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Index > Trucks or Parts WANTED > Thread: Anyone have an extra Reactor
Thread: Anyone have an extra Reactor [' This thread is 2 pages long: (1) 2 ']
Zebug


1st Gear
Wishing
Posts: 13
posted February 02, 2002 10:56 PM

Anyone have an extra Reactor

I just wanted to know if anyone has an extra thermal reactor that is in good shape. Since I have a 77, and live in CA, Headers are unfortunatly not an option since I have to pass smog still (which I did last time by disconnecting the trailer lead). The valve that leads to the smog pump is broken and I have had to plug the hole to keep it from melting th tube or blowing off. If anyone can help me, let me know.

          
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repuguru


Redlining
Posts: 319
posted February 03, 2002 09:54 AM

I have one. I'll look for it next day or two.

       
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Klaus43


Rotorhead
Posts: 1259
posted February 04, 2002 12:27 AM

I probably still have one also...bet it's off an rx4. Also have at least one air pump around... I knew there was a reason I didn't throw that junk out!
Passing smog's gotta suck either way... why not get the header and go with a hi-flow cat system, then get a fresh tuneup and run a can of Amsoil Power Foam thru your motor?
All that and a little leaner mix than you'd really want to run might just do it!

       
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Klaus43


Rotorhead
Posts: 1259
posted February 04, 2002 12:31 AM

forgot to mention:

beware of reactors without funtioning airpump--temps./temp. retention can get to the point of de-arcing seal springs from the excess heat. Modification of the reactor setup might prevent this...

       
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Jeff20B


Moderator
Posts: 661
posted February 04, 2002 09:06 AM

klaus42, what kind of modifications do you recommend to prevent excess heat build up? I don't need to pass emissions, but I do need to pass a visual inspection. It originaly had a '76 reversed runner intake manifold (Cosmo style!) but now has a '74 manifold on it which is missing one of the air pump connections. I don't know enough about the reactor to know if leaving the air pump belt on (for the inspection) but not having its air blowing anywhere will cause the reactor to overheat and damage the springs.
If I need to swap manifolds back to their stock engines, it's no problem; just a bit inconvenient. Please advise.
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
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Klaus43


Rotorhead
Posts: 1259
posted February 04, 2002 10:17 AM

"Never Remove"...

Good Morning!
Let me just begin with this caveat/caution: I'm not as expert as an experienced engine builder, which I'm not; you may wish to confirm what I believe to be true by consulting with one of the 'big boys', such as Yaw, Atkins, Hayes, Mazdatrix, R. Beat, etc. ...
That said, I used to own a '77 rx-4 wagon w./ a newer 4-port 13-B, on which a previous owner had removed the airpump but retained the thermal reactor. If I remember correctly, the reactor has inserts in it that direct the exhaust pulses into one another, ostensibly for quieting the exhaust note. This also had the effect of increasing heat; these need to be removed...
I don't believe that your choice of intake manifold comes into play here at all, at least not directly--tho I thought the reverse-runner setup was specific to the rx-3 SP... Other emissions connections are also completely irrelevant, as far as I know, and should be removed and plugged, if possible.
Since you must retain the reactor, and the pump for visual purposes, why not retain a functioning airpump and it's connection to the reactor? Even a modified reactor could likely benefit from the cooling effect(or was that fresh air just there to complete the burn, resulting in higher reactor temps, but lower emissions...? I forget...)
Bottom line: It's all about flow. How much heat is too much? Unknown: we're talking about longer-term engine longevity... Better flow=less heat. Headers have the added benefit of less mass vs. reactors=less retained heat after shutoff...which is probably of consequence long-term.
The other major influence on exhaust temp. tho is carb. tuning--after perusing Yaw's amazingly infodense website I think I have a much better understanding than before. I'd be curious as to his opinion on this. Also, just found pineappleracing.com ; I've met Rob & hung out a while back, but have no firsthand experience with his motors--but he's a nice guy and could be good for an opinion. ...
If it were me, I'd do whatever it takes to run a header and free-flowing exhaust straight back; ditch that heavy reactor, plug all the BS, remove the pump with it's "never remove" sticker, and register your REPU where it's not such an issue...
Hope I could help, K.

       
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Jeff20B


Moderator
Posts: 661
posted February 05, 2002 09:12 AM
Edited By: Jeff20B on 5 Feb 2002 09:33

Oops, I should have said the reactor is on my Cosmo. Sorry. Luckily, my REPU never has to pass any sort of inspection ever again. My Cosmo, however, needs to pass a visual.

