Pulling Forum - D17 pistons

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D17 pistons

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Forum Name: Pulling Forum
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URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=193660
Printed Date: 05 May 2024 at 6:55pm
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Topic: D17 pistons

Posted By: LouSWPA
Subject: D17 pistons
Date Posted: 21 Feb 2023 at 11:11pm

I noted in the data book the WD45, and D17 had pistons in the LP engines with a compression ratio 8.?. If they are still available, would they work in the WD45 and D17?

Also, under the rules I have, I am limited to 2500RPM and 4 MPH. Extrapolating from Terry Deans data book, the WD would be exceeding 4MPH at 2500rpm. I have a set of mismatched combine tires, 26inch, but they look taller than the 28-13's that I have!?!?

Anyways, any ideas how I can take advantage of the full 2500rpm? shorter tires is the only thing I can think of

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I am still confident of this;
I will see the goodness of the Lord in the land of the living.
Wait for the Lord;
be strong and take heart and wait for the Lord. Ps 27

Replies:

Posted By: WF owner
Date Posted: 22 Feb 2023 at 4:44am

According to Tractordata.com:

Rated RPM pf a WD45 is 1400.

Rared RPM of a D17 is 1650.

Rated RPM of a 175 is 1800.

I, personally, think you are putting too much emphasis on the 2500 RPM limit. Chances are good that you aren't going to have to worry about that.

Listen and watch what the guys, that are pulling now, are using for tires. I, personally, would stay away from mismatched tires. It's hard enough to figure how tires are going to react to different tracks without trying to figure out how two different tires are going to hook up. A good pair of 18.4 x 30 tires (from a 185) might be a good starting tire. They are easy to find, easy to sell if you don't like them and an easy bolt on replacement.

The last I knew 8.25/1 pistons were still available, but hard to find. 7.5/1 pistons are easily available.

Posted By: tbran
Date Posted: 23 Feb 2023 at 3:38pm

We built a few in the past using WD 4 1/8 " pistons - too much compression to farm with - on regular gas - but with higher octane worked fine.

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When told "it's not the money,it's the principle", remember, it's always the money..

Posted By: DrAllis
Date Posted: 23 Feb 2023 at 7:26pm

Low gear in a straight stick WD with 15.5 x 38's is approx 4 MPH @ 1800 RPM. A WD45 rear end would be 1925 RPM for the same ground speed. That's not too bad really, because you keep opening the throttle the farther you go down the track keeping your actual ground speed at 4 MPH even tho you are having some wheel slippage. A WD45 diesel rear end would be about 2200 RPM, as the ring and pinion is 15% slower. D-17 LPgas pistons were 8.2 or 8.25 to 1, which is the same piston as the 175 gas engine.

Posted By: HudCo
Date Posted: 23 Feb 2023 at 9:11pm

was in the reliance catalog today they only list the 7.5 .1 x 4 1/8 piston for the wd 45 all the way to the 175 all the same part number . wd must have a differant pin hieght. 4 1/8 wd flat top said call for avialability and they arnt given those away

Posted By: DrAllis
Date Posted: 24 Feb 2023 at 6:32am

I guess I need to calculate piston height for a 4 1/8" flat top piston (.990" pin) to come up with 12 to 1 compression and a stock head gasket, and then see what a set of eight or sixteen would cost. Then, see if Reliance or someone else would sell the same amount of new 4 1/8" sleeves and have some kits available for pullers.

Posted By: WF owner
Date Posted: 24 Feb 2023 at 6:46am

Jenn Sales still lists the 8.25/1 pistons in 4", but I don't know if they are actually available.

https://www.jensales.com/products/ep-111149-allis-buda-piston-assembly-allis-chalmers-g226.html" rel="nofollow - Piston Assembly | Allis | Buda 226 Engine | 111149 (jensales.com)

Posted By: WF owner
Date Posted: 24 Feb 2023 at 11:32am

A question for Doc:

Which would make more power; a 226 cubic inch engine with 8.25/1 compression or a 240 cubic inch engine (4.125 bore) with 7.5/1 compression?

Posted By: DrAllis
Date Posted: 24 Feb 2023 at 12:23pm

A D-17 with 4 1/8" M & W's 7.5 to 1 was called 57 HP at 1650 RPM. A 175 gas (4 inch at 8.25 to 1) was 56 HP at 1650 RPM with a similar sized carb and with a different camshaft, but a 12 GPM hydraulic pump dragging on it. So, I'd guess the output between the two pistons/compression would be close to the same. The best is 4 1/8" at 12 to 1 tho.......

Posted By: WF owner
Date Posted: 24 Feb 2023 at 2:12pm

Thanks Doc!

