Help Support IH Cub Cadet Tractor Forum:
Ryan:
If you want power put a smoker in the cub. Look on e-bay for a Kubota Diesel. Many sell for less than $1000.00. Complete. HP is around 16-18 hp. You would not lack for power and a turbo could be added. Just check with Travis, I believe he has a hair dryer on his diesel.
If you want power put a smoker in the cub. Look on e-bay for a Kubota Diesel. Many sell for less than $1000.00. Complete. HP is around 16-18 hp. You would not lack for power and a turbo could be added. Just check with Travis, I believe he has a hair dryer on his diesel.
Todd,
I've always read that having the ignition source (spark plug) in the hottest area of the combustion chamber(over the exhaust valve)is the preferred location. After ignition, it is desired to have the flame front proceed towards cooler surfaces, thereby reducing the probability of autoignition, then detonation of the pre-combusted mixture. In the K301, .040 off the head raises the compression ratio one full value (from 6.5 to 7.5:1). In a K321 with larger bore, this same .040 will raise the ratio a bit higher, probably (guess) closer to 8:1. In an L-head engine, there is a fine line on balancing breathing ability (volumetric efficiency) with compression ratio. Too much off the head and the "trench" becomes restrictive, negating any benefits that the higher CR might contribute. My recommendation, especially if you're burning gasoline (vs. alcohol) would be to stick with the K321 head with .040 to .050 off the surface.
I can't really advise you on cam selection. I've never degreed a K361 cam, but I did check out the one I bought through Madson's. Lift is stock at .312 to .315 but more overlap and duration than the stock K301 cam. Most noticeable is the lift rate (valve acceleration) is quite a bit higher on both inlet and exhaust. You can hear this when the engine runs - it has more valve noise than a stocker. It's not objectionable, you only hear it at idle, and I've grown to like it. Has that tweaked-on hint about it.
I'm honored that your following my build-up. Please post some pictures as you proceed, so we can all see your progress.
I've always read that having the ignition source (spark plug) in the hottest area of the combustion chamber(over the exhaust valve)is the preferred location. After ignition, it is desired to have the flame front proceed towards cooler surfaces, thereby reducing the probability of autoignition, then detonation of the pre-combusted mixture. In the K301, .040 off the head raises the compression ratio one full value (from 6.5 to 7.5:1). In a K321 with larger bore, this same .040 will raise the ratio a bit higher, probably (guess) closer to 8:1. In an L-head engine, there is a fine line on balancing breathing ability (volumetric efficiency) with compression ratio. Too much off the head and the "trench" becomes restrictive, negating any benefits that the higher CR might contribute. My recommendation, especially if you're burning gasoline (vs. alcohol) would be to stick with the K321 head with .040 to .050 off the surface.
I can't really advise you on cam selection. I've never degreed a K361 cam, but I did check out the one I bought through Madson's. Lift is stock at .312 to .315 but more overlap and duration than the stock K301 cam. Most noticeable is the lift rate (valve acceleration) is quite a bit higher on both inlet and exhaust. You can hear this when the engine runs - it has more valve noise than a stocker. It's not objectionable, you only hear it at idle, and I've grown to like it. Has that tweaked-on hint about it.
I'm honored that your following my build-up. Please post some pictures as you proceed, so we can all see your progress.
F
farmall gray
Guest
David K,
That makes sense on the head. I know that in a high RPM flathead that breathing is more important
than compression. But I wasn't sure in a stock RPM
engine. I figured if I used the 10 head, I would have to open the head up slightly around the exhaust valve since the 321 has the large exhaust valve. It is easier to use the K321 head anyway because I won't have to change the top baffle.
I don't think there is much difference in the depth of the chamber on the 2 heads. The 10 head
has a bulge that comes out between the valve pockets that makes the compression higher. Although that bulge probably hurts the breathing
by shrouding the valves.
