Hi,

I've had FP, SF and FX engines. I just recently got my first LA.

Both a friend and myself purchased used 40 LA engines through eBay. A thorough examination of both engines showed that the case, sleeve and head are different.

The major difference being that my friends engine (which is well used and looks old) has 4 ports in the case/sleeve and mine (which looks run about 5 minutes total) has only 3.

We were wondering what the performance differences are between these designs? And, because the nickle is peeling off of his sleeve, if a 4 port design replacement sleeve can be purchased? I assume the replacement sleeves available at hobby shops is the newer 3 port design.

If a 4 port sleeve can not be obtained how will his engine run with a 3 port sleeve? Thanks for your time.

Regards,
Robert

The O.S. Max .40 LA engines all run about the same, regardless of whether the older 4-port or the newer 3-port liner is installed. There's really no benefit to trying to get a 4-port liner for the newer engine because the case isn't cut out for a boost port.

It turned out that the basic timing of the engine didn't allow it to get much benefit from the boost port, so O.S. eliminated it.