Hon-Doo
Member
Hey guys,
I recently bought an 08 Summit with an Arctic Edge 860BB kit in it. The sled was set up to run in the 5000' + range with a stock head shaved to provide 13.5:1 compression. (Pump gas kit for that altitude). It is running a single stock pipe with a thing can. I will be running the sled in the mountains this winter with some luck but want to be able to use it in Yellowknife @ 1000' as well.
The fuel here in town is definitely shy of 91 octane @ the pump so I have already bought some Klotz octane boost (advertising a 4 - 5 octane number increase @ 1QT per tank roughly) and have a line on some 100LL should I need to go that route. The previous owner / builder said the sled would run @ 2000' on pump gas but that he took it easy at those altitudes. I picked up a KOSO dual egt kit to install as well as a few sets of larger jets to work my way down through and it already has 0.030" of shim under the needles.
My question is this, should I look at buying a lower compression head to run when I am at these low elevations? If so who do you recommend I talk to / what brand would you recommend? Or on the cheaper side of things, could I possibly just add a second base gasket to effectively lower the compression? I have been reading some of Kelsey's technical articles on RK Tek's website and it looks as though that could work.
I have no issue doing the work myself but have no experience with the math involved or the amount of time it might take to do either of these swaps. Time to swap a head? Can it be done in the machine? I don't necessarily want to pull the engine twice a season to swap base gaskets if the only difference is going to be the $400 for a second head.
Trying to come up with solutions before snow flys and I start getting antsy to ride. (That's only a couple months away here) Thanks for your input!
I recently bought an 08 Summit with an Arctic Edge 860BB kit in it. The sled was set up to run in the 5000' + range with a stock head shaved to provide 13.5:1 compression. (Pump gas kit for that altitude). It is running a single stock pipe with a thing can. I will be running the sled in the mountains this winter with some luck but want to be able to use it in Yellowknife @ 1000' as well.
The fuel here in town is definitely shy of 91 octane @ the pump so I have already bought some Klotz octane boost (advertising a 4 - 5 octane number increase @ 1QT per tank roughly) and have a line on some 100LL should I need to go that route. The previous owner / builder said the sled would run @ 2000' on pump gas but that he took it easy at those altitudes. I picked up a KOSO dual egt kit to install as well as a few sets of larger jets to work my way down through and it already has 0.030" of shim under the needles.
My question is this, should I look at buying a lower compression head to run when I am at these low elevations? If so who do you recommend I talk to / what brand would you recommend? Or on the cheaper side of things, could I possibly just add a second base gasket to effectively lower the compression? I have been reading some of Kelsey's technical articles on RK Tek's website and it looks as though that could work.
I have no issue doing the work myself but have no experience with the math involved or the amount of time it might take to do either of these swaps. Time to swap a head? Can it be done in the machine? I don't necessarily want to pull the engine twice a season to swap base gaskets if the only difference is going to be the $400 for a second head.
Trying to come up with solutions before snow flys and I start getting antsy to ride. (That's only a couple months away here) Thanks for your input!
