Long Rod Motor/Indy Dan
- Thread starter TRS
- Start date
Pulled the Long Rod motor down today. This motor has been run hard. It has all stock Polaris components, except for the long rods and shim plate. It failed a leak down test. Rings are junk, flaking. Polaris needs to fix this ring issue, it has been going on for to long. Pistons are in good shape, no knife edging as we have seen with the stock rod. Cylinders look awesome. I had taken a dozen pictures of the rings, only two are somewhat clear.
9
96sherm
Member
So I ask this question, not trying to be a dink, moron, or otherwise, not trying to stir a pot, start a fight, etc. Just looking for further education. If Indy Dan and his long rod motors are so good, why would he still use stock piston/rings when its obvious that there are still some issues with them? If you've went through the trouble of building an awesome cylinder and long rod system, why not use a better piston/ring kit...something lighter, stronger, "better"...
Again, just looking for education...not trolling!!!
Again, just looking for education...not trolling!!!
Also wandering about pistons. Dare not mention brand or vendors, but non OEM pistons have been run for thousands of miles with no problem ?
What I am wondering though is the clutching you run? 46/32 seems a long way off from the 60/40 we've been running for 3 seasons now? Curious.
What I am wondering though is the clutching you run? 46/32 seems a long way off from the 60/40 we've been running for 3 seasons now? Curious.
Just for your info. Dan did not build this motor. Dan did the crank for me. I put this motor together with stock Polaris parts. To prove a point. There has been a lot of discussion of rod ratio on this forum.
I believe the 132mm rod has a rod ratio problem. If you run the 132mm rod in the old TSR program you will find the CFI2, CFI4 motors have a rod ratio problem. I had Dan long rod a crank to verify that finding. How many of the old big block 800's had the piston, cylinder issues we are seeing with the CFI2/4? Why? Their 136mm rod have something to do with it?
The ring issue caused this tear down. If the rings did not fail it would still be on the snow. The pistons or monoblock did not fail. In fact they are in great shape. Better than any CFI2 or CFI4 motor I have disassembled that has failed a leak down test. To be honest, most riders would not have known there was a issue starting with their motor.
OEM pistons
You are running a 60-40.46 or .36
I am running a progressive 46/32 or 46/34 with a 120#-200# secondary spring. Primary with 120-310 spring and 61-62 gram Lightning weights.(8-10,000') 19-46 gearing.
I have a few of these kits out. Over a 1000 miles of hard mountain miles on belts. Smiles from all the guys running this setup.
Lightning gram weight depends on rider size and track length.
I also have a, off the wall, clutch setup for the 2013 Pro.
Yes, I did call Dan, and he is out. Looking for replacement pistons. Polaris is on backorder.
Dan did not build this motor, he long rod the crank for me. Do not get this mixed up or compare it to one of Dan's motors.
Because most times the OEM piston is more readily available than an aftermarket version...?
I posted rings last spring. Polaris needs better control or vendor. Ski-doo had this pitting and fixed it pronto. TRS your right, you can feel it in the rope. Feels like it has more compression. Takes 4 to 5 pulls in the morning instead of 3. Takes 2 to 3 pulls when hot instead of 1.
I did not add any oil to the tank. I personally do not believe in running oil through my injectors, fuel filter, and pickup screens in the tank.
I did turn up my oil pump. It will run anywhere from 40:1 to 32:1. It depends on how hard of a fuel day I had. If I run a tank out in 2.5 hrs it runs 32:1 if it's a 5 hr. tank 40:1. Some days I only get 43-46 miles to a tank.
Tony: That's a unfair video for the masses. ( its all about measuring tools. ) Not hand wiggle comparisons.
Every high performance 2 stroke that's making in the 70+ hp per cylinder range is going to have wiggle at the top.
Most high performance 2 stroke pistons have huge taper from bottom to top. and I mean HUGE !!!
like in the .010 to .015 thou depending on who's piston your measuring.
Then you have to take in to account that a fresh 800 pro cylinder set at lets just say exactly 3.346 with a new Cast Polaris piston ( stock rod motor ) . ( This combo will feel pretty good at the top because the tight clearance at the bottom will hinder movement at the top especialy with a lot of oil in the bore.
Next example same exact motor with 500 miles on it. ( Most of the oil burned out of it, and skirts stressed relieved and settle in .002 to .003 thou. Now the wiggle test at the top will feel .010 worse at the top just because the bottom of the piston is now smaller.
So all I am saying is the wiggle test is not a good test.
The Polaris piston is a good piston with a bad ring, Its the most dependable and strongest made. ( and most forgiving )
Any form of forge piston is going to be less forgiving and hard to warranty long term. one wrong move with a semi cooled down motor at full throttle and a forged piston is more likely to hit the cylinder. ( This is not breaking news. ).
I use 3 different cast pistons ( depending the application of the motor ) with rings that hold up much better then stock.
And as TRS Tony said, He wanted to try stock Pistons and I don't blame him for making that test. I always try to build the most dependable package with as many OEM parts as possible to make it easier to get parts. TRS Tony also mentioned the old Big Block 800 136mm rod motor that had zero piston problems.
I also build a LRTM5 - 5 year warranty not advertised at this time that uses the Old Polaris 800 Big Block piston. this motor is built with super long life in mind ( But it uses a completely different head and the cylinder height is also much different then the Standard Long Rod Motor. )
Dan
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Talked to Dan today and said that my long rod motor has been shipped. I am very excited to run this with all of his clutching setup. I will now have the complete tornado package in my sled and this one is going to be fun. Anyone that is hesitating on anything from Dan should stop thinking about it and get your stuff to him asap as he will only be getting busier as the year goes on. Don't ask questions, his stuff flat out works. I look forward to feedback after I get to ride this thing. Thanks for everything Dan. you have now made my 800 as reliable as ever, gonna be a fun winter.
