13b-AP going in my 85..
05-15-15, 08:21 AM
#1
13b-AP going in my 85..
some background, picked up a 79 limited (brilliant black) for the gf with this 13b-ap in it.
front rotor has stuck side seals, will run off rear but front wont come un stuck
i've done 3 ATF treatments
my 85 has a strong 112k mile 12a in it that's VERY reliable, so after the east coast rotary bash on june 6th, im going to give her my 12a for her 79 and take her 13b-ap apart
Mazda Wankel engine - Wikipedia, the free encyclopedia
to rebuild/port and throw in my 85.
it already has everything needed to be put in, should be a direct drop in, after the rebuild/port obviously
anyone else have this engine in their fb ? any idea what hp i'll be making with a bridgeport? i was thinking a 48 side or downdraft to pair to it, right now the 13bAP has a 45 dellorto sidedraft atm
just making the thread to gauge interest and hear from the community
anything i should/shouldnt do when doing the swaps?
front rotor has stuck side seals, will run off rear but front wont come un stuck
i've done 3 ATF treatmentsmy 85 has a strong 112k mile 12a in it that's VERY reliable, so after the east coast rotary bash on june 6th, im going to give her my 12a for her 79 and take her 13b-ap apart
Mazda Wankel engine - Wikipedia, the free encyclopedia
to rebuild/port and throw in my 85.
it already has everything needed to be put in, should be a direct drop in, after the rebuild/port obviously
anyone else have this engine in their fb ? any idea what hp i'll be making with a bridgeport? i was thinking a 48 side or downdraft to pair to it, right now the 13bAP has a 45 dellorto sidedraft atm
just making the thread to gauge interest and hear from the community
anything i should/shouldnt do when doing the swaps?
05-15-15, 01:01 PM
#2
ATF shouldn't go into an engine. It never works as well as you think it does, and ruins rubber parts like oil seals. Good thing you're tearing this engine down.
13B AP, huh? That's what you're calling it? You could say I've rebuilt a lot of these. Without pictures I can't tell you what year yours is.
Yes I have one of these in my FB, and everything else. I did the only kind of port these engines respond well to, that is 74 spec. There is no point in going bridge because the rotating assembly is heavy. 11.5 pounds per rotor. These hate high RPM where a bridge likes to be.
You said it will just drop in. Not if you bridgeport it. You don't have a loud free flowing exhaust that will work well with the bridge. It will be too loud for the street. And because it won't have EFI, it won't run very well. Ever.
If you do a bridge, do it the peejay way. He has had at least some success with the concept and a tuneable EFI setup. But now you'll need a different intermediate plate, like from an RESI or a GSL-SE with injector holes. But then the ports are small to keep velocity up. Do you really want to have such small primary ports?
How much power would it make? Some advice for you: If you're doing a build for power, look into forced induction. An FD can make 400HP on stock ports. Stock FD secondary ports are the same open and close timing as 74 spec. You just need to open up your old school AP exhaust ports to T2/FD spec, unless they're really old school 74-75 which have dinky little 12A size sleeves. You can't do very much with these. Can't tell what you have without pics.
You will need a GSL-SE oil pan and an RB front mount bar to get a 13B to fit in your 12A chassis. All AP engines came with a different shape oil pan and pickup tube which doesn't fit a 1st gen.
By the way your current dellorto is a very small carb. Even the 48mm that RB sold back in the day was only recommended on a small 12A size ported 13B. RB did not recommend the dellorto on the REPU because it came stock with 74 spec ports. It was only recommended on the 76 Cosmo and RX-4 because they had 12A size ports in the AP (anti-polution) setup.
If you want to get technical:
12A spec intake ports close at 40 degrees
74 spec intake ports close at 50 degrees
FD and T2 secondary ports close at 50 degrees
Do you see a pattern? 50 degrees is like the perfect port for the street. Awesome midrange and high end, plus the low end is still good. Anything bigger hurts low end and makes it less fun to drive. In other words, because it's a 13B, you can get away with 74 spec ports and not really notice a loss of low end like you do with a 12A.
You'll ruin that old school engine if you bridgeport it. That's my opinion and I've stuck to it for years now and I've not been disappointed.
So did I ruin your day? lol
13B AP, huh? That's what you're calling it? You could say I've rebuilt a lot of these. Without pictures I can't tell you what year yours is.
Yes I have one of these in my FB, and everything else. I did the only kind of port these engines respond well to, that is 74 spec. There is no point in going bridge because the rotating assembly is heavy. 11.5 pounds per rotor. These hate high RPM where a bridge likes to be.
You said it will just drop in. Not if you bridgeport it. You don't have a loud free flowing exhaust that will work well with the bridge. It will be too loud for the street. And because it won't have EFI, it won't run very well. Ever.
If you do a bridge, do it the peejay way. He has had at least some success with the concept and a tuneable EFI setup. But now you'll need a different intermediate plate, like from an RESI or a GSL-SE with injector holes. But then the ports are small to keep velocity up. Do you really want to have such small primary ports?
