Con rods breaking on turbo motors...

fredw · Dec 9, 2014

just doing a survey on conecting rods that have broke on turbo 800 etec motors, I know I have seen a few pictures but never took it further than that

had some info from a well known builder that there is some cast bonding issues on certain years with stock rods, and aftermarket rods are now a replacement choice to prevent, but it seams to be only on turbo sleds

i had a broken con rod on a 2013 crank with around 1200 miles, there was no reason for it happening, 8 lbs of boost and happened right after wot... Plans are to go with a aftermarket rod

What have others seen or had similar issues with con rods!!

drew562 · Dec 9, 2014

fredw said:
just doing a survey on conecting rods that have broke on turbo 800 etec motors, I know I have seen a few pictures but never took it further than that

had some info from a well known builder that there is some cast bonding issues on certain years with stock rods, and aftermarket rods are now a replacement choice to prevent, but it seams to be only on turbo sleds

i had a broken con rod on a 2013 crank with around 1200 miles, there was no reason for it happening, 8 lbs of boost and happened right after wot... Plans are to go with a aftermarket rod

What have others seen or had similar issues with con rods!!

I believe Rene had 2 motors blow. TSS kit. . Ghostbuster (Jason) also went down that road and is now on a stock sled again.

fredw · Dec 9, 2014

Yes it get expensive in a hurry when it takes cases and jugs out flapping around... Pretty much a new motor needed, and always speculation what had caused it, when it could be just a bad forged rod where under boost it became evident quickly

oler1234 · Dec 9, 2014

Put me down... I think a lot of it has to do with loading. Boost can be tuned to come in very early producing massive amout of torque, which a person can clutch for. Our tuning was very similar to hot rods, load the hell out of it to create higher exhaust temps and more volume. This in turn will typically result in faster turbo spools, provided while doing this you can maintain some sort of traction. As a result the extra loading essentially is put onto the engine to achieve this result. In a NA sled it would just bog but a turbo sled typically muscles through it, and there is a failure as a result. If boost would come in later then there would be less internal engine stress as rpm ranges are higher. tracks spinning at excessive speeds and your either trenching or moving at a high pace. Mine was at 5-6lbs, full boost at 5500rpm or less.

when completing a tear down it was evident, as base gasket looked to be intact and bottom end bearing wear is little to none, not even heat scored.

whenever we are doing boosted small/big clock Chevys, you do not use lightweight rotating assemblies like you would see in a snowmobile engine. Most everything is built like a diesel, solid and stout.

cheeky24 · Dec 9, 2014

Oh O i don't like the sound of this thread. So should I start a engine fund, I thought these motors were holding up to boost real well.

Backcountrypro · Dec 9, 2014

It is like this, you tend to only hear the negative on these forums. People have problems and here is where they come for answers. Very few come here to praise their current set up, a few do but most don't. My advice is to know your set up, take good care of it, clutch it right, give it a healthy diet of high octane fuel if running higher boost and have fun. Don't loose any sleep about so called problems with connecting problems......life is too short for that crap!

ABMax24 · Dec 9, 2014

Does anyone have any theories on what actually loads the rod in tension enough to do this? Or is this because the rod is too brittle and eventually breaks because of the hammering on it? Just curious most engines I know of bend/shorten rods under boost because of increased compression forces in the rod during compression and power strokes, unless the rod is a cryogenic/heat treated piece that increases strength at the cost of reduced ductility, or just a p!ss poor casting.

drew562 · Dec 9, 2014

Backcountrypro said:
It is like this, you tend to only hear the negative on these forums. People have problems and here is where they come for answers. Very few come here to praise their current set up, a few do but most don't. My advice is to know your set up, take good care of it, clutch it right, give it a healthy diet of high octane fuel if running higher boost and have fun. Don't loose any sleep about so called problems with connecting problems......life is too short for that crap!

Fyi. ^^^. Its not like that. For some reason guys don't post failures with skidoo. I posted once that 2 of 3 of my etecs were belt spitters. Then 59 guys post they have the same belt for 3 yrs and ran 4 liters of oil in one season. Oh and etecs go for days on a tank of fuel. Well I burn the same oil as the cats I ride with and somedays a tank plus 5 gallons and still run out 6 km from the truck. It's a Doo thing. Loyal polaris guys admit premature failure all the time. Cat guys help each other with the new chassis belt issues fixes. Doo guys seem to be blinded by the yellow color. And I'm a Doo guy at the present saying this. Etecs work well boosted. Yes. Are they built proof or ready for a factory turbo. Not even close. IMO of course.

fredw · Dec 9, 2014

I was a bit skeptical after hearing from engine builder that he seen and heard well over a dozen boosted sleds breaking rods on etecs, but it's starting to look like it's possible

talking with randy and motor teck in golden, they had lost one boosted rod snap last year as well, and I was told Frenchie lost one a few years back on his tss, I did a search and a few more came up

[h=2]"Re: Turbo XMs[/h]

Me personally I would choose either tss or aero period. I like my aero cuz I can put the sled back to stock with the aero kit no problem. Also complete install w/snow to air, clutching, reeds, venting and install takes me 12 hours approx. Now that i've installed it and removed it three times lol. Both kits have pros and cons. I think tss has better electronics and major mountain experience and uses generic turbos that are readily available. Aero has worked with brp racing to build as close to a factory sanctioned kit as your gonna get. Aero kits can be do it yourself are fairly basic to install and tune, tss no, they wanna do it so no install problems. I have run aero from the beginning of etec kits, had some major ups and downs with it. but over all on the 2011 I logged 2500km at 6lbs with no intercooler before rod failure. Time will tell with the xm. Make sure when you do install you get your oil pump turned up by brp. Something they dont tell you in the instructions.

