My VW baja - potential rotary project
11-23-08, 11:19 PM
#76
Senior Member
I ran a Kennedy stage 1 pressure plate in my 74 super with a 12A, Even with 185mm tires it grabbed the stock Sachs disk hard enough to rip the rivets and clutch face right off. That being said you will be running a lot more torque through that beast than I was with those big ole tars. If the Dakin slips and you still want to run the stock pressure plate check out the copperhead disk. Organic on one side, puck on the other.
Awesome Baja by the way!
Awesome Baja by the way!
11-24-08, 07:50 AM
#78
Senior Member
yep same deal, http://www.aircooled.net/new-bin/vie...23200833753089
11-25-08, 02:12 AM
#81
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Thanks for the tip on the alternator. I really want this thing tucked under the hood without standoffs.
Jeff, I will eventually be needing a dizzy. (hit me up) I pulled the stock EFI and I'm taking photos of everything. (injectors have been to Witchhunter) Would your friend be interested? or is he going custom?
I'm fairly certain that I want to get a RB Holley setup for 6 port. I know it's not the best performer, but it is progressive and I believe it will run decent out of the box.
BTW, my motor was run in a Bay window bus before I got it, with the stock disc and pressure plate. The clutch was in great shape, so lately I've been running it in my ACVW. I did get a Kennedy stage1 for the rotary, but with a stock unsprung disc.
Jeff, I will eventually be needing a dizzy. (hit me up) I pulled the stock EFI and I'm taking photos of everything. (injectors have been to Witchhunter) Would your friend be interested? or is he going custom?
I'm fairly certain that I want to get a RB Holley setup for 6 port. I know it's not the best performer, but it is progressive and I believe it will run decent out of the box.
BTW, my motor was run in a Bay window bus before I got it, with the stock disc and pressure plate. The clutch was in great shape, so lately I've been running it in my ACVW. I did get a Kennedy stage1 for the rotary, but with a stock unsprung disc.
11-26-08, 02:09 PM
#82
I probably have done three cars in that time. 
rotorbugg, see how much room you have with the stock FC waterpump too. If you need slightly more clearance, consider a 1st gen waterpump. We're talking about a half inch or so.
Yeah, I have a few spare dizzies.
My friend already has some stock S4 injectors, so thanks anyway.
You might be interested in an Edelbrock carb because they do seem to run well right out of the box. Rogue Wulff has one on the same engine and RB manifold and it is really excellent. Cheaper than an RB Holley, too. I actually have two spare Edelbrock 600 Performer series, three, actually. One is on a Camden 7", one will go on a camden 5" soon, and one just sits.
I don't like the heavy feel of the Kennedy. If my disc slips I'll get a copperhead.
rotorbugg, see how much room you have with the stock FC waterpump too. If you need slightly more clearance, consider a 1st gen waterpump. We're talking about a half inch or so.
Yeah, I have a few spare dizzies.
My friend already has some stock S4 injectors, so thanks anyway.
You might be interested in an Edelbrock carb because they do seem to run well right out of the box. Rogue Wulff has one on the same engine and RB manifold and it is really excellent. Cheaper than an RB Holley, too. I actually have two spare Edelbrock 600 Performer series, three, actually. One is on a Camden 7", one will go on a camden 5" soon, and one just sits.
I don't like the heavy feel of the Kennedy. If my disc slips I'll get a copperhead.
11-27-08, 08:52 PM
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I hear what you say about the Kennedy. My ACVW had a generic 1700 lb plate when I got it and I was so happy to put a stocker in at the first opportunity. I'm looking forward to hear how yours works on the rotary. Seriously, I've been worried about the stress on the cable tube - I had to replace one once and I don't think I will do it again.
So about the carb, you mean I can get an Edelbrock that will run out of the box without rejetting? If so let me know what model. (that would definitely save a few bones) And does that fit on any Holley compatable manifold?
I'm gonna just run the stock water pump and cut the apron. If you saw how much I've cut the car up already you would understand.
