Rotary-MG

iTrader: (1)

I just got done removing the AC and related components, air-pump, exhaust manifold, and all the cats. It's amazing how much of the engine compartments opens up without all the ancillaries. All the nuts and bolts were firm, but nothing stripped, nor seemed to be all that tough to get off. I can't imagine that these are the bolts to a 27 year old car that's been stored outside all it's life. It is California afterall.

Getting to my question.
The instructions from Racing Beat says that after removing the air-pump, Air-value, and exhaust manifold; there will be two small tubes on the stock air-cleaner canister that need to be crimped or closed off. I can't figure which two tubes they are speaking of. All the tubes look to me that they still have a place to attach to. The only ones left danging are the large thumb size tube that came directly from the air-valve, a similar large tube that feed the air pump, and an even larger hose that took heated air off the exhaust manifold.

Any idea which two 'small' tubes they are talking about? I'm going to assume they are talking about the large tubes that went to the air-valve, and air-pump. The real small tubes all look like they are doing something. Keeping the rats nest for now.

I might cut some large holes around the sides of the canister to increase air flow.

j9fd3s

iTrader: (3)

don't do that, it doesn't work. we tried that on the pro7 cars, and its actually better to gut the little flapper out of the intake snorkel (look in there, you'll see it) and then run a 3" or bigger tube to cold air, than it is to cut holes in the thing.

Rotary-MG

iTrader: (1)

Thanks for the info on the air-cleaner. Saved me some headache time. Funny you mention the flapper. That was the last thing I did last night before calling it quits. Took out the litltle locking rings and the flapper just fell out.

Everything bolted up just fine, just like I've been reading for years on this forum. I was extra careful getting the studs back into the block. Cleaned up the threads and test fitted everything, put some never freeze on the threads. But it 'feels' like to me that one of the studs is 'slipping.' It's tight, but it feels like if I apply more torque, I'll be be able to strip it out of the block. I hope I don't end up with an exhaust leak, or else I'll have to tap the threads or something....I know I've read here in the past about someone stripping the threads on the rotor housing.

I bought and installed caps to the two not so 'small' tube openings left homeless by the departure of the air-pump and control-valve.

Images are of:
- Old and new exhaust laid out side by side, and a trash can loaded with AC and emissions items removed this weekend.
- Small block-off plate provide for the removed air tube that lead to the exhaust.

I'd love to fire it up this morning, but there are some other things I'd like to get to while the car is up on stands. Sevenstock is less than 2 weeks away!

Will my air/fuel mixture lean out now?

Rotary-MG

iTrader: (1)

Messed up my upload.
sry for the double post.

Jeff20B

iTrader: (13)

You used orange sealant. You will get an exhaust leak now. Sorry to tell you bad news.

ray green

iTrader: (14)

Rotary MG, there's a guy in Massachusetts who buys 1st gen cats for recycling, for a very good price (and he pays shipping). You could probably get $150-200 for the main cat and two precats in the pic. Here's a link he has in our SE section: https://www.rx7club.com/se-sale-want...erters-958819/

Also that AC condenser in the trash can would probably fetch a good return at your local metal re-cycler. These are just a couple of the less familiar perks that come with the RB system and cleaning up under the hood.

And yes, your RB header sure does look nice!

DivinDriver

iTrader: (15)

Those are the important ones, since they lead to the area "inside" the air filter. I wouldn't crimp them myself, on the off chance you may want that air cleaner able to do 'stock' duty sometime in the future. Just seal them up with silicone or similar at one end; your caps should work fine. Or you could saw them off and weld/braze/fiberglass them over if you were really motivated to do so.

The one that the riser pipe from the heat stove connected to (below the 'flapper') is outside the filter, so it doesn't really matter if you block it or not. If you're worried about hot air pickup and planning to do CAI, then blocking it would be good since you're removed the flapper that used to block it when the engine's hot.

Oh, and keep an eye on that lower rad hose; she's looking a little soft and bulge-y.

j9fd3s

iTrader: (3)

keep the cats you will need them to pass smog someday!

radiator hose looks to be the original one, while the OEM hoses do last 30 years, its due. replace it with another OEM hose, and then you don't have to worry about it until 2042

Qingdao

iTrader: (3)

You used RTV on the exhaust?

