building a small groomer puller

Liquifire 4/6 · Post by **Liquifire 4/6** » Sun Oct 19, 2008 10:49 am

I didn't think the charging system in this engine would be up to the task of running all the electrics on this machine.....so I installed a 65 amp alternator (1992 Ford Tempo). I fabbed up an aluminum pulley that mounts outboard of the water pump drive pulley and mounted the alternator under the engine for two reasons: a) I think it'll be cooler under the mill than on top which should give me better alternator life b) I'm hoping that the downward tension of the alt drive belt will be somewhat offset by the upward tension of the w/p drive belt resulting in less stress on the crank than if they were both pulling the same way?

Not sure how much of a load the alternator will put on the engine as I've never attempted to drive an alt with a sled engine before. I'm thinking it'll be a significant of a drag at lower engine speeds, but hopefully not too much once it's into it's powerband. So for easier starting ( and low speed running), I decided to install a belt tightener on the alt belt so I can engage or disengage it with a console mounted lever in the cab. Maybe, it wasn't necessary...but I figured it's better to install it at the outset rather than have to add it later. If I find I don't need the feature, I'll remove it later as the set up added another 12 pounds or so to the rigs already substantial weight.

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_FIII · Post by **_FIII** » Sun Oct 19, 2008 11:08 pm

coming along very nice Pete. I am sure the end result will justify all your time, keep it up!

PS- has a date been set for your local vintage derby? Starting to plan out my winter, but do not want to miss the Roblin derby.

Post by **ICCSF 108** » Mon Oct 20, 2008 6:48 am

Pete, very good work, I too agree with the alt. down theory, I do think that a car Alt will take a quit a bit of HP, ( at least from a 2 stroke motor )..
Just food for thought here & I'm sure you already thought about this, Just wondering how your going to handle this, I assume your going to have a hand throttle or an awful heavy springed foot throttle on this as any other way would probably result in jerky acceleration/de-acceleration while cruising down the ruff trails?? My point being is that the motor will be at a constant RPM unless needing more speed or power, when this cruising speed happens & I know the carbs can be jetted to handle this no problem, But won't the exhaust manifold get real extremely Hot? Or is the motor going to be out in the open to compensate for any extreme exhaust heat? Or don't you think this will happen?

Kenny

Liquifire 4/6 · Post by **Liquifire 4/6** » Mon Oct 20, 2008 8:47 am

_FIII wrote:
PS- has a date been set for your local vintage derby? Starting to plan out my winter, but do not want to miss the Roblin derby.

Hiya Richard. I still haven't set a date for the vintage derby. I intended to have a meeting with the local snowmobile club in early October and get a date finalized.......but our harvest dragged out so long that we just haven't got together yet. Probably will meet with the gang in a week or two. It's hard to figure out a date that works with everyone. January runs the risk of being bitterly cold with possibly marginal snow, but generally doesn't conflict with too many other events. February is usually the best snow conditions around here, but tends to conflict with other vintage events. Early March snow conditions are usually excellent and the temps are normally quite nice, but again.....there are some vintage races during that time. Here's a question for you, Richard.......what weekend would suit you the best? And would a saturday or a sunday work best with you? I'm leaning towards a saturday in late Feb or early March, but I'm really open to suggestion. Looking forward to your opinion.

Liquifire 4/6 · Post by **Liquifire 4/6** » Mon Oct 20, 2008 9:07 am

ICCSF 108 wrote: Just wondering how your going to handle this, I assume your going to have a hand throttle or an awful heavy springed foot throttle on this as any other way would probably result in jerky acceleration/de-acceleration while cruising down the ruff trails??

won't the exhaust manifold get real extremely Hot? Or is the motor going to be out in the open to compensate for any extreme exhaust heat? Or don't you think this will happen?

Kenny

Hi Kenny. The throttle will be controlled by you guessed it, a heavy springed foot pedal. I figured it was the only way I could operate a CVT tranny in a machine that has a steering wheel instead of handlebars. I'm hoping it'll work ok and I'm kinda used to the foot feed in our club's Tucker Snow Cat. Here's a pic of the front side of my go pedal. Pardon the messy welds and the rusted look. I'm not the best welder in these parts. I've basically been tacking stuff together and will get a buddy of mine to go through all the welds and pretty them up when I dismantle the machine to get it ready to paint. Pretty much all the metal is new, but it's amazing how fast it begins to show rust just by sitting unpainted in the shop. I plan on sandblasting everything before priming and painting it.