Please post some pics of your exhaust when you have time. Thanks!
So about the carb, you mean I can get an Edelbrock that will run out of the box without rejetting? If so let me know what model. (that would definitely save a few bones) And does that fit on any Holley compatable manifold?
I'm gonna just run the stock water pump and cut the apron. If you saw how much I've cut the car up already you would understand.
Please post some pics of your exhaust when you have time. Thanks!
03-08-09, 01:13 AM
#89
nivekdodge, is that a kelmark?
rotorbugg, I was wondering when you were gonna get back with it.
I got it up and running and man is it fast! Almost too fast for the brakes. Kinda scary.
It turns out the engine I built for it had a stuck side seal so I yanked it and dropped in a known running old used one (actually an S4 NA 13B with a jetted 12A Nikki carb and modded manifold to fit). It idles like a bug but drives like a rotary.
Seemed to run cool enough at just under 190°F water and around 200°F oil in the pan (where it's hottest). I used a convenient compost bin thermometer poked down the dipstick hole.
The plan now is to tear down the first engine, fix what ever it needs and throw it back together. Since it's a fresh rebuild I think I'll break it in in something else for a while so I'll be able to rip on it when it goes in the baja. That's a lot more fun than babying it around town for 500 to 1500 miles while it beds in, don't you think?
So, when will yours run? Any plans on posting anymore to that big thread on the Samba?
rotorbugg, I was wondering when you were gonna get back with it.
I got it up and running and man is it fast! Almost too fast for the brakes. Kinda scary.
It turns out the engine I built for it had a stuck side seal so I yanked it and dropped in a known running old used one (actually an S4 NA 13B with a jetted 12A Nikki carb and modded manifold to fit). It idles like a bug but drives like a rotary.
Seemed to run cool enough at just under 190°F water and around 200°F oil in the pan (where it's hottest). I used a convenient compost bin thermometer poked down the dipstick hole. The plan now is to tear down the first engine, fix what ever it needs and throw it back together. Since it's a fresh rebuild I think I'll break it in in something else for a while so I'll be able to rip on it when it goes in the baja. That's a lot more fun than babying it around town for 500 to 1500 miles while it beds in, don't you think?
So, when will yours run? Any plans on posting anymore to that big thread on the Samba?
03-08-09, 01:58 AM
#90
Oh yeah, I can describe the exhaust note as literally coming in loud and clear. I would prefer an exhaust manifold for the two important roles they play on a rotary. 1) increasing low end torque over a header setup, and 2) mixing both pulses together thus quieting the system thereby allowing the removal of at least one muffling component from the system. It's true. They do work, but can it fit in a VW conversion?
I know rotorbugg had to use two header flanges stacked to bring the outlet flange far enough away from the trans to allow fitment of a pipe.
Exhaust manifolds get a bad rap. It's the cats and stock mufflers that hurt performance. The cats mainly. Ask PercentSevenC. His 1st gen has a manifold, two straight through Rotary Engineering glasspacks, and a dual Monza tip. It's kinda loud but not bad sounding. A 7" Camden SC on a streetported R5 13B rounds out the package. It has a ton of torque thanks to the exhaust manifold, and what's interesting is that it doesn't seem to hurt high end performance. He could rev it up to 8k in almost a split second when it had the Weber (there's a youtube video somewhere around here showing it). Really light flywheel or not, you don't need a header to do it.
rotorbugg, I'm very curious to know how your car runs and drives with the exhaust manifold if you intend to keep it. I kinda wish I had gone with one because it would make my exhaust system quieter, and increase low end torque WITHOUT hurting whatever high end my engine may be capable of with stock ports and a stock carb. Keep in mind the example I pointed out above was streetported and had an aftermarket intake and even with all that the manifold was not a bottleneck as far as we could tell.
That said, he's getting an RB header and presilencer in a week or two so it will be interesting to see whether the low end is effected any more than the high end.
