Marcus

Aluminium will definatley work ! So long as there is good contact to the exhaust port areaI know of a few people who make up inserts from this material and TIG it to the inside of the exhaut port just inside the rotor housing surface. They do this on Peripheral Port Turbo engines (can you spell EXHAUST TEMPERATURE !)

To give you an idea of heat transfer (you most probably already know this, but for the benifit on newbies ) It's a bit like the high school experiment you did with a paper cup, Put a bunsen burner flame under it and it will ignite & burn up very quickly ! Fill it with water and try the same thing ! The paper cup will not burn ! Infact you can get the water to boil.......

I know it's a "gay" example but the theory is the same.

In practice, nothing happens to the rotor housing around the exhasut port area.

Now here comes the important bit, for our new Aluminium sleeves I would not make them as thick as the others you made previously as from rough calculations the localized temperature of the surface of the sleeve would be quite extreme for this material, It would need the water jacket extended into the new Insert, this would give the sleeve the best chance of being able to handle the heat load, If they were made the same as the ones rotary god picture I am guessing that the Alumium ones would suffer from material failure (originating from the inside surface) over a period of time due to not being able to disipate the heat. I am having a guess here (calculated guess) but would say the limit for an Aluminium sleeve Insert would be no more than 1/2 inch at it's thickest point, also it would need to be a very tight fit on the inside of the port area to allow good heat transfer, either a tight fit or TIG welded to the rotor housing.

 

heres a stupid idea. why not just weld your header tubes right to the steel part of the rotor housing?
rotarygod: do you pass smog like that?

mike

 

Why not just weld more metal right in to the rotor housing (after removing the steel sleeves of course) and then port it as you see fit? No worries about if it'll transfer heat well enough...

 

Yours and Rice's port designs merit some study. I'll have to start flow testing that.

 

Rice maybe you should sketch something and mail it to me and i can start making a program to machine it.


you cannot weld directly to the housing unless you plan on resurfacing the sides, they will warp. if the sleeve fits tight and can be welded w/o using filler rod it may work. i think that small 1/8 spring pins on the face would hold them in and allow you to remove them if there is a seal casualty!!



MWW

 

I think I need some help before I make a mistake while constructing my manifold.

I'm in the process of making a manifold for my stock ported 13B-RE engine that will have a TD07, 25g compressor and 17cm devided turbine housing. I have the flanges made already and also have 1.5" schedule 10 304L SS pipe (1.68id 1.9od) that I plan on using. Will using this small of pipe melt my turbine wheel even with the stock sleves in place?

Here is a link to a thread I have going in the single section that shows pictures. https://www.rx7club.com/forum/showth...hreadid=109194
Any input would be great before I make a mistake.

Thanks
Cam

 

What's going on setzup! I replied on your thread. I don't think you'll have the problem of melting turbines since the turbulence inherent in the stock sleeves in such that the air not only slows down but also cools down as well. that small of an i.d. pipe would work with the new sleeves in place but I'm not sure how well they'll wok with the stock ones. I'm assuming of course that you are going to use some kind of reverse cone to smoothly blend the sleeve opening to the smaller runners.

 

that is too small for your primaries...hate to tell you tha bad news! i cannot tell you if you will melt the turbine or not but i do know that you will end up restricting your power unless you plan on running dual WG's to relieve some back pressure but as Rice said (and i totally agree) you do not want to have more than 2psi over your boost level for BP or you will lose power.


MWW

 

I chose the 1.68ID because thats what the exit of the stock port is and I can form it to match the devided turbo flange nicely. The cosmo port isn't 2" like all the other13b's. I dug up this old pic to show a little better what I am doing.
I had a custom engine flange made that is offset .150" twards the rear of the engine so the pipe would line up nicely with the port. I will have to bend the pipe a little though to match the bends of the port.

Do you guys still think it is too small? I don't plan on making 600hp or anything, I think 350 at the wheels would be more than enough for my little FB.

 

If thats the size of the stock port openings then it should work fine. Not sure how hot your turbo will get though.

 

No, setzep you should change those ports.. They suck.. At least put in some sleeves from a normal 13B...


They are not the same inside.. they just cause more of a restriction..


-Zach

 

This thread is full of ideas, I like it.

 

I definitely agree the sleeves should change If you absolutely have to keep those then use the closest matching size runners you can.

 

I would love to get some FD sleves or anyother sleve in there for that matter but to do that I'd have to take the engine apart and I'd hate to do that when it has 120psi on both rotors. I know they aren't the most desireable sleves but untill my engine decides it needs to be rebuilt they are going to have to stay in place.

