Who has a Long Rod Engine Upgrade?

So has anyone done the long rod upgrade to a pro 800 motor yet? Please tell us who's rod kit it is and if it was made by the actual seller or just sold by the installer.

I personally know of 3 engine builders who use and install this kind of upgrade. I have heard that one of the builders has a us manufactured rod and the others are using a china stamped rod. No I am not looking for a us to china quality argument since I know most all of us prefer the USA made products.

If you have had any long rod kit experience please advise which kit and what you are running for replacement pistons like stock, cast, or forged and what you did with the jug if you had it repaired or replaced.

I am looking for actually feed back from any one who has had any of the above mentioned upgrades done and how it has worked out to date with how many miles you have put on so far or how long ago you had it done. Also who did the work for you or indicate if you did this work yourself.

Please feel free to share you thoughts and opinions about your long rod kit. Last but not least I am not comparing any of the engine builders but this information is more about the upgrades & options and your expierence to date to evaluate the results. I would like this thread to stay away from the bickering between vendors and to see actually how many of these kits are being used to date.

xc6rider said:

IndyDan for one...

He's got a post with some info halfway down this page or so.

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XC6, thanks for the input and i have read the thread you referenced but I want to hear from the end use or a sled owner who has bought Indy Dans lomg rod jit and to see how it has worked to date.

I also know Brad at PAR offers a long rod kit but I have no clue if the kits are the same or how they are different?

xc6rider said:

Ok. I cant remember without re-reading that post of his engines.... But i think he kind of released it late season, and not sure if any users had chimed in yet or not. If any SW users had even used one.

Definitly be interested in hearing such! All of Brads stuff sure seems to come highly liked, but again not sure ive read much of his BB/ longrods.

Pickin new engines is exciting as well as annoying! Its like finding a new girlfriend, ya wanna ride em all . Atleast engines my cost ya less!

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XC6, Yes here in MN the polaris dealer charges $6300 parts, labor, & sales tax to install a new poo short block.

It is crazy expensive to buy another engine that only has a 30 day warranty on a short block with the same defects. I am asking these questions since I am currently having a short block built with the long rods and I trust Indy Dan but he is much more expensive.

diamonddave said:

Suprised you're going that route since you have first hand experience with the fix kit.

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DD, Yes I have been happy with the mtntk kit and it has proven to be reliable with excellent support from PMS. To be clear the motor I have being built right now has never had the fix it kit from mtntk.

To be honest last year I picked up a 08 D8 for my boy that had previously had the engine repaired after the common piston failure we have read about and discussed here on the IQ forum.

The engine repair was done by one of the guys here in MN and he is on this forum and he is good and knows his stuff. The jugs were done up and new measured to fit and were with in the correct piston to cylinder wall tolerance specs. as required to do a better job then the factory did.

Anyhow the sled has a PC5 with the the correct tune and orignal 08 map and head. On the first ride the sled ran well but at the end of the day on the way down the mountain on the trail the rod broke free from the piston and took out the jug and the case besides a throttle body and injector rail and or boss.

After spending time talking to Brad at PAR and Dan at Indy Spec. I was intrigued with the long rod options. So to make a long story short I bought a used 800 motor that was in running condition and it had the polaris 10 updates with the piston, jug, and head.

Obviously the engine ran when the sled was crashed but when we tore it down we found the same old piston story we have read here on the 4M. So I have bought some stock in the long rod design that is theory is supposively a better repair then the fix.

I like the theory of the long rod kit and it may be better in theory then the longer piston kit but obviously you can install the fix it kit with the motor in the sled. But you obviously have to remove the engine and disasemble the motor to install the long rod kit. Obviously this is not exactly a cost comparable situation by comparing the two options.

I have also heard that the long rod kits being sold may have two different lengths besides that they are made in two different country's. I feel like I am still gambling with these 800 polaris motors and I respect the fact that Mtntk, PAR, Indy Spec., and RTK care enough to support upgrades and changes to make these last longer and maybe even make them right?

AKSNOWRIDER said:

what the m8 or any other motor out there has is irrelevant to the cfi-2 motor..it has to do with the combo of parts...poo motor is a small motor..both in sheer size and in amount of metal used.(polaris trying to make it as light as possible)..so you end up with a motor that is more prone to expansion/contraction then other motors, tie this in with worse cylinder cooling ability(small castings less material and physical size means smaller water jackets and on the pro with a big exhaust port and powervalves means not much coolant flow right around the exhaust side of the cylinder..meaning it expands/contracts more which distorts thecylinder out of round more then normal...which can scuff pistons..now along with this polaris opens the piston wall clearence to avoid scuffing pistons and all of a sudden you are seeing skirt loads that the piston and cylinder cant handle..so how do you lessen skirt loads if you cant tighten bore clearence enough?..easy way..and it does other things as well, is to lengthen the rod..this moves the piston up and away from the crank which lessens the load the crank puts on the skirts and BDC,,,but..it also changes how the motor breathes, since the longer rod slows down the piston at bdc and the time the piston resides around bdc...allowing more filling time for the air/fuel...its hard to visulize..on many race motors the builder will play with rod/stroke/bore and porting(both size/shape and flow rates) to make the best usable power for said engine use..and best longevity for intended use...thats one reason why you are seeing the long rod motors pop up..can you fix this motor in other ways? yes..and no... while it is possible I doubt you can make a silicon based piston ever last on a stock cast mono cylinder for any extended period of time(say 10000 miles in a sled), you can change to aftermarket cylinders which are beefier, better cooling then stock and most likely add life(such as carls 900 kit) or you can do what brad and dan are doing..long rod the motor(brad even adds aftermarket cylinders as well)...pick your poison....

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AK, thanks for the play by play break down it adds much more definition to the theory of operation and why issues exist. I truly could not of said it any better or clear then you just did so thanks for the input.