How much power would it make? Some advice for you: If you're doing a build for power, look into forced induction. An FD can make 400HP on stock ports. Stock FD secondary ports are the same open and close timing as 74 spec. You just need to open up your old school AP exhaust ports to T2/FD spec, unless they're really old school 74-75 which have dinky little 12A size sleeves. You can't do very much with these. Can't tell what you have without pics.
You will need a GSL-SE oil pan and an RB front mount bar to get a 13B to fit in your 12A chassis. All AP engines came with a different shape oil pan and pickup tube which doesn't fit a 1st gen.
By the way your current dellorto is a very small carb. Even the 48mm that RB sold back in the day was only recommended on a small 12A size ported 13B. RB did not recommend the dellorto on the REPU because it came stock with 74 spec ports. It was only recommended on the 76 Cosmo and RX-4 because they had 12A size ports in the AP (anti-polution) setup.
If you want to get technical:
12A spec intake ports close at 40 degrees
74 spec intake ports close at 50 degrees
FD and T2 secondary ports close at 50 degrees
Do you see a pattern? 50 degrees is like the perfect port for the street. Awesome midrange and high end, plus the low end is still good. Anything bigger hurts low end and makes it less fun to drive. In other words, because it's a 13B, you can get away with 74 spec ports and not really notice a loss of low end like you do with a 12A.
You'll ruin that old school engine if you bridgeport it. That's my opinion and I've stuck to it for years now and I've not been disappointed.
So did I ruin your day? lol
05-17-15, 05:05 PM
#3
Nope you did not ruin my day! Aha thanks for the useful info,
Idk if you read my whole OP or not, i said the engine is currently in my gf's 79sa22, with the correct oil pan, front cover.. Etc so it would be a direct drop in to my 85
As far as exhaust it has a full RB dual pipe exhaust on it, even that won't be high flowing enough you think?
So as far as ports, that's a no then? Well will I be happy or sad if I rebuild it and don't port? I have a gslse rear in my 85 so the lsd and she weighs 2139lbs, I want enough power to have fun with
So in your opinion, what should I do? Sell the engine as running needing a rebuild (I think I mentioned it runs on one rotor, right?) and buy a ported 12a, TII or fit an FD engine in my fb? Or rebuild it and put it in my fb ?
Idk if you read my whole OP or not, i said the engine is currently in my gf's 79sa22, with the correct oil pan, front cover.. Etc so it would be a direct drop in to my 85
As far as exhaust it has a full RB dual pipe exhaust on it, even that won't be high flowing enough you think?
So as far as ports, that's a no then? Well will I be happy or sad if I rebuild it and don't port? I have a gslse rear in my 85 so the lsd and she weighs 2139lbs, I want enough power to have fun with
So in your opinion, what should I do? Sell the engine as running needing a rebuild (I think I mentioned it runs on one rotor, right?) and buy a ported 12a, TII or fit an FD engine in my fb? Or rebuild it and put it in my fb ?
05-17-15, 07:53 PM
#4
Ok, I must have glanced over the part about already having a GSL-SE oil pan. As for the exhaust, that's what peejay has on his bp. Most complain that it is too restrictive, but I don't think it is because 84stock set a record with his supercharged FD shortblock at 227RWHP or something like that. A quick search will find the details.
Just go 74 spec. The engine will thank you. My GSL-SE with the same RB dual pipe exhaust and a 74 ported "AP" engine could start trying to break them loose on dry road in warm weather last year when I'd open the mechanical secondaries on my hogged out Nikki. It has LSD so the right rear was trying to break loose but it would send the power to the left wheel and make that slight shuddery effect of the stock LSD "working" lol. The point is this thing was really amazing to drive. It was a great way to tide me over until I could get a turbo in it.
See, I didn't bother with funky ports to get the power. I just went with simple basic 74 spec and a modest carb with a modest exhaust. The result was anything but modest. But not in a jungle cat way. More in a "this is more fun than like 90% of all cars on the road today" sort of way. And I put it together myself. Oh and I don't have to fight it every time I drive it.
Now you'll see my bias. I have access to a torn down T2 shortblock and an FD shortblock. The T2 is spoken for but the FD is available. I also have access to a streetported 12A. A really nice one too, but I stick with the AP style engine because it's just so much better. Old school enough but it's within the range of the car, carbed with full size primary runners & port area, and the low end torque of a 13B. Best of all worlds. And I'll never ruin it or any other engines with bridge ports. If you're gonna go big, go peripheral. Make it worth the extra effort to build then set up properly. Apparently p-ports drive way better than bridges too.
Just go 74 spec. The engine will thank you. My GSL-SE with the same RB dual pipe exhaust and a 74 ported "AP" engine could start trying to break them loose on dry road in warm weather last year when I'd open the mechanical secondaries on my hogged out Nikki. It has LSD so the right rear was trying to break loose but it would send the power to the left wheel and make that slight shuddery effect of the stock LSD "working" lol. The point is this thing was really amazing to drive. It was a great way to tide me over until I could get a turbo in it.
See, I didn't bother with funky ports to get the power. I just went with simple basic 74 spec and a modest carb with a modest exhaust. The result was anything but modest.
