commodore64

Hey all! I was wondering if it was ok to test to see if an engine works without it actually being attached to anything. I bought this engine off eBay and want to see if it works, so I screwed it to some timber and added a servo...

I haven't actually started it yet 'cause supposedly I need a starter box :\ So I was gonna buy a phillips head bit for my drill and start it that way... is that ok?

DaveG55

Starting it and letting it idle should be ok. You want to be very careful about reving it up w/o a load though. Have an emergency shut down plan in place in case it starts to "run-away" on you. Uncontroled high reving on an unloaded engine is a real good way to blow it up.

commodore64

Just wanted to idle and give it a quick blip Should it be ok to jab a drill in to the screw holding the clutch bell housing, to start the engine up?

The engine doesn't actually fit in my car, so I was thinking I might cut out another chassis from some spare aluminium and make the front the same as the back so I can stick a spare rear diff. at the front and make it 4wd somehow... getting this car driving is turning out to be a pain in the arse.

commodore64

I couldn't wait, so I tried. Turns out some idiot decided it would be best to make screws undo in the direction I need to turn it to start the engine. *cries*

I am all up for new ideas on starting this thing.

EDIT-Bleh! I tightened the screw enough that I could spin it the other way without coming undone. Nothing!

I am beginning to think the lack of compression is bad.

enyaengine

Lack of compression may appear to be bad but I have an aero engine, an OS 32SX which has practically no compression but still runs very strong. It's just hard to start because there's no compression lol.

andrewtexas123

I reccomend you get a proper starter. Another way you might ruin the engine is not haveing a air filter on it!

buggymangp

i made a test stand for all my engines.
all i did was use an old savage side rail
and the savage engine mount with a small rs4 75cc tank.
i didn`t even hook up any servos.
i think this is the way to go after repairing engines without putting it
back in the car. i ran many engines this way at idle with just blimping the gas
and i run them for a minute for two.

DaveG55

First a nitro engine has pinch and compression. They are related but different. Pinch is the tapered fit of the psiton in the sleeve. Compression is the air fuel mixture being compressed once the pinch seals off the combustion chamber.
You can have great pinch and zero compression but you canot have poor pinch and have good compression.
You can check you engine (w/o running it) in either of two ways.
First, using just 1 finger, turn the flywheel one full revolution. There should be a point where the flywheel gets very hard to turn. On a newish engine you should not be able (or nearly not) to turn the engine past that point with just a single finger. If it turns easily all the way around then the piston/sleeve is worn out and needs to be replaced.
The second way is to dissassemble the engine and take the piston and sleeve and try to push the piston through the sleeve from the bottom. You should not be able to. In fact, if the piston does not stop at least 1/8 of an inch from the top of the sleeve then they (the p/s) are worn out and should be repalced.
Before you start ordering parts do yourself a favor and compare new engine prices against the parts costs. Often it's better to just get a new engine rather than rebuild. With a new engine you get, well a new engine including a warranty rather than a well worn one with a couple new parts.

hands without shadows

Have you thought of turning that into a dyno?

commodore64

Oh the pain. I pulled it apart and noticed the only time it actually was hard to push was if there was a glow plug in sealing it and it was at the top of it's stroke (even then it wasn't much resistance, I get more out of my 10 year old Thunder Tiger Magnum GP10 (so I presume it means it has no pinch?)), and the resistance offered matched the resistance that came from coming up from the bottom of the stroke.

I can't find anywhere that sells piston sleeves, I don't even know what kind of engine it is other than it being an SH Engine, and it closely resembling a PT007.

Evil thing!!


I don't know much about these things.. but um, it appears to have 6 ports + the exhaust port. If that's any help and someone was willing to try and identify it Then maybe I could find replacement parts.

buggymangp

thats a good idea. something to thing about.