Regarding the exhaust temp..........Yes, the engine bay will be completely enclosed and I do have some concerns about high exhaust temperature as well as excessive heat in the clutch/belt system. I thought at first that some strategically located vents would suffice to keep the heat at a reasonable level. However, due to the slow travel speeds while grooming, I'm beginning to doubt that vents alone would be enough to take care of it. Now I'm leaning towards placing one air vent on the LH side of the engine bay, just to the left of where the driven clutch sits and another vent on the rear close off panel (just behind the expansion chamber). My plan is to install an electric fan on the RH side of the sled (to the right of where the drive clutch is located). My thinking is that it should pull cool air from the LH side of the sled over the clutches as well as suck some cold air from the rear of the machine and reduce the exhaust temp. I don't think I want the fan to run continuously as it might be too cold during initial warm up of the machine and it could also possibly be too much of a drain on the electrical system. I don't want that alternator to be running at max any more than it needs to be as I know it'll tax the little 2-stroke when it's loaded down producing charge. And I don't think a manual switch would work the best as it would be too easy to forget to flick it on when the engine bay heat is getting up there. So I'm wondering if you can buy a 12 volt thermostatic switch that could be adjusted to turn on the fan when the ambient engine bay temp hits a certain level........I'm thinking around 120 degrees F would be about when I'd like to see the fan cut in. The proper location of the thermo switch within the engine compartment will be something to figure out too. Do you know where I can get such a switch?

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JDT · Post by **JDT** » Mon Oct 20, 2008 9:56 am

A radial fan that runs on 12vdc maybe what you are looking for. Say one that is 10" and has a grille built right into the frame. MCM has them for $100. Type in DC fan on the search engine and it is on the bottom of the page. It will move over 8 cfms. Put it on top of the engine compartmet and the intakes on the sides. That way the intakes will not suck in snow if it is falling. It will also look neat to have a plume of warm air blowing out the back.
You can also get a temp switch from MCM or even go one better.... get a varibale speed unit. This would also save on amp draw as it would only run at max speed if needed.

Liquifire 4/6 · Post by **Liquifire 4/6** » Mon Oct 20, 2008 3:15 pm

Todd.....I really like the idea of placing the fan the way you suggest. It'd look pretty nifty blowing upward from the engine bay. I haven't checked for space yet, but if it'll fit that way, I'll do it. I actually have a new 10" fan that I ordered in error and didn't return. It's not variable, but I'm gonna run with it for now. I'm not familiar with the MCM company, however I'll check them out for switches. The thought just occured to me that some of the air cooled Polaris ATV's have a cooling fan located above the cylinder head and it is controlled with a $20.00 thermal switch. I'm pretty sure I can make one of those work if I find the right spot for it. I'm planning on going to Yorkton,SK today and will stop by the Polaris dealer and see if they have one.

I spent most of this morning still finishing off the alternator engagement mechanism. I decided to place it just to the right of the seat. I hadn't built a console for that area yet, so it took me awhile to make one out of aluminum. I think I'll put the ignition switch and choke lever there as well. Anybody have an idea where I can find a dual pull Mikuni choke cable that's at least 90" long? I could likely make one by using a dual pull throttle cable splitter box and adapting two choke cables into it, but that's something I'd prefer not to have to spend time on.

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Mr. Deere · Post by **Mr. Deere** » Mon Oct 20, 2008 3:58 pm

WOW Nice Work.

JDT · Post by **JDT** » Mon Oct 20, 2008 6:44 pm

I see I did a typo on my last post. It would pull 800 cfm's not 8.

A decent fart is good for 8 cfm and you want get any air exchange from that.

Liquifire 4/6 · Post by **Liquifire 4/6** » Fri Nov 14, 2008 2:57 am

I'm still plugging away at it. We're starting to get some snow here now and in a few days I'll likely be more keen on doing some riding instead of working on this, but I really want to get her up and running before the new year. I fitted a few of the body panels yesterday...decided to go with aluminum checker plate instead of sheet metal. I think it might have looked better with a painted body, but I figured that overhanging branches on some of the trails would scuff and scratch a painted body and the aluminum should handle it a bit better.

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S_Kyle · Post by **S_Kyle** » Fri Nov 14, 2008 9:39 am

Wow, I'm impressed with you progress. Looks great

Scott :thinksnow:

427cobra · Post by **427cobra** » Fri Nov 14, 2008 10:54 am

That thing is so cool....keep the pictures coming

Mr. Deere · Post by **Mr. Deere** » Fri Nov 14, 2008 3:17 pm

Sweet.

Liquifire 4/6 · Post by **Liquifire 4/6** » Tue Nov 18, 2008 1:25 am

Today, I sorta got the rear close off panel finished up. Here's a copule pics of it...one with the LED taillights off and abother with them hooked up to a battery. Thanks to an annonymous member here for supplying the LED's at no charge. Tommorow, I'll get started on the hitch.

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tipitup · Post by **tipitup** » Tue Nov 18, 2008 12:47 pm

Don't get it stuck!!!