Exhaust bolt repair

harrym

Member
Seeing a lot of exhaust bolts stripping out the head. Customers would drill and put in a Heli-coil (which I'm not a fan of), or drill it out to the next size and try to thread it. How I fix is to drill out the bolt holes to 3/8". I machine a piece of aluminum round stock to fit the hole. I champfer the hole with a counter sink. I insert the plug with some aluminum epoxy into the hole. Let it dry and weld up the plug and dress it off.. I use a header flange as a template and mark the hole with a transfer punch and drill and tap the hole. I bolt the flange down and using a transfer punch, I mark the second hole and drill and tap it. I insert studs and use tall coupler nuts that I drill for safety wire. Head saved.
 

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Freezeman

Premium User
Nice fix harrym, I could be wrong yet I don't think you can legally weld on a LO206 head. I also question the term I liked that you used
"dress it off". Just pretend for a moment that tech allowed Welding and Dressing of the intake side. I am pretty sure I could use that to create an advantage. Then again I might just be an old grump?
 

harrym

Member
Nice fix harrym, I could be wrong yet I don't think you can legally weld on a LO206 head. I also question the term I liked that you used
"dress it off". Just pretend for a moment that tech allowed Welding and Dressing of the intake side. I am pretty sure I could use that to create an advantage. Then again I might just be an old grump?
lol.....I am an old Grump! Karting today sure isn't like it was "Back in the day!" Karting , and any racing today has no innovation anymore. It's "buy & bolt". Something breaks....buy a new one. Too much Spec everything...sealed motors, no one is a loser, everybody gets a trophy! My biggest gripe is..."Leveling the playing field!" To me , that means you don't know how to set your chassis as good as me, build an engine as good as me or manage your tires as good as me, so instead of you coming up to my level, you want me to come down to yours. You have a cylinder head that is already seasoned and heat cycled, why throw it away and buy a new one when it can be repaired? I know there are a lot of people who take advantage of some things. Karting used to be the biggest bang for the buck, but now days, I don't believe that. I try to save my customers money, especially ones just getting into the sport. Buying new all the time scares them off from the sport. I love the sport and promote it as much as I can. In fact, I am the President of the oldest and richest street race in the country.. When a dirt oval racer spends $3,000. on tires in a weekend, something is wrong. Off my soap box.
 
^ I hear ya, but the L206 class was designed to be more of a plug-n-play class and not for blueprinting, etc. We already have plenty of blueprinted classes to choose from (and btw, most of those do not allowing welding to the head either.)

You cannot weld on the cylinder head in the L206 class...BUT, you can certainly save that same head by using thread inserts. If you don't like Heli-coils, then there are a variety of thread inserts, Keenserts, etc. that will work, and are available in different wall thicknesses.

Keep in mind, if a shop charged their going rate for all the work/time you put into your repair...it might cost as much as a new head. I know that you do not charge that much simply because you like to help racers out and your love of the sport, but you can see where this could go.


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🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
32 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 

harrym

Member
^ I hear ya, but the L206 class was designed to be more of a plug-n-play class and not for blueprinting, etc. We already have plenty of blueprinted classes to choose from (and btw, most of those do not allowing welding to the head either.)

You cannot weld on the cylinder head in the L206 class...BUT, you can certainly save that same head by using thread inserts. If you don't like Heli-coils, then there are a variety of thread inserts, Keenserts, etc. that will work, and are available in different wall thicknesses.

Keep in mind, if a shop charged their going rate for all the work/time you put into your repair...it might cost as much as a new head. I know that you do not charge that much simply because you like to help racers out and your love of the sport, but you can see where this could go.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
32 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
I know all about what the LO206 was designed for. I was giving Briggs and Dave Klauss feed back on the Intek engine before they came out with the Animal engine. I did a lot of testing on my dyno. I know the rules very well, Briggs, WKA, and AKRA... also a Tech man. If I repair something, it goes back to spec. I repaired a LO206 cylinder head from a blown head gasket and it will pass tech. I understand you are in the parts business and I can see you take a dim view of people repairing parts, but that's OK, Every engine I build or repair will pass tech....visual or otherwise. Racing cost enough, but when a guy brings me a cylinder hear with exhaust bolt holes drilled to 1/2" and wants to repair it, I will. Yes I can do it cheaper and probably quicker than it would to swap out a head. I have been a machinist and fabricator for over 50 yrs and have worked on some aero space stuff. I am not a hack.
 
I know all about what the LO206 was designed for. I was giving Briggs and Dave Klauss feed back on the Intek engine before they came out with the Animal engine. I did a lot of testing on my dyno. I know the rules very well, Briggs, WKA, and AKRA... also a Tech man. If I repair something, it goes back to spec. I repaired a LO206 cylinder head from a blown head gasket and it will pass tech. I understand you are in the parts business and I can see you take a dim view of people repairing parts, but that's OK, Every engine I build or repair will pass tech....visual or otherwise. Racing cost enough, but when a guy brings me a cylinder hear with exhaust bolt holes drilled to 1/2" and wants to repair it, I will. Yes I can do it cheaper and probably quicker than it would to swap out a head. I have been a machinist and fabricator for over 50 yrs and have worked on some aero space stuff. I am not a hack.
Don't be offended. It's just an open discussion. I did not imply that you are a "hack." I do not take a dim view of people repairing parts. I do take a dim view of those who do not follow the rules or justify circumventing them by their own reasoning. What makes this even more unappealing is that you are also a tech man. This is a good example of why we need certified tech men in our sport...so everyone is on the same page with rules and interpretation.
FWIW, we offer an L206 tech class @ OVKA show each year. It is conducted through Lewis Stout and AKRA.
 
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