I don't have any specs on the cam I used in my K301 to compare to either. I got it used from a friend of mine who is an experienced puller and engine builder. He said that grind was designed to
work good in a mild K301. I know Brian Millers page says that the K361 cam is longer duration than the cam for the flatheads. I'm
kind of leaning towards the cam you used. Since you are happy with it and it is the cheapest of my options. I
probably wouldn't notice the difference without a dyno anyhow. They are probably all similar grinds.
As for pics, I don't have a digital cam so I probably
won't take too many pics. Mine won't look as nice as yours anyhow. It probably won't get painted till the rest of the tractor does.
That makes sense on the head. I know that in a high RPM flathead that breathing is more important
than compression. But I wasn't sure in a stock RPM
engine. I figured if I used the 10 head, I would have to open the head up slightly around the exhaust valve since the 321 has the large exhaust valve. It is easier to use the K321 head anyway because I won't have to change the top baffle.
I don't think there is much difference in the depth of the chamber on the 2 heads. The 10 head
has a bulge that comes out between the valve pockets that makes the compression higher. Although that bulge probably hurts the breathing
by shrouding the valves.
I don't have any specs on the cam I used in my K301 to compare to either. I got it used from a friend of mine who is an experienced puller and engine builder. He said that grind was designed to
work good in a mild K301. I know Brian Millers page says that the K361 cam is longer duration than the cam for the flatheads. I'm
kind of leaning towards the cam you used. Since you are happy with it and it is the cheapest of my options. I
probably wouldn't notice the difference without a dyno anyhow. They are probably all similar grinds.
As for pics, I don't have a digital cam so I probably
won't take too many pics. Mine won't look as nice as yours anyhow. It probably won't get painted till the rest of the tractor does.
D
dvogt
Guest
the theory David gives on the heads is what we normally go by . but for some reason in a stock 14 it don't fly. we've done alot of testing on that . we ran both styles of heads several times but always go back to a 10 hp head. they put out more torque and hp lower in the RPM band. the 14 hp head worked good over 3600 , how long can you run there? it seems the 10 hp head flows more than enough air if you run a goverend engine. thats with .017 off the block , .015 off the head & the head gasket squished in a press to .045. we figured the comp ratio in the 9's . it would not detonate on preminum gas with the ign. advanced to 24 deg. . The Kohler 10 hp LP head has no dump area at all and they are still a good head for a 12 hp SA that runs with no gov.. so the plug location don't seem to make the difference one would normally think.
for cams the Vogel cam you picked up used is very close to the K361 cam . but Chuck will grind a advance in for you. I put one in a 16 with a 7 deg advance. the K361 cam I used in my 14s I put in I advance a bit more than that. Steve Hackman of Seymore small engines in Seymore IN. grinds some very good cams also . I spoke to Scott about their cams some time ago & could not get one that had a advance ground into the profile of the cam. cam. .
for cams the Vogel cam you picked up used is very close to the K361 cam . but Chuck will grind a advance in for you. I put one in a 16 with a 7 deg advance. the K361 cam I used in my 14s I put in I advance a bit more than that. Steve Hackman of Seymore small engines in Seymore IN. grinds some very good cams also . I spoke to Scott about their cams some time ago & could not get one that had a advance ground into the profile of the cam. cam. .
Don,
Thanks for the info. Theory can get you headed in the right direction, but nothing beats actual test data and experience on a given engine. The truth is always told when engine meets dyno.
Todd,
Don's info on the cams is interesting. I would take his advice on that also. Good rule of thumb on cam timing: advance timing for better low end power, retard timing for top end power. Thus a cam grind with fairly high overlap and duration can be made "milder" by advancing the valve events relative to crank position.
Thanks for the info. Theory can get you headed in the right direction, but nothing beats actual test data and experience on a given engine. The truth is always told when engine meets dyno.
Todd,
Don's info on the cams is interesting. I would take his advice on that also. Good rule of thumb on cam timing: advance timing for better low end power, retard timing for top end power. Thus a cam grind with fairly high overlap and duration can be made "milder" by advancing the valve events relative to crank position.
