Piston wash TPE 1105 thoughts ?

[Wetbuffalo]

Thats definately an issue on strokers, not so much on the 964 as its a SS. I have had to cut pistons many times to make them fit with the longer stroke. Mocking it up will tell you for sure.

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So the thing about TPE motors is that they use the same piston, 1200-964. It’s a 95mm piston with a long skirt. As it comes from wiseco it is about 1200 length. As the stroke is decreased more length from the skirt is removed.

The 1021 is an exception because it is essentially a 964 block with a 4mm stroker crank and custom domes. The piston actually comes out of the deck a good bit and equally moves further down at the bottom of the stroke, hence why I had clearance issues.

There is also some to be said about the skirt shape and how it tapers down as I have run two different shaped skirt pistons and noticed a huge difference in hit off the bottom end.

Between these pistons and custom cut domes my 964 is pushing a 157mm pump. Everyone who has rode the ski asks if it is an 1105 or bigger.

 

[Freakrider]

So the thing about TPE motors is that they use the same piston, 1200-964. It’s a 95mm piston with a long skirt. As it comes from wiseco it is about 1200 length. As the stroke is decreased more length from the skirt is removed.

The 1021 is an exception because it is essentially a 964 block with a 4mm stroker crank and custom domes. The piston actually comes out of the deck a good bit and equally moves further down at the bottom of the stroke, hence why I had clearance issues.

There is also some to be said about the skirt shape and how it tapers down as I have run two different shaped skirt pistons and noticed a huge difference in hit off the bottom end.

Between these pistons and custom cut domes my 964 is pushing a 157mm pump. Everyone who has rode the ski asks if it is an 1105 or bigger.

You've got it backwards in the first paragraph on what u mean ?

 

[Wetbuffalo]

You've got it backwards in the first paragraph on what u mean ?

What do you mean backwards?

 

[Blue]

This part..
As the stroke decreases more skirt from the piston is removed.

Should say. As stroke increases more skirt from piston is removed.

Piston travels closer to crank at BDC.

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[Wetbuffalo]

This part..
As the stroke decreases more skirt from the piston is removed.

Should say. As stroke increases more skirt from piston is removed.

Piston travels closer to crank at BDC.

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Actually the way I said it is correct. The casting of the 1105 is taller then the 964. Also don’t forget about the longer rods used on stroker motors.

 

[Blue]

Actually the way I said it is correct. The casting of the 1105 is taller then the 964. Also don’t forget about the longer rods used on stroker motors.

I see what your saying. The bigger motor has longer rods too. This puts the piston farther away from the crank. Most smaller cc motor just change the stroke with a stock length rod which requires skirt trimming pretty much every time. I havent had the pleasure of rebuilding any TPE 1105s or 1200s yet.

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[Freakie]

Hi Wetbuffalo.....see my pic......new piston needs to be modded to same profile as old to get the rotation and clearance.....can I use my artistic and engineering skills with a dremel to to do the mod.....and then balance both pistons using a scale down to 1 gram ?.....or is there more tooling magic to this ???...

 

[Wetbuffalo]

Hi Wetbuffalo.....see my pic......new piston needs to be modded to same profile as old to get the rotation and clearance.....can I use my artistic and engineering skills with a dremel to to do the mod.....and then balance both pistons using a scale down to 1 gram ?.....or is there more tooling magic to this ???...
View attachment 403390

With them being that close you can just use a dremel tool. Pay attention to how the edges are rolled on the bottom of the skirt as to make sure nothing is snagged.

 

[Freakie]

Hi there

Ok job is done and new pistons in place and all works together very smoothly.....just need to do a compression test before firing up. Thank you very very much for your invaluable advice Wetbuffalo , I really appreciate it. A big shout out to Jr. The condition of the crank bearings and the old parts are actually unbelievably good.....likely due to fully synthetic fuel I use and an engine very well built.....took a pic if the builder

 

[Freakie]

would be interesting to know what the significance of 001 is ......it has been here in Cape Town for the last few years hitting big surf and flatwater depending on the season......big up to McDog who sent it to New York where I picked it up at a Fedex centre and checked it in as on board luggage on Emirates business class. (30 kgs) flying back to SA

 

[Jr.]

Yes, I built that motor back is 6/2014. The 001 is a serial number I assign to all motors I have built.
Its the first TPE motor I have sold to clients. Several were before I that were test base motors, without serial numbers assigned. Including a personal 964 I ran myself for several seasons. Love the TPE platform!
Hope you enjoy your motor! Feel free to continue contacting me with any questions you might have?

Ski ya, Paul

 

[Freakie]

wow ....deja vu moment for me.....your motor is in my carbon Freak Tem built.....best combination of ski I have ever owned in 30 years..... I have a rickter and a Krash 50 cal with 900 DASAs but they will never match up to this combo....I ride surf and flatwater....no total loss and compression is lowish...so powerband very linear............incredible power but can be a gentle beast tks Paul

 

[cpolaris502]

Hmmm, my TPE 1105 also has the 001 stamp from LPW.

 

[Jr.]

Hmmm, my TPE 1105 also has the 001 stamp from LPW.

On cyl or case? Please pm photo? There was a 001-1 that was a warranty replacement for client.
Cyl had bad water jacket, that allowed water into PV slide path. Was an issue on several early 1105 cyls, until sand casting was repaired.

 

[cpolaris502]

You are right. My 001 is on the cylinder. And mine did take out the connecting rod last year because of water leaking into the exhaust port through the jacket.

 

[Crab]

005 here, in my avatar!