Old guys with 12As club meeting
#7926
Mr. RPM
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Low Mileage 12a for sale
1st dibbs to all OGTA members before I advertise it for sale. I know some of you have been looking for a 12a which is getting impossible to find. This is a low mileage 12a running in excellent condition. Did I say excellent condition!!! 35k. This baby purrs like a kitten. No hiccups at all cold or hot! It comes complete from carb to oil pan. This includes a modified Nikki by Yaw performance, intake manifold, also alternator & distributor is included. Just drop in and go. Anyone interested PM me.
-roland
-roland
#7929
Quad - be careful putting that 465CFM on the 13b. According to Racing Beat which I just read you need a 600CFM for the 6 port 13b. The 465CFM is not enough fuel. Just though you may want to know this before you have another rotary running on 1 rotor.
The Holley-supplied Racing Beat 600 CFM carburetor that is included in this kit has been disassembled and re-tuned at the Racing Beat facility to our specifications to optimize the power output for the 13B 6-port application. This carburetor features mechanical secondaries and a manual choke.
-roland
The Holley-supplied Racing Beat 600 CFM carburetor that is included in this kit has been disassembled and re-tuned at the Racing Beat facility to our specifications to optimize the power output for the 13B 6-port application. This carburetor features mechanical secondaries and a manual choke.
-roland
Quad
#7930
Waffles - hmmm good
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Is Holly the only OGTA-er to come up for the B3R run? Looks to be a good time.
https://www.rx7club.com/se-rx-7-forum-35/blue-ridge-parkway-oct-24-25-a-864584/
https://www.rx7club.com/se-rx-7-forum-35/blue-ridge-parkway-oct-24-25-a-864584/
#7931
Mr. RPM
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I just got off the phone with MazdaTrix. I do not know who you spoke with but you have wrong info. Mazdatrix sells the carb & intake combo which is actually the Racing Beat system. It is a 600CFM! 465CFM is not enough fuel. BEWARE of flying objects out your exhaust. You may end up with 2 - 1 rotors. Just trying to give some advise. Good luck.
#7932
I know Mazdatrix sells the 600cfm carb for the 13B, but the 465cfm will run and not blow up the engine. The 465 isn't the recommended size, but it will run, just not really well.
Quad
Quad
#7935
#7937
![Dunno](https://www.rx7club.com/images/smilies/dunno.gif)
Quad
P.S. I don't remember who it was, I think it was Collin, who said they would let me borrow their car for the day? I again have a hot date 2 hours from me, and request humbly the use of your car. I'll pay if you so desire. I just don't trust the 1 rotor to make it...
Last edited by KevinGallo; 10-16-09 at 05:39 PM.
#7940
yes i'd try one step larger jet. but see how it does as it first.
we're always going to have different opinions on the subject. just don't make me look like i have no clue as to what i'm talking about. since i can't take the time to look for it as i'm at work, someone here has in there sig the formula to calculate carb size. i tried it once and the results i got even the 465 is too big. i've also read where some were using the 465 on sp 12as, and for the sp 13b i have is 600. i've come up in rotaries thinking that when porting these engines, the 12a and 13b will produce around the same hp, only the 13b would yield alittle more torque due to the slightly larger displacement. now i could be wrong in everything i've ever learned about rotaries, and i'm sure u've building a lot more engines than i have and have way more tuning experience. mine has never been tuned. a friend had it with this engine in his rx4 right out of the box. when i took possession of the engine for a rebuild, i also rebuilt the holley. it's been running ever since. this is how i'm seeing it. the 465 will flow 465cfm of air. the 600, 600cfm of air. making the 465 alittle richer would make it handle the 6 port 13b better but not being able to flow as much air as the 600 will cause the engine to not perform as well at full throttle as it would with the 600.
