Offset Grind G149
Printed From: Unofficial Allis
Category: Other Topics
Forum Name: Pulling Forum
Forum Description: Forum dedicated to Tractor and Garden Pulling
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=168561
Printed Date: 30 Oct 2025 at 7:57pm
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Topic: Offset Grind G149
Posted By: 1955allisca
Subject: Offset Grind G149
Date Posted: 24 Feb 2020 at 6:48am
| Has anyone had their G149/G138/G160 crank offset ground? What rod did you end up using? My crank is going to need turned so I'm thinking about going ahead and getting some more power while im at it. |
Replies:
Posted By: DrAllis
Date Posted: 25 Feb 2020 at 9:13am
| The offset grinding of a crankshaft was never intended to be used on an engine that was expected to go back to "work". The strength of the crankshaft is compromised (weakened) by doing this. You want more HP ?? Use higher compression pistons and a larger carburetor. Grind the crank to whatever makes it smooth and round hagain. No one will offset grind your crank for the same price that they will just grind it the normal way. |
Posted By: 1955allisca
Date Posted: 25 Feb 2020 at 12:31pm
| I already have the higher comp pistons just looking for some more displacement. |
Posted By: Lonn
Date Posted: 25 Feb 2020 at 1:02pm
|
Why? ------------- -- --- .... .- -- -- .- -.. / .-- .- ... / .- / -- ..- .-. -.. . .-. .. -. --. / -.-. .... .. .-.. -.. / .-. .- .--. .. ... - Wink I am a Russian Bot |
Posted By: tbran
Date Posted: 27 Feb 2020 at 2:42pm
|
listen to the sages, or go with a G160 engine. If you had seen the broke cranks we used to see .......................... ------------- When told "it's not the money,it's the principle", remember, it's always the money.. |
Posted By: PaulB
Date Posted: 28 Feb 2020 at 1:53pm
If you want POWER, TURBOCHARGE it   After I finish with work that is needed in the rear and transmission, it will get bigger tires. If you remove the pan, you'll see how close the top of the rod bolts get to the cam as things are now. There is really no room to get closer. As the cam is hollow, you don't want to go grinding into it for clearance.. The rod journals are small enough already, so you really don't want to go using a different rod with a smaller journal if you expect it to live. I've seen a motor that the fellow said was a 4" stroke, although all he could show me was an inspection hole in the right side. ------------- If it was fun to pull in LOW gear, I could have a John Deere. Real pullers don't have speed limits. If you can't make it GO... make it SHINY |
Posted By: DrAllis
Date Posted: 28 Feb 2020 at 1:57pm
| It would sure be nice to know exactly how the tractor will be used...……….. |
Posted By: 1955allisca
Date Posted: 01 Mar 2020 at 7:19am
| It will just be used to hook to the sled a few times a year. Mainly tug pulling but possibly some speed pulls. |
Posted By: DrAllis
Date Posted: 01 Mar 2020 at 8:15am
| Larger carb and improved manifold is external and easy. Taller pistons to raise compression up to 240 psi or a little more would require racing fuel, but will increase your HP/torque if you aren't at that level already. What does your engine currently have for cranking compression pressure ??? 120 Psi ?? |
Posted By: 1955allisca
Date Posted: 01 Mar 2020 at 8:26am
| Yes my 3 other g149s have around 120-150. I was wanting to make this engine a little meaner. I bought this engine stuck and have most of what I need to put it together just thought I'd see if anyone was running an offset ground crank for a little more power. |
Posted By: DrAllis
Date Posted: 01 Mar 2020 at 8:35am
| You have thee PERFECT opportunity to make it better than ANY of your other engines. 240 psi of cranking compression and 110 octane gasoline is a very easy upgrade, especially when replacing pistons anyway. Remember ignition timing will have to be retarded to around 20 degrees BTDC instead of 30 degrees. Dyno timing is the best to know where the sweet spot is. |
Posted By: Justin Vandy
Date Posted: 20 Jul 2020 at 3:47pm
| DrAllis is there a piston currently for this application or is it custom made? I have the 160 specifically that I wouldn't mind sticking high compression pistons in. |
Posted By: frnkeore
Date Posted: 20 Jul 2020 at 5:59pm
|
Here is another option: https://www.ebay.com/itm/Allis-Chalmers-Basic-Engine-Kit-Fits-D10-D12-D14-D15/171376201231?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649" rel="nofollow - https://www.ebay.com/itm/Allis-Chalmers-Basic-Engine-Kit-Fits-D10-D12-D14-D15/171376201231?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649 I don't know what you get for C/R with it but, it gives you 154.5 CI. Since your crank needs to be turned, you can get 1 more CI (155.5) and a little more compression, if you can get your local machine shop to offset grind your crank .025 (.0125 off center) for a 3.900 stroke, by using .030 under rod bearings. The compression rise would be similar to using a .012 thinner head gasket. If the distance from the pin to the top of the piston (CH) is the same as a stock piston, you gain compression there too. ------------- Frank 1959 D17 Series I #24001+, '59 D14 '55 & '59 Ford 850 & 861 Ferguson TO 35 Deluxe, Oliver 70 and 5 more. |