4-Rotor FC Build
11-17-11, 11:31 AM
#130
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Just read through the entire thread and I am absolutely astonished by the amount of work and ingenuity. Looks absolutely amazing!!! Definitely subscribing. I was planning on building a 4-rotor when I finish school and acquire a job etc. Keep up the good work!!!
11-17-11, 03:57 PM
#131
Did some machining on the stationairy gears. Had to machine cut-outs that lock and align the two gears together. Small job, still took me 2,5 hours because I had to make sure it was accurate.
Pretty tough material too, it ate a HSS endmill in a few seconds. No worries though, tiAIN coated VHM tooling got the job done
By the way, if anyone knows the output flow volume of the stock 13B oilpump please reply or PM me.
I did some research, found some numbers and did some calculations, but when selecting an industrial oilpump I end up with a pretty big one
, so a second opinion would be nice.
Well so far it's not so bad. If you haven't noticed already I pretty much do everything myself, which makes a night and day difference in term of costs. There are some things you just have to buy of course, like fuel injectors and stuff. But when done the engine should be worth more than I've put into it.
Should be a while. I put in all the spare time I have (which isn't a lot 
), but there is just a lot to do. Short list of things to do before the engine can be put together:
- Finish stationairy gears and fit them in the center iron
- Modify iron's (close intake ports, sandblast and paint them)
- Finish e-shaft, and have it nitrated and ground
- Get a clutch and lightweight flywheel
- Fabricate custom counterweights and bob weights.
- Get the rotating assembly balanced.
- Get rebuild parts such as seals ect.
And then theoretically the engine can be assembled, but I think I'll put it together without internals as a mock up engine first, and fabricate the oil pan, engine mounts, cooling and oiling systems ect. before final engine assembly.
I've got a KDFI ecu (basically a megasquirt) with a Techedge 2J9 wideband lamba controller. For fuel I've got an external bosch 044 fuelpump with 4 ID1000 injectors, no staged injection. Ignition will probably be direct coil with 4 dual-output coils.
We were planning the same thing then, I finished school a few months ago.
Pretty tough material too, it ate a HSS endmill in a few seconds. No worries though, tiAIN coated VHM tooling got the job done
By the way, if anyone knows the output flow volume of the stock 13B oilpump please reply or PM me.
I did some research, found some numbers and did some calculations, but when selecting an industrial oilpump I end up with a pretty big one
, so a second opinion would be nice.Well so far it's not so bad. If you haven't noticed already I pretty much do everything myself, which makes a night and day difference in term of costs. There are some things you just have to buy of course, like fuel injectors and stuff. But when done the engine should be worth more than I've put into it.
), but there is just a lot to do. Short list of things to do before the engine can be put together:- Finish stationairy gears and fit them in the center iron
- Modify iron's (close intake ports, sandblast and paint them)
- Finish e-shaft, and have it nitrated and ground
- Get a clutch and lightweight flywheel
- Fabricate custom counterweights and bob weights.
- Get the rotating assembly balanced.
- Get rebuild parts such as seals ect.
And then theoretically the engine can be assembled, but I think I'll put it together without internals as a mock up engine first, and fabricate the oil pan, engine mounts, cooling and oiling systems ect. before final engine assembly.
I've got a KDFI ecu (basically a megasquirt) with a Techedge 2J9 wideband lamba controller. For fuel I've got an external bosch 044 fuelpump with 4 ID1000 injectors, no staged injection. Ignition will probably be direct coil with 4 dual-output coils.
We were planning the same thing then, I finished school a few months ago.
11-18-11, 10:38 PM
#133
Full Member
[QUOTE=We were planning the same thing then, I finished school a few months ago.[/QUOTE]
If you don't mind me asking what did you take in school. I am guessing some sort of engineering since you seem to know a fair amount of force and flow analysis and solid works. I am currently in Mechanical Engineering and as stated before VERY impressed and will be following this thread religiously.
If you don't mind me asking what did you take in school. I am guessing some sort of engineering since you seem to know a fair amount of force and flow analysis and solid works. I am currently in Mechanical Engineering and as stated before VERY impressed and will be following this thread religiously.
11-18-11, 10:54 PM
#134
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excellent build! i really like the rotor housings, those sleeves are cool. the injector placement looks good too
on the exhaust side, you might consider moving the top exhaust stud, you'll see that when you bolt a header on, it'll be really close to the intake, which is why the MFR housings had the stud moved down.
the big tuning problem with at PP is that there is overlap, and since there is always lower pressure in the intake than the exhaust, the rotor wants to push the exhaust gas around again, basically intake vacuum is bad. mine is a carburetor, but drilling holes in the throttle plates made it run shockingly like a stock FC.
on the exhaust side, you might consider moving the top exhaust stud, you'll see that when you bolt a header on, it'll be really close to the intake, which is why the MFR housings had the stud moved down.
the big tuning problem with at PP is that there is overlap, and since there is always lower pressure in the intake than the exhaust, the rotor wants to push the exhaust gas around again, basically intake vacuum is bad. mine is a carburetor, but drilling holes in the throttle plates made it run shockingly like a stock FC.
