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-   -   Help! I think my engine just died (https://www.rx7club.com/1st-generation-specific-1979-1985-18/help-i-think-my-engine-just-died-938906/)

pagefaulted 01-22-11 01:27 PM

Help! I think my engine just died
 
So I was driving home and BOOM BOOM BOOM a lose lots of power and the engine died. It runs very lumpy, backfires and cant get past 20 MPH.

Looks like the front rotor/housing died. If I pull off the spark plug wires off the front spark plugs the engine runs exactly the same. I changed spark plugs, coil and swapped spark plug wires (Im running wasted spark.) I tested spark and its good.

I tried sea foam but no help

Here is the kicker :( I sprayed water into the carb and steam was coming out the oil filler tube.

Is it dead?

Jeff20B 01-22-11 02:06 PM

Sounds like a broken apex seal which could have hurt a side seal causing some blowby. Do you need a 12A or a 13B?

Man_in_black49464 01-22-11 02:52 PM

+1 sorry man she is toast do you have a cat on it?
If you have a catalytic converter you can pull it down and see if the apex or side seal is inside the cat to confirm.

pagefaulted 01-22-11 03:00 PM

:( I hope its not hard to swap a used engine in.

Man_in_black49464 01-22-11 04:07 PM

nope its not hard, im not sure in a MG but it only takes me a hour to swap engines in my FB with two people. you can lift the engine out by hand.

pagefaulted 01-22-11 04:12 PM

Now I really want to open her up and see what really happened. Because the motor only had 100k, I didn't think apex seals broke that early.

Man_in_black49464 01-22-11 04:48 PM

well Kentetsu had 211,000 on his original engine before it smoked itself
I have had my gs burn one up at 78,000 and two more burn them self out at 100,000

Its not uncommon for 100,000 miles being the ending time for a rotary.

typically the problem is a result of carbon build up making the apex seal stick in place in the compressed position and ether stay stuck or can become loose without the guide of the housing and the corner seal can wiggle and break a bunch of stuff.

rwatson5651 01-22-11 06:05 PM

Thats what recently happened to mine after about 65 k of hard use. After a long period in storage the oil consumption and startup smoke increased markedly, which I suspect caused a buildup of carbon and then the BOOM BOOM BOOM part.

I reccomend rebuilding, I had never done one before but with a few videos and some micrometers/calipers etc, it was not difficult.

pagefaulted 01-22-11 07:08 PM

It's a little odd, because the motor didn't smoke much. I was mixing 3.5 oz. / gallon of pre-mix oil with OMP delete. I wonder if it was a little too much because the spark plugs were fouled in 200 miles of driving or maybe that damn Holley 390 CFM was over rich.

Man_in_black49464 01-23-11 02:05 AM

woah thats why man you had too much oil build up i bet.
I run 1 ounce to one gallon and that is like the standard the high heat race guys run less then one ounce to gallon.
Oil build up + Heat = sludge sludge + rotary heat = Carbon build up
I would say thats what did her in, its just a theory i would say is a possibility maybe some other guys can confirm it but i would lean to that.

pagefaulted 01-23-11 10:39 AM


Originally Posted by Man_in_black49464 (Post 10430206)
woah thats why man you had too much oil build up i bet.
I run 1 ounce to one gallon and that is like the standard the high heat race guys run less then one ounce to gallon.
Oil build up + Heat = sludge sludge + rotary heat = Carbon build up
I would say thats what did her in, its just a theory i would say is a possibility maybe some other guys can confirm it but i would lean to that.

Oops. That was a typo :) I meant that I use 3.5 oz a tank and the MG has a 7 gallon tank, so .5 oz / gallon.

81WideMariah 01-23-11 11:19 AM

Why speculate? Just tear it down already.. the suspense is killing me.. ;)

Seriously though... it's all over but the shouting now, so might as well as get your hands dirty.

pagefaulted 01-23-11 12:12 PM


Originally Posted by 81WideMariah (Post 10430577)
Why speculate? Just tear it down already.. the suspense is killing me.. ;)

Seriously though... it's all over but the shouting now, so might as well as get your hands dirty.

Oh I will tear it down :) but probably not till late feb or march. Right now my focus is getting that parts, tools and knowledge to swap in a new engine so I dont have to drive the GF's car to work. I'll get one of those rebuild vids that will step me through the tear down.

Taking a week off work sometime in Feb to install the new engine and while I'm at it replace the starter, clutch and swap out the 390 Holley for a DCOE 45. All firsts for me :)

acekid7 01-23-11 12:39 PM

good luck man im doing the same right now almost done pulling out the old short block. I just need a engine hoist. Its not hard at all just study, have a haynes manual handy and the internet close by to ask these guys questions.


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