Had Me A Pretty Good Day

TheRainbowBoxer wrote:

You could put the transaxle on end and use the steering action to make rear suspension...

I don't understand what you mean...

Instead of the U joints allowing the wheels to turn left or right, the transaxle would be tipped up on end, and the u joints would allow the wheels to flex up and down... it would need some kind of spring/shock setup on it of course.

They'd just pivot a bit, really. You'd have to extend the shafts outboard of the U-joint to get any travel. They're pretty short.

Rear steer! I want   lol

tractor_guy wrote:

4x4 would be cool but hard to keep stock lookin. But, use a mtd frame with tall dash and hood, loft motor, run one belt from motor to transaxle, on trans use double pulley. Run another belt from rear to front. You could even build a second clutch for the 4x4 belt to have selectable 4 wheel.

I more or less just meant make one that looks clean and like it belongs that way. I would like to try it eventually, but it would be tough with the limited room up front to make everything work correctly.

They say a picture's worth a thousand words, so here's your thousand words:



Having stripped the engine, tranny, axle, and deck out- you get a pretty clear view of the stamped chassis pan. Quite clearly not your regular Sears LT 10/11/12 etc.

I'm still trying to get a line on the exact model. I believe it is a variant of the Sears LT8, but in my searches I'm finding LT8's that more resemble the full size ones that we are all familiar with. Still looking. Still wishing I had the hood.

Please! please don't scrap it out! it is to rare to do that!

He's doc sprocket, i dont think he'd scrap the worst of the worse lol, hes like me, i think theres still some use to a 3" long piece of steel....

I am pretty bad for not getting rid of things. When I have done so in the past, I have almost invariably ended up regretting it later, so I try not to do that...

O.k. I just saw it in peaces and thought that you where scrapping it and just keeping the 700

Fantastic! I tore down the "seized" 12hp outta the Noma AWS, and the parts I need to repair my own 12hp are still good. Looks like I will be saving the engine.

Recap- MULE's original engine, a Briggs 28 flatty had to be retired early. A counterweight bearing spun and ate itself, hogging out the journal in the counterweight.

This engine was supposed to be seized due to lack of oil. It WAS frozen, it had no oil. Yet- the only issue I found inside was that the same counterweight bearing was semi-frozen to the crank lobe it rides on. Having taken it apart, it appears that it was partially corroded in place, however it cleaned up well. It would seem that some water or condensate or something got in there, round about the time it was last used then stored for a season. When the guy went to start it up, no dice. Probably, he finally decided to check the oil and found it dead low, and therefore assumed the engine was locked up forever...

So- the plan is, to completely rebuild one, using the best of the two engines. They are a 1989 and a 1990 and identical except for the alternator. I'm going to do some performance tweaks to it for the hell of it, and perhaps present it to my son for the racer he is dreaming of.

I'm going to hone the cylinder and lap the valves, as well as complete new seal and gasket kit. I have already checked the rings. MULE's rings are well within spec, the Noma's rings are right at the reject dimension. MULE's rings it is.

*Shaving the eyebrows
*Porting
*Increasing the compression ratio using Russ' head gasket trick
*Advancing the timing

Doc Sprocket wrote:

a Briggs 28 flatty had to be retired early. A counterweight bearing spun and ate itself, hogging out the journal in the counterweight.

This engine was supposed to be seized due to lack of oil. It WAS frozen, it had no oil. Yet- the only issue I found inside was that the same counterweight bearing was semi-frozen to the crank lobe it rides on.

Are you talking about one of those syncro-balanced motors with the giant cast iron weights inside? I was wondering if you could remove these from the engine without the engine destroying itself. Do you think they actually change the balance of the running parts much or mostly just prevent vibration transfer to the rest of the machine? I had one where the small connecting rod that keeps the weights in line disintigrated. I think the 11hp briggs I have for my sears also has the same setup and was thinking of just taking them out.

Yup- that very same setup. Having torn a couple down and had a real close look, I can offer the following-

The factory crankshaft counterweights are "cut down"- they are smaller than normal, and I am pretty sure that those big cast iron dingleberries are needed to some degree or other to compensate.

I've looked around and done some research, and found that there are 2 possible goodies available to the engine owner that has racing in mind-

1)You can get a billet replacement for that little connecting rod, apparently the factory one is failure prone when you really push the engine.
2)Another option I have found allows you to take out the factory counterweights, the dogbone (connecting rod) AND the lobes on the crankshaft that the weights ride on. ALL of this is replaced with a pair of brass counterweights that go on the crankshaft in place of the factory lobes. They basically make up for the missing weight on the factory crankshaft. This is preferable, as they are not "moving parts" per se/

I found myself wondering what would happen if you just ditched the dogbone and dingleberries, and ran it as is. It's a fair bet that the vibes would be fairly nasty, and it probably wouldn't be TOO long before it hammered it's own guts out. I CAN find out.

After I am done building up the "good" engine, I may just for spits and giggles put the other one together to test the theory. If I do, the video camera will be present...

Thanks for the info. I forgot I asked about this and just happened to think about it. I had one engine on a mower that was actually used for mowing where that dog bone rod broke. The weights didn't go through the block or anything, so I cleaned everything up and put in a new rod. It was ok after that. I recently took that motor off of the tractor, so maybe I'll do a little testing at some point also.

