L206 specs. im a bit disipointed

E

Elmer Patterson

New member
Received the 6 engines i ordered ( friday. ) I opened all the boxes pulled the builder sheet , selected two engines based on the specs head and pop up . well big big surprise ,
sad to say one was 003 in the hole and 035 on the head not even close to the spec sheet the other was closer. even worse the inside of the head where the milling cut passes over the combustion chamber was full of burrs on the edge .
Not what i would expect to see either, now it looks like im going to need to pull the head on all engines. To say im a bit disipointed would be an under statement .
 
In your expert opinion, how would this effect the performance if these engines were to compete against each other in an, "out-of-the-box" class?

From the desk of Al Nunley
Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory.
(Al Nunley)
 
Maybe you should have ordered them from me, Elmer - I just got in 5 from the most recent factory build and all 5 were +.001 pop-up!
I am just joking - you can order them from whomever you wish - I just got a real consistent batch is all.

Question, were the specs you measured identical to what was on the QC sheet? Were they within advertised specs for the 206? Sounds like they were.


I have seen the "burrs' on the leading edge of the combustion chamber that you are talking about where the flycutter left some aluminum rolled over. It looks like the tooling was getting dull, or not enough coolant used. With the current production levels, I guess some of this is to be expected. I'd like to see a little better finish as well, even some deburring around the pushrod galley (block and head) would be nice. Engines have been in great demand this spring in particular and I'm sure the factory is working hard to get all orders shipped in a timely manner. For what it's worth, I've seen more aluminum wheels, cnc'd aluminum kart parts, etc having burrs this time of the year as well than in the fall when production levels are lower. I wouldn't sweat the -.003" over one that is even or out a thou or two...you won't see it on the dyno. This is why we don't bother to cut the decks on the LO206s any more. The return on investment (time) simply isn't there. I don't pull the heads on every 206 that I sell, BUT, on the ones that I have pulled, if I see that rough rolled aluminum next to the gasket surface, I take a small razor and clean it up the best I can before re-installing. What's more concerning to me is the same tooling curl of aluminum left at the top of the intake runner where the two machined surfaces meet - port and bowl - (quite possibly the most critical part of the IN runner for air flow - the inside radius.) This edge is a stringent tech item (both LO206 and animal) and I see this being a stumbling point in the not too distant future. Some just look nicer than others and for sure some flow nicer than others.

All in all, the LO206 is not perfect; it is not foolproof. It IS certainly better than the alternatives!



--
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cuts
www.CarlsonMotorsports.com
Celebrating 25 years of service to the karting industry
765-339-4407
bcarlson@CarlsonMotorsports.com
 
Part of the issue ... if this is a pull it out of the box and go racing engine what ive found causes some future issues im not comfortable to allow the burr and aluminum flakes will cause issues down the road . I had to de burr all heads . next the tech limits + OR - all with in the guidelines one engine has a .003 in the hole on the piston the head is almost .036 thats .014 minus different is anyone going to tell me this wont make a difference up front next because i care about my customers ive been able to work with the 6 engines by swapping heads to come real close to making them all equal again +or - .004 i found one engine with a plus .003 on the pop up and one head which was .031 contrary to what some might do i used both items to bring others close together and set all engines on the shelf for a blind draw so no one can ever say i was not fair Last the engines were all built by several different techs ,and several different code dates at Briggs. There were two with less than minimum head bolt torque in these the head gasket came off with out a spec of material stuck to the block .Last i would like to think all this work would be un necessary but glad i did it 4 hrs and 6 head gaskets is a small price to pay for happy customers in the end i hope this will be a learning experiance for everyone (ps brien you have a pm )
 
The combustion chamber burrs concern me. Those become detonation points that can vastly effect performance and damage the engine.
With that I'll touch on a story of my past with import cars. A friend of mine had a Honda CRX with a newer Integra engine swapped into it with a T3/60-1 turbocharger. He carefully de-burred the valve reliefs in the pistons, rounded all the chamber edges, and only using a full engine ARP bolt/stud kit on otherwise stock parts put down 405HP to the wheels at 28psi.
Another guy in town copy-cat'd the setup exactly but didn't remove any of the burrs and sharp edges. The first time he put his foot in it, it ventilated the block big time.
 
You must log in or register to reply here.
Back
Top