2004 800ho compression

[maxwell]

Have you had a failure directly related to SPI's?

I've never had a SPI failure, used them in 670 Rotax, 800 Pol twin, 800 series 3, 780 Rotax and in my 809 mod. Pistons Bill Cudney sell also look suspiciously like SPI's. Elko's are good but for 1/3rd the price it's hard to beat SPI's.

MCB is also selling a dual ring piston that supposed to be good also $250-300 USD for a top end "kit" bearings, gasket etc.

on my personal sleds no i havent.

but ive rebuilt far to many sleds with those pistons in them with premature failure..glad you have made them work.

and from the feedback on the internet its about 10 to 1 for sucess vs failure.

wiseco is a better product, better piston, better manufacturing process.

get what you pay for...goes for anything

that being said its more work. the oem pistons are a good product aswell.

under the microscope the low end pistons have way to many flaws.

the battle of cast vs forged.

 

[Modman]

Here's some information to read before you buy pistons. S&M has been down this road before - let's not beat a dead horse.
https://www.snowandmud.com/forum/f55/spi-vs-wiseco-pistons-13410.html

SPI's are cast and hypereutectic. They are good pistons for the price IMO.

Run what you want, just make sure you are aware of the clearance issues with Wiseco's if you choose them.

Hope that helps.

 

[powerteker]

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the battle of cast vs forged.[/QUOTE]
More internet race:ding

 

[Canuk]

I recently read all I can and there is no clear answer, but alot depends on the application (race vs. weekend warrior vs. weekend tourist). Kelsey at RK teck told me to stick with cast so that was the swing vote for me. Probably 6 vs. 1/2 doz.

I do agree that new pistons before failure could save you a bunch of cash. No one want's a broken piston skirt falling into the crank.

 

[mmagic]

I recently read all I can and there is no clear answer, but alot depends on the application (race vs. weekend warrior vs. weekend tourist). Kelsey at RK teck told me to stick with cast so that was the swing vote for me. Probably 6 vs. 1/2 doz.

I do agree that new pistons before failure could save you a bunch of cash. No one want's a broken piston skirt falling into the crank.

We have Kelsey's head/piston upgrade kit in stock at Mountain Magic for the series III motor. (800 H.O.) He is saying 15 to 18 more horsepower with the kit. To get max benefit from the kit you want to run the motor at 8400 RPM. Running at 8000 RPM is still OK . The ones we have in stock are 13.5 to 1 compression (premium fuel) but we can get anything you want. They are a dual ring piston and you get all the benefits of his head design. The kits come complete with gaskets ready to install. Phone us at (780) 474-9400 for details.

 

[dooryder]

i just checked mine today and my sled has 3500 km and it has 148psi on both cylinders