Ready for the off season
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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=129273
Printed Date: 24 Nov 2024 at 8:13am
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Topic: Ready for the off season
Posted By: 48ACWD
Subject: Ready for the off season
Date Posted: 27 Sep 2016 at 7:45am
| Pulling season is winding down so time to do a little R&D work. Did pretty good this season with my wd45 puller with the stock gleaner motor making 50hp on the dyno. Had enough for our 4500lb class but lacked power in 5500 so.. what's the thoughts for the off season? Well let's just start with what's the best I can make hp wise without stroking a crank and spending a bunch of money. Any ideas I would appreciate some help. Thanks |
Replies:
Posted By: DrAllis
Date Posted: 27 Sep 2016 at 11:12am
| Larger carburetor. |
Posted By: 48ACWD
Date Posted: 27 Sep 2016 at 11:23am
| I'm running a tsx871 drilled out at the moment. What should I be running on it |
Posted By: bigcountry48
Date Posted: 27 Sep 2016 at 12:33pm
|
How many rpms are you running? You could bump up to a heavier 175 spring. That and get a 175 carburetor and cam shaft. That should get you a little more power anyways. ------------- 1950 B, 1952 pulling wd, and 1954 wd45 |
Posted By: LeonR2013
Date Posted: 27 Sep 2016 at 2:07pm
| Compression. |
Posted By: Robacpuller
Date Posted: 27 Sep 2016 at 8:47pm
| Mill the block and head. Port the head and intake, bigger valves. Bore carb take choke out.if not done make a pipe and k and n air cleaner. |
Posted By: 48ACWD
Date Posted: 28 Sep 2016 at 7:30am
| What's to gain if I do 4 1/8 bore with flat top pistons head and manifold work |
Posted By: Charlie175
Date Posted: 28 Sep 2016 at 8:16am
Be Careful on the 4.125 kits. Some of them are lower compression than 4" kits. ------------- Charlie '48 B, '51 CA, '56 WD45 '61 D17, '63 D12, '65 D10 , '68 One-Ninety XTD |
48ACWD wrote:Posted By: wi50
Date Posted: 28 Sep 2016 at 8:23am
|
Your compression is so low in a stock engine, you won't mill enough off of anything to gain anything significant. Don't wreck your parts by taking some bad advice. If I wanted to make some power and not spend any money, 1. Advance the camshaft. Currently the intake centerline is 112-113* atdc and this is to late. Closing the intake valve earlier will trap more air and build more cyl pressure. 1 tooth advanced (13.333*) will help, though it would be best to make an offset key, or cut a new keyway and get in the intake centerline 103-105* range. 2. The carburetor just plain doesn't flow much air, the venturi sits on the bottom bowl and has to shear air at a 90* angle from the bottom bowl with basically no short side radius. If you were to build a "tounge" on the roof of the barb bowl, you could force the air around a large radius and increase what the carb flows. I've tested several and they are 95-99 cfm of air stock, after I build the tounge and replace the venturi they run about 145 cfm. I either make the venturi or buy some from a carb parts place in Washington..... I'll have to find the name. 3. The manifold is terrible. Where the neck from the carb joins the runners, it's a sharp 90* corner. I don't care who bored the manifold how big, you can't draw air over a sharp edge. Knocking that corner back and radius it will help. For example a manifold flows about 115 cfm in stock form, a few minutes spent on the corner and 140 cfm, or spending time and welding the outside and cutting a larger radius and working the floor where it turns to join the head and 180 cfm is easy. I fill the top corner also, I cut the floor flat and wide, fill the top to keep the air condensed on the floor. 4. The head also suffers from corners with no radius. Blend the corners of the intake port, it's T shaped and radiusing the corners will help. Valve and seat work can help, but depending on what you can and want to do there's to many options to take time to explain now. There's simple things that can be done with spending very little money. You'll get the most benefit from altered camshaft timing and the carb modification. ------------- "see what happens when you have no practical experience doing something...... you end up playing with calculators and looking stupid on the internet" |
Posted By: Charlie175
Date Posted: 29 Sep 2016 at 10:36am
|
I'm curious about the "Tongue" you mention I thought you could radius the bottom of the bowl to make a ramp to keep the air from going 90*? This should increase intake velocity? ------------- Charlie '48 B, '51 CA, '56 WD45 '61 D17, '63 D12, '65 D10 , '68 One-Ninety XTD |
Posted By: wi50
Date Posted: 30 Sep 2016 at 7:17am
|
