I recently did some work for a friend on his 82 12A. Rebuilt and modified the carburetor to mechanical secondaries, and removed the emissions.
I also blocked off the coolant passages to the engine with 20mm freeze plugs.
Now when it runs there is a significant amount of steam coming from the exhaust.
I talked to my friend and he said it did steam a little bit a start up prior to me working on it.
Is it possible that blocking the intake passage for the coolant increased the pressure enough to introduce coolant into the combustion chamber?
Has anyone else seen this before or experiencing similar problems?

 

I bet the coolant ports in the rotor housings are not sealed right and it's dripping coolant around the intake mani and onto the exhaust. Or sucking some into the intermediate runners and burning it.

Your mod won't change coolant pressure per se, that' controlled by the radiator cap and how good the water pump is.

When you say steam coming from the exhaust, do you mean out the tailpipe or from the engine compartment?

 

Robert- Sounds familiar. Sure the tension bolts are tightened? LOL. btw bringin the 7 out of storage next month. Let's cruise, yeah?

 

Out the tailpipe.
According to the owner, it was rebuilt about 10, 000 miles ago, however it has been sitting for a few years.
From what I can tell the rebuild was done by Hayes Rotary.

I will do a coolant pressure test this weekend, and see if it holds pressure.
This cold be a problem that was already existing, and became more evident now that the engine has had some attention.

 

Hi Ian.
I have not had the engine out to check the tension bolts...
Heck ya I'm down for a cruise!!
I just fired up the GSL-SE out of winter storage last weekend. Aside from the dead battery, it started right up. Man that thing wants to zoom zoom!!
Its still in storage for now. I have a few other projects to wrap up first.
Hit me up.
-Robert.

 

For sure, dude. I threw on an RB header so every time I'm in portland, I start it up and run open header through the neighborhood rippin up to 8K to let the yuppies know what's up!

 

If the engine sat for a few years, could be the coolant seals.

I installed one out of storage a few years back, ended up with blown coolant seals, and I really didn't want to swap yet another motor in. Tried a radiator sealant called Alumaseal, and I've been fine since. Over 30,000 miles on that motor without issues. Just a thought.




.

 

If it sat with coolant in it for a few years it could be the old coolant going thru electrolysis and eating the aluminum rotor housings. Definately pressurize that coolant system and see if it holds or if coolant enters the combustion chambers.

 

What kind of sealant did you use on the plugs in the rotor housings?

I used Permatex #2 and treated them like freeze plugs. No issues.


Just sounds like a previous problem reared it's ugliness.

 

I might try some alumaseal if it comes to that. I'd rather open it up and SEE what the problem is and fix it right though. I have heard good things about that product. I will use it if it comes to that.

Thats what I'm thinking. I will do a pressure test on the coolant system here soon.

I used Permatex RTV Ultrablack. I was out of Right Stuff at the time so I used the next best thing. I did check that area, and it WAS NOT leaking from there.


Thanks for the input guys,
-Robert.

 

Yeah, if you have the time/ability/equipment to do a rebuild then go for it. That would be the correct thing to do.

I suggest Alumaseal for those who aren't in that position, and don't really care what went wrong, they just want their car back on the road.

 

https://www.rx7club.com/members/rw-7-76246-albums-engine-builds-3993/

 

lol, yeah, like I was saying....

 

hey my name is pablo and i live here in the portland area also i had the same issue a while back but it wasnt due to removing any lines or passages i just replaced all coolant hoses and did a pressure test small leak on passenger side but all fixed. i got an 83 gs let me know when you are going on that cruise if im not too late maybe you guys can give me tips/pointers on what to do next to my beast