1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

I have a choice of 3 engines...which one to get?

Thread Tools
 
Search this Thread
 
Old Oct 21, 2010 | 04:03 PM
  #1  
Thread Starter
Senior Member
Tenured Member 05 Years
 
Joined: Nov 2003
Posts: 264
Likes: 0
From: Shoreline, Wa
I have a choice of 3 engines...which one to get?

Hey friends! Long time no see, I still haven't replaced my RX from years ago but am not building an old VW GT40 replica from the 70's and am putting a rotary in it. My goal is the least money and most power. I found a guy locally that has 3 engines available for me for approx $500 and I'm not sure which one to choose.

Option 1: 12a Street Ported, rebuilt by Atkins with 5000mi on rebuild
Option 2: 12a Bridge ported, rebuilt by some other local company, 30k on rebuild
*note: both 12a's come with a delorto setup and he thinks they have upgraded apex seals and springs from atkins
Option 3: Stock 13b, not sure if it's rebuilt but atkins ran compression tests on it and it came out perfect, 130k mi on it total, maybe less if rebuilt.

Again, I'm looking for the most power for the cheapest price. I can get either of the three for the same price, and then will have maybe another $500 for tuning to get them how I want. My thought is that the 13b might be good since it's easier to turbo (right?) but if I got one of the ported 12a's and spent the money getting that turboed it would probably make much more power than the 13b...please talk amongst yourselves.
Reply
Old Oct 21, 2010 | 04:18 PM
  #2  
Directfreak's Avatar
I am a Jeeper Now.
Tenured Member 20 Years
iTrader: (2)
 
Joined: Dec 2001
Posts: 9,371
Likes: 4
From: 3OH5
Sophies Choice...
Reply
Old Oct 21, 2010 | 04:37 PM
  #3  
food7373's Avatar
Kid
iTrader: (2)
 
Joined: Sep 2009
Posts: 851
Likes: 3
From: PA
12A bridge is my vote! But if you had the money to get the 13B rebuilt and ported and turboed, go for it!
Reply
Old Oct 21, 2010 | 05:15 PM
  #4  
jshiz's Avatar
Actin Like I'm Drunk
Tenured Member 05 Years
iTrader: (4)
 
Joined: Jul 2007
Posts: 1,663
Likes: 0
From: Charleston, South Carolina
buy the two 12a's. bridge port the other one. get the stuff to make a 24a. install engine and procced to decimate all.
Reply
Old Oct 21, 2010 | 05:17 PM
  #5  
jshiz's Avatar
Actin Like I'm Drunk
Tenured Member 05 Years
iTrader: (4)
 
Joined: Jul 2007
Posts: 1,663
Likes: 0
From: Charleston, South Carolina
almost forgot,

take out a good life insurance plan
Reply
Old Oct 21, 2010 | 05:22 PM
  #6  
Jibaro 12A's Avatar
searching...
Tenured Member: 15 Years
iTrader: (8)
 
Joined: Dec 2009
Posts: 1,022
Likes: 1
From: Chicago
I'd go with option 1
Reply
Old Oct 21, 2010 | 05:45 PM
  #7  
Thread Starter
Senior Member
Tenured Member 05 Years
 
Joined: Nov 2003
Posts: 264
Likes: 0
From: Shoreline, Wa
Originally Posted by jshiz
buy the two 12a's. bridge port the other one. get the stuff to make a 24a. install engine and procced to decimate all.
Ahhh i've missed this place.
Like I said, after buying the engine I'll have around $500 to put into the engine...so buying the 13b, rebuilding and porting and turboing it would likely cost a tad more than $500. The idea of buying both the 12a's isn't bad though...just in case right?
Is there a "buying a used rotary engine" guide anywhere? Like tips from the experienced on things to check out in particular?
Reply
Old Oct 21, 2010 | 05:47 PM
  #8  
theNeanderthol's Avatar
the torquinator
Tenured Member 15 Years
iTrader: (1)
 
Joined: Nov 2001
Posts: 951
Likes: 3
From: Las Cruces, NM
Option 1. Lowest mileage, it will probably have the longest life before you'll need to rebuild it, and it'll make good power.
Reply
Old Oct 21, 2010 | 05:49 PM
  #9  
theNeanderthol's Avatar
the torquinator
Tenured Member 15 Years
iTrader: (1)
 
Joined: Nov 2001
Posts: 951
Likes: 3
From: Las Cruces, NM
^^^ He's from Puerto Rico. Listen to him. The rotary knowledge flows through the veins down there. Ha ha
Reply
Old Oct 21, 2010 | 06:12 PM
  #10  
PercentSevenC's Avatar
I need a new user title
Tenured Member 10 Years
 
Joined: Oct 2005
Posts: 2,646
Likes: 1
From: Yaizu, Japan
What year 13B?
Reply
Old Oct 21, 2010 | 06:49 PM
  #11  
rx71king's Avatar
the diabolical one
Tenured Member 05 Years
iTrader: (6)
 
Joined: Jul 2005
Posts: 939
Likes: 1
From: queens n.y.
which 13b ?
Reply
Old Oct 21, 2010 | 06:58 PM
  #12  
jshiz's Avatar
Actin Like I'm Drunk
Tenured Member 05 Years
iTrader: (4)
 