we're always going to have different opinions on the subject. just don't make me look like i have no clue as to what i'm talking about. since i can't take the time to look for it as i'm at work, someone here has in there sig the formula to calculate carb size. i tried it once and the results i got even the 465 is too big. i've also read where some were using the 465 on sp 12as, and for the sp 13b i have is 600. i've come up in rotaries thinking that when porting these engines, the 12a and 13b will produce around the same hp, only the 13b would yield alittle more torque due to the slightly larger displacement. now i could be wrong in everything i've ever learned about rotaries, and i'm sure u've building a lot more engines than i have and have way more tuning experience. mine has never been tuned. a friend had it with this engine in his rx4 right out of the box. when i took possession of the engine for a rebuild, i also rebuilt the holley. it's been running ever since. this is how i'm seeing it. the 465 will flow 465cfm of air. the 600, 600cfm of air. making the 465 alittle richer would make it handle the 6 port 13b better but not being able to flow as much air as the 600 will cause the engine to not perform as well at full throttle as it would with the 600.
#7941
Mr. RPM
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we're always going to have different opinions on the subject. just don't make me look like i have no clue as to what i'm talking about. since i can't take the time to look for it as i'm at work, someone here has in there sig the formula to calculate carb size. i tried it once and the results i got even the 465 is too big. i've also read where some were using the 465 on sp 12as, and for the sp 13b i have is 600. i've come up in rotaries thinking that when porting these engines, the 12a and 13b will produce around the same hp, only the 13b would yield alittle more torque due to the slightly larger displacement. now i could be wrong in everything i've ever learned about rotaries, and i'm sure u've building a lot more engines than i have and have way more tuning experience. mine has never been tuned. a friend had it with this engine in his rx4 right out of the box. when i took possession of the engine for a rebuild, i also rebuilt the holley. it's been running ever since. this is how i'm seeing it. the 465 will flow 465cfm of air. the 600, 600cfm of air. making the 465 alittle richer would make it handle the 6 port 13b better but not being able to flow as much air as the 600 will cause the engine to not perform as well at full throttle as it would with the 600.[/QUOTE]
My reply was not to you - so please do not feel offended. I never said you did not know what you were talking about! This guy is new to rotaries. My point was he has already blown up a 12a and I was trying to save him trouble with his 13b!
My reply was not to you - so please do not feel offended. I never said you did not know what you were talking about! This guy is new to rotaries. My point was he has already blown up a 12a and I was trying to save him trouble with his 13b!
#7942
we're always going to have different opinions on the subject. just don't make me look like i have no clue as to what i'm talking about. since i can't take the time to look for it as i'm at work, someone here has in there sig the formula to calculate carb size. i tried it once and the results i got even the 465 is too big. i've also read where some were using the 465 on sp 12as, and for the sp 13b i have is 600. i've come up in rotaries thinking that when porting these engines, the 12a and 13b will produce around the same hp, only the 13b would yield alittle more torque due to the slightly larger displacement. now i could be wrong in everything i've ever learned about rotaries, and i'm sure u've building a lot more engines than i have and have way more tuning experience. mine has never been tuned. a friend had it with this engine in his rx4 right out of the box. when i took possession of the engine for a rebuild, i also rebuilt the holley. it's been running ever since. this is how i'm seeing it. the 465 will flow 465cfm of air. the 600, 600cfm of air. making the 465 alittle richer would make it handle the 6 port 13b better but not being able to flow as much air as the 600 will cause the engine to not perform as well at full throttle as it would with the 600.
My reply was not to you - so please do not feel offended. I never said you did not know what you were talking about! This guy is new to rotaries. My point was he has already blown up a 12a and I was trying to save him trouble with his 13b![/QUOTE]
Well, if you're right, you can say told ya so and slap me on the wrist. I've had word from 3 people now saying it will run, just not well, and two saying it won't. No offense to you or your knowledge, but 3 beats 2. And desperate times call for desperate measures. It's either keep driving on a busted 12A which could blow at any moment, or attempt to resurrect the 13B until I can get my hands on a 600. I don't plan on leaving it a 465, but it will do for a short while until I can sell this body and motor and get some cash in my pocket.
Quad
#7943
Mr. RPM
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Quad[/QUOTE]
I understand - Good Luck!
#7944
![Talking](https://www.rx7club.com/images/icons/icon10.gif)
Some pictures from installing the Holley Blue onto "Nightmare" today with Ben and his girlfriend. (I forgot her name, Sorry!)