Thanks for the info. Back before I put a header exhaust on my REPU, it had the reactor on it and I remember those inserts. I can't remember if I removed them though. It doesn't matter now since that old reactor is dead and gone. But now with my Cosmo, I'm curious as to which parts to modify. Should I go ahead and remove the sleeves? It would give me peace of mind. (It wouldn't pass the visual with headers.) Then I could go ahead and leave the air pump on and functioning even if the air isn't really flowing anywhere (I think the air gets stuck somewhere inside the ACV, which no longer functions correctly).

Guess what, I found something very disturbing about running my Cosmo's carb on my truck's engine. The intake manifold I'm using on my REPU is the reversed runner from the Cosmo (the carb and manifold are a matched set). Anyway, I've been getting lots of misfires and accelerator pump stumbles lately that I never experienced when it was on my friend's truck. I had originaly figured that puting the the Cosmo carb on my truck would be a pretty good idea because it ran very well on my friend's REPU ('77 engine in a '74 truck). Well, it turns out that the Cosmo's carb is jetted for the flow rate of '76-'78 and not for '74-'75. Quite simply, I was getting lean misfires and my spark plugs were even white-ish. Very BAD! I'm assuming that my ports flow way more air than what the carb was jetted for. That would explain the misfires and probably the accel pump probs which weren't even an issue on my friend's engine. It could also be caused by my fuel pump, which is a somewhat old Facet from RB.

When the Cosmo's carb was on the Cosmo, it didn't want to run hardly at all. I tried my truck's carb and it seemed to do better, but still would die now and then. I put this project on the back burner and concentrated on other projects for a while. I later found out that there were a bunch of vacuum leaks. I fixed as many as I could find, but when the time came to try to get the Cosmo going again, its carb was on my friend's engine, so the only carb I could test run was my truck's carb. The Cosmo ran quite well with it, so I went under the impression that only my truck's carb would run good on the Cosmo. It wasn't untill I saw how bad my truck's plugs were that I realized my impression was based on the circumstances at the time. Now I know it runs way too lean on my truck's engine, but ran fine on my friend's '77 engine (his plugs were brown). This means that if I run my truck's carb on the Cosmo, it will most likely run too rich. The Cosmo's carb should be just fine on the Cosmo, based on how it ran on my friend's similarly ported engine, if the accel pump probs and misfires don't pop back up (we'll see). It's an automatic so it needs all the smoothness and drivability it can get.

Then there is still the intake manifold issue. I think I may leave the Cosmo's reversed runner manifold on my truck for right now because the truck's engine was rebuilt incorrectly. It has an intermediate housing from an EGR 12A (it has gas nitriding and a port at the top for an EGR valve, which has been blocked off). The rest is true '74 all the way; its exhaust ports are the small '74 size and only the front and rear cast iron end plates are large (nearly streetport sized) ports. This is where the reversed runner intake manifold shines through. It lets me have mamoth primaries at the expense of tiny 12A secondaries. 90% of my driving is on primaries anyway, and when my secondaries open, they hit harder than my friend's '77 engine when it had the Cosmo's carb on it. The low end torque feels the same as it did with the original damaged manifold I used to use (so again, my impression is a bit wrong). Well, the way I figure it is I can either spend a pretty penny and rebuild this engine which runs tight and risk messing up something, or leave it alone and continue with the reversed runner manifold setup. If the Cosmo runs ok with my (good) '74 manifold, then there would be no reason to swap back to the reveresed runner.

The only prob my truck's engine seems to have is a rev limit of 6250 to 6500 RPM and some vibrations possibly due to an out of balance flywheel (its got heat spots and cracks). But then again, the carb is stock, and so are the ports. My friend's engine, however, could get up past 8k RPM rather easily (without the vibes) on what we think are stock ports using the Cosmo carb.

Maybe just for S&G I ought to install my good '74 manifold on my REPU and see if the primaries flowing through 12A EGR sized ports will cause it to run better than it does with the reversed runner manifold. Then again, maybe not. I'd still like to put one of these 13Bs into my MG Midget because it needs an engine. I doubt the reversed runner manifold will fit in the MG due to its larger size. The '74 manifold barely fits as it is (after hack sawing off the rear heat shield bolt hole casting dealy). Hmm, I need to get the MG running before making any money decisions as far as rebuilding engines goes. If I could afford a light steel flywheel from RB, I'd get one and use the Cosmo's engine in it. Or I could do a counter balance to flywheel swap and be all set. My bro may be getting a TII engine and SC for the Cosmo.