I must say I am open to the possibility of swapping my super short mini baja header to a manifold if it means I can keep the RE glasspack and reduce unwanted noise while dramatically increasing low end torque. In my previous post you'll recall I said it idles like a bug and runs like a rotary. Yeah, like a typical rotary where there isn't much low end torque, dag nab it! The header and presilencer going on percent's car are actually from my 1st gen. I swapped my car over to a stock setup temporarily in preperation for something else, and wouldn't you know it, my low end torque went way up witht he stock setup! What gives? Mind you I lost power in the sweet range from 4k-6k, but I blame the cats. For around town driving though, oh man the driving enjoyment factor shot through the roof.
Is that what I've been missing all this time? Interestingly, the car it came off of was a stock ported 12A which interestingly enough didn't have much low end torque (kinda like my 13B with the header) but did have decent high end power up past 6k (kinda like my 13B with the header... did I just say that?). It seems the 13B runs the stock system out of breath by 4k what took the 12A above 6k to do. Interesting. Seems HP is a function of exhaust CFM, no? Kinda like how you'd size a radiator according to your HP output (heat generation) and not necessarily by engine size alone. Same difference I suppose.
So what have I learned? That it would be ok to cut and slice my baja header to add an exhaust manifold (if it will fit past the trans mount) because a) I will never outflow it on a stockport with stock carb as long as the rest of the system is free-flowing and b) it will reduce noise while at the same time increase low end torque which are two things I've been wracking my brain about for the past two weeks since getting the baja up and running. Oh and c) I don't really want to use a Supertrapp on my tailpipe.
Sorry if I've misspelled or misstated anything here. It's kinda late and we've got that daylight savings bs tomorrow.
I know rotorbugg had to use two header flanges stacked to bring the outlet flange far enough away from the trans to allow fitment of a pipe.
Exhaust manifolds get a bad rap. It's the cats and stock mufflers that hurt performance. The cats mainly. Ask PercentSevenC. His 1st gen has a manifold, two straight through Rotary Engineering glasspacks, and a dual Monza tip. It's kinda loud but not bad sounding. A 7" Camden SC on a streetported R5 13B rounds out the package. It has a ton of torque thanks to the exhaust manifold, and what's interesting is that it doesn't seem to hurt high end performance. He could rev it up to 8k in almost a split second when it had the Weber (there's a youtube video somewhere around here showing it). Really light flywheel or not, you don't need a header to do it.
rotorbugg, I'm very curious to know how your car runs and drives with the exhaust manifold if you intend to keep it. I kinda wish I had gone with one because it would make my exhaust system quieter, and increase low end torque WITHOUT hurting whatever high end my engine may be capable of with stock ports and a stock carb. Keep in mind the example I pointed out above was streetported and had an aftermarket intake and even with all that the manifold was not a bottleneck as far as we could tell.
That said, he's getting an RB header and presilencer in a week or two so it will be interesting to see whether the low end is effected any more than the high end.
I must say I am open to the possibility of swapping my super short mini baja header to a manifold if it means I can keep the RE glasspack and reduce unwanted noise while dramatically increasing low end torque. In my previous post you'll recall I said it idles like a bug and runs like a rotary. Yeah, like a typical rotary where there isn't much low end torque, dag nab it! The header and presilencer going on percent's car are actually from my 1st gen. I swapped my car over to a stock setup temporarily in preperation for something else, and wouldn't you know it, my low end torque went way up witht he stock setup! What gives? Mind you I lost power in the sweet range from 4k-6k, but I blame the cats. For around town driving though, oh man the driving enjoyment factor shot through the roof.
Is that what I've been missing all this time? Interestingly, the car it came off of was a stock ported 12A which interestingly enough didn't have much low end torque (kinda like my 13B with the header) but did have decent high end power up past 6k (kinda like my 13B with the header... did I just say that?). It seems the 13B runs the stock system out of breath by 4k what took the 12A above 6k to do. Interesting. Seems HP is a function of exhaust CFM, no? Kinda like how you'd size a radiator according to your HP output (heat generation) and not necessarily by engine size alone. Same difference I suppose.
