Archive through September 28, 2006

[wheinsohn]

Ryan,
When I rebuilt my K301 in my 129, the machine shop said my cam showed some wear. They ground it to an 18 HP cam specs. I also shaved the head some. my 129 will now handle a 50" deck as good as my rebuilt 149 with everything standard on it. And to add to it, my 149 uses more gas to do the same job. The 129 has also been very respectful when pulling a plow at the few Plow Days that I took it to.

 

[rwilke]

Wes H.,

Thanks for the reply!
Sounds like your 129 buildup is about what I'm looking to do as well.

I'm not too sure my machine shop will have the ability to re-grind my cam nor even know what or where to locate the specs for a 18HP cam. Maybe they'll surprise me or maybe I'll have to come back here looking for the 18HP cam specs....

Did you use OEM K301 lifters & valves with the re-ground cam?

Do you recall how much you shaved your cylinder head?

Thanks again!
RW

 

[wheinsohn]

I used the standard valves and lifters. I do not know how much I took off the head. I used the old glass with sand paper on a flat bench method but it was warped bad. I did an awful lot of sanding by hand to get it flat.

 

[rwilke]

10-4, Wes. I understand.

Ryan

 

[dfrisk]

RYAN - The old K241 I rebuilt some 21 yrs ago had a really warped head....it was reground flat almost 1/16th of an inch.... .060" It's a double-edged sword in a flathead engine....the smaller combustion chamber volume raises compression but chokes off the flow area from the valves to the cylinder. It was a low-buck rebuild.... The machine shop ran a hone thru the cylinder to break the glaze, ground the valve seats, knurled the piston, I put a new rod & rings in and it still runs O-K after 1400 operating hours. I did have a close call with it about 2-3 yrs after I rebuilt it. I got a call from My Buddy to bring My Cubbie to mow His back yard. When I got there He had green grass over a foot tall, dead grass almost two feet tall, plus windrows from the bushhog that mowed the yard the summer before. My Cubbie ran FLAT OUT for about an hour before I started hearing a bit of detonation, I idled it for a few minutes and went back to mowing a bit less agressively. After I mowed a swath about 6 feet wide We had a windrow that was as big as anything I ever fed into the old IH #55 Baler I drove as a Kid.

 

[rwilke]

Dennis F,
Thanks for the reply!

I hear what you're saying about the milling the head of a flathead engine being a double-edged sword. I was guessing that the fuel/air FLOW wouldn't suffer THAT much (with a fairly stock rebuild) because the engine stays well below 4000rpms. Although I was considering that maybe a little relief grinding at the the piston side of the "valve pocket" to unshroud it wouldn't hurt - but again, with a 'operating limit' of <4K rpms, the valve unshrouding may not make much of an improvement. Of course, too much grinding will then increase combustion chamber volume and thus I'd loose whatever compression increase I'd of gained with a head shaving increase. I was merely thinking that a compression increase of 1 or 2 would be a noticable power increase. However, I don't know to what level of effect it would have with keeping it cool (since these are air-cooled engines) or with extra work for the OEM starter. Although I have read somewhere where you can rebuild your starter for more torque to handle higher CR engines.....

You mentioned that your machine shop, "...knurled the piston..."? I never heard of doing that. Knurling the valve guides, yes, but haven't heard of knurling pistons. Hmmm... why not, I guess.

What do you/anyone think about exhaust system changes versus benefits?

I'm thinking that a gutted muffler like what David Kirk did in his, "Killer Kohler Part II" article, would be a big gain for even a stock-ish engine for little cost. Nor would such a muffler put a strain on the engine; unlike higher compression, more heat generated, a thinner head, higher rpms, etc.

Ryan

 

[dfrisk]

RYAN - Knurling Pistons....the thrust faces looked just like the handles of those cheap imported wrenches You see at flea markets...same cross-hatch pattern. Instructions from the machine shop Manager was to slide the piston & a .002" feeler gauge into the bore and selectively file until the piston slipped in. I'm curious what the piston & bore will look like when I pull the engine apart. I've never even had the head off in the last 21 yrs. & 1400 hours.
When the K321 goes into this tractor it will have a straight pipe exiting over the S/G pulley. I can't run upright stacks due to too many low branches on trees. And the salt-shaker mufflers would be WAY too restrictive.

 

[rwilke]

Fellas,

Over on the IHCC Forum there has been some dicussion regarding the differences in power and torque between the Onan twin cylinder engine versus the single cylinder Kohler engines....with claims that the Kohler has more power and torque, but also has more vibration. If both units were dynamically balanced, why would this be the case?

I would think that the balancing should cure the majority of any vibration issues. As far as the power & torque, I would think that the engine with the larger displacement (I'm guessing that would be the twin) would have the higher power & torque values... correct? ....Of course, I'm assuming both engines were operating at the same rpm, or isn't that a safe assumption?

Ryan W

 

[dvogt]

A twin will cancel itself out. no matter what you do to a single it still fires once every other time. balencing helps but the firing order isn't very conducive to smoothnes

 

[rwilke]

Don V.,
Thanks for the reply!

I understand what you're saying that dynamic balancing of the rotating assembly will reduce SOME of the vibration in a single cylinder engine, but because the Kohler is only ONE CYLINDER, a similarly-balanced TWIN CYLINDER engine should be EXPECTED to operate with less vibration since the harmonics of one cylinder will help cancel out the harmonics of the second cylinder.

What are your thoughts regarding the general claims of a single cylinder Kohlers having MORE POWER AND TORQUE than a Onan twin engine?
Ryan W

 

[dvogt]

some of those Onan twins are huge in the ci department. so a 68 ci Onan should out horse a 34 ci Kohler single. lets gop Inch for inch and see what happens

 

[rwilke]

Thanks, Don V.!
That's kinda what I was thinking as well.....

Ryan W. <cheers>

 

[mmasheris]

Finally got the turbo on the donor motor for the 982TD project.It has a definate whistle to it.Now to get the injectors opened up.

 

[gerickson]

Mike, are you gonna do the injectors yourself or take em somewhere like Hypermax in Gilberts to laser them out?

 

[cengelking]

I seen and heard Mike's turbo. Sound and runs great and it whistles.

 

[rwilke]

Fellas,

I don't know beans about turbos...the fact that Mike's turbo whistles, is that a good or bad thing?

Ryan W

 

[digger]

Ryan W.
That's a GOOD thing.
Ever listen to a semi tractor going down the road?
More whistle, means mor power!!!!!

 

[ewank]

Here is an actual photo of one of the first ones.

 

[ewank]

Previous photo is of a drop box we make to put a Kubota engine in a cub frame and have it line up and turn the rearend in the correct direction. I noticed your turbo oil drain runs up into the valve cover. Normally you want to get the turbo drain oil out of the turbo as fast as possible by dumping it straight down with a big line and into the oil pan.

 

[mmasheris]

Thanks for the input still in the early stages.What is involved in changing the tip of the injector to get mome fuel? Looks like just put a bigger tip and needle.