welcome to the hobby!
Hey rc amego's I'm sorta new to the nitro engine tech side, so ill be asking questions from time to time and i thank you all for any and all info and help you are willing to give .so here go's ..i have a few used Traxxas 2.5 Nitro Engines, need replacement piston & sleeves ,will only a 2.5 p&s fit the blockk or can other p&s be used is there a fitmemt chart or do i go by inside block mm measurement
TL;DR yes you will need
TRX 2.5/(R) piston sleeve for a
TRX 2.5/(R).
For the most part only TRX 2.5R and
TRX 2.5 (currently the same as 2.5R but early versions were slightly different porting) piston and sleeves will work in TRX 2.5 blocks. there is a small chance that another company will have similar bore in the crankcase for the sleeve, but the piston bore will be different. thus needing a new piston but every company uses their own dimensions for con rod openings to connect to crankshaft and wrist pin.
many other brands typically are based off a few different engine manufacturers (e.g. Dynamite, Losi, XTM, LRP and a few others, are all based/made by SH engines) and alot of parts between similar sizes are compatible with each other from the same make. but traxxas is an odd one out where they have their own design all around.
Note: always replace as a unit, the piston and sleeves wear in matching each other, and will usually not match to other pistons/sleeves even of the same make and model. as a last ditch effort it may work combining used, but pairing an old and new of either will typically just prematurely wear one more than the other.
you can get old pistons and sleeves pinched to give them another bit of run time as long as they are not damaged beyond normal wear.
Rayaracing.com is a well known and inexpensive option that has the correct tooling.
dont do the hose clamp "pinch", unless you dont care if it gets damaged beyond repair as the clamping force of a hose clamp is not uniform and it will oval your sleeve.
