SH Engines PT21XT3-P8 .21 On Road Engine
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CA Residents Prop 65 Warning
WARNING: This product can expose you to chemicals including Di(2-ethylhexyl)phthalate (DEHP), which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov Details...Reviews3.8 · 5 reviews
It has good top end but never could get the LSN right and the overall carb just never seemed to dial in (I'm not new to nitro). Even after proper break-in and a gallon of fuel the LSN needed to be set to almost 100% in but engine was still getting too much fuel on the low side (HSN was spot on). After much frustration bought a REDs, put it in the same car, same fuel, same fuel lines, same fuel tank and it runs like a champ, required very little tuning.
I am not an owner of this engine but a friend of mine bought this engine and during break in his engine started to run funny. He took it apart and the con rod bushing was worn and the piston and head button were ruined. I’m pretty sure the way to prevent this is to add a head shim but it is a good idea to either have the shim there from factory or put in the description that a head shim is needed. I’m sure the engine is very good when shimmed and tuned well but the fact that happened is very unfortunate. Thankfully the engine isn’t crazy expensive.
Fast engine. Have not run it much so cannot say what the reliability is. Had one problem with the carb but it was fixed by a local hobby shop.
Great motor strong Great top end speed. Break in was easy and tuning was super easy.
SH engines are amazing for the amount of money. So far the engine runs great and is very strong. Cant wait to see the car go around a track.
Reviewers largely praise the engine's top-end speed and strength, and several describe break-in and tuning as easy and value for the price. Opinions diverge on tuning: one verified owner, an experienced nitro user, could not get the low-speed needle set correctly and switched to another engine. One secondhand report, from a non-owner, describes a con rod bushing, piston and head button failure during break-in, which the reporter attributes to a missing head shim. One owner had a carburettor problem fixed by a local hobby shop. Long-term reliability is not yet established, as most reviewers have run the engine only briefly.
- + Strong top-end speed
- + Strong power output
- + Easy break-in and tuning for some owners
- + Good value for the price
- − Low-speed carburettor tuning difficult for some
- − Reported con rod bushing and piston damage during break-in
- − Head shim reportedly needed but not supplied
- − Carburettor issue required shop repair