Con rods breaking on turbo motors...

ktmsx350f

Active VIP Member
Joined
Nov 9, 2014
Messages
587
Reaction score
514
Location
fort mcmurray
On the way home from Val last year we got 2 flat tires and stuck on the side of the road .....I was thinking of doing a turbo on my 14 xm so I went on kijiji and called every turbo add in all of Alberta and BC and lots of shops for pricing and options ......my findings were everyone loved their tss set up but every tss set up had had a motor replaced no one seamed to have dislikes of aero charger and only 1 had a broke rod every shop had heard of it ......so for this year 2015 to stock and a cat with boost next year rods and aerocharger for the t3
 

sledneckx69

Active member
Joined
Mar 5, 2008
Messages
147
Reaction score
143
Location
camrose
Fred. The 3 or 4 like this that I have seen all had blue bottom journals. Even tho the rod broke the same as yours I am not convinced the problem is a weak design or materials, but no doubt the stronger sno-x rods would be an improvement. If you watch the video you posted from JJ Machinery again you will see the same thing I saw…overheated bottom bearings. A connecting rod is designed to be able to take a massive load in the vertical or near vertical direction. Higher cylinder pressures (8-12lbs boost) normally are not enough to cause this kind of catastrophic failure. But what a rod is not designed to handle is more force in the horizontal direction, like what a hot or seizing bottom bearing would cause. But that's only my opinion. When the e-tecs were introduced the case lost the ability to have the fuel help move the oil around. It's splash only now and as little oil as possible to meet emissions. Not a good scenario for the extra load that boost introduces. The new cranks that I have seen going into these engines on boost not only have stronger rods but a lot more relief and notches around the bearing for lube. It's great to hear that at least a couple of shops are aware of the problem and offering an upgrade.

Is it really that complicated, the oil issue I mean? I asked a builder about oil after boosting and he told me that he sets the oil back to break in mode. I'm no doctor, but he made it sound simple.
 

Toro

Active member
Joined
Dec 31, 2012
Messages
90
Reaction score
112
Location
Sherwood Park, Alberta
All of the posts made for interesting reading, the idea of installing a turbo system on my sled is appealing but it seems that there's still a lot of unknowns. Has anyone ever taken the failed components to a metallurgist to define exactly what the cause of the failure is? Is it a material failure due to heat, due to lack of strength in the material it self? Does replacing the the "con rods" with higher strength material now leave another component in the engine subject to failure? If it's a case of weak material "cast con rods" it's cheaper on a mass production scale to go to forged rods. Cast anything never has the strength of forged materials.
 

fredw

Active VIP Member
Joined
Jan 15, 2010
Messages
3,317
Reaction score
3,586
Location
medicine hat
Yes it's a little funny, some guys dont like to report carnage... I am just the opposite for that... If it breaks and its not my fault, I spread the word..

Well rods and new crank finally showed up, so we will see how it holds together:d:d
 

Attachments

  • image.jpg
    image.jpg
    66.8 KB · Views: 590

deaner

Active VIP Member
Joined
Nov 6, 2008
Messages
3,238
Reaction score
11,260
Location
Creston, BC
I wonder how many guys are turning their oilers up when boosting xms? I just picked up a 2014 TSS XM with a new engine in it. Most unreal sled I have ever been on. Even if a guy cant get the engine to last more than a season it is seriously worth it. At 7lbs it feels like this thing has a friggin small block chevy in it.
 

fredw

Active VIP Member
Joined
Jan 15, 2010
Messages
3,317
Reaction score
3,586
Location
medicine hat
Well first 100 miles with new crank and snowx rods on bb turbo..

Seen a few times boost at 4.5 to six pounds or so... Hard to read gauge and navigate...

happy to spread the word that no rods broke, will need to find more fuel under boost on this build... Hi a/f numbers with fuel controller maxed out
 

fredw

Active VIP Member
Joined
Jan 15, 2010
Messages
3,317
Reaction score
3,586
Location
medicine hat
Is it really that complicated, the oil issue I mean? I asked a builder about oil after boosting and he told me that he sets the oil back to break in mode. I'm no doctor, but he made it sound simple.

On this fresh motor I turned up oil on stock ecm to number three.. It was at 5 with candoo... And uses around 1 liter of oil per 50 miles approx
 

popcorn popper

Active VIP Member
Joined
Nov 26, 2008
Messages
464
Reaction score
511
Location
central alberta
Fredw Allrevsrule has the direct number for nasa's titanium division. I'm sure they could help you out!! He has the market covered on titanium shares so you have to go through him!!!
 

fredw

Active VIP Member
Joined
Jan 15, 2010
Messages
3,317
Reaction score
3,586
Location
medicine hat
Few more to report, dealer in Colorado lost one on a ero setup last year and became a tss dealer this year, lost a rod on their kits now, this is on a 15 t3

few more in Cdn as well builder mentioned this last week, on 15s.. Some guys are relating high a/f to motors that lose rods.. Not sure what tss runs on average a/f but my aero was 13 or so when it went down
 

sarem

Active member
Joined
Nov 3, 2012
Messages
55
Reaction score
29
Location
sexsmith
i broke one at 800 kms. up to 2200 now. hasnt missed a beat. 2014 tss instaboost. abused hell out of it last weekend too.
 

sarem

Active member
Joined
Nov 3, 2012
Messages
55
Reaction score
29
Location
sexsmith
not really. i still had my blinders on. you know, just pull rope and go!. now im running lower boost- 7 to 8 - i clutched for it and all smiles
 

young-gun

Active VIP Member
Joined
Mar 24, 2010
Messages
388
Reaction score
656
Location
edmonton
Well after reading this, I pulling motor and sending down to linderman for a little work. Getting new rods, head, case and cylinder porting.
 

mmagic

Mountain Magic Snow Machines
Joined
Aug 18, 2008
Messages
297
Reaction score
556
Location
Edmonton
Website
www.mountainmagic.ca
We carry complete billet rod turbo cranks from two different engine builders have a season on both and no problems at 10 psi . Call for pricing 17804749400
 
Last edited:

Diamondledinc

Active VIP Member
Joined
Nov 17, 2012
Messages
429
Reaction score
277
Location
Calgary
you're right. not cheap, but who wants to spend another 3 after spending 7-10.... like... where does it end? haha!
 
Top Bottom