Morning,

Before you see that I have only a few posts, I can share that I've been involved as a race team owner with over 50 RX-8 Renesis builds, 5 RX-8 race cars and have a Pro Racer relationship with Mazda. I've been road racing for over 5 years and last year we finished 2nd in the SCCA Pro Racing World Challenge TC class. This is my first effort with the RX7Club forums and have been avidly sharing our experiences on the sister RX8Club Forum.

I have a unique 13b 4 port engine still sold by Mazda that was made for Natural Gas.

I'm looking for someone who knows specifics on this. This is not a joke. The engine is very rare.

Eric

 

Can you post the info about this engine? For example, pictures? And if sold by Mazda, a part number?

 

So its not the 13b-t? Thats the only 13b engine I know of thats a 4 port. By the way welcome to forum! I see you live in the racing capital of the U.S.

 

Just found out the skinny. T2 with 9.7 rotors. One spark plug hole/rotor tapped. One blank.

 

Weird, you should post up some pictures. Its cool that is has N/A rotors inside.

 

Oh, just for the record, you'll find 4 port NA 13Bs in the RX-4, RX-5/Cosmo and REPU....off the top of my head.

 

.

 

Well hello Eric--fancy meeting you here.
Guys if you ever want mountains of good data collection--this is the man.
If you ever want a header for a zero overlap engine (13b msp) that actually will give you some gains--then this is the man again.
Note of interest-- there is a fellow that is converting to LPG--we are following his progress/outcomes.
OD

 

Seems to me that in one of my conversations with Bumpstart he mentioned that he was running LPG .

 

Haha If only I knew about the old school rotaries Id already have known that. Im familiar with second gen rx7s, thats it.

 

http://www.easytuning.gr/images/stor...lpg_engine.jpg
http://www.easytuning.gr/images/stor...lpg_switch.jpg
http://www.easytuning.gr/images/stor...y_lpg_tank.jpg

this looks like a nice set up.
OD

 

Oldragger, isnt that an RX-8?

 

^^ looks like an rx8 to me. sweet setup though.

 

yes--it is.
Good example of how it can be done though.
Go to their site--I believe that they are converting the liquid to gas before it goes into the engine?
OD

 

Denny my man! I've come over to the other side.

I've since got the entire skinny on the engine. They did make this for the natural gas generator market. Approx 300 were made and the market idea didn't fly. They sat around and were bought up and dismantled. 9.7 rotors and Turbo II port config.

We had it worked over by Darryl Drummond for a custom project and it's never seen an engine bay. Made 297 flywheel NA

 

Oh, we are running race gas on our new project--an REW with an incredibly flat power curve just under 350 rwhp to meet our approx 350 limit.

Denny-will be testing it at the NASA Road Atl December effort. I suspect we will turn 1:33's if there is heat in the track.

 

Years ago, I converted boingers to LPG. It's strictly a carburation problem. You need a LPG liquid outlet tank, a couple of pressure relief valves, some airequip hose with appropriate fittings, a vaporizer/regulator sized to the horsepower of the engine, and an air-horn carb adaptor. A little elementry wiring for the liquid fuel selanoid valve and you're cooking with gas!

Using Propane or Butane (the LPGases) will allow advanced timing due to it's slower burning characteristics and higher (than pump gas) "Octane" rating (around 120, as I recall.

You'll be slower off-the-line but within a car length or 2 will match a similar gasoline powered engine in a vehicle of = weight.

The engine will retain an almost "like new" quality internally, and you can double the oil change period (no fuel dilution and less carbon contamination).

Using a 3-way - 2 circuit switch (x o x) and an additional solonoid, you can run gasoline OR LPG, switching on the fly, if you wish. If the LPG tank fuel level sending unit is adjusted properly you can use a duel switch, switching which sending unit supplies power to the fuel gauge.

I suggest using an auxillary 2-stroke oil tank, OMP, and warning light/buzzer system.

Cons:

1. Not as fast off the green light (slower burning fuel)

2. The heavier fuel tank (offset somewhat by lighter fuel and modern aluminum tank construction).

3. In a Hatchback, where to put the tank (high pressure [100PSI+ working pressure] safety concerns/rules/laws)

See: http://www.propanecarbs.com/examples.html