Farm Equipment - Q's for future project, WD45 engine mods.

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Q's for future project, WD45 engine mods.

Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=39529
Printed Date: 27 Jul 2025 at 7:30am
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Topic: Q's for future project, WD45 engine mods.

Posted By: 79fordblake
Subject: Q's for future project, WD45 engine mods.
Date Posted: 25 Oct 2011 at 9:03pm

I have been reading lot lately about engine mods for the WD45..Eventually(hopefully not to long from now) I want to completely restore my '57 WD45 which was my Grandpa's. Tractor runs great but I want to go through everything when I restore it.

I will probably do things like plow days with it after its redone....I still use it alot currently.

I want to raise the power some when I get around to doing all this. I figured I would ask questions now and copy the info and save it.

What will the compression be if I put flat top WD pistons in it? Would it still be a working tractor if I wanted to use it? What would the HP be?

Or should I go with pistons from a 175 that are 8.25 compression ratio? I have read posts that this is a good option and the tractor can be worked with regular gas. What would this do HP wise?

Should I have something done to the camshaft? I'm not expecting big numbers just more than stock.

Thanks for any help.

Replies:

Posted By: DrAllis
Date Posted: 25 Oct 2011 at 9:11pm

Anything you do will require 12 volt starting. If it was MINE, it would get a std D17 AGCO piston/sleeve kit, which raises the compresssion from 6.5 to 1 to 7.25 to 1 and will increase the HP from 43HP to probably 53HP at 1400 rpm's. Believe me, that is enough to rip all the teeth off of the PTO gears if you ever get rough with it. The kit drops right in with no hassles and will still sound like an AC PowerCrater engine.

Posted By: 79fordblake
Date Posted: 25 Oct 2011 at 9:23pm

Oh....did not know that....that sounds like plenty to me. The tractor has already been converted to 12 volt. Should I do anything with camshaft or just make sure it passes factory WD45 specs?

Posted By: Steve M C/IL
Date Posted: 25 Oct 2011 at 11:03pm

You'll get a little more UMPH at upper rpm with a 170-175 cam.Likely need the drive gear too(press VS bolt on) and then you'll need the drive gear for oil pump from series 4 D17 and later. I can't say if it's worth the extra effort.It won't be like night and day.

Posted By: LionelinKY
Date Posted: 26 Oct 2011 at 2:25pm

Dr. Allis-How does a D17 piston/sleeve kit vary from a WD45 piston/sleeve kit to raise compression? I guess this is what Dad refers to concerning our WD45 with the D17 kit put in it the last time it was rebuilt in the early 70s. Dad has always said it dynoed at 56 pto hp once all tuned correctly. He also said numerous times how it initially would keep burning valves using WD45 specs which vary for exhaust vs intake I think. It took a little trial and error to get the settings which work(and have worked for years). It hasn't burnt a valve in my lifetime(I'm 40). I forget the setting even though Dad has told me many times but I do remember that intake and exhaust have the same setting now. I hope to rebuild it once again some day though even now it doesn't act like it needs it yet.

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"My name is Lionel and I'm an Allisoholic"

Posted By: Kip-Utah
Date Posted: 26 Oct 2011 at 4:36pm

I like Dr's advice. Stay away from flat tops for your intended use. I don't even like them in a pulling engine. Another option is the Power Seal 4.125" sleeve and piston kit for WD45, D17, 170...This is essentially the modern iteration of the old M&W kit. These are around 7.75:1 and the bigger bore will take your WD45 to about 240 cid. Good stock spec. cam & lifters should be fine. You might also consider using a D17 gov. spring. None of this is very exotic, but the 45 was/is pretty darn impressive just like it shipped from West Allis. Kip

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HANSEN'S OLD ORANGE IRON. Showing, Pulling, & Going!!

Posted By: m16ty
Date Posted: 26 Oct 2011 at 9:56pm

I've got 4.125" M&W pistons and sleeves in my 45. I haven't dynoed it but I can tell you it's got lots of power. It does drink the gas though. When I had the same engine in a pulling WD I had to bolt the hand clutch plates together to keep it from slipping when hooked to the sled. I haven't had the clutch slipping problem with field work in the 45. I just can't keep it hooked to the ground when I pull the throttle down.

I'm not sure M&W pistons are available anymore but many aftermarket 4.125" bore kits are out there.

Posted By: Steve M C/IL
Date Posted: 26 Oct 2011 at 10:26pm

Kip,The modern "M&W's" are only 6.5 compression like factory 45's.The originals were 7.25 or 7.3.I put the new ones in my 45 last year and noticed the bowls looked bigger.The rest of the piston was an exact replica.Did a CC measure on bowls and the new ones held around 10 CC's more. I don't remember the exact #'s and can't find my notes but doing the math,they figured approximatly 6.5:1.In heavy bush hoggin and plowing you can tell the difference.PWR Seal doesn't advertise comp ratio.Guess why!

Lionel...the 45 was 6.5 and the 17 was 7.25. More compression make more power.