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-   -   Removing and swapping rotor housing exhaust sleeves (https://www.rx7club.com/2nd-gen-archive-72/removing-swapping-rotor-housing-exhaust-sleeves-401058/)

eriksseven 03-02-05 04:04 AM

Removing and swapping rotor housing exhaust sleeves
 
I'm going to be re-rebuilding my TII block using some good quality N/A housings (all that's available). And I was told that instead of having to grind out the N/A exhaust diffuser, I could instead remove the N/A sleeves and replace them with the TII sleeves.

Is this possible with basic tools, or do I need some crazy machine or something?

Thanks guys

wpgrexx 03-02-05 09:20 AM

yeah you can switch them over. You need to tap threads into the roll pin and than screw in a bolt and pull the pins out, than the sleeve should fallout. But you do know that turbo housings have a coolant feed in the rear housing for the turbo, you will have to cut the NA hosuing to get that coolant source again

eriksseven 03-02-05 01:05 PM

^ ya, I am aware of the coolant feed...

I don't know what you mean by "tap threads into the roll pin, then screw in a bolt and pull the pins out." Not because you did a bad job explaining it, but because I don't know what a "thread" or a "roll pin" is.

I think I'm just going to grind out the exhaust diffusers (since anyone can do that).


Thanks wpg

Aaron Cake 03-02-05 03:16 PM


Originally Posted by eriksseven
and pull the pins out." Not because you did a bad job explaining it, but because I don't know what a "thread" or a "roll pin" is.

Then I'm not sure you should be building an engine. :)

Essentially, he was saying that you need to create a set of threads inside the pin that holds the sleeve to the housing. Put a screw or bolt into that thread, and use it and a pry bar to pry out the pin.

wangerrr 03-02-05 09:17 PM

I'm pretty sure that people need to start somewhere, and to learn from something/someone. Keep up the good work and persistance on your engines Erik. I know that I would have given up by now.

BDC 03-02-05 09:25 PM

Aaron, please sticky this thread if you could; perhaps move it to Rotary Performance section as it will come in more handy there in my opinion.

---------------

Basically, I'm copying this over from NoPistons forum so please don't shoot me. This one has been a personal pet peeve of mine for a long, long time. I've had to pay other people money to get these damn rollpins out. But, recently, I finally figured out a sure-fire way of doing them.

First, purchase some #6, 1/2" long (no longer) sheet metal screws made from Zinc (not stainless-steel!) at your local Home Depot Motorsports and Racing Development store. These screws are self-tapping and, at their midway point, are just a hair bit wider than the inner diameter of the rollpin.

http://bdc.genxracing.com/RollPinRem...etalScrews.jpg

From there, grab yourself a 1/8" or 7/64" diamond-coated, conical grinding stone on an 1/8" shank (as pictured below), using WD40 or other cutting oil, and grind out the top portion of the inner diameter of the rollpin. This will widen the inside of the pin out a bit to allow the #6 metal screw to begin tapping and threadding instead of flattening the sides of the screw.

http://bdc.genxracing.com/RollPinRem...rindingBit.jpg

After that, whilst applying force, use a screwdriver to tap the #6 screw into the pin. You may need to use a hammer to lightly 'start' the screw into the pin. Once the screw begins to tap and thread, it will become increasingly more difficult to continue. Once it stops or has gone a good portion in, it's good-to-go.

http://bdc.genxracing.com/RollPinRem...ntoRollPin.jpg

Once completed, use the prying end of a hammer to gently pry the pin/screw pair out. Be careful as the side of the aluminum rotor housing is used as the counter-pivot point for the hammer. I recommend placing some cloth or something down.

Place the pin/screw combination in a vise.

http://bdc.genxracing.com/RollPinRem...crewInVise.jpg

Unscrew the screw from the pin. Toss the screw. The rollpin is re-usable. All-done!

http://bdc.genxracing.com/RollPinRem...wedFromPin.jpg

There ya go.

B

eriksseven 03-02-05 10:22 PM


Originally Posted by Aaron Cake
Then I'm not sure you should be building an engine. :)

Essentially, he was saying that you need to create a set of threads inside the pin that holds the sleeve to the housing. Put a screw or bolt into that thread, and use it and a pry bar to pry out the pin.

yeah, I'm still making my transition from n00b to knowledgable. But with the pics (thank you BDC!) everything now makes perfect sense.

I actually JUST disassembled my 3rd motor in three days (all the motors I've got, lol). I finally struck gold after pulling and taking apart my '87 N/A's "swapped" 60k mi. motor, that had died prematurely due to coolant seal failure. I didn't know what good rotor housings looked like until I compared these to the 140k mi. housings from my TII and the 170k mi. housings from my original N/A block.

This is great ^ (pics and info) because now I won't have to spend 3 hours grinding out the diffusers, yeahhh!

Thanks guys

RETed 03-02-05 10:38 PM

I've had zero luck with any of those sheet metal screw procedures on a recent project.
If you do a search, you would've come across a post by Scalliwag that has an alternate procedure.

Those damn roll pins are SUPER hard!
It'll eat even stainless steel screws.

1/8" drill bit - this almost requires a *carbide* drill bit
McMaster-Carr has them for a little under $20.
Some seller on eBay sells them for $9.90 for a set of 10...from Hong Kong.
You need to drill the center of the roll pins out to a larger size.

#6 - 32 tap
McMaster-Carr sells a carbide one for SIXTY-FOUR dollars!
If you can afford one, this is a bonus!
There is one seller on eBay that sells HSS ones for like $14 for a set of 12.

You need to tap the center of the drilled roll pin to this new size.

Get a 1" or longer bolt in #6 - 32 threads - I recommend stainless steel or Grade 8 cap socket screw for the hardness so you don't strip the threads - the cap socket hex makes it easier to handle if you got hex or Allen keys.

You also need a nut of similar material and a 1/4" fender washer.

A 1/2" tall bushing or similar (I used a big nut I found laying around the garage) to help you remove the roll pin.

So...

Shoot the roll pin with your favorite penetrant.
I recommend to bang the sleeve itself with a mallet to loosen the roll pin - this really helps!
Drill the roll pin with the 1/8" dill bit - if you're lucky, the drill bit will seize into the roll pin and spin it loose - if this happens, you should be able to pull the pin out now.
If the roll pin is still in there, tap the inside of the roll pin with the #6 - 32 tap.
Tap at least half-way through, or about 1/4" down.
Remove tap and try to get as much of the metal chips out - I would shoot the hole with penetrant to try and get the chips out.
Put bushing (or large nut) over hole.
Position large fender washer over the bushing or nut.
Thread nut onto cap socket bolt then thread bolt down into threaded pin.
Allow the bolt to bottom out and thread the nut as high up as possible to allow the bolt to thread all the way down.
Now, using a hex key, keep the cap socket from spinning.
With a wrench, no spin the nut down - this puts pressure onto the fender washer which should remove the roll pin.

Good luck!


-Ted

eriksseven 03-02-05 11:43 PM

^ right on. I'll try BDC's method first because it's so simple (and he's got pics, lol). But if I fail to remove the pins using his method, I'll try your "heavy duty" removal technique. Thanks

Aaron Cake 03-03-05 03:35 PM

Moving a copy to the archives...


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