But not in a jungle cat way. More in a "this is more fun than like 90% of all cars on the road today" sort of way. And I put it together myself. Oh and I don't have to fight it every time I drive it.Now you'll see my bias. I have access to a torn down T2 shortblock and an FD shortblock. The T2 is spoken for but the FD is available. I also have access to a streetported 12A. A really nice one too, but I stick with the AP style engine because it's just so much better. Old school enough but it's within the range of the car, carbed with full size primary runners & port area, and the low end torque of a 13B. Best of all worlds. And I'll never ruin it or any other engines with bridge ports. If you're gonna go big, go peripheral. Make it worth the extra effort to build then set up properly.
Apparently p-ports drive way better than bridges too.
05-18-15, 06:49 AM
#5
Ok, I must have glanced over the part about already having a GSL-SE oil pan. As for the exhaust, that's what peejay has on his bp. Most complain that it is too restrictive, but I don't think it is because 84stock set a record with his supercharged FD shortblock at 227RWHP or something like that. A quick search will find the details.
Just go 74 spec. The engine will thank you. My GSL-SE with the same RB dual pipe exhaust and a 74 ported "AP" engine could start trying to break them loose on dry road in warm weather last year when I'd open the mechanical secondaries on my hogged out Nikki. It has LSD so the right rear was trying to break loose but it would send the power to the left wheel and make that slight shuddery effect of the stock LSD "working" lol. The point is this thing was really amazing to drive. It was a great way to tide me over until I could get a turbo in it.
See, I didn't bother with funky ports to get the power. I just went with simple basic 74 spec and a modest carb with a modest exhaust. The result was anything but modest. But not in a jungle cat way. More in a "this is more fun than like 90% of all cars on the road today" sort of way. And I put it together myself. Oh and I don't have to fight it every time I drive it.
Now you'll see my bias. I have access to a torn down T2 shortblock and an FD shortblock. The T2 is spoken for but the FD is available. I also have access to a streetported 12A. A really nice one too, but I stick with the AP style engine because it's just so much better. Old school enough but it's within the range of the car, carbed with full size primary runners & port area, and the low end torque of a 13B. Best of all worlds. And I'll never ruin it or any other engines with bridge ports. If you're gonna go big, go peripheral. Make it worth the extra effort to build then set up properly. Apparently p-ports drive way better than bridges too.
Just go 74 spec. The engine will thank you. My GSL-SE with the same RB dual pipe exhaust and a 74 ported "AP" engine could start trying to break them loose on dry road in warm weather last year when I'd open the mechanical secondaries on my hogged out Nikki. It has LSD so the right rear was trying to break loose but it would send the power to the left wheel and make that slight shuddery effect of the stock LSD "working" lol. The point is this thing was really amazing to drive. It was a great way to tide me over until I could get a turbo in it.
See, I didn't bother with funky ports to get the power. I just went with simple basic 74 spec and a modest carb with a modest exhaust. The result was anything but modest.
But not in a jungle cat way. More in a "this is more fun than like 90% of all cars on the road today" sort of way. And I put it together myself. Oh and I don't have to fight it every time I drive it.Now you'll see my bias. I have access to a torn down T2 shortblock and an FD shortblock. The T2 is spoken for but the FD is available. I also have access to a streetported 12A. A really nice one too, but I stick with the AP style engine because it's just so much better. Old school enough but it's within the range of the car, carbed with full size primary runners & port area, and the low end torque of a 13B. Best of all worlds. And I'll never ruin it or any other engines with bridge ports. If you're gonna go big, go peripheral. Make it worth the extra effort to build then set up properly.
Apparently p-ports drive way better than bridges too.cool, sounds like a simple tear down, fix the front rotor issue and rebuild will do it then !
thanks for the info, i'll try to get some pics up of the engine & 13b stamps on it and the exhaust ports this week
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05-23-15, 09:30 PM
#13
Oh well, I know when to admit I was wrong :3
So now what are the new thoughts on this ? These engines like ports iirc?
06-08-15, 08:30 AM
#16
Update, they are gslse rotors, the front stack was cracked as was the front stat gear
Irons were toast (probably opm failure and wasn't premixing)- thankfully I have spares in good condition
The housings can still be used as can the rotors, however I'm going with some s5 n/a rotors
Decided on a half bridge per mike Vargas' recommendation
I need to sell the 5 letter rotors and CW's and pick up some s5 hardware, going to go with Goopy seals
Engine is at angel Motorsports in VA beach getting ported and then will be back up here to be put together in a few weeks
Can a mod change my thread title to 13b Frankenstein going in my 85
?
Irons were toast (probably opm failure and wasn't premixing)- thankfully I have spares in good condition
The housings can still be used as can the rotors, however I'm going with some s5 n/a rotors
Decided on a half bridge per mike Vargas' recommendation
I need to sell the 5 letter rotors and CW's and pick up some s5 hardware, going to go with Goopy seals
Engine is at angel Motorsports in VA beach getting ported and then will be back up here to be put together in a few weeks
Can a mod change my thread title to 13b Frankenstein going in my 85
?
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