There seems to be way too many decisions for me to make. I also should rebuild my cosmo's engine because it smokes. I may street port it at the time too.

So anyway, to be on the safe side, should I go ahead and remove the reactor sleeves? Thanks for reading the whole thing!
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
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repuguru


Redlining
Posts: 319
posted February 05, 2002 11:01 AM

Those inserts face each other inside of your reactor.Or rather their outlets do. They help to create a dynamic sound chamber inside of your reactor or some shit.. The old SCCA trick was to take the back one and turn it toward the rear of the car, that way the tech inspectors that were inspecting the then Show room Stock pre-81 rotary cars couldn't cry foul when inspecting the exhaust of someone being protested.Everything was there.
But since you aren't in any showroom classes with your truck I'd pull them out.
The 76' reverse runner manifold is sotra the little hop up secret the local Atlanta crowd has been using for some time. Both 12a and 13b's got then for the year. Jim Downing liked it them his RS cars, so since he is a hometown guy alot of his secrets trickled out of Maz-Mart over time. The manifold supposedly has a flow rate at high rpm that the other rotary manifolds did not enjoy. Of course the trade off for that is that the velocity at low rpm was not as great as the short port manifolds. One of my personal requirements for my engines is to use the tall port intermediate housing when assembling them. Just in case I want to drag my reversed 76 manifold out to try it again.

       
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Klaus43


Rotorhead
Posts: 1259
posted February 05, 2002 08:58 PM

stumbling, lean misfires, no hirpms???

Jeff-
Lotsa info there... depending on how long the motor got run this way, and other details only you could be aware of, I'd want to check the following, just to be sure:
1.) Despite your past experiences with 'em, go over the entire intake side, once again checking for vacuum leaks, just in case...
2.) Again, just to be sure, I'd want to rule out water o-ring leakage from the intake manifold as well.
3.) Is there any possibility your timing got outta whack???
I'd also verify the operation of the entire ignition system.
4.) After ruling out all else, I'd be real curious about conditions inside your carb...sounds like a thorough cleaning/rebuild with jetting ID'd might be in order...
5.) You're right about your fuel pump possibly being the culprit... I'd test it and check the entire line for obstruction as well. (Clogged filter? Crap in tank?)
When everything's been made fully functional, your carb works OK, and you've got a fresh tuneup, consider spending an entire can of Amsoil power foam thru your motor. I've watched it work amazingly well--it'll clean everything out of your motor! Warm it up thoroughly, spray into your carb w./the motor running until it dies, (Iknow, I know...but trust me!), and keep on spraying until the can's empty--literally fill up your carb & intake with foam. When it dissipates, fire up your motor& stand back--huge clouds of stinky black smoke will billow out... but your rotary will thank you! Proceed to take it out on the open road and run the piss out of it. It'll keep running better and better over the next 50-500 miles!
P.S.-- You probably already know your choice of sparkplugs has a profound impact on performance at various RPM ranges...the various types are really different...I've been loving the performance and longevity of the BUR series, recommended for the newer rotaries... in an engine that smokes excessively, perhaps a step hotter plug would be good.
Happy Wankling :), K.

       
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Jeff20B


Moderator
Posts: 661
posted February 06, 2002 08:40 AM

Hey guys, thanks for the info! I'll put it to good use.

Zebug, do you still need a reactor? Well, if you can wait for an indefinite period of time, you might be able to use mine. No guarantees though. Indefinite means I have no idea how long I'm going to have to keep the reactor. I may end up getting headers at the same time as other engine upgrades, but who knows at this point.
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
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Jeff20B


Moderator
Posts: 661
posted February 06, 2002 05:39 PM

I know this thread has gone off topic, but I didn't want to start a new one when this is going as well as it is. You've both given great advice about the reactor. Thank you!

I'm starting a new thread for my carb and manifold swap stuff.
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
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repuguru


Redlining
Posts: 319
posted February 08, 2002 04:07 PM

ZeBug the one I found had damage to the air inlet. Like it broken off. I think I have another in a box somewhere?

       
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Zebug


1st Gear
Wishing
Posts: 13
posted February 10, 2002 03:52 PM

No Problem

I am willing to wait for one. I have one on currently, it is just that the air intake valve is busted. I know I will have to pass smog by May, but I may still be able to do it regardless of whether I get a functioning Reactor. The only real problem I do have without the functioning valve is that I get a lot of afterburn when the engine is still cold. It is real bad just after the truck comes off the choke. Just let me know when one of you finds one, and are willing to part with it, and let me know how much you want for it.

