Spi Axys pistons

[raleigh111]

here is exhaust side, pto on right

 

[cbc24]

Rktech pistons are wiseco pistons.

I thought they used wossener pistons? Also ran them on my old pro and liked them .

 

[Indy_500]

Do you have any pictures? I thought mine looked pretty good with 3000 miles and was still pulling 120 compression. My pto side had some slight scuffing but i ingested a lot of snow last year with a torn intake screen and a leaky air box. Not the pistons fault.

 

[Sheetmetalfab]

I thought they used wossener pistons? Also ran them on my old pro and liked them .

they did use wossener pistons for years. (Trash talking the wiseco the whole time)

now they use wiseco pistons.

go figure.

 

[ADDIE]

Chinese Pistons (SPI) = Chinese Quality.

USA Pistons = USA Quality

Saving a few bucks is not worth the risk IMO.. Your opinion may differ.. But having an engine failure in the backcountry due to Chinese parts will cost you a lot more in the end.
Like anything made in China... some last some do not...

IMO< best option is to never skimp on internal engine components..

 

[Indy_500]

Chinese Pistons (SPI) = Chinese Quality.

USA Pistons = USA Quality

Saving a few bucks is not worth the risk IMO.. Your opinion may differ.. But having an engine failure in the backcountry due to Chinese parts will cost you a lot more in the end.
Like anything made in China... some last some do not...

IMO< best option is to never skimp on internal engine components..

While I do agree about Chinese vs USA quality, every encounter I’ve had with forged pistons in snowmobiles has ended badly. I’ve ran SPI pistons in over a dozen sleds (never an 800 yet) with absolutely 0 issues. Personally I think a cast SPI piston will outlast a forged Wiseco any day of the week as it can take temperature swings, but that is just my opinion...

 

[ADDIE]

While I do agree about Chinese vs USA quality, every encounter I’ve had with forged pistons in snowmobiles has ended badly. I’ve ran SPI pistons in over a dozen sleds (never an 800 yet) with absolutely 0 issues. Personally I think a cast SPI piston will outlast a forged Wiseco any day of the week as it can take temperature swings, but that is just my opinion...

I think your opinion is one shared by many because of old horror stories and experiences.
It is unfortunate that this opinion is still present but it is understandable.

Forged is always stronger than cast. This is important.
Also you can not just assume all forged pistons are the same. Making this assumption would be incorrect.

All forged pistons are machined from an existing forging. Where (and how) this forging is produced is very important. This is a backbone of a forged piston. You are only as good as your forging and your rings and pin.

There is very good science as to why any high powered race engine will be using a forged piston. They simply are stronger and last longer.

A good USA made forging can not be beat! A Chinese forging can be beat easily!

Once you start with a quality USA made forging, the next critical process is how they are machined. Every forged piston is machined to the correct specs from the existing forging. this "spec" is very important and varies with the design and application. This is where the differences lie between the same forged piston from different "shops". The machining and added treatments to the forging determine how well it performs in the engine.

It is unfortunate, that many assume that all forged pistons made by one particular manufacturer are the same. Nothing could be further from the reality!

How the forging is machined and what is added, or nor added, to the piston can be and usually is, very different from one shop to another.

In the end, support USA made products they usually are superior and in this case certainly are!

Forged pistons, when properly machined to a spec that supports the application, are stronger and more resilient than any cast piston (dues to the properties of forged vs cast)

The old "idea" that all forged pistons require special handling is simply not true anymore. Any quality forged piston (USA made) will outlast and out perform any cast piston IMO.

We are in the 21st century, processes have been improved and knowledge has been gained.

Lastly, All forged pistons are NOT equal. This is important. The added treatments and geometric design is what, ultimately, determines how well the piston performs and lasts. AND the piston ring is very important. You can have a great forged piston design and install a poor ring and it will render the piston junk! The ring is very critical.

 

[cbc24]

they did use wossener pistons for years. (Trash talking the wiseco the whole time)

now they use wiseco pistons.

go figure.

Thanks for letting me know, I will no longer be using that product in the future

 

[kyle89]

I think your opinion is one shared by many because of old horror stories and experiences.
It is unfortunate that this opinion is still present but it is understandable.

Forged is always stronger than cast. This is important.
Also you can not just assume all forged pistons are the same. Making this assumption would be incorrect.

All forged pistons are machined from an existing forging. Where (and how) this forging is produced is very important. This is a backbone of a forged piston. You are only as good as your forging and your rings and pin.

There is very good science as to why any high powered race engine will be using a forged piston. They simply are stronger and last longer.

A good USA made forging can not be beat! A Chinese forging can be beat easily!

Once you start with a quality USA made forging, the next critical process is how they are machined. Every forged piston is machined to the correct specs from the existing forging. this "spec" is very important and varies with the design and application. This is where the differences lie between the same forged piston from different "shops". The machining and added treatments to the forging determine how well it performs in the engine.

It is unfortunate, that many assume that all forged pistons made by one particular manufacturer are the same. Nothing could be further from the reality!

How the forging is machined and what is added, or nor added, to the piston can be and usually is, very different from one shop to another.

In the end, support USA made products they usually are superior and in this case certainly are!

Forged pistons, when properly machined to a spec that supports the application, are stronger and more resilient than any cast piston (dues to the properties of forged vs cast)

The old "idea" that all forged pistons require special handling is simply not true anymore. Any quality forged piston (USA made) will outlast and out perform any cast piston IMO.

We are in the 21st century, processes have been improved and knowledge has been gained.

Lastly, All forged pistons are NOT equal. This is important. The added treatments and geometric design is what, ultimately, determines how well the piston performs and lasts. AND the piston ring is very important. You can have a great forged piston design and install a poor ring and it will render the piston junk! The ring is very critical.

Well forged is stronger than cast, but I think alot of peoples seizures with them are from incorrect piston to wall clearance/ring gap and or not warming up.

I believe manufacturers put in cast for the simplicity that alot of riders dont warm up long enough, or stop for lunch ect. The rate of expansion is different between the 2 metals.

I think from a company's warrenty standpoint, putting in cast pistons are a safer bet for less warrenty work (and cheaper to buy)

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