What if I just made the runners longer? Would that help cool the temps before it hits the turbo?

 

You don't need to do that setzep. not with the sleves you have... they where made to direct the pulses towards the stock twins..


You want your turbo manifold ~13"


-Zach

 

Hmm, I liked reading this thread. Gotta bring it back.

Any further results with the small exhaust ports? Did you guys try this insert with a N/A engine? Say a PP by any chance?

 

I have made some alu inserts with a taper angle of 7' on a 13B PP. It made 297 hp on a engine dyno. I was using 54mm inner dia primaries and observed 800-850'celsius exhaust temp. When switching to 48mm primaries the temp rised to about 920-950. Made some flow testing before testing the inserts and it showed some 15-20% increase compared to stock sleeve with the same port timing. As an example a stock FD port flows 98cfm@10" with a good streetport job it flows 135-140cfm. On some PPs i done the exhaust flows anywhere from 175-200cfm (Mazda factory round port PP 168cfm) I definetily recommend using alu sleeves on N/A engines. Plans for future is to have different port timed exhaust sleeves and change the same day in the dyno!

 

That sounds like a good idea. It would be nice to try to spread the torque peak out a little and still be able to make 300 hp.

 

so let me get this straight rice?you run no sleeves whatsoever?

if this is true then what manifold tubing diameter do you use?

 

TURBOSTREETFIGHTER was running no sleeves what so ever. Sadly he doesn't post here anymore that I have seen since he sold the race car. He removed the sleeves, ported them out as big as they could go, and then had that opening ceramic coated. This was not a street car. It was a half bridgeport that used 2 single turbos, custom built intake manifold with short runners (3 of them! Siamesed primaries) a huge plenum, mustang throttlebody, and ran off of methanol. There was nitrous on top of that! I believe his exhaust runners were 2.25" and then went to a reverse cone at the turbos. I saw that car a few times in person at his shop and this is what it appeared to be. Since the race car was an auto and he revved the snot out of it, who knows how bad lag was or not.

The key to a nice torque spread is to use the proper size turbo with your engine combo. Too many people go way to big on turbos because they have seen others use it or because they were just told it works good. Bigger must be better right? The 60-1 HIFI turbo (the smaller one) at 15 psi, on a streetport, can pump out a good 425 rwhp! It is all about using the right turbo for the job. A T66 or larger aren't even fully in their efficiency range at this level. Raise the boost though and watch out!

If you try to run the new sleeves with stock turbos, they will absolutely, positively self destruct within minutes!!! It is only for a very well modified car.

Lasse: Your findings match mine and others perfectly. More flow due to less turbulence, but alot more heat. A neat idea instead of changing sleeves all the time is to design one that is as large a possible, but to then have inserts that can be installed without removing the engine that changes the timing. This is more or less what you are taliking about. I would think this would be easier and cheaper. It is a good idea though.

 

I realize this is a VERY old topic and it's been 'umbrella corp'd' once already, but frankly it's the ONLY thread of it's kind and quality on the fourm, I'm about to do a RE and I'd like to find out what peole have done via this or other discussions and how its worked, I've mentoined somewhere else that i'm looking to hit 550 FWHP with a T70 ( .84, P trim turbine side or a 1.15 depending..).

I've been looking at a modified version of both techniques; using the outside , non sleeved wall as the starting form and working back with a 7 degree slope per wall taper, opening the inside wall port to a more ovalized shape tapering out both the trailing and leading edge of the apex seal sweep.

my big question is the inner sleeve, or lack of, is it poosible to use a high quality alloy sleeve ( 7075 ) into the port then have it double coated with a fireball plasma coating.. I'm hoping that this will work otherwise I'll need to do a cromoly or stainless sleeve which i don't want to do given differences in expansion rates..

hopefully thier's new info and results to share..

 

inconel period. they use this stuff in rocket and f1 engines, inconel can take a bunch of heat and stress.



-mike

 

Invar, Iconel has been mentioned, and dont forget cast iron. If you use aluminum, very good heat transfer is most important so it must be made to high tolerance and pressed in and/or welded (TIG) as was previously described.

 

Bump.

Any thoughts on using cosmo housing or just the sleeves on a mildly ported 6 port for n/a applications.

It seems that the cosmo sleeves have the same idea in mind as rotarygods custom sleeves.

 

the cosmo sleeves are designed to take the air pump air and put it back into the engine, to ensure a lower smoother idle.

there is a little bulletin or paper in japanese floating around, good pictures though