Question about engine shims
 

I currently have the stock .21 losi engine that came with the rtr its still running smooth after 4 gallons but i was told to add a shim to keep it running longer is this true and why what does it do for me and are there any other options for extending the life of this engine I already clean it after every race and use after run oils I just wanna get the most out of it moneys tight and I wanna keep racing lol:nod:

Adding head shims will lower compression, which reduces some stress on the rod and crank but also reduces performance. Usually shims are added only if you're going to be running a higher concentration nitro fuel or if you're fishing for better mileage.
Adding a shim to an older engine will also cover up a common malady which is a sloppy rod bearing which may allow the piston to travel up far enough to damage the glow plug or the head itself. It would be better to replace the rod...

Thanks thats great info
 

thanks