and another one on snowest fourm...

iceman 56

Who all has toasted there motor or knows somebody that has?? My buddies Etec lasted about 150 miles on boost before sending a rod through the block:face-icon-small-fro
TSS turbo with W/A intercooler, 7psi boost straight Av gas at 8-10,000ft never hit DET sensor.
Just wondering if this is gonna be a common thing with the Etecs or this was a freak deal just sh!tty luck? I was under the impession the Etec was a pretty stout motor but maybe not.

mareshow · Dec 9, 2014

I didnt have any issues in the 5000 km I rode mine through... best of luck figuring it out though I know i'm going to keep reading

Canadian Snow · Dec 10, 2014

I like this thread keep the info coming, I wonder why you see a TSS kit loose a rod in a couple hundred km then have a TSS kit with 5000 km, bad luck for one guy or self inflicted ? Is the failure to do with which kit insta boost vs standard ? What is Rene running from TSS, I'd be done after 2 failures?

deaner · Dec 10, 2014

drew562 said:
Fyi. ^^^. Its not like that. For some reason guys don't post failures with skidoo. I posted once that 2 of 3 of my etecs were belt spitters. Then 59 guys post they have the same belt for 3 yrs and ran 4 liters of oil in one season. Oh and etecs go for days on a tank of fuel. Well I burn the same oil as the cats I ride with and somedays a tank plus 5 gallons and still run out 6 km from the truck. It's a Doo thing. Loyal polaris guys admit premature failure all the time. Cat guys help each other with the new chassis belt issues fixes. Doo guys seem to be blinded by the yellow color. And I'm a Doo guy at the present saying this. Etecs work well boosted. Yes. Are they built proof or ready for a factory turbo. Not even close. IMO of course.

Exactly! I think there are a few other factors at play as well. One is people that are sponsored by either the manufacturer or turbo kit maker are probably putting on the most miles and hence having the most failures; but probably arent going to advertise anything bad out of fear of losing their sponsorship. Another factor is guys not wanting to kill the resale on thier used turbo. If you have a turbo etec and have engine problems, alot of guys are going to keep that quiet so they are able to get rid of the thing.

Great thread Fred. I was super close to buying a used tss xm but the more I dig around, the more of this stuff there is that you dont hear about. Not saying that people shouldnt ride turbo doos at all.......sounds like they rip. But has to be guys that dont mind footing the bill for an engine or helicopter ride.

lsone · Dec 10, 2014

Like posted already. its directly related to load. If you can have a turbo light very fast with a heavy load... the turbo will outrun the engine and will rip it apart(or the drivetrain, whichever is weaker). No lag is cool with good parts. Turbos on a stock engine and finally grenading is much like a diesel guy complaining that his "crazy uncle buck wild" level 7 programmer made his allison 6 speed s*** its guts onto highway 2.

Bnorth · Dec 10, 2014

In general low rpm power in a boosted motor is harder on rods than high rpm. The compressive forces on the rod at low rpm with boost exceed the centrifugal forces on the rod at high rpm. So if you're spooling quickly that rod is seeing more load than if it spools later. This is something I just learned after talking with some diesel guys that make a lot of power in their race trucks and twin vs large single turbo setups.

Bnorth · Dec 10, 2014

Canadian Snow said:
I like this thread keep the info coming, I wonder why you see a TSS kit loose a rod in a couple hundred km then have a TSS kit with 5000 km, bad luck for one guy or self inflicted ? Is the failure to do with which kit insta boost vs standard ? What is Rene running from TSS, I'd be done after 2 failures?

Gotta keep in mind Rene puts on well over 10k km a season.

cheeky24 · Dec 10, 2014

So if a guy want to stay on the safe side, what should he do. I'm running good fuel, adding a little extra oil, should I keep the boost down low around 6 to 7 lbs

drew562 · Dec 10, 2014

Bnorth said:
Gotta keep in mind Rene puts on well over 10k km a season.

His turbo saw less miles than LH freaks wedge

drew562 · Dec 10, 2014

cheeky24 said:
So if a guy want to stay on the safe side, what should he do. I'm running good fuel, adding a little extra oil, should I keep the boost down low around 6 to 7 lbs

I hear way less bad news stories at 5-6 lbs on etec.

lsone · Dec 10, 2014

cheeky24 said:
So if a guy want to stay on the safe side, what should he do. I'm running good fuel, adding a little extra oil, should I keep the boost down low around 6 to 7 lbs

in short, yes.

You gotta remember... its a stock engine...

Ive turbo charged LS engines in cars... yea they make retarded power but you have to understand they are always on borrowed time. Ive learned that borrowed time is a reality too lol.

fredw · Dec 10, 2014

my rod let go just after a second or two of wot, and that morning I had turned boost up.. There was no det codes are det on the piston

Making sense that biggest load on rotating parts is on spool up.. Rather than at wot

maybe we have just max out the load cabability of the stock rod, it's just time to replace with Carrillo rods like they do on the nitro motors when they do a 300hp kit..

also so heard a good reply from randy at motor teck... He said his son picked up a 5000km sled last year and installed a turbo, never touched Pistons or crank, then drove the hell out of it to 8000 Kms at 6 lbs boost and never touched the motor...

I have discussed this with aero and from their findings they have not heard or seen much of con rods breaking... So maybe it just a Cdn thing

Con rods breaking on turbo motors...

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