^ That looks like a lot of work.

http://racingbeat.com/photos/11488.jpg there. It looks like it takes for ever, but they only charge $90 that's an hour of shop labor I wonder how they do it? I'm just going to cut the **** out of my housings and hope it works! LOL!

I would be careful with just hacking up your housings. Try on a spare one first I know you have them https://www.nopistons.com/forums/pub...IR#>/smile.png Get down a techniques and then have at the ones that you are going to put your engine together with.



I personally would use a small diameter dremel tool that has a wide stance. I think that would work the best.

Nar a piller drill with a round Carbide Bur works the best.



You can set the drill at difrent levels and you just run move the housing to cut your groove. Alot quicker.

Ahhhh I see what you mean a carbide ball on like a drill press. Welp dremmell it is... LOL!!!

Does this mod actually give results?



I understand the concept behind it, but have always wondered why the cuts do not go parallel to the water flow. Seems like there would be less resistance and therefore less turbulence/cavitation in the water passages.

the turbulance allows more water to be in contact with the housing there fore more water to remove heat from the housing... I've heard nothing but positive results from it. If you search you can find a bunch of positive results, but there's never any pix cause the threads are usually from 2002.

rezcar. Imagine that you have laminar flow through the passages. Essentially all that water would not be mixed, sure the coolant on the edges would be cool but right in the center it would still be hot. Make sense?

Here's a pic from an older Mazda SAE paper (#860560) that shows the temperature distribution around the rotor housing when the engine is run under high load. Looks like the coolant passages surrounding and below the plugs would be the areas to focus on with this type of mod.

[attachment=38896:attachment]

It does work but don't make the Grooves to deep, I belive becouse the Grooves hold Air and can Hinder the Cooling so there is a set depth you go to increase the Surface area but not create Air pockets.

Thanks for the explanation guys, that makes sense! I will do this mod in the future.



But here I go again with my crazy ideas...what if you were to cut angled grooves parallel to water flow, but at angles, so that the water would essentially swirl while going forward???

It would work better than parallel lines. I bet it would actually work great, but good luck getting them perfect.

Thats what I have gathered from literature on the subject. I also read its only needed under extreme racing conditions, however I'm sure it can't hurt in any other case.

Well I was going to do it today, but I was running out of day light, so I just stacked my engine togather. I'll do it on the next build...

I blew my coolant seal on the REW and it was on the side of the plugs...just thought I would say that since it is kind of in reference to the pic provided...

Thats what I have seen on customer's cars also.

Yeah, I might just have to do this mod. I took a look at the busted center iron and it appears as if the part broke right where the lower plugs would sit.



To tell you the truth I looked long and hard for a good iron but it appears as is this is a common failure for the REW. Most of the people that were parting their block(good internals) had blown a coolant seal. I wonder why it is not more commonly practiced.



Anyone have a picture of a carbide ball? I am interested to see if it is the piece that I am thinking of...

I'd like to see some demonstrable proof of this, as well.



B

REW engines usually die from a bad coolant seal, seems like they run a little too hot for a long time....



and the REW rotor housings already have a rudamentary version of this cooling mod

Would a spiral pattern like a thread not give better results?

The spinning force would keep turbulance in the water and also force it out against the walls of the water way so you get maximum contact.



I must admit this is a mod ive never heard of before but il definately be giving it a go on one of my engines soon and see if it makes any difference to running temps

If the cuts were to go parallel to the water flow you would be encouraging laminar flow though the housing you want turbulent flow even though it is slower. This is because in laminar flow the water that stays closest to the housing with act as a insulator to the water farthest away from the housing as it heats up. Cutting parallel to the flow would increase cooling but only because of increased surface area but the perpendicular cuts will increase surface area as well as increase turbulent flow. But I don’t think any one will be seeing any major difference in water temps but instead a decrease in housing temperature by only a couple of degrees tops. in fact its even a possibility that one will see an increase in water temps as heat is being more evenly distributed between the motor and water.

A decrease in housing temps is the whole point. Lower housing temps= safer working coondition for the engine.

I think that his main point was that he think that this mod is useless. I would like to hear how others feel about this. I really do not feel like digging out my thermodynamics book and calculating.



Also what are other REW owners doing to decreace temps?



Z

Well I think that increased surface area is definitely going to increase cooling. But the whole laminar vs turbulent argument is beyond me.



Here's a pic of a carbide ball.

http://www.mcmaster.com/catalog/112/...e/4292ap4l.gif

I don't understand how you can make those cuts with this. Seems like it'd just make everything dull and

round. Maybe they're using a real small diameter? BTW, Mcmaster-carr sells these.

Yeah the decrease in housing temp is the whole point I’m just saying that people only looking at the water temp will probably be disappointed in what they find.



And as far as how much of a difference it makes, it can’t hurt so if you have free time why not? But I think the rough surface on the inside of the housings pretty much get the job done, to a point, as far as turbulence goes.

and depending on how deep those cuts are i bet the precentage the surface area increases will be pretty small, thus not all that much of a cooling increase.

Well if Racing Beat recomends it on all applications over 400 hp it must be worht it. They don't do anything that they feel isn't worth the gain.

thats all opinion, but yeah i will probably do it to my next engine.

just need to find some free time in a ACed garage

any one know of one in tucson az https://www.nopistons.com/forums/pub...DIR#>/wink.png

Talk to moremazda on the other forum. He is a rotary Gawd and tought me most of what I know. He actually lives in TUK SON. LOL! I lived at Ft. Huachuka for a few months. And he lived in Seatown b4 he moved. So he's actually the best resourse IMHO!!!

if you do what they say you wont have problems. https://www.nopistons.com/forums/pub...#>/biggrin.png

its funny you mention moremazda (ryan) as right before i posted i was over at his house helping him on his new car. he just picked up a new FC. unfortunatly he does not have a ACed garage.

ikari, do you have personal experiences with this? You speak as if you have seen the results it can create. Or are you talking from just theories.

sorry just theories, so dont take any of this as any sort of proof or any thing. but its undeniable that there will be benefits, it doesent seem like any one knows exactly how beneficial it will be.

Yeah, that is what I assumed. I would love to hear if anyone has personal experience with this. I have one day to decide.

i would do it but dont pay any money to have it done. it cant be all that hard to do and there really cant be any draw backs, in most cases.