BrewerBob

Lucy,
You got some splaining to do...


I've got two e-mails from the shop about my FB. Last week, the engine had "very low compression". Yesterday, I got "carbon locked" and "seals stuck to rotor".

Do I have this right?

1. Carbon locked = engine seized
2. Compression test = cylcing engine so pistons go up/down, rotoros go round and round.
...
3. Therefore 1 prevents 2 from being tested.


What am I missing here? I am assuming the engine is still in the engine bay. I suppose you could test compression like gas pipes are tested by charging them with air and looking for a drop in pressure but you'd only be able to test on the cylinders that have closed valves. On a rotary, you'd only be able to check one or mabe two rotor faces. At the very least you'd have to block both the intake and exhaust manifolds and pressure test the engine as a whole. This would tell you all the seals are holding or something is broke. It wouldn't tell you WHAT is broke. And who the hell would check an engine that way??!??

gsl-se addict

iTrader: (3)

Normally, carbon locked means that the engine is seized and will not turn over (can't test compression). From what you are saying, I think that the apex seals are stuck in the grooves due to carbon buildup. This will also cause low compression as the apex seals cannot move outward to seal against the rotor housing. Why not ask the shop what they mean?

Anyway, you could pull the exhaust, turn the engine over by hand and try to work the apex seals up/down with a screwdriver or something similar. The other option would be to dump some seaform or MMO down the engine, rotate it some, and let sit to try to break up the carbon.

BrewerBob

I'm talking to the shop but via e-mail so it's one question per day. What you said makes sense in context to the e-mails tho. I hadn't thought of that possiblity. Thanx.

I've got an engine apart in my shed. I need to go take a loop at it and see what there is to see.

BrewerBob

.

Kentetsu

Good God! Don't let a mechanic work on your rotary!!!!

If a rotary floods, it will show very low compression and will be damn near impossible to get starting again unless you know the secrets. Like Kent said, you can dump a couple ounces of Seafoam down the carb and then crank it over, she'll probably start right up. Very few mechanics truly understand rotary engines, and will almost always tell you to get a new motor...

84olschool

yeah been thru that before had too buy a short block from atkins about 10 years ago because of my so called <good mechanic> make sure they know what the deal is. before u have two spend major duckies for nothing.

BrewerBob

Here is the link to the "mechanic". I have heard good things about them from some of the semi locals to the DC/Balto area. I would never trust a normal mechanic with a rotary.


I do have an update from him. Talked on the phone yesterday. The engine was cabon locked in that it would only rotate slightly. He soaked it with some ATF and it fully rotates now but only has compression on one rotor face per rotor.

The only thing that concerns me is he used ATF. It works but it is a shade tree mechanic trick. Surely there is is something available to professionals that is infinitely better. I don't know what this Seafoam stuff is that you've mentioned either (will Google in a bit).

Here's what I want...from some Chem major... something that eats iron oxide (rust) but not iron or whatever else is inside of a rotary engine. And I want it by the gallon so I can fill the entire engine. I would also think that a hot engine would clean easier as well. How do I go about heating a non-running engine to a "hot" temp?

yetterben

get it running on the one rotor and dump seafoam down the carb worth a shot anyway!