I was wondering when the rocks would start flying?
About two years ago I bought six LA25s (made in China) so far I'm using four of them in speed limit combat. To start with they were the worst engine I ever ran to break in. They wouldn't hold a needle setting using a bladder for a fuel tank. I only used Power Master 10% Nitro, 22% oil GMA fuel. All the piston and liners felt like they had a tight fit but not really pinching at the top. It wasn't until they really loosened up that they would run steady and needle good on the bladder, but at the same time they wouldn't hold compression at TDC.
I am not throwing rocks, but I do see the same thing time after time, where a perfectly good engine suddenly needs all sorts of modifications, while everyone else goes on with it working fine.
Mine took about 15 flights to break in and run correctly, which is pretty much dead consistent with other people's experience. I would suggest, in the future, that you run it on the ground with *all the stock parts* and *the stock venturi* and a *conventional tank* before attempting to convert it to a bladder and whatever you use for a venturi/spraybar. Do a few 5-minute runs with cooling, then hook it up to a 16 ounce clunk tank, set it running, and more-or less walk away from it aside from running the needle in as it loosens up. It is broken in when the front end runs cool - it will be boiling hot on the first 5 runs or so. At least then, you will be separating the problems associated with your conversion and operating conditions from fundamental issues with the engine.
From my experience with Brian's ABC piston & liners in the past, I know when we get his ABC set and put them in the LA it's going to be one amazing motor!
Agreed, no one is debating the quality of Brian's work and it will be great. And it sounds like there is a market for it, to by all means, go ahead. I just hope it is the *stock* version *exactly as it came from the factory*, because that's the one that is known to work well for stunt.
Brett