Engine teardown/rebuild guidance?

[Amoeba]

I searched but couldn't find anything on this...

Is there a good guide on the process of tearing down and engine for rebuild? I've got an older HPI MT with stock engine that could probably use the maintenance but I'm not entirely certain what to check or fix/replace once I've got it torn down. Piston ring & fit obviously but what other components should I be looking at or assessing? Any step-by-step would be appreciated.

 

[MrClean]

I searched but couldn't find anything on this...

Is there a good guide on the process of tearing down and engine for rebuild? I've got an older HPI MT with stock engine that could probably use the maintenance but I'm not entirely certain what to check or fix/replace once I've got it torn down. Piston ring & fit obviously but what other components should I be looking at or assessing? Any step-by-step would be appreciated.

I found that exploded views help me the most, especially when putting it back together. Check your crankshaft bearings, while you have it apart. A lot of people will suggest replacing the bearings when replacing the piston and sleeve. You have to weigh the cost of the piston, sleeve, connecting rod and bearings versus just buying a new motor. But it still never hurts to tear one down and put it back together. Get some high temp, sensor safe RTV and seal the engine and carb while it's apart. You can find 'how-to' videos on YouTube.

 

[Amoeba]

I found that exploded views help me the most, especially when putting it back together. Check your crankshaft bearings, while you have it apart. A lot of people will suggest replacing the bearings when replacing the piston and sleeve. You have to weigh the cost of the piston, sleeve, connecting rod and bearings versus just buying a new motor. But it still never hurts to tear one down and put it back together. Get some high temp, sensor safe RTV and seal the engine and carb while it's apart. You can find 'how-to' videos on YouTube.

RTV?

Are the piston, rod, & bearings really that expensive? I can see how the sleeve might be. I'm trying to get a handle on just how much life I should expect from a well-maintained engine. I've seen recommendations for rebuild after 3-4 gallons run through which seems.... odd. With new quality engines coming in around half to up to 3/4 cost of a new RTR I'm wondering just how much cash I'm looking to sink into the hobby

 

[biggin]

Any one of the major RC magazines have done articles on motor rebuilds. You can also google Nitro engine rebuild and see what comes up.

Its not that hard if you have the correct tools check out Amain Ofna makes a rebuild tool kit that only costs $68.
The hardest thing is removing the bearings.

You can also check amain for prices on engine parts they very greatly. Depending on the intial engine cost the parts can be pricey.

Good Luck

 

[MrClean]

RTV?

Are the piston, rod, & bearings really that expensive? I can see how the sleeve might be. I'm trying to get a handle on just how much life I should expect from a well-maintained engine. I've seen recommendations for rebuild after 3-4 gallons run through which seems.... odd. With new quality engines coming in around half to up to 3/4 cost of a new RTR I'm wondering just how much cash I'm looking to sink into the hobby

Most of the parts are that expensive. With the TRX3.3, it costs more to rebuild one than it does to send it in and use the Traxxas ERP (engine replacement program). That doesn't mean you shouldn't rebuild an engine. Some of the higher quality engines, people have gotten over 10 gallons through them. Cheaper ones will most likely be a lot less.
Lots and lots of cash

 

[RevoMan76]

Good video guide!

These were the most helpful videos I have come across, hope this helps?

 

[Captain Chaos]

Good info on changing the bearings.If you own a TRX 3.3 you will need to know how to do this

 

[Candyman]

I didn't watch the vids, so I don't know if they stressed this. But when you're tearing down the engine, make absolutely sure you mark the orientation of the piston, sleeve and conrod so you don't try to reassemble them backwards. Usually the sleeve has an index mark or pin so that's simple. But use a Sharpie to mark the piston by rotating the piston to top dead center and putting a hash mark on the sleeve and at the same spot on the piston. I'll also put a "B" on the side of the conrod that faces out the back of the crankcase (B=back) so you'll always get it right.