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The 3 cars
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Fuel from the fuel line just wouldn't stop, so I used my oil catcher (clean, never used)
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It poured like this for probably 10 minutes....
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Size: 27.3 KB](https://www.rx7club.com/attachments/se-rx-7-forum-35/702586d1501884704-old-guys-12as-club-meeting-8927_1158405596446_1116930059_30453.jpg)
For laying in that puddle of gas to install that Holley Blue, I donated what we caught in the oil pan, random bucket I had, and even an old 2 liter of root beer.
Interesting install. Still not done, need to get some new fuel hoses, the old ones aren't long enough to reach all the way around the pump. Need some clamps too to get the hoses to stay, the nozzle is so small and the fuel lines are so big...
We'll see what happens soon enough. This is only the beginning...
Quad
![Name: 8221_1158408716524_1116930059_30453.jpg
Views: 39
Size: 48.7 KB](https://www.rx7club.com/attachments/se-rx-7-forum-35/702583d1501884704-old-guys-12as-club-meeting-8221_1158408716524_1116930059_30453.jpg)
The 3 cars
![Name: 8221_1158408276513_1116930059_30453.jpg
Views: 46
Size: 21.4 KB](https://www.rx7club.com/attachments/se-rx-7-forum-35/702584d1501884704-old-guys-12as-club-meeting-8221_1158408276513_1116930059_30453.jpg)
Fuel from the fuel line just wouldn't stop, so I used my oil catcher (clean, never used)
![Name: 8221_1158407796501_1116930059_30453.jpg
Views: 44
Size: 35.2 KB](https://www.rx7club.com/attachments/se-rx-7-forum-35/702585d1501884704-old-guys-12as-club-meeting-8221_1158407796501_1116930059_30453.jpg)
It poured like this for probably 10 minutes....
![Name: 8927_1158405596446_1116930059_30453.jpg
Views: 41
Size: 27.3 KB](https://www.rx7club.com/attachments/se-rx-7-forum-35/702586d1501884704-old-guys-12as-club-meeting-8927_1158405596446_1116930059_30453.jpg)
For laying in that puddle of gas to install that Holley Blue, I donated what we caught in the oil pan, random bucket I had, and even an old 2 liter of root beer.
Interesting install. Still not done, need to get some new fuel hoses, the old ones aren't long enough to reach all the way around the pump. Need some clamps too to get the hoses to stay, the nozzle is so small and the fuel lines are so big...
We'll see what happens soon enough. This is only the beginning...
Quad
Last edited by KevinGallo; 10-16-09 at 08:30 PM.
#7945
Rotary Freak
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Is Holly the only OGTA-er to come up for the B3R run? Looks to be a good time.
https://www.rx7club.com/showthread.php?t=864584
https://www.rx7club.com/showthread.php?t=864584
See you next weekend.
#7946
Well, I can get a Holley 600 shipped to me for $450. Full unit, so I could sell the 465 as soon as the 600 gets here. I'll even have a spare manifold to sell. But I don't have the money now. I can afford about $250 now, unless Ben gives me some more deposit on the SE or Ray will advance me the $100 on the motor....
Unless someone wants to pay me for the 465 or the RB manifold ahead of time, so I can get the 600....
Quad
Unless someone wants to pay me for the 465 or the RB manifold ahead of time, so I can get the 600....
Quad
#7947
I agree that the 465 Holley is plenty. In fact, I doubt you would even see a performance increase with the 600. In fact, I don't see how you could possibly benefit from the 600 without a bridgeport, boost, or nitrous.
A 13b = 80 cubic inch, so it moves 80 cubic inches of air per rotation. Assume 7000 RPM redline:
7000 RPM*80 cubic inch / (12*12*12) = 324 cfm
Add 15% to give some margin and you get: 324 * 1.15 = 372 cfm
Even at 8000 rpm, you would need about 425 cfm
This all assumes 100% filling of the combustion chamber and even that typically isn't true at higher rpm (filling is less). So 465 cfm is plenty. There is no way that you need more without adding a rotor, increasing the redline a bunch, boosting, etc.
