LO 206 blocks grenading

I

Izzy-racing

New member
Looking for people’s thoughts on this.
I have been involved in the LO 206 program for over 8 years and other than people forgetting to put oil in their engines, I have not seen any catastrophic failures until a resent race where 2 engines blew big holes at the top of the block by the kill switch that took out an entire corner and front top of the block out. Both engines still had oil of the proper amount, Is there a tech item that should be looked at?
 
Out of the hundreds and hundreds of L206 engines that we've had come through our shop - only 6 (that I am aware of) suffered catastrophic failure. Every single one of them was due to oil compatibility. We've had engines run without oil that ended up getting shortblocks (just in case,) and we've had a couple of the early engines with cam lobe failures. I have yet to see a failure that I can trace back to the factory assembly or anything that a builder had done other than that.

Oil compatibility is a REAL issue and needs to be taken seriously. PAG & PAO base stocks DO NOT MIX! I still hear people saying they never heard of this issue! I finished a World Formula (Jr Sprint engine) that ran 8-10 laps and seized (but didn't break) - Definitely an oil issue.

Parts can certainly break and mistakes can be made during assembly, but these engines have really proven themselves to be more reliable than any of their counterparts in my opinion.

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🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
www.youtube.com
34 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
I agree with Brian that the number one killer of the LO206 is oil type, amount and maintenance. How did lzzy-racing know that the correct amount and type of oil was used with these two motors this time and the last times they were used? As far as tech issues IMO the recent talk of twisting/changing cam timing with out breaking the seal in the LO206 program would go along well with some people all of the sudden having problems with motors blowing up from damage accruing from having that done to their motor.
 
Freezeman said:
I agree with Brian that the number one killer of the LO206 is oil type, amount and maintenance. How did lzzy-racing know that the correct amount and type of oil was used with these two motors this time and the last times they were used? As far as tech issues IMO the recent talk of twisting/changing cam timing with out breaking the seal in the LO206 program would go along well with some people all of the sudden having problems with motors blowing up from damage accruing from having that done to their motor.
Click to expand...
Thanks for your response, oil was drained to show 480ml type should have been 4T as that is supplied to all the racers…
 
CarlsonMotorsports said:
Out of the hundreds and hundreds of L206 engines that we've had come through our shop - only 6 (that I am aware of) suffered catastrophic failure. Every single one of them was due to oil compatibility. We've had engines run without oil that ended up getting shortblocks (just in case,) and we've had a couple of the early engines with cam lobe failures. I have yet to see a failure that I can trace back to the factory assembly or anything that a builder had done other than that.

Oil compatibility is a REAL issue and needs to be taken seriously. PAG & PAO base stocks DO NOT MIX! I still hear people saying they never heard of this issue! I finished a World Formula (Jr Sprint engine) that ran 8-10 laps and seized (but didn't break) - Definitely an oil issue.

Parts can certainly break and mistakes can be made during assembly, but these engines have really proven themselves to be more reliable than any of their counterparts in my opinion.

-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
www.youtube.com
34 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
Click to expand...
Thank you Brian for the info on PAG & PAO
 
Izzy-racing said:
Thanks for your response, oil was drained to show 480ml type should have been 4T as that is supplied to all the racers…
Click to expand...
4T was supplied to the racers, but what was run in the engine(s) previous to them getting 4T? That's where the problem lies. They're not mixing the two oils together, it's the use of one FOLLOWED BY the use of the other that's causing problems.
Not knocking either oil brand, BUT, here's an example of how to blow up your engine:
Use Thor (light, mdm, or heavy) for one race day. The next race day run 4T.
You'll run about 10 laps before kaboom.
Similar scenario:
Use 4T one race day. The next race day run Thor.
Same result = kaboom after about 10 laps.

If you're lucky, you'll seize the engine (rod journal to the crank) and be able to use the shortblock for a future build (super stock, alcohol animal, limited, open, etc.)
If you're not lucky, it'll blow a hole through the front or top of the block and everything internally is wiped out.

This is the reason that we ask our customers what oil they will be running before we dyno their engines here. We want to be sure that what they plan to run, and what they have access to, is the same oil that was run in their engine here on the dyno.
My preference for the L206 is Briggs 4T. Honestly, I don't care if a guy wants to run bean oil - they can run whatever they wish - just let me know ahead of time so we can use the same oil here in their engine.
 
I prefer to avoid the oil that doesn’t mix with anything else. Customers will run out of oil and grab whatever is available at the track and avoiding catastrophic failure is priority #1.
 
CarlsonMotorsports said:
4T was supplied to the racers, but what was run in the engine(s) previous to them getting 4T? That's where the problem lies. They're not mixing the two oils together, it's the use of one FOLLOWED BY the use of the other that's causing problems.
Not knocking either oil brand, BUT, here's an example of how to blow up your engine:
Use Thor (light, mdm, or heavy) for one race day. The next race day run 4T.
You'll run about 10 laps before kaboom.
Similar scenario:
Use 4T one race day. The next race day run Thor.
Same result = kaboom after about 10 laps.

If you're lucky, you'll seize the engine (rod journal to the crank) and be able to use the shortblock for a future build (super stock, alcohol animal, limited, open, etc.)
If you're not lucky, it'll blow a hole through the front or top of the block and everything internally is wiped out.

This is the reason that we ask our customers what oil they will be running before we dyno their engines here. We want to be sure that what they plan to run, and what they have access to, is the same oil that was run in their engine here on the dyno.
My preference for the L206 is Briggs 4T. Honestly, I don't care if a guy wants to run bean oil - they can run whatever they wish - just let me know ahead of time so we can use the same oil here in their engine.
Click to expand...
Any idea why this happens, does the combination turn to goop and block passages?
 
Chipg56 said:
Any idea why this happens, does the combination turn to goop and block passages?
Click to expand...
Good question, but my guess would be it chemically looses its good lubricating properties and causes the rod to seize to crank journal. The you know the rest of the story ………
 
Chipg56 said:
Any idea why this happens, does the combination turn to goop and block passages?
Click to expand...
They don't turn to goop or thicken at all. I'm no chemist to be sure, but it's like the two base stocks repel each other. They will quickly separate in a glass container. There must be little to no lubrication at that point as every one I've disassembled to do the autopsy on, has bluing (heat) on the rod journal of the crank. It'll definitely seize the rod to the crank first. Sometimes the cylinder looks like new, other times it's got piston melted to it. Sometimes it starts to seize and the driver catches it before it goes kaboom, (still too late for sealed engines.) Other times the big end of the rod seizes resulting in the rod snapping and exiting the front or top of the block.
 
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