im trying to figure out if this engine i bought is really good before i go install it in my car. its a 12a from an 85 rx7. i got it from a forum member, with aparently 110,000 kms, (65,000 miles) who says it ran fine when removed from car.

its sitting here, not installed in the car with the exhaust manifold removed

it seems that each i get 2 pop sounds from the exhaust port, for every revolution of the flywheel. it is hard to tell, because of the inconcistency in speed that i turn it over by hand, that all 6 pop sounds are there. it seems that i am only getting 5. when i look in the exhaust port, and turn the flywheel, i can see each time the rotor passes the exhaust port, and makes the pop sound, except on one half rotation, when i see the rotor pass, but no pop sound.

anyone?

 

That is not apex seal problem, it is side seal problem. Most likely carbon buildup on side seal. I say since its out of the car still throw some ATF in it. I usually dont recommend ATF, but since it is out of th car and you wont be running it any time soon then go for it. Shouldnt hurt and could fix the problem.

 

atf is CRAP and will get you NOWHERE! I used to use it too, but then I discovered something cheaper and MUCH better: DIESEL!

buy 1 liter of diesel (about 90 cents these days)... you don't even really need a liter though.
pour 300ml down the throad of the carb witht he throttle plates open, rotate the engine a little bit slowly, then pour a bit more down (maybe another 300ml)..

and let it sit, at least for a few days just to be sure.
diesel eats EVERYTHING! but it doesn't eat oil seals since they're designed to withstand gasoline (which is far more corrosive, if you step in a puddle of gas it will melt your shoe! not so with diesel).

it turns the carbon soft and gooey, but the carbon needs to soak in it.
I also did this with the motor on my 10AE, when I bought it the numbers were like 0-0-0 and 0-0-30, now it's above 100PSI front and rear!
that '79 I was talking to you about only made 5 chuffs when I bought it too.. after I ran it (and it ran fine) it makes all 6 again.

 

Sounds like a good idea to me.

 

And there were no problems starting it up after? I may have to try this....

 

Sounds promising. Your apex seals are probably ok because if one of them were stuck you'd only have four pops rather than five. Still, while you have the exhaust manifold off it's a good idea to turn the engine over, stopping as each apex seal comes into view through the exhaust ports. visually inspect the apex seals and use a screwdriver to push inward on them to confirm they are sufficiently spring-loaded and floating freely in their grooves.

 

How many pops per revolution are we listening for 1 complete turn of the flywheel?

 

You should hear two pops per complete revolution of the eccentric shaft. It takes a total of three turns of the shaft to cycle all three faces of each rotor, hence the need for hearing six pops in three revolutions of the e-shaft.

 

the easiest way to tell is to pull the leading plugs and turn it over with the starter.

if it goes woosh woosh woosh woosh woosh woosh etc then it's OK!
if it sounds like a galloping horse, then it's not, and time for further inspection to see if the seals are intact or if it's time for a rebuild/new motor.

listening through the plug holes is a MUCH better indication than through the exhaust or intake ports, you can't really hear or tell wtf is going on through them. it can "sound" OK and not be, and vice versa.

yes if you use diesel, just clear the engine with the starter and then put in clean plugs and it will fire right up! Assuming a good carb/etc.

it seems to me that my 10AE fired on the first try (after the injector ground was connected anyways lol).

it will still smoke like hell though obviously (due to the amount of liquid you just put in it!)

 

well, i just dumped almost a litre of diesel into my motor via the carb....i turned the motor on its side so the plugs are facing down, exhaust ports up (manifold is off the engine). i turned it over a little each time as i added more diesel.

in the next few days, i'll keep rotating the engine to make sure all parts get a dose of diesel

oh god i hope this works, and i really hope i don't damage anything.

main reason i didn't mind doing this is the engine has sat a long time, and it won't be needing to run any time soon.