F
farmall gray
Guest
Don and David,
Thanks for your help. I guess I'll try the 10hp
head. I remembered that I have a top baffle that
will fit it too. I'll just have to get some new bolts for it. I hadn't been on here for a couple days, and by the time I read Don's post, I already sent my cam to Scott. Hopefully it will work as good for me as it did for David. The cub fund is a little tight and it was the cheapest.
David,
I have another Q for you. In your buildup you
mentioned having to tweak the compresssion release. Could you expand on that a little. The reason I ask is because I had some trouble with the cam in my K301. When I first put it together
it wouldn't start. I finally figured out that is was releasing too much compression. I tried bending the tab down and it broke. So I tore it back down, made a new rivet for the release, and put a release off another cam on it. Then I ground
the release tab till I got the kohler specified
valve lift. I don't remember the exact spec but I
think it was .037-.045. I had to keep taking the cam back out and grinding a little more till I got that spec. Did you use that spec, or did you
do it another way? I also have an old kohler manual that gives a spec by how far the piston is BTDC when the comp rel closes the valve. This didn't work I assume because of the different cam timing with the reground cam. It is still not perfect but at least I can start it most of the time. I may try milling the head a little and increasing the valve clearence a couple thousanths at some point. What I believe is happening is that it is firing, but not with enough force to start, but with enough force to
get it spinning fast enough to disengage the comp rel and then it kicks back. It works better if I
retard the ign timing, but then it loses power.
Obviously, I want to avoid all that hassle on this new K321 I'm building. Sorry for such a long post, but I enjoy this hot rod talk.
Thanks for your help. I guess I'll try the 10hp
head. I remembered that I have a top baffle that
will fit it too. I'll just have to get some new bolts for it. I hadn't been on here for a couple days, and by the time I read Don's post, I already sent my cam to Scott. Hopefully it will work as good for me as it did for David. The cub fund is a little tight and it was the cheapest.
David,
I have another Q for you. In your buildup you
mentioned having to tweak the compresssion release. Could you expand on that a little. The reason I ask is because I had some trouble with the cam in my K301. When I first put it together
it wouldn't start. I finally figured out that is was releasing too much compression. I tried bending the tab down and it broke. So I tore it back down, made a new rivet for the release, and put a release off another cam on it. Then I ground
the release tab till I got the kohler specified
valve lift. I don't remember the exact spec but I
think it was .037-.045. I had to keep taking the cam back out and grinding a little more till I got that spec. Did you use that spec, or did you
do it another way? I also have an old kohler manual that gives a spec by how far the piston is BTDC when the comp rel closes the valve. This didn't work I assume because of the different cam timing with the reground cam. It is still not perfect but at least I can start it most of the time. I may try milling the head a little and increasing the valve clearence a couple thousanths at some point. What I believe is happening is that it is firing, but not with enough force to start, but with enough force to
get it spinning fast enough to disengage the comp rel and then it kicks back. It works better if I
retard the ign timing, but then it loses power.
Obviously, I want to avoid all that hassle on this new K321 I'm building. Sorry for such a long post, but I enjoy this hot rod talk.
Todd,
I did spend a lot of time getting the compression release working correctly on the Madson-supplied cheater cam. The .037 to .045 opening height is what you should strive for with .014 lash clearance. The most important thing is the valve should be seated a few crank degrees prior to ignition at 20 deg BTDC. What I did was to use a rubber mallet and tap on the exhaust valve until the clearance and closing point were in spec. Sounds crude but it works. I also had the camshaft in and out of the block several times. It pays to take your time and get everything right during the buildup. I'm sure you'll do the perfectionists job.
When you get the cam, there will be scale on it due to carburizing. Take a Scotchbrite pad and polish both cams to a bright finish, then clean thoroughly. Before you button the engine up, smear white lithium grease on both cam surfaces, all the way around. This keeps things well lubricated for the first start.