Posted By: DrAllis
Date Posted: 25 Feb 2023 at 5:38pm

After a little more research, here is what I've come up with. The W-226/WD-45 engine at 6.5 to 1 compression ratio made 60.0 flywheel HP @ 1800 RPM's. The G-226/D-17 engine delivered 67 flywheel HP with 7.25 to 1 compression @ 1800 RPM's. Same carb and camshaft used between them and only a compression ratio increase of .75 to 1 yielded 7 total HP !! So, a compression ratio increase from 7.25 to 1 to 8.25 to 1 would/should? gain at least 4 to 5 more flywheel HP ?? which would be 71 to 72 flywheel HP with the 4 inch bore/8.25 to 1 compression ratio. Now, we know M & W's were 57 PTO HP @ 1650 RPM ( which is 67 HP flywheel) and an increase to 1800 RPM should also be 4 to 5 more HP, which would then be 71 to 72 flywheel HP with the 4 1/8" bore/7.5 to 1 compression ratio. All these engines are using the same camshaft grind and carburetor. The W and G-226 HP numbers are from a 1960 A-C sales book I have on power units. I think it really is a HP wash between the two different displacement/different compression ratio engines. Edit: I think, if you found some 4 1/8" bore with 8.25 to 1 compression that would be another 3 to 4 HP on top of 71 to 72 flywheel HP.

Posted By: Yard Art
Date Posted: 01 Mar 2023 at 2:45pm

I would buy a set of those pistons if you decide to do that.

Posted By: DrAllis
Date Posted: 01 Mar 2023 at 8:17pm

Years ago, Ross pistons would make me anything I wanted, even if I wanted the power crater bowls. I sent an e-mail to them last night and haven't heard back 24 hrs later, so we'll see if they even do these custom jobs anymore. My design specs are for 11 to 1 compression ratio.

Posted By: DrAllis
Date Posted: 02 Mar 2023 at 6:53pm

Got an e-mail back today. My cost for 4 1/8" pistons to my specs with rings and pins is $1430 for a set of eight. Shipping on top of that, naturally. So, I'd have to get two people to agree on what compression ratio to make them or maybe someone wants to buy a set of eight. I haven't looked into what 4 1/8" sleeves cost, and the sleeves really should be purchased first and measured for bore size and then they will make the pistons to the correct diameter. His email says 11 to 12 weeks wait time. I was shooting for 11 to 1 compression ratio, but maybe someone wants less than that ??

Posted By: HudCo
Date Posted: 02 Mar 2023 at 9:31pm

did we decide what the 4 1/8 wd piston flat tops would do ? how much differance would a hi compression power crater design make ? i would rather have the piston be standard and finnish hone / bore the sleave in case of differant counter bores

Posted By: DrAllis
Date Posted: 02 Mar 2023 at 9:54pm

Compression height of 2.550" is what I want for 11.3 to 1. Compression height of 2.500" would be about 10.2 to 1.

Posted By: HudCo
Date Posted: 03 Mar 2023 at 9:04am

how about small block 400 chevy pistons ithink they are suppossed to be the right pin diameter it looks like their are alot of dome sizes but probley all wrong wrong for the head.

Posted By: DrAllis
Date Posted: 03 Mar 2023 at 9:15am

BBC has a .990" piston pin, which matches the A-C rod. SBC is a smaller pin diameter.

Posted By: HudCo
Date Posted: 03 Mar 2023 at 10:13am

the machine shop must have told me wrong or i told them wrong , i can come up with piles of 454 pistons for r&d . still wonder about what would be most effective with the head domes, flat top, or a bowl , my buddy uses ross pistons in his big block pulling truck , if they could make some hi compression power crater desighn pistons think they could be sold getting excited about the fact we may have some real tractor pulling here

Posted By: DrAllis
Date Posted: 03 Mar 2023 at 11:48am

Flat top with a flat cylinder head is very good. I think Power Crater could be better, but surely as good. That's what I've always used. Anything else with a flat cylinder head would be a non-starter with me. The dynomometer is thee only way to know for sure and I don't have the time or $$$$$ to assemble an engine multiple times to test. Power Crater would (I assume) cost a little more for each to be custom made.

Posted By: DrAllis
Date Posted: 17 Feb 2024 at 6:19pm

To the top !!

Posted By: steve fischer
Date Posted: 18 Feb 2024 at 11:53am

The Ross pistons ,I think I got the other 4 that time ,how many years ago was it

Posted By: DrAllis
Date Posted: 18 Feb 2024 at 4:57pm

Pretty sure more than 20 years ago.