So what have I learned? That it would be ok to cut and slice my baja header to add an exhaust manifold (if it will fit past the trans mount) because a) I will never outflow it on a stockport with stock carb as long as the rest of the system is free-flowing and b) it will reduce noise while at the same time increase low end torque which are two things I've been wracking my brain about for the past two weeks since getting the baja up and running. Oh and c) I don't really want to use a Supertrapp on my tailpipe.
Sorry if I've misspelled or misstated anything here. It's kinda late and we've got that daylight savings bs tomorrow.
03-08-09, 03:02 AM
#91
I did forget one thing. In order to use an exhaust manifold, I have to make sure my rotor housings don't have thermal reactor air injection ports. The engine core I had intended to use has them, so I must come up with another set of rotor housings...
03-09-09, 07:30 PM
#92
Waffles - hmmm good
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Interesting that you guys are discussing the stock exhaust manifold in VW conversions.
I'm planning one in the future and my plan was to use the stock manifold pointed towards the rear axle and then bring it back 180 degrees towards the back via one presilencer and then run it along the back with either another presilencer and the muffler exiting in the right rear well or just running a muffler across the back and have it come out under the right side of the rear apron.
My reasons for using the stock manifold were the same as what Jeff20B stated. I figured that it wouldn't hurt flow that bad and it would quiet it down really well. Glad to hear I'm on the right track with it.
Now if I could just convice the CFO that I can get that roller VW SB I want ...
I'm planning one in the future and my plan was to use the stock manifold pointed towards the rear axle and then bring it back 180 degrees towards the back via one presilencer and then run it along the back with either another presilencer and the muffler exiting in the right rear well or just running a muffler across the back and have it come out under the right side of the rear apron.
My reasons for using the stock manifold were the same as what Jeff20B stated. I figured that it wouldn't hurt flow that bad and it would quiet it down really well. Glad to hear I'm on the right track with it.
Now if I could just convice the CFO that I can get that roller VW SB I want ...
03-10-09, 02:53 AM
#93
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Congratulations! Man I would love to hear/see it run. Youtube? 
Do you think the motor would be better off with working aux ports? I often wonder about getting a sidedraft setup to keep them working.
Can't wait to spend some time on my project. I had a s4 FC for a bit, a nice 2 month detour. Bought it "not running" for $650 with a blown 80A fuse. (PO tried putting the battery in backwards) Too bad she also put an illegitimate 2009 sticker on the plate and lied about it... another $432 and I had a decent running FC. I really learned a lot from the experience; got my feet wet and didn't drown. But alas, it became clear that I would never finish my other projects if I kept it. (plus it was an automatic) It was a fun 2,000 miles though. I've got a touch of work left on the fresh motor in my ACVW to make it a daily driver and then I'll be back on track.
About the manifold, I really wanted to ditch it (and the spacer/flanges) for the weight, but it sounds like it's worth keeping. I've attached some pics of the manifold mounted as far on as it will go. It may be possible to just run one spacer, but my motor is out right now so I can't check. I know that 2 fits well. Keep in mind I'm running the stock motor mounts/carrier; the solid mount plate should allow more clearance. Even with the extra space from my flanges, I would probably need a heat shield to keep from melting the poly motor mount. I think I'll get solid mounts and not worry about it. By clearancing the mount and maybe using shorter studs(or bolts?) it may just fit.
If you can weld to cast iron??? ditch the ears/studs and make a permanent extension to the manifold. That would definitely fit. Also wondering now if the whole manifold could be flipped the other direction... the first time I tried that I still had the stock water pump housing (no go) but now it may be an option. (see the last pic)
Last thing, the thermal reactor air injection ports... That's 12A right? My s4 13b has some little air holes, one of which looks like it is designed to blow acv air into the manifold. That's not going to be a problem if I don't have an air pump, right?
