worked for a Deere dealer 50"s & 60"s. This wisdom was from Deere service school instructors. If you are boring a block for a Waterloo 2 cylinder horizontal engine such as an A,B,G,H, tractor, Deere advised that the boring bar be aligned from the crankcase end as it was not always square with the cylinder head end. they said that boring from the head end could cause excessive piston pin wear because the cylinder wealls were not square with the crankshaft when bored from the front end.

Patsdeere · Nov 19, 2009

So that means I should bore it from the bottom side (crankcase side)?

Dang, I guess I will have to take out all those darn studs, or maybe just let the shop take them out.

Mike M · Nov 19, 2009

DO NOT PULL THE STUDS OUT unless absolutly needed. A good modern shop with BIG equipment can set them up from the crankcase end and bore them with the studs in. Pulling the studs out on a lettered series only leads to more problems as they go into the water jacket and the back of the studs get eat up and tear up the threads on the way out. I can't remember for sure if the models 50,60,70 have blind holes or ones bored into the water area ?

Now on the bore size. If you need .045" over you go 5.5" plus .045". The PISTONS are to be made to allow for any extra clearance needed. I have yet to see any that weren't. Easy enough to check beforehand.

johndeereman · Nov 19, 2009

most people i called to do my power blck wasnt worried about the width of the cylinder but the length seems most bars go that wide but not that long

relaurain · Nov 20, 2009

The pistons based on type/material will set the bore size needed, and the rings will set the final hone grit used.

El Toro · Nov 20, 2009

George Miller that post's on some of these forums has a machine shop and he bores the JD blocks for pullers. Give him a call at 410-452-5255. Hal

General block boring question

Patsdeere

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Anonymous-0

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Anonymous-0

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Patsdeere

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Gene Davis(Ga.)

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Patsdeere

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Mike M

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johndeereman

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relaurain

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El Toro

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