I am not sure why they recommend the 600. I think that they, like most, thinks that bigger always is better. Usually the reverse is true. A carb that is too large will hurt low end performance and not increase top end at all.
You may not need to rejet either. I would run it the way it is. You can toss a wideband O2 sensor on sometime and see what your AFRs are and then you'll know if you need to bump up your jetting or not.
A 13b = 80 cubic inch, so it moves 80 cubic inches of air per rotation. Assume 7000 RPM redline:
7000 RPM*80 cubic inch / (12*12*12) = 324 cfm
Add 15% to give some margin and you get: 324 * 1.15 = 372 cfm
Even at 8000 rpm, you would need about 425 cfm
This all assumes 100% filling of the combustion chamber and even that typically isn't true at higher rpm (filling is less). So 465 cfm is plenty. There is no way that you need more without adding a rotor, increasing the redline a bunch, boosting, etc.
I am not sure why they recommend the 600. I think that they, like most, thinks that bigger always is better. Usually the reverse is true. A carb that is too large will hurt low end performance and not increase top end at all.
You may not need to rejet either. I would run it the way it is. You can toss a wideband O2 sensor on sometime and see what your AFRs are and then you'll know if you need to bump up your jetting or not.
#7948
Holy ****. I'm loving this advice. Saves me SO MUCH MONEY! I love all of you. With a passion.
Holy ****. I'm literally beaming with glee as I type this. Thanks Kurt. You are a savior to my heart and bank account...
How would I go about donning the wideband O2 sensor?
Quad
Holy ****. I'm literally beaming with glee as I type this. Thanks Kurt. You are a savior to my heart and bank account...
How would I go about donning the wideband O2 sensor?
Quad
#7949
You mean, Kent.
I do have a brother named Kurt, though. hehe
For a wideband, you just need to have a bung welded on you exhaust. You can use a narrow band (like the GSL-SE O2 sensor) and an A/F ratio gauge. This is the cheapest solution. They aren't the most accurate, though. They basically will tell you if you are lean, rich, or in between, but not very good at telling you exactly how rich/lean.
A wideband O2 sensor is more expensive (say $200 and up), but they will tell you exactly how rich or lean you are. You really only need it to tune, so sometimes it makes sense to get a couple people together to buy one and then you can switch it between cars for tuning. Once you get your jets dialed in, you can remove the O2 sensor if you wanted.
The narrow band setup would be about $40-$50 plus whatever to get the bung welded to your exhaust. I know Crit has the narrpw band setup on his GSL-SE, so you could probably talk to him about how he likes it. Wideband is better for tuning, though.
![Smilie](https://www.rx7club.com/images/smilies/smile.gif)
For a wideband, you just need to have a bung welded on you exhaust. You can use a narrow band (like the GSL-SE O2 sensor) and an A/F ratio gauge. This is the cheapest solution. They aren't the most accurate, though. They basically will tell you if you are lean, rich, or in between, but not very good at telling you exactly how rich/lean.
A wideband O2 sensor is more expensive (say $200 and up), but they will tell you exactly how rich or lean you are. You really only need it to tune, so sometimes it makes sense to get a couple people together to buy one and then you can switch it between cars for tuning. Once you get your jets dialed in, you can remove the O2 sensor if you wanted.
The narrow band setup would be about $40-$50 plus whatever to get the bung welded to your exhaust. I know Crit has the narrpw band setup on his GSL-SE, so you could probably talk to him about how he likes it. Wideband is better for tuning, though.
#7950
I said Kent. Shhhh.....
And I guess I'll stick with the 465 for now. I trust Kent. Not that I don't trust you Roland, it just saves me a ton of money. If it runs like someone pooped in the motor, I'll go to the 600. We will see in the next few days...
Quad
And I guess I'll stick with the 465 for now. I trust Kent. Not that I don't trust you Roland, it just saves me a ton of money. If it runs like someone pooped in the motor, I'll go to the 600. We will see in the next few days...
Quad
Last edited by KevinGallo; 10-16-09 at 09:31 PM.