Welcome! Please use the navigational links to explore our website.
PartsASAP LogoCompany Logo Auction Link (800) 853-2651

Shop Now

   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver

Discussion Forum

JD 70 gas bore

Welcome Guest, Log in or Register
Author 
Todd

08-25-2001 20:40:55




Report to Moderator

Can a 5 7/8" 70 gas block be bored out to 6 1/8" to fit in a G JD piston. If it can, is there any danger of the cylinders skirts being to thin, and are the wrist pins the same? I need info only, I'm not interested in discussing what brand tractor people think are the best.




[Log in to Reply]   [No Email]
G Taylor

08-30-2001 21:31:18




Report to Moderator
 Re: JD 70 gas bore in reply to Todd, 08-25-2001 20:40:55  
The 70G cylinder block swaps with the 70 AllFuel or G cylinder block. That will give you the 6-1/8 bore with enough wall thickness to prevent power loss from blowby or loosing excessive heat into the water jackets. Going from 379.5 to 412.5 cu" will only gain 4.2HP if the induction exhaust system can deliver the extra flow. Serious extra HP requires boring/sleeving at least 1/2" overbore, stroking or more RPM. And this only works if breathing isn't restricted. How much do you have to spend? A budget 70G with LP pistons in a G block, a Roberts cam, LP manifolds, dry airfilter & 15.5x38 23 degree Firestones is a serious contender in the 6500lb "stock looking" class.

[Log in to Reply]  [No Email]
Gman

08-28-2001 18:52:31




Report to Moderator
 Re: JD 70 gas bore in reply to Todd, 08-25-2001 20:40:55  
Todd bore the engine .125 and sroke the stuffins out of it if you want to pull,these engine pull like you woulden beleive,my sroker is alot smoother than my other engines,of course you would want to plow with it,but stroking makes these old two cylinders come alive. Gman's two cents



[Log in to Reply]  [No Email]
Justin

08-28-2001 05:26:12




Report to Moderator
 Re: JD 70 gas bore in reply to Todd, 08-25-2001 20:40:55  
I know the A, B, and G blocks can be bored .250 before you have to sleeve them, I'm pretty sure it's the same for the other Deere blocks.

Justin



[Log in to Reply]  [No Email]
ToddF

08-27-2001 07:47:16




Report to Moderator
 Re: JD 70 gas bore in reply to Todd, 08-25-2001 20:40:55  
Hi Todd,
I was asking similar questions around a year ago about my 70 gas. Somebody gave me the name of Kieth Merfield at 319-582-8710. He should be able to answer any questions that you have. He seemed quite knowledgable and willing to give advice. He has done some 70's so he talks from experience. Good luck, I'd like to hear how you make out with it.--ToddF



[Log in to Reply]  [No Email]
Jack

08-27-2001 05:19:06




Report to Moderator
 Re: JD 70 gas bore in reply to Todd, 08-25-2001 20:40:55  
Hello Todd.I had my 70gas bored .125 thousanths and went hi comp. aluminum pistons and there was not too much thickness left in the cylinder walls sticking out from the bottom of the block.And this only took mine from being a 379 cu to being a 396 cu.I am interested if it does work if you will let me know.Thanks.



[Log in to Reply]  [No Email]
JDGnut

08-26-2001 14:55:56




Report to Moderator
 Re: JD 70 gas bore in reply to Todd, 08-25-2001 20:40:55  
Todd.. I have been told that this will work.. but I can not tell that it will.. I have not tried it.. I have bored G blocks a lot more than the amount U are going to have to bore.. and the pin is the same.. I have wanted to do this.. but I have too many other projects going that need to be finished first... Good luck..
JDGnut



[Log in to Reply]  [No Email]
ToddF

08-27-2001 09:04:35




Report to Moderator
 Re: Re: JD 70 gas bore in reply to JDGnut, 08-26-2001 14:55:56  
Hi JDGnut,
Have you stayed within the limits of the cylinder skirts or do you sleeve the block in order to go a lot more? Can you sleeve these blocks or are there some other limitations that prevent it? Does anybody even make a sleeve for these things? Thanks and take care--ToddF



[Log in to Reply]  [No Email]
Leroy

08-27-2001 19:03:08




Report to Moderator
 Re: Re: Re: JD 70 gas bore in reply to ToddF, 08-27-2001 09:04:35  
Bore it, sleeve it, bore the sleeves.



[Log in to Reply]  [No Email]
JDGnut

08-28-2001 11:49:44




Report to Moderator
 Re: Re: Re: Re: JD 70 gas bore in reply to Leroy , 08-27-2001 19:03:08  
I have gone .300 over on a G block.. that's 6.425 without sleeveing it.. but I also have not started the tractor yet.. so time will tell... the machine shop said as long as I wasn't trying to run some crazy compression like 15 to 1, I would be OK.. but it is thin.. trying for about 10.5-1 if I ever get it all finished... If you can find a machine shop that can do a sonagram.. (I think that's what they call it) to check the block.. I would do that.. this checks the metal in the block. (I did not have this done.) An unstyled G block does not have as much metal in the block, and it is harder to find a block to bore this big without sleeving.. most of the Style G block you can more.. I just took a chance.. Good luck with the 70... JDGnut

[Log in to Reply]  [No Email]
DeereMan

08-28-2001 20:56:30




Report to Moderator
 Re: Re: Re: Re: Re: JD 70 gas bore in reply to JDGnut, 08-28-2001 11:49:44  
.300 over thats it. i would just leave it stock. if you are goin to bore it, then bore it. same thing for strokin. if you are gonna get more horsepower go for it all.



[Log in to Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:


TRACTOR PARTS TRACTOR MANUALS
We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

Home  |  Forums


Copyright © 1997-2023 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters

Website Accessibility Policy