Bored G149 vs G160
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=143475
Printed Date: 22 Nov 2024 at 10:51pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: Bored G149 vs G160
Posted By: 1955allisca
Subject: Bored G149 vs G160
Date Posted: 15 Oct 2017 at 7:11pm
|
Which engine will make more hp, a stock 160 or a 149 w/ 3 9/16 high dome pistons? Has anyone dynoed an engine with the pop up pistons?
|
Replies:
Posted By: DrAllis
Date Posted: 16 Oct 2017 at 7:14am
|
The G-160 will win because the carburetor is larger.
|
Posted By: 1955allisca
Date Posted: 16 Oct 2017 at 7:21am
|
Dr Allis, I have a stock G149 with 160 carb and manifold right now. So what would win, bored high comp 149 with 160 carb and manifold or stock 160?
|
Posted By: DrAllis
Date Posted: 16 Oct 2017 at 12:10pm
|
"High-Compression" means what ??? The G-160 engine is 8.0 to 1 compression ratio, so if both engines are the SAME compression ratio (7 to 1 or 8 to 1 or whatever) and have the same carb and manifold, the G-160 will still win because it still will have more cubes, unless you are greater than 160 cubes and I doubt it.
|
Posted By: PaulB
Date Posted: 16 Oct 2017 at 4:07pm
Been there done that. I have a D10 block that I've installed the domed 3-9/16 pistons, 155 CID. The exact compression ratio is unknown, however it really doesn't like regular gas. This engine had slightly bigger valves when it was built. With it install in a CA chassis it does just a tic over 40HP at stock PTO speed. the 160 in the same chassis did closer to 50. When the 160 was tested it was still factory stock, before I did head and cam work.
-------------
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: steve(ill)
Date Posted: 16 Oct 2017 at 5:43pm
Paul, a High Compression 155 inch is 40 HP, and a 160 standard compression is 50 HP... that's 3% difference in cubes and 20% difference in HP ?? Is there more to that story ?
-------------
Like them all, but love the "B"s.
|
Posted By: PaulB
Date Posted: 17 Oct 2017 at 11:35am
|
All I know are the results. I should have also mentioned that both above mentioned motors are available, I'll answer PMs for the details. Both are currently able to hear running. The 155 has the domed pistons ans nearly everything was new when the motor was built and It has only been a pulling engine with very little use. This engine has the D10/12 manifold and the front step down studs to be a bolt in engine for a B, C or CA The 160 I brought as a good running engine and have since done some cam and head work. This engine also has the step down front studs to bolt into a B,C or CA. Currently it has a D14/15 manifold.
-------------
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: Butch(OH)
Date Posted: 18 Oct 2017 at 5:58am
Waaaay back when I was a senior in HS I rebuilt Dads series 1 D15 with a kit from Central Tractor that was overbore and domed pistons instead of power crater. Too long ago to remember the bore specs but the tractor dynoed at 45HP. I think the series 2 (160) were rated at 46? It would pull the 3 bottom plow one gear faster than before, high 2nd vs low 3rd and we had to back the timing back from the book so it didn't ping on regular gas. Does any of this answer your question, probably not, LOL
|
Posted By: DMiller
Date Posted: 18 Oct 2017 at 6:52am
There are so many variables to change to get higher HP, adding fuel may get SOME, adding more valve opening may achieve SOME but not a lot for either, simply adding higher compression probably will not. HP is a factor of Cu. In. displacement, compression ratio against fuel supplied and timing efficiency where RPM is the major player in gasoline engines and on diesels the amount of moving mass denotes higher torque for a given HP against the other points.
Leave RPM at the same point, the same amount of mass moving within the engine(flywheel, rods, pistons, crankshaft) and not change the rest of the equation and you gain very little with what seems major changes for fuel, compression, etc.
|
Posted By: 1955allisca
Date Posted: 18 Oct 2017 at 7:53am
|
So it sounds like a bone stock 160 will still out pull the 155, I was just wondering bc it's a lot cheaper to just put the engine kit in a 149 than work on a 160
|
Posted By: DrAllis
Date Posted: 18 Oct 2017 at 9:09am
|
It would be interesting to actually run a cranking compression test on both engines and see which one has the most compression. D-15 S2 will run 170 to 180 psi with the Power Crater piston design.
|
Posted By: 1955allisca
Date Posted: 18 Oct 2017 at 6:17pm
|
I know the 160 has crater pistons and the 155 has dome pistons I wonder if the rods are longer on the 160? How could a crater piston even compete with a dome in almost the same block?
|
Posted By: DrAllis
Date Posted: 19 Oct 2017 at 7:13am
|
Rod length is the same between those engines. You'd have to hold the two pistons side by side to see why things are as they are. Power Crater designed pistons work well with a flat cylinder head. It sounds like the dome design may have more of a detonation problem with a flat cyl head.
|
Posted By: injpumpEd
Date Posted: 19 Oct 2017 at 8:16am
I think the lesson learned here is that high compression alone does not add hp. It is very important how you increase the compression, by shape of the chamber, along with cam profile, cam timing to the crankshaft, head flow, and intake and exhaust tracts too. Like Dr pointed out above, a high compression cylinder of poor design will just take more power to pull itself with pumping losses.
-------------
210 "too hot to farm" puller, part of the "insane pumpkin posse". Owner of Guenther Heritage Diesel, specializing in fuel injection systems on heritage era tractors. stock rebuilds to all out pullers!
|
Posted By: DrAllis
Date Posted: 19 Oct 2017 at 9:15am
|
I've written about this before, but here it is again. 25 or so years ago, I was asked to overhaul a Customers WD. It was his twice daily cattle feeding tractor that was never unhooked from the feeder wagon. It had the original design flat top AC aluminum pistons. I did some calculating and figured a set of 175 pistons and sleeves would yield the same compression ratio with the standard 4 inch stroke crankshaft. I had a 175 motor kit on the shelf. Realizing the HP risk was very small (he didn't plow or disc with it) that's what got installed. Cranking compression was right at 100 psi, just like a WD should be. The surprise was this: the sound of the exhaust was much more like the "crack" of a WD-45, not like a normal WD. Why would this be???? My $$$$ has always said the Power Crater bowl design is what changed the sound of the exhaust. Believe it or not, I choose to believe it does.
|
Posted By: steve(ill)
Date Posted: 19 Oct 2017 at 1:13pm
I believe it...... crater pistons would puddle the gas/ air in the center right below the spark.. a DOME would leave the gas/ air in a donut ring around the outside, still with the spark in the center... That might be more of a determent than an advantage. I can see the crater design adding more HP.
-------------
Like them all, but love the "B"s.
|
|