Do you think the motor would be better off with working aux ports? I often wonder about getting a sidedraft setup to keep them working. Can't wait to spend some time on my project. I had a s4 FC for a bit, a nice 2 month detour.
Bought it "not running" for $650 with a blown 80A fuse. (PO tried putting the battery in backwards) Too bad she also put an illegitimate 2009 sticker on the plate and lied about it... another $432 and I had a decent running FC. I really learned a lot from the experience; got my feet wet and didn't drown. But alas, it became clear that I would never finish my other projects if I kept it. (plus it was an automatic) It was a fun 2,000 miles though. I've got a touch of work left on the fresh motor in my ACVW to make it a daily driver and then I'll be back on track.About the manifold, I really wanted to ditch it (and the spacer/flanges) for the weight, but it sounds like it's worth keeping. I've attached some pics of the manifold mounted as far on as it will go. It may be possible to just run one spacer, but my motor is out right now so I can't check. I know that 2 fits well. Keep in mind I'm running the stock motor mounts/carrier; the solid mount plate should allow more clearance. Even with the extra space from my flanges, I would probably need a heat shield to keep from melting the poly motor mount. I think I'll get solid mounts and not worry about it. By clearancing the mount and maybe using shorter studs(or bolts?) it may just fit.
If you can weld to cast iron??? ditch the ears/studs and make a permanent extension to the manifold. That would definitely fit. Also wondering now if the whole manifold could be flipped the other direction... the first time I tried that I still had the stock water pump housing (no go) but now it may be an option. (see the last pic)
Last thing, the thermal reactor air injection ports... That's 12A right? My s4 13b has some little air holes, one of which looks like it is designed to blow acv air into the manifold. That's not going to be a problem if I don't have an air pump, right?
03-11-09, 07:47 PM
#94
It looks like it's more trouble than it's worth for me to cut up my existing setup to use a manifold. I'll have to use a Supertrapp.
A sidedraft could work for you, if you don't want to bother with EFI. I'm glad my simple carbed setup worked. If you can keep the aux port sleeves working, that's a very good idea. They basically need a way to route exhaust pressure into the ACV port area; there are a few ways to do this. You recall that the exhaust manifold has a tube in it and the rotor housings have small holes below the large exhaust port. The tube sends exhaust pressure into the ACV cavity which pressurises at mid to high RPM due to a build up in backpressure downstream in the exhaust system (in the cats I think) and then in turn moves the aux port actuators thus opening the aux port sleeves.
This setup may still work on your bug if you drill a hole through both header flanges. As for whether your exhaust components can produce enough backpressure to open the aux sleeves without any cats in the system, I really don't know. Then again you're in CA so you may have to use a cat.
If you choose to do a header like mine, consider that RB makes some of their presilencers with a small pipe installed in the exhaust stream to route exhaust pressure outside of the presilencer for easy hook up to another pipe which then routes into the ACV area. Mazdatrix told me (a long time ago) that the way RB did it doesn't produce enough pressure to reliably open the sleeves so Mazdatrix began adding a bung directly on the header, which solved the problem. I'm not sure how either of these compaines recommends plumbing the backpressure sensing pipe into the ACV chamber so I can't comment on how to do it, but what I can tell you is there is a way to do it and it does work even without cats.
I'm not sure what else I can say about 6 port stuff because I'm really not all that familer with it myself. All I know is what I just told you, and I have no plans on making it work on my engine because the modded manifold has no provisions for it, plus I'm not going to use this engine forever so 6 port stuff is not on my list of things to figure out.
12As and 13Bs from '76-'78 and probably some J-spec 13Bs up to '80 had thermal reactor air bleed ports. Before and after this oddball time in Mazda's history they did not have them.
A sidedraft could work for you, if you don't want to bother with EFI. I'm glad my simple carbed setup worked. If you can keep the aux port sleeves working, that's a very good idea. They basically need a way to route exhaust pressure into the ACV port area; there are a few ways to do this. You recall that the exhaust manifold has a tube in it and the rotor housings have small holes below the large exhaust port. The tube sends exhaust pressure into the ACV cavity which pressurises at mid to high RPM due to a build up in backpressure downstream in the exhaust system (in the cats I think) and then in turn moves the aux port actuators thus opening the aux port sleeves.