Filling the back, bottom corner of the bowil doesn't cure the problem, but it needs to be done when filling the top. When I do the back bottom corner I also build a vane leading in front of the emulsion tube. That little vane gave me a significant improvement on the flow bench. But let's cover the important one, the top. Think about it like an upside down cylinder head port......the venturi base is like the valve seat. Stick your tounge out of your mouth and curl it up toward your nose. This is the shape to build on the top of the carb bowl, or roof of the inlet. Leave a gentle radius and a lead in angle.to the venturi. When done it looks like.the intake port of a high performance automotive cylinder head. The venturi in a stock bowl is grabbing air from the roof of the bowl, or short side radius....this radius is really non existent in the carb, it's a sharp corner. Building this tounge with a large radius leading to the venturi would give us a "short side radius", and this is where the air is traveling, that back bottom corner is a dead area. But by filling both and shaping them correctly we can make out venturi or " orfice" much more efficient. Let's say the venturi can flow xxx cfm, but the air is very turbulent atthe inlet, by doing the shaping of the inlet correctly, I can increase the efficiency of the orfice. If I took a plate of steel and drilled a hole through it that was say 1.129" diameter, that hole would have 1 square inch of area. If I bolt that plate on the flow bench and draw 28" h2o depression on the bottom side of it, it may flow 85-90 cfm of air depending on conditions..... But if I bored a hole through a piece of material say 4" thick and shaped the inlet in a radius and the exit like a radius, tuba or French horn shape, but the choke point in the center was still that same 1.129" diameter and I drew the same 28" depression through that orfice, it would flow 180 cfm depending on how well it's shaped. Your carb venturi is no different, shaping the inlet will greatly increase the efficiency. This is why I make the venturi and make it longer so I maintain the choke point at the emulsion tube ending, but I can shape the inlet with aa more gradual radius leading to the choke point....stock venturies are not shaped very well. So here's some free and good information that I spent a very long time shaping things differently and testing on the flow bench to learn. During the winter months I'll do some carb work for people, but I feel I've spent enough time getting it right that I don't need to give away all the information. ------------- "see what happens when you have no practical experience doing something...... you end up playing with calculators and looking stupid on the internet" |
Posted By: wi50
Date Posted: 30 Sep 2016 at 8:07am
|
Most answers are always "a bigger carb". But you never hear about making it more efficient. There are 2 depression areas in the engine, one is in the cylinder under the intake valve, the other is on the other side of the intake valve between the carb and valve. Cylinder depression will be higher than manifold depression. Now the piston moving down create the depression and the 2 restrictions separate the depression areas, intake valve and carb, or cylinder depression and manifold depression or vacuum. But the piston does not suck air into the cylinder, what you believe is only partially true. The truth is air is pushed into the cylinder from atmospheric pressure. Bench more power at sea level than at 10,000 ft elevation, piston is doing the same thing, but there's a difference in atmospheric pressure at the 2 elevations. When making the carb more efficient, or having a higher air density and speed in the venturi, we can increase the draw it has on the emulsion tube. If we simply keep going bigger with a carb, eventually the air speed and density become to low to draw and atomize the fuel at the emulsion tube. This is why as an engine slows down, it will cough and stall. But by increasing the efficiency of the orfice or venturi, just maybe we can actually keep the air speed higher, even through a bigger hole......hence less manifold vacuum. It is possible to build a carburetor that flows more air than that magic "larger carb", and has the ability to work at a lower engine speed. Now the answer is to fine a match with just the right physical size to allow us to have one big enough for maximum performance for the application but small enough to work at low speed and then build and shape it correctly. Air hates to expand, it's easy to condense air, but expanded air just slows down and causes a "backing up" effect at the choke point. It is very easy to have a throttle bore of the carb that is to big allowing the air to expand to much and sometimes a bigger carb, just flows less than a smaller one will in the same application. ------------- "see what happens when you have no practical experience doing something...... you end up playing with calculators and looking stupid on the internet" |
Posted By: Charlie175
Date Posted: 30 Sep 2016 at 8:22am
Excellent!  Thank you ------------- Charlie '48 B, '51 CA, '56 WD45 '61 D17, '63 D12, '65 D10 , '68 One-Ninety XTD |