Joined: Jul 2007
Posts: 1,663
Likes: 0
From: Charleston, South Carolina
If it's a 4 port 13b, that **** is gold.
Reply
Old Oct 21, 2010 | 07:15 PM
  #13  
Thread Starter
Senior Member
Tenured Member 05 Years
 
Joined: Nov 2003
Posts: 264
Likes: 0
From: Shoreline, Wa
Ill be talking with him again tonight and will ask if it's a 4 or 6 port engine. Ok time for a n00b question...is it possible to see the size/shape of the intake port job on a 12a with the intake off without tearing it apart?
Reply
Old Oct 21, 2010 | 07:38 PM
  #14  
Jibaro 12A's Avatar
searching...
Tenured Member: 15 Years
iTrader: (8)
 
Joined: Dec 2009
Posts: 1,022
Likes: 1
From: Chicago
Originally Posted by theNeanderthol
^^^ He's from Puerto Rico. Listen to him. The rotary knowledge flows through the veins down there. Ha ha
Good one! Easiest way to check compression would be with a power drill (if they are out of the car) IMO. A 13B would be awesome but the 12A only has 5K miles and was built by Atkins Rotary. Either way make sure you keep us informed and post pics when you make up your mind. Oh I've used a telescoping mirror to check out ports. Works well, just need to remove the intake manifold.
Attached Thumbnails I have a choice of 3 engines...which one to get?-ullhte-2.jpg  

Last edited by Jibaro 12A; Oct 21, 2010 at 07:42 PM.
Reply
Old Oct 21, 2010 | 09:08 PM
  #15  
Thread Starter
Senior Member
Tenured Member 05 Years
 
Joined: Nov 2003
Posts: 264
Likes: 0
From: Shoreline, Wa
A telescoping mirror...that's simple and smart! I'll keep you guys updated for sure.
Reply
Old Oct 22, 2010 | 07:38 AM
  #16  
Keith13b's Avatar
Senior Member
Tenured Member: 20 Years
iTrader: (6)
 
Joined: Jul 2005
Posts: 566
Likes: 0
From: Orlando, FL
Option 1 is clearly the winner - a fairly fresh re-build by a reputable company and is street ported. @ $500 thats a steal! But what proof do you have that it was rebuilt by Atkins? Receipts?

Option 2 is a waste of $$$ imho. 30K miles on a Bridge? I call BS. Check the compression - its most likely way down - not to mention...have you ever driven a bridge? And tuning them is a bitch if the carb wasn't built right!

Option 3 - actually was a tough call. I'm a believer in 13bs for stock power and reliability. The SP 12A is probably higher HP, but the 13b has more long term potential. Your call.

My choice for the budget minded buyer is option 1. Best bang for the buck.
Reply
Old Oct 22, 2010 | 08:31 AM
  #17  
Directfreak's Avatar
I am a Jeeper Now.
Tenured Member 20 Years
iTrader: (2)
 
Joined: Dec 2001
Posts: 9,371
Likes: 4
From: 3OH5
Option 1 - Keep the 12A, and you don't have to modify anything else in your system.
It will be bolt in - especially if you keep your Webers, and no real tuning will be necessary.
Save the Dell'Ortos for a future 13b or sell them to make back half your money.
Reply
Old Oct 22, 2010 | 09:01 PM
  #18  
jpieps's Avatar
Full Member
 
Joined: Mar 2010
Posts: 111
Likes: 0
From: MN
My vote goes for the 12a streetport hands down. Especially considering your situation, and the fact that it has by far the lowest miles and it was rebuilt by a reputable company.
Reply
Old Oct 23, 2010 | 05:28 PM
  #19  
Thread Starter
Senior Member
Tenured Member 05 Years
 
Joined: Nov 2003
Posts: 264
Likes: 0
From: Shoreline, Wa
The guy with the engine said the Atkins engine has a stamp or something welded on it from Atkins that they do when they rebuild an engine, is there any truth behind this?
Reply
Old Oct 23, 2010 | 05:36 PM
  #20  
Keith13b's Avatar
Senior Member
Tenured Member: 20 Years
iTrader: (6)
 
Joined: Jul 2005
Posts: 566
Likes: 0
From: Orlando, FL
Never heard of that, but that doesn't mean he is incorrect. Have him show it to you, then call Atkins to confirm.
Reply
Old Oct 24, 2010 | 02:13 PM
  #21  
Thread Starter
Senior Member
Tenured Member 05 Years
 
Joined: Nov 2003
Posts: 264
Likes: 0
From: Shoreline, Wa
Alright sounds good, I've been searching for info on them doing that but have not been able to find anything. I haven't been able to call since they aren't open on weekends. Hopefully i'll be able to check the engines out this evening or something, if so I'll take pics and post them up.
Reply
Old Oct 25, 2010 | 08:22 AM
  #22  
Keith13b's Avatar
Senior Member
Tenured Member: 20 Years
iTrader: (6)
 
Joined: Jul 2005
Posts: 566
Likes: 0
From: Orlando, FL
Good luck!
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
renjiv2
3rd Generation Specific (1993-2002)
57
Jan 25, 2024 03:34 AM
He's On Toroids
NE RX-7 Forum
48
Oct 19, 2015 08:58 PM
Ian_D
Single Turbo RX-7's
25
Oct 14, 2015 12:31 PM
Feffman
SE RX-7 Forum
1
Oct 7, 2015 06:57 AM




All times are GMT -5. The time now is 07:11 PM.