          
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Jeff20B


Moderator
Posts: 661
posted February 10, 2002 09:05 PM

Ok.
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
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repuguru


Redlining
Posts: 319
posted February 15, 2002 05:04 AM

Hey I found one that didn't have the valve broken off. The little valve is frozen in place open, but it looks like it could be worked loose.
Its off of a 74 truck, but I think they are the same as 77'. I'll get a pic and send it to you ZeBug

       
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Klaus43


Rotorhead
Posts: 1259
posted February 16, 2002 08:28 PM

Went searching for reactors...found a 12A manifold, but not my old 13B reactor...yet. My apologies; I must keep looking...don't think I scrapped it last time I moved...
I DID find the other emissions junk I kept: airpump, two of the whatchamacallit(air control valve?) that screw up the intake manifold, stock thermal reactor heat shields (2), and an exhaust/emissions-related fiber-jacketed funky tube maybe 15" long... all this stuff'd be vintage rx4; also have all the crap for '83 12A... Be happy to let any of it go,cheap.
Of course, shipping a reactor'd cost some...
I'll try to remember to look up the part # listings for the reactors for the different REPU's...I know there was a CA. model before the end... at least on paper.

       
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repuguru


Redlining
Posts: 319
posted February 17, 2002 05:05 AM

A California model. Thats news.
I found two tickets buried in between a crack in the nether reaches of my 77 cab that said Califonia State Fair back when I first bought it. I have always wondered the history of my truck because of that. Maybe its one of the Cali trucks. I flew to Okie City, OK to get it so maybe it rolled around the S.W. till I found it in early 96'. I wish there were a way to trace titles of older cars and trucks for their history. Most of the searches engines and such don't go back past 80'.

       
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Klaus43


Rotorhead
Posts: 1259
posted February 18, 2002 11:53 AM

...and the DMV is useless in that regard?

...well, here's what I'm able to decipher from the 'parts sheets' I got...they're from a body shop estimating guide, though...but it does list OEM part #'s, prices, and applications per year... I'd guess it must've been current circa 1980 or so...
1.) Some items, such as the heater core, are listed identical for 74-75 and 76-77, respectively. The motor and fan, however, are different for 76 and 77...
2.) Radiator support, grille, and horizontal mounting show differences in parts and prices for 74-75 vs. 76 vs. 77; also differences for the fan, fan clutch, shroud, and even the water pump...
3.) Curiously enough, the front fenders are listed as identical for all years, though the wheelhouse (fender internal), is different for 74-75 vs.76 vs.77...
4.) It is also interesting to note that for many "crash parts" such as the bumper ends, parking lamps, headlight housings, etc. the prices are vastly different (higher) for the LT vs. the RT part...
There's actually too much info here for me to list, so I'll just conclude with the exhaust and emission system listed differances for now...feel free to contact me for a copy of these 'parts sheets'--I'd be happy to make them available for a minor donation to cover postage & xerox costs...
5.) Manifold(reactor) listings change for 74-75 vs. "federal"76-77, vs. Calif. Std. 76... rear muffler and diffuser changed from before 10/74 to after... heat sheilds changed from 74-76 vs. 77...
6.) The air pump was the same for all years, but the air control valve is listed seperately for standard vs. auto. trannies--although it lists identical part #'s for them for 75-76 vs. 77-- so only in 74 were they different for standard vs. automatic, otherwise different only by year...
the exhaust cntl. (EC) is only listed for 74-76... and the altitude compensator changed from 3/74 on...
CAVEAT: This information may or may not be reliable and accurate--although I believe it to be so to the best of my knowledge. Hope it's of some use!

       
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zebug


1st Gear
Wishing
Posts: 13
posted June 04, 2002 12:10 PM

I was able to pass CA smog with my Truck as it was. I just had to disconnect the trailing lead. But no problem, even with the smog valve in the reactor plugged. Thanks anyways. By the way, what area of Georgia do you live RepuGuru? My dad is moving to Acworth, GA.

          
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Rotor


Revvin Up
certifiable rotorhead
Posts: 70
posted August 23, 2002 03:48 PM

The Guru is just south of ATL.

I've had no problems passing the E-tests with my 75 w/headers by bolting a cat in place of the RB pre silencer, and running full air injection to the cat from a stock air pump. No air control valve, or any other mods.

Thankfully, I no longer have to pass the E-tests, as the truck is now old enough to smoke and drink! ;-)



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