someone awhile back inquired about why when a motor blows its more usually the rear one. rotary resurrection chimed in himself and conjectured it might be due to the fact that it does get preheated coolant. in fact just last year when i tore open my engine that had nearly 140K original miles much of the seals at the rear were carbon locked in while the front was a breeze. that arrangement i think was an error of mazda's. the rotary is still in its early stages and must be improved upon if it ever hopes to survive in a world that has been ruled by pistons for nearly 100 years. i have hope one day of its widespread acceptance beyond the boundary of race engines.

 

I was killing time with the question, “Can you guess how to get an extra 8.8 sq. inches of surface area?" This was because I had failed to take a picture of that area before assembly and since the car is running......

I had to mod an old RE housing for the picture.

 

Each through-bolt hole has 4.451 sq. inches of area. 450” x 3.14 x 3.150”= 4.451 sq.inches.

Then depending on how may holes you use, I used two, and added 8.9 sq in per rotor housing, or 17.8 sq in total of added cooling surface!

The holes are drilled at a 45ş at the top of each housing to help bleed air initially.

Barry

 

Do you do this on both sides? You want the water to flow in and flow out, correct?

 

Yes Javrosario, a 3/32" hole on each side on the top at a 45ş angle.
Barry

 

Again I have to give credit to Carlos Lopez. He opened my eyes to it being a heat problem not a flex from pressure problem that would require dowels and studs.

I don’t however know Mr. Lopez's secrets for cooling. He has many according to those who have had engines built by him. It would be great to have his thoughts on my experiment, to know if this is the right direction.

He did tell me two other things that I took to heart. The 3rd gen pump was one of the poorest and the 2nd gen / RE pump was better.

RE Pump- Notice the foil shape of the blades and the bullet center, it says flow.

 

[QUOTE=internal heat exchange fins, but inline with the direction of coolant flow to reduce flow losses.[/QUOTE]

i agree with this statement

we do similar work to water passages easily modified with a spirial cut to add surface area and add water contact time as it were

but our efforts may pale in comparisin

i liks fins that are more with the flow or coolant direction

 

Cutting fins in the direction of flow will hurt the stregth of the rotor housings significantly more then cutting them perpendicular. Enough for damage? I don't know, but I doubt you'd see a significant increase in cooling going from inline to perpindicular to warrant the risk.

~Mike..................

 

afgmoto1978 (Adam) and cooldude,

I think you guys are correct for enhancing flow but possibly what we need is the effect of vortex generators causing turbulence.

We should not allow laminar flow but continually mix cooler layers to interface with the housing.

Maybe even golf ball type dents would work!

Adam, I was talking with Jonathan..... if we could figure the flow pattern of the intermediate plate, it may be able to introduce a cooler flow to the rear rotor housing! Maybe a vane with one side directing the hotter water down (from the front housing) to the next horizontal slot. Then the other side (of the vane) might direct cooler water into the rear rotor housing hottest slot.

Barry

 

how about finning the outside area around the spark plugs as with a air cooled motorbike with a ducting to it ? the fins on motore bikes are for cooling from air ?
just a thought

 

rx3_pp good thought, but nothing beats water for heat transfer if you can keep it from boiling.

I gravitate toward higher pressure and more flow.

Barry

 

well i dont mean as an all round solution to your problem or our problem but just as an aid the same as studs weber jets on th rotor squirtes you know all the little things add up

i would personally run and electric pump craig davies no cavitation and it is variable speed

and obviously more flow means more heat transfer

i use electric with no issue

wate jacket light scolloping there

 

I agree with using an electric water pump for sure! I will be going this route asap.
-J

 

*cough* one of my previous employers went to great lengths to minimize and blueprint the clearance distance between the water pump impeller blades and the housing. It's amazing how much damage an extra .005" of clearance can do.

 

yeah been there done that.....But an electric pump is far better no matter how you look at it.

-J

 

The impellers that I measured were very loose at over .030". Probably .005" is more appropriate. What did you use?
Barry

 

Barry,

I've been giving the vane idea some though, but in a slightly different way. It's rather cumbersome, complex and potential adds more leak paths, but the best I can think of as far coolant performance...

Create and external coolant line that directs unpreheated coolant directly to the Rear spark plugs. Meaning create two to four coolant nozzles that flow cool coolant directly onto the surface of the spark plug plugs. These vanes would draw from the single external coolant line. Plus, in addition to these nozzles create block-off plate that redirect the preheated coolant away from the rear spark plugs.

I think I will physically tinker with this idea on my now destroyed rotor housing before I potentially destroy a perfectly good one. See attached Photos for a visual idea.

In addition to this I think I'm going to bite the bullet and go EWP as well.

Adam

 

Adam, great pictures as usual. Your electric pump makes me think!

With an electric water pump there would be no real need to have the in/out ports on the front of the engine. Ideally if the cooled water was introduced first at the middle plate between the spark plugs and went fore and aft through the engine, and then exited on the other side of the engine between the exhaust, both rotors would “see” similar cooling patterns.

The pump was put on the front of the engine originally because of the mechanical fan/pump combo needing proximity to the radiator. Not the best for heat balance of the rotors.
Barry

 

hmmm. . . now we're talking. Damn I wish I had the means for real R&D. I think where this is going is about the optimal cooling configuration imaginable. Obviously impractical for an OEM manufacturer for the reasons Barry just mentioned, but for those who are seeking the best in performance, it seems like THE way to go.

 

Yeah, I was thinking along the same lines for a "what if", but it's really not feasible with what we have. It would require a completely new design of the front and center plates, a reversal of rolls. The center plate would require the coolant outlet to be the highest point of the coolant system though, so an outlet near the exhaust wouldn't be feasible, it would have to be where the primary ports & injectors are or just above them. Then the front plate would be where the oil filler neck and dipstick would be. Then no more stuffing your arm into a small hot hole to find the dipstick to check oil levels and then it would save yourself 3 minutes to put it back in when it's dark out.

Though, if you made the center plate wider, ala 20B center plate you might be able to do this.......

And then just create a transition coolant plate on the front housing.....

 

Finished the external cooling system modification on my rear rotor housing. Will be doing the rest later this week.

Two slotted 1/8" wide 5/16" holes, further ported with a bulb shaped porting bit. -6 AN fittings welded in, I used a heat transfer prevention jell to prevent warpage (used way too much and had to remove most of it before I could actually weld the fittings on.

 

I ported the coolant passages around the spark plugs as well.

 

Man, you are not scared to get the ball rolling! Nice work Adam.

There is another mod that we should try. The floating housing next to the bolt holes (per Rotary Problems) and used on the RX8 housings.

Barry

 

Thanks Barry

People who are afraid to try new things will be left in the wayside eventually.

I not quite picturing what your talking about Barry. You got a picture of this floating housing?

 

thats some very interesting views there. Here's a crazy idea that might help after scratching my head on this. If that area is really giving that much problems, why not block it off from the rest of the cooling system, and have a deticated water pump, and radiator for that area. The flow would be as follow, the outlet of the pump puts out the cold water through the center Iron, and the water would flow outwards from 2 sections on the housings something like what Adam did. Then that would go through the radiator and back in the pump. i know it would be quite a bit more weigh added but if its really going to save our engines why not?