low gearing for tobogan pulling

[bootsnixon]

I've got a 76 jag 340 f/a. It's my main tobogan pulling sled and with the age of my kids, never sees above 20mph. It gets pretty hot going so slow, pulling a sled so I would like to gear it down. I have a 20/39 gearing right now. I've found a 16 tooth upper gear, if I leave the bottom gear will that cause problems?
Thanks

 

[Scotty]

Not sure how much play you have with your chain tensioner on that old boy but you will need it if you drop to a 16 tooth upper gear. If things are getting hot dragging the kids on the toboggan maybe you need to go way FASTER! Its a fan!

Enjoy Snow and Mud... lots of good info from good people here.

 

[white ghost]

its hot because of the slow speed... not the gearing

 

[bootsnixon]

You're right that it's not getting much air across the cylinders but it would certainly be cooler if it was not working as hard. Good point about the chain tensioner but I think there is enough play in the spring loaded tensioner that the chain would stay tight.

 

[highmark x]

Maybe you need a doo to pull the kids lol. Just kidding sounds like not enough speed and air to cool the cylinders. Don't think gearing down will help you.

 

[Sledderglen]

Put a 12 volt cooling fan under the hood to blow cool air over ther clyinders. Cant be any worse idea than trying to gear down. You need air moving over the cylinders to cool. Maybe get the kids one of those enclosed sleighs and pull it faster.

 

[Murminator]

ya i think if you gear down the RPM's would be higher creating more heat

 

[shawnmcgr]

I think gearing down will help. It'll get your rpms up without adding much load so you should run cooler. Can't tell you whether that gear will work with your current chain though.

 

[Ancient Sledder]

Could always run it with the hood off. That would help get rid of some heat.

 

[bootsnixon]

Thanks for the advice guys. I'm going to try a 18 tooth gear. An Arctic Cat 16 tooth was $116 (!!!) and a jobber 18 tooth was $20. I could get a 16 tooth online but I guess I'm impatient. A 12v fan is a good idea. I could probably scab up some shrouding to help move the air across the cylinders. A couple of factors are working against me that a fan could help. I'm not moving fast at all and we tend to only go sledding when it's warm out. Lastly the old Jags do not have the cylinders sticking out of the hood like most free airs did. Making a it a shadetree fan cooled should really help.