Is there some rotary only reason why?

Seems like that would create a god offal smell.

j9fd3s

iTrader: (3)

offal would be good! i've never had a problem with RTV, but the exhaust is hot enough to burn it up where it can get to it

Rotary-MG

iTrader: (1)

Hi Jeff, long time no see.

Dam you guys are good. Yes, the instructions state to use a silicone gasket sealant. This was a tube I had sitting around from i don't know what project. Afterwards I noted that it's rate to only 700 degrees...ooops. I think my bigger problem is that upper right stud that feels like it's going to strip.

~What would be the proper sealant?

~What's a good fix for a stripped thread on the rotor housing?

As for the cats, thanks for the info on selling them. I don't plan on attempting another honest smog check on this car. It's either going to be trailered to a track after this registration period (2 years), or I'm going to be a big tipper. The first cat is hollow. I don't know why, but it's always been empty as far as I know. The second cat has less than 5,000 miles on it. And them Main cat is all there.

I was checking out that lower hose before I took these pictures. Funny how the pictures make things more clearer, more objective. In person that engine appears spotless, LOL~!

Qingdao

iTrader: (3)

I've never had an issue out of the supplied crush gaskets alone from RB sealing it up proper.

Striped thread... extract the old stud and replace it. You might be able to work a dye down on it but that might be a pain in the rump due to location.



EDIT: I think the "red" is the high temp silicone from RTV. The black tube is also some heavy duty stuff (but its for oil based applications). That looks like copper gasket maker.

EDIT 2: Yeah, this will lean out your carburator tune... By how much IDK, but I can tell you that a larger main jet wouldn't hurt.

j9fd3s

iTrader: (3)

the carb meters fuel based on air velocity, and if you increase that, by putting an exhaust on, you get more fuel, which is pretty neat.

the effect isn't linear i think in a nikki it actually goes rich.

Qingdao

iTrader: (3)

Yeah, the rods go up and down with manifold vacume at partial throttle, but at WOT its all up to the little hole in the jet to deliver fuel. If that is too small then it will be lean.

Jeff20B

iTrader: (13)

Rods?

DivinDriver

iTrader: (15)

(Maybe he means the vacuum power valve actuators?)

Qingdao

iTrader: (3)

The edelbrock manual refferes to them as metering rods... I've always refered to them as needles. But saying needle tends to lead to confusion with the needle and seat.

j9fd3s

iTrader: (3)

ah, the nikki/webers et all don't use rods, its a 'mericun car thing

Qingdao

iTrader: (3)

lol

Rotary-MG

iTrader: (1)

The top right stud was stripped. When I pulled it out the first time there was a small chunk of aluminum balled up on the bottom most thread that ate up everything in its path as it came out. Not being able to tighten the stud caused that characteristic "rat-tat-tat" sound of an exhaust leak.

So I pulled off the header.
Got all the RTV off.
Drilled out the hole in the rotor housing.
Re-tapped the hole.
Installed a Helicoil insert.
Put everything back together (no RTV).
No more exhaust leak.

Not to say that this was difficult to do, but drilling into the aluminum rotor housing was nerve racking. Not something I want to screw up. Had to do this from underneath the car, and it was pushing 100 again today. Things turned out well, but it could very easily turned out to be a bad day.

Drove her around in the late afternoon, and WOW, it feels like someone lifted a burden from the car. Used to be a struggle to get her into the 7k RPM range, but not anymore. Idle is high, and she was stumbling on idle, then I realized that I had knocked off one of the trailing wires from the distributor....but the power was good even without that one plug.

Also installed the double pulley today with new belts. No more squealing belt.

I've been sitting on the fence all these years thinking about making these changes to my RX7. Having read literally hundreds of posts from you guys about this stuff had helped me out immensely. The knowledge is there, but getting down and finally doing them is a whole another story.

Today I feel like I made some progress, and nearly ready for the Severnstock track event. Looking at the registrants, this is one of 3 or 4 1st gen RX7s braving the track this Saturday.

Rotary-MG

iTrader: (1)

Double pulley installed today.
It was a hand me down part I had for years.