As I am working on the "good" 12hp, I am spec'ing and selecting parts. The ones I reject are going to get assembled into a test engine, to see exactly what id going to happen without the counterweights. I have already chosen my block, crank, piston, conrod, rings, and head. Soon, I will have the two parts piles complete.

I will be running the test engine governed- I am hoping that if it shakes, it at least doesn't explode. Most of the parts are still good spares for the "good" engine.

Doc Sprocket wrote:

As I am working on the "good" 12hp, I am spec'ing and selecting parts. The ones I reject are going to get assembled into a test engine, to see exactly what id going to happen without the counterweights. I have already chosen my block, crank, piston, conrod, rings, and head. Soon, I will have the two parts piles complete.

I will be running the test engine governed- I am hoping that if it shakes, it at least doesn't explode. Most of the parts are still good spares for the "good" engine.

I was thinking last night as far as engine tests, could you get a eletric motor good for say, 9K RPM, bolt a flywheel on there and slowly crank it up and see what happens? That would be awesome, and dangerous, and awesome.

Believe it or not, I have put a LOT of thought into that. No matter what I come up with, the test is rendered nearly useless. Here's what I've got:

*Since the flywheel bore is tapered, it would take $$$ to get a machinist to make a matching mandrel to adapt to a straight shaft for testing. My budget sucks.

*Common AC electric motors are available in 1725 and 3450 RPM. I would have to mount the 'wheel to a jackshaft and use pulleys to run the speed higher. $ again. PLUS- This does NOT factor in the harmonics and balances of the engine itself. Sure, it might cause a wheel to frag at say 10k RPM, but without the engine itself, this really means nothing.

Now- here's the other thoughts-

*I COULD us an AC motor to drive a complete test engine through the PTO shaft. However- the test is still flawed. While I may be driving the reciprocating assembly, the harmonics still aren't there. Plus, with the crank driving the piston and not the other way around, any vibrations or harmonics that DO occur, aren't "true".

*The harmonics cause by the power stroke are not going to exist no matter what.

Either way I look at it, I MAY succeed in blowing the crap out of the 'wheel, it is much more likely the rod will go (like usual) and even then the test data does not hold true.

The ONLY way to get a halfway true test, is to get an engine to spin ITSELF fast enough to start blowing parts- which is nearly impossible completely stock. Then, the results would be crap too, since you only tested ONE engine. You'd need to test mutiple brands of multiple sizes of engine to attain a halfway believeable average. And no, I DON'T get enough sleep...

So, you haven't tried building yourself a dynomometer yet? I always was going to make one, but haven't gotten too it yet. Finally I think I may have a fairly simple way of doing it. I'm going to use a hub, bearing, disk brake, and caliper off of a junk car and mount it on a table/frame of some sort. Then I'll run a lever operated master cylinder to the brake caliper. In the brake line somewhere will be a pressure guage to get an idea of how much braking effort is being applied to the engine. Then you need a tach that you can hook up to any engine easily. With just that setup, you can make comparisons between changes in the same engine at specific rpm. Although you can't calculate hp. What you need to do is find out about how much effort is required to turn the brake rotor at specific pressure readings, then you have all the info to get some kind of hp reading. I think with a good size rotor, heat build-up won't mess with your readings too much with a small engine. I was thinking of trying this out in the near future. It always bothers me to cut some material out of a port or change the exhaust around without actually knowing if it's hurting or helping.

mr.modified wrote:

So, you haven't tried building yourself a dynomometer yet? I always was going to make one, but haven't gotten too it yet. Finally I think I may have a fairly simple way of doing it. I'm going to use a hub, bearing, disk brake, and caliper off of a junk car and mount it on a table/frame of some sort. Then I'll run a lever operated master cylinder to the brake caliper. In the brake line somewhere will be a pressure guage to get an idea of how much braking effort is being applied to the engine. Then you need a tach that you can hook up to any engine easily. With just that setup, you can make comparisons between changes in the same engine at specific rpm. Although you can't calculate hp. What you need to do is find out about how much effort is required to turn the brake rotor at specific pressure readings, then you have all the info to get some kind of hp reading. I think with a good size rotor, heat build-up won't mess with your readings too much with a small engine. I was thinking of trying this out in the near future. It always bothers me to cut some material out of a port or change the exhaust around without actually knowing if it's hurting or helping.

Good thoughts there!

I was looking into similar arrangements some time back. There's a couple how-to's on YouTube, for setting up a basic dyno, that actually can let you calculate HP and torque. Although, that might be more of a pain than it's worth. Like you, I would just rather have a benchmark to compare to, then at least you could express performance gains as a percentage.

To complicate matters futher- I tweak on engines both horizontal AND vertical- so I'd have to build two different units or find a way to adapt to both orientations without SERIOUSLY skewing the results.

[quote="Doc Sprocket"]

mr.modified wrote:

To complicate matters futher- I tweak on engines both horizontal AND vertical- so I'd have to build two different units or find a way to adapt to both orientations without SERIOUSLY skewing the results.

I thought about this. For myself, I would probably just build it for horizontal. I'll have to do a little more research on it.

Love the front wheel weights how did you come by them