I did spend a lot of time getting the compression release working correctly on the Madson-supplied cheater cam. The .037 to .045 opening height is what you should strive for with .014 lash clearance. The most important thing is the valve should be seated a few crank degrees prior to ignition at 20 deg BTDC. What I did was to use a rubber mallet and tap on the exhaust valve until the clearance and closing point were in spec. Sounds crude but it works. I also had the camshaft in and out of the block several times. It pays to take your time and get everything right during the buildup. I'm sure you'll do the perfectionists job.
When you get the cam, there will be scale on it due to carburizing. Take a Scotchbrite pad and polish both cams to a bright finish, then clean thoroughly. Before you button the engine up, smear white lithium grease on both cam surfaces, all the way around. This keeps things well lubricated for the first start.
D
dvogt
Guest
Dave , Sure does. got to visit with it at the Kewanee pull
Regarding the blown cub on e-bay. This sold about a year or more ago, for somewhere around $2500. They say it was never pulled. The way the blower is hooked up, I wonder if it is for looks only. I have a bunch more pics of this whole tractor. If anyone is interested, e-mail me and I'll send them your way. It looks like whoever built it definately paid attention to detail!
Keith, It looked pretty cool, like you mentioned though. Theres a lot of things out there that "look good" A lot less work.
Don, I took pictures of three real nice tractors there. Outside, even moved them around to get the light right and not a one picture off that roll took. The next time I was there I got those two but Dads was already put away. He might just get "on line" this winter. That guy knows a lot about cubs.
Don, I took pictures of three real nice tractors there. Outside, even moved them around to get the light right and not a one picture off that roll took. The next time I was there I got those two but Dads was already put away. He might just get "on line" this winter. That guy knows a lot about cubs.
F
farmall gray
Guest
David,
I tried tapping on the valve and the tab broke.
This cam had the hardened ACR tab. Some of the early ones could be bent but this one obviously
couldn't. The valve was just barely closing before TDC even after I ground the tab for .037-.045. On this new one I'll have to look close
at the shape of the tab before I grind it down.
Maybe I can play with the shape of the tab to get the timing of the ACR correct. I'll make sure
to work with the ACR before I start the assembly
process this time. I milled my head for it today.
I decided to use the 10hp head. I milled about
.060" off of it. I then milled about .020" out of the valve pockets to maintain clearence. I also
did a little grinding on the back side of the valves for better flow. So with that I probably
didn't raise the compression too much.
I tried tapping on the valve and the tab broke.
This cam had the hardened ACR tab. Some of the early ones could be bent but this one obviously
couldn't. The valve was just barely closing before TDC even after I ground the tab for .037-.045. On this new one I'll have to look close
at the shape of the tab before I grind it down.
Maybe I can play with the shape of the tab to get the timing of the ACR correct. I'll make sure
to work with the ACR before I start the assembly
process this time. I milled my head for it today.
I decided to use the 10hp head. I milled about
.060" off of it. I then milled about .020" out of the valve pockets to maintain clearence. I also
did a little grinding on the back side of the valves for better flow. So with that I probably
didn't raise the compression too much.
R
roundy fendered cubs rule!
Guest
Keith,
Thanks for the blower pic!
Thanks for the blower pic!
S
still gt pulling with my turbo diesel 1782
Guest
Well with the pulling season behind me I am glad to say the turbo diesel 1782 has been quite a success overall. It was this season's points champ by a whisker over my wife's Kohler powered Stock Altered. Looks as if our club is gonna allow alcohol S/A for 2004 to keep standardized with NQS. Good idea.
ps> Know what else that means?.... I can add a second turbo for 2004!! Twin turbos on my 53 C.I. diesel. Looks like fun!
ps> Know what else that means?.... I can add a second turbo for 2004!! Twin turbos on my 53 C.I. diesel. Looks like fun!
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