Getting Block Bored Out?

[super99]

It's time to get back to work on my JD 70 gas project. Started to tear it down to overhaul, and the pistons are shot. They have them here for about $450 and they are .045 over. I will have to have the block bored out,$150 to 175 depending how much they have to take out. Should I go ahead and have the block bored, or should I get the pistons first and take them in so they can make them exact fit? Have heard to do it both ways, what do you guys think? Also. Should I take the wrist pins and rods it to get them fitted or just put them in myself? This should probably be on the JD page, but I hang out here and am more comfortable asking you guys. I trust your info as much as anybodys. Thank, Chris

 

[Bob]

You HAVE to have the pistons at the shop, so they can "finish hone" the block to the final dimension, after boring, for the EXACT desired piston oil clearance.

However, it's best to have the shop guys VERIFY they can clean the bores up @ .045" OS, BEFORE ordering the pistons.

AND, it's just common courtesy to at least give the shop a "shot" at $upplying the parts BEFORE simply getting them from an outside source.

Most often, you will find the parts through the shop to be a bit MORE than you can get them for from another source, however, often your final bill will be NO more, if they supply the parts, 'cause, often, the shop prices tend to get "adjusted" upward a bit, if YOU supply the parts. At least, give them a "shot" at it, if they sell parts.

After going this far, WHY would you even consider NOT taking the rods in, and having them checked, as well as "pin fitted", rebushed, if necessary?

 

[Leroy]

This has been years ago (early to mid 50's) Dad had a 1929 Buick that was made into a buckrake that we put up all our hay with. It got so bad on blowby that it would only start by pulling any more. Dad decided to have the engine rebuilt, Mom's sisters husband was a mechanic and was going to do the work. Found out it would need boring, checked different places, all said the pistons were readily avaible and go ahead and get it bored, when bored done of them could get the pistons so only thing we could do was junk the Buick. Now had we gotten the pistons before it was bored out we would have been OK but no luck with that. Even if we could not get the pistons if we would not have had it bored we could have gotten new rings and put them in and it would have run but not as good as with the new pistons in a rebore. So before I do anything that is to change to sompthing other than the orignal or even with the orignal I make sure I have the new parts on hand before I start the job. That Buick buckrake we put a bed on when it was not making hay and was our only truck, would carry more than most 1/2 ton trucks. So I would say have parts on hand before boring no mater who supplies them.

 

[Anonymous-0]

Why not take the pistons along that way there should be no problems when re assembling

 

[glennster]

i agree with bob, check with your machine shop, ask them if they want to get the parts of if they want you to get em. i just got my super m motor back from the machine shop. he wanted me to get the parts, less hassle for him to search suppliers. hey will measure up everything and let you know what to get. like bob said, have them do the rods and size them for the wrist pins. may also want to put hardened seats in the valves for the no lead gas too. now is the time to get it all done right, if you cut a corner, its prolly gonna bite ya in the behind!!

 

[Bill in Colo]

Leroy, where are you at? Still some great buckrakes here in Northwest Colo,the last of them were retired about three years ago. A few would have made hotrods.

 

[Earl - IL]

Thanks Bob, I had a shop for 30 plus years. If you buy your parts from the shop you can create a better relationship with your machinist. Where else does it happen in the trades? I never had any luck taking my own hamburger into Steak & Shake and ask them to fry it for me. LOL Did we do a job where the customer furnished the parts? Yes we did. Did we charge more. Yes we did. 15 % discount on labor if we furnished the parts.We quoted our labor as if we sold no parts. Then offered a 15 % discount if they bought the parts from us at a discount that was competitive to the market.Consider freight & COD charges if they don't take credit cards. Damage or wrong parts if you need to make a return. In the shop we would bore the most worn cyl to see what it would clean on. Order parts . Then 2 step finish hone to correct piston to cyl clearance. Earl In Illinois

 

[Dick Lemmon]

To put some thought into Bob's comments.
In the early 1970's it was my job to call RJ Reynolds Tobacco's purchasing department every morning. A story was related to me by the late Charley Johnson who was the purchasing manager. Seems Charley had forgot his hat at a restaurant while entertaining some guests that were at the company headquarters. He had to approve every ones expense account in the company except his own. RJ Reynolds's president had to OK his. He placed a 20 dollar entry for the hat. The president crossed it out and deducted the 20 dollars from the total. The next month when Charley submitted his expense account he penciled in at the bottom of the form,(The hat is in there, see if you can find it)

When you get a bill the pistons could be in there, see if you can find them. ^D

 

[super99]

Thanks, Guys, When I checked with the Parts store that has machine shop, I asked if they could get pistons for JD70 and they checked and said none of their suppliers handled them and I would have to find them myself. Didn't ask about gaskets and such, if they can get them, I'll get them from them. Guess I'll check with them again before ordering parts to be sure. Merry Christmas to all, Chris

 

[Leroy]

Ohio, and after the Buick was gone the rake was put on a 2 ton 1946 Dodge truck for a year till traded off on a baler