This setup may still work on your bug if you drill a hole through both header flanges. As for whether your exhaust components can produce enough backpressure to open the aux sleeves without any cats in the system, I really don't know. Then again you're in CA so you may have to use a cat.
If you choose to do a header like mine, consider that RB makes some of their presilencers with a small pipe installed in the exhaust stream to route exhaust pressure outside of the presilencer for easy hook up to another pipe which then routes into the ACV area. Mazdatrix told me (a long time ago) that the way RB did it doesn't produce enough pressure to reliably open the sleeves so Mazdatrix began adding a bung directly on the header, which solved the problem. I'm not sure how either of these compaines recommends plumbing the backpressure sensing pipe into the ACV chamber so I can't comment on how to do it, but what I can tell you is there is a way to do it and it does work even without cats.
I'm not sure what else I can say about 6 port stuff because I'm really not all that familer with it myself. All I know is what I just told you, and I have no plans on making it work on my engine because the modded manifold has no provisions for it, plus I'm not going to use this engine forever so 6 port stuff is not on my list of things to figure out.
12As and 13Bs from '76-'78 and probably some J-spec 13Bs up to '80 had thermal reactor air bleed ports. Before and after this oddball time in Mazda's history they did not have them.
03-12-09, 07:24 PM
#95
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nice job I just got done playing with the watercooled vws and the aircooled ones are simple, just too much **** to fix on a vw. All I have to say is this, BOOOOO ROLLLLL THEEEE FLLLIIIICCKKK ALLLLREADYY.
10-29-12, 04:49 PM
#96
I picked up a copperhead disc mentioned earlier in this thread.
I also got one of these. The #2 to replace my #1 short stock one.
Then I drilled it to look like #3.
Getting it installed was a chore to get the spring wrapped back around. But I somehow managed.
I would have left the spring off, but realized this is a VW. Certain things work a certain way.
Pedal effort went from about a 5 to about a 3.5 on my scale. This is on a stock duty Sachs pressure plate. I've got a KEP stage 1 sitting here ready to go in. Just need a steel flywheel to work with the copperhead disc. You can't use this disc on a cast flywheel, which is what's currently installed. That's fine. It's kind of a piece of junk anyway. Too heavy and weak at the ring gear teeth. My old starter is grinding too. I've got a good low mile one sitting just waiting to go in.
I also got one of these. The #2 to replace my #1 short stock one.
Then I drilled it to look like #3.
Getting it installed was a chore to get the spring wrapped back around. But I somehow managed.
I would have left the spring off, but realized this is a VW. Certain things work a certain way.
Pedal effort went from about a 5 to about a 3.5 on my scale. This is on a stock duty Sachs pressure plate. I've got a KEP stage 1 sitting here ready to go in. Just need a steel flywheel to work with the copperhead disc. You can't use this disc on a cast flywheel, which is what's currently installed. That's fine. It's kind of a piece of junk anyway. Too heavy and weak at the ring gear teeth. My old starter is grinding too. I've got a good low mile one sitting just waiting to go in.
03-31-13, 10:56 PM
#98
Yeah, some updates here. Turns out I needed a steel flywheel to use the copperhead disc so I got a new KEP. It's lighter than the old one too.
Check out the marked difference in height. No wonder my old setup required so much adjustment just to work.
16.5 pounds vs 12 pounds! That's almost an RB light steel flywheel (those are 13 pounds). I love the way the light steels drive on an R5 engine, so this should be excellent!
Check out the marked difference in height. No wonder my old setup required so much adjustment just to work.
16.5 pounds vs 12 pounds! That's almost an RB light steel flywheel (those are 13 pounds). I love the way the light steels drive on an R5 engine, so this should be excellent!
