got my old traxxas running trx 2.5 engine

[babi_hrse]

the thing overheats after 10 minutes of bashing. thinking a rebuild is on the cards as i get the feeling the previous owner didnt know how to mind an engine. whil looking at parts i got to wondering can it be converted to a trx2.5R with a new 2.5R piston, sleeve and the 3.3 cooling head or is it not that simple to cheat the engine gods of another engine being converted.

 

[Zdragon71]

The 2.5, 2.5R, and the 3.3 all use the same Block,carb, and connecting rod and i believe the same crank as well. You can order the 2.5R piston/sleeve for your 2.5 part number is TRA5230X. Also you can use the bigger blue cooling head for the 2.5R on the 2.5 part number for it is TRA5237. Also replace the gaskets part number TRA5229. If your rod is not damaged use it with the new piston. I suggest you buy from ebay because if not traxxas wants like $70 for the piston set where ebay you can get it for around $45.

 

[Nitro4910]

While they use the same con rod, carb, back plate the 2.5/R & 3.3 do not use the same block, P/S, or head.

You can use the 2.5R head on the 2.5, that's the only difference between the 2.5's today.

 

[Childresshunt]

Unless u just wanna rebuild that motor then go for it but would be much more fun to drive if you bought a 3.3 without a carb for like 90 bucks on ebay brand new and used the carb u have on the 3.3 it would give you much more power

 

[babi_hrse]

just really weighing up my options!
total cost of rebuild vs new engine with efra pipe... i seen a picco .21tm with ofna pipe for 115 pounds sterling thats about 160 euros while. seems on average all engines cost 80 - 120 euros so getting a pipe thrown in seems like a good deal yeah?
reckon the conrod is still good but I'm pretty sure the previous owner never did the bdc trick or used after run oil on his engine.
he sold me the truck with the original gallon of fuel, controller, truck and ez start. no toolbox of supplies which leads me to believe he drove this straight as a RTR truck with basically everything that was in the box and a gallon of fuel.

without putting too much investigating into it id presume the sleeve and piston have been eating each other from day one.

but basically the 2.5R sleeve can be bought to change the characteristics of the 2.5 classic engine? does this aid in the much talked of porting?
i can get a piston and sleeve for 52 euros. in your opinions is it worth paying for third of the cost of the picco with pipe or is it still going to be an aspirated machine and i should just put the money towards the picco?

 

[Childresshunt]

If i were u i would just put the money towards the picco i myself prefer not to rebuild a motor unless its high end and a more expensive motor then its usually worth it. with less expensive motors the rebuild is half the cost of the motor then you have to worry about your bearings in your motor going out due to already being used and been hot if your rebuilding its a good idea to replace bearing to so at that point u may as well buy a new motor. go with picco u wont be dissappointed i havnt owned one yet but have ran friends cars and trucks with them much better than the trx 2.5 and 3.3 imo and hold a tune better

 

[hotrodrob]

Are you sure the p/s is shot? Does it Still have a good pinch? It may just need a good sealing,..just a Thought.

 

[Nitro4910]

Unless the 2.5 is really old it has the same P/S as the 2.5R already as the later 2.5/2.5R's only difference is the blue machined billet head.

I'd just get a new one myself, if there is any debris in there your gonna need to clean it out real good & get some new bearings.

You mean OS .21TM? Is it new & what pipe is it coming with?

 

[2revo1maxx]

^That's right^. A new 2.5 can be had real cheap on ebay.