11-20-11, 03:10 PM
#138
Yes it will be done before christmas, just not this year's christmas
If you don't mind me asking what did you take in school. I am guessing some sort of engineering since you seem to know a fair amount of force and flow analysis and solid works. I am currently in Mechanical Engineering and as stated before VERY impressed and will be following this thread religiously.
excellent build! i really like the rotor housings, those sleeves are cool. the injector placement looks good too
on the exhaust side, you might consider moving the top exhaust stud, you'll see that when you bolt a header on, it'll be really close to the intake, which is why the MFR housings had the stud moved down.
the big tuning problem with at PP is that there is overlap, and since there is always lower pressure in the intake than the exhaust, the rotor wants to push the exhaust gas around again, basically intake vacuum is bad. mine is a carburetor, but drilling holes in the throttle plates made it run shockingly like a stock FC.
on the exhaust side, you might consider moving the top exhaust stud, you'll see that when you bolt a header on, it'll be really close to the intake, which is why the MFR housings had the stud moved down.
the big tuning problem with at PP is that there is overlap, and since there is always lower pressure in the intake than the exhaust, the rotor wants to push the exhaust gas around again, basically intake vacuum is bad. mine is a carburetor, but drilling holes in the throttle plates made it run shockingly like a stock FC.
11-20-11, 03:22 PM
#139
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Don't know the specifics of the exhaust system yet though. It has to be quiet enough to drive on the street but as non-restrictive as possible. Maybe I'll remove the gastank and the spare wheel part, go with an fuel cell in the trunk and fabricate a really bigass absorption silencer in the stock fuel tank's location
FC's with duals are almost always more quiet then FD's, so you could take the benefit of the space you got underneath.
a big presilencer and dual at the back should do some good. you're in luck you don't need to have a cat over here
i think you will need more soundproofing under the hood then under the car anyways
11-20-11, 05:56 PM
#140
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I don't plan on moving the studs if I don't have to. If it clears the slide intake I'll keep them where they are. Yes I know any intake or exhaust restriction is bad for performance with this engine, that's why I'm planning on using the slide intake. Don't know the specifics of the exhaust system yet though. It has to be quiet enough to drive on the street but as non-restrictive as possible. Maybe I'll remove the gastank and the spare wheel part, go with an fuel cell in the trunk and fabricate a really bigass absorption silencer in the stock fuel tank's location
exhaust is a weird topic, if you looked at the 787B it has nothing fancy, its just 4 equal length pipes into 3" with a small straight thru muffler. its pretty quiet for a race car too. pipes are in the 500mm range, but that's by eye.
theoretically the 4 rotor is quieter than the 2 rotor just because there are less pulsations in the exhaust.
good luck! after finding a header length mine likes, its muffler shopping time
11-22-11, 04:52 PM
#142
Did another pair of stationairy gears today 
I found a tiny nick in the ones I already did. It seems like the socket screw I used to align the stationairy gear in the jig made a little mark in a gear teeth. I thought the gear was much harder than a regular screw. Guess I was wrong, the screw didn't have a mark. The nick is really small because I didn't tighten it a lot but I still didn't feel comfortable using it. Would be a shame to have a 4-rotor engine fail due to a bad stationairy gear. Modified the jig to accept a softer brass insert, which worked, so the new ones came out perfectly. You can see the mark in the left upper gear, just above the oiling hole.
Yes, I can imagine no air cleaner being loud, I guess having a peripheral port makes the intake sound a bit louder also. Maybe I should fabricate an airbox with a cold air intake. Should silence the sound a bit and provide cooler air.
How are you planning to find the correct header length? Start with a long exhaust and keep cutting pieces out of it, welding it back together and dynoing it untill you get it right? I'm trying to figure out exhaust runner length right now, but it's not as easy as intake length.
I found a tiny nick in the ones I already did. It seems like the socket screw I used to align the stationairy gear in the jig made a little mark in a gear teeth. I thought the gear was much harder than a regular screw. Guess I was wrong, the screw didn't have a mark. The nick is really small because I didn't tighten it a lot but I still didn't feel comfortable using it. Would be a shame to have a 4-rotor engine fail due to a bad stationairy gear. Modified the jig to accept a softer brass insert, which worked, so the new ones came out perfectly. You can see the mark in the left upper gear, just above the oiling hole.
there is a lot of noise from the intake too, i fired mine up with no air cleaner and the neighbor came downstairs holding his head.
exhaust is a weird topic, if you looked at the 787B it has nothing fancy, its just 4 equal length pipes into 3" with a small straight thru muffler. its pretty quiet for a race car too. pipes are in the 500mm range, but that's by eye.
theoretically the 4 rotor is quieter than the 2 rotor just because there are less pulsations in the exhaust.
good luck! after finding a header length mine likes, its muffler shopping time
exhaust is a weird topic, if you looked at the 787B it has nothing fancy, its just 4 equal length pipes into 3" with a small straight thru muffler. its pretty quiet for a race car too. pipes are in the 500mm range, but that's by eye.
theoretically the 4 rotor is quieter than the 2 rotor just because there are less pulsations in the exhaust.
good luck! after finding a header length mine likes, its muffler shopping time
How are you planning to find the correct header length? Start with a long exhaust and keep cutting pieces out of it, welding it back together and dynoing it untill you get it right? I'm trying to figure out exhaust runner length right now, but it's not as easy as intake length
.
11-22-11, 05:13 PM
#143
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You sir, should view this article, and try to replicate the build of the header in similar fashion. I'm sure you could be able to do it, seeing as how you're already building a freakin 4-rotor lol.
http://speedhunters.com/archive/2011...prototype.aspx
http://speedhunters.com/archive/2011...prototype.aspx
11-23-11, 01:30 PM
#148
Got rid of the shell I was going to use
No worries, I've got another FC shell that would be better to use, so I removed the engine and drivetrain from the TII one, and sold the shell.
They did a good job there, titanium is a bit out of my league though, haven't welded something like that yet. I'll stick to 304 stainless 
. Problem is knowing how long to make the primairy headers before the 4-1 collector. I'm going with a short system because it's difficult to fit 4 long primairies underneath the car, and there will be more room for silencers this way. Best thing would be to build an exhaust that can fairly easily be adjusted in length, but with a 4-rotor that's a hard thing to do.
No worries, I've got another FC shell that would be better to use, so I removed the engine and drivetrain from the TII one, and sold the shell.
You sir, should view this article, and try to replicate the build of the header in similar fashion. I'm sure you could be able to do it, seeing as how you're already building a freakin 4-rotor lol.
http://speedhunters.com/archive/2011...prototype.aspx
http://speedhunters.com/archive/2011...prototype.aspx
. Problem is knowing how long to make the primairy headers before the 4-1 collector. I'm going with a short system because it's difficult to fit 4 long primairies underneath the car, and there will be more room for silencers this way. Best thing would be to build an exhaust that can fairly easily be adjusted in length, but with a 4-rotor that's a hard thing to do.
11-23-11, 02:46 PM
#149
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Yes, I can imagine no air cleaner being loud, I guess having a peripheral port makes the intake sound a bit louder also. Maybe I should fabricate an airbox with a cold air intake. Should silence the sound a bit and provide cooler air.
How are you planning to find the correct header length? Start with a long exhaust and keep cutting pieces out of it, welding it back together and dynoing it untill you get it right? I'm trying to figure out exhaust runner length right now, but it's not as easy as intake length.
How are you planning to find the correct header length? Start with a long exhaust and keep cutting pieces out of it, welding it back together and dynoing it untill you get it right? I'm trying to figure out exhaust runner length right now, but it's not as easy as intake length
.after trying 2 systems, and seeing mazda's SAE paper, i'm reluctant to pick a length, i want to let the engine pick a length. i've found that if i make the engine happy, it's actually very tame, but if you try and apply what you think will make the engine happy, you can end up with a bucking snorting un driveable monster.
with the header, i have a racing beat piece, which is 26" and RB sells thickwall pipe in 4 foot lengths, and the plan is to buy 3, cut one in half and then with some exhaust clamps, i get 26, 50ish, 75, and 90. so it should be really easy to make 4 dyno runs and see which length the engine wants.
after that depending on how much room i have, i fill it with mufflers!
11-23-11, 05:30 PM
#150
I agree that it's best to just give the engine what it wants, the problem is that you can't just ask an engine nicely what it wants. You'll have to give it a bunch of different things and see what it likes the most. That's difficult in an cramped 4-rotor engine bay. Maybe I'll make a dyno-header that can be easily modified, like this:
If I fab up a simple cheap steel equal length manifold with all the primairy runners sticking out on the top like on a tractor, and slide a slip-on collector over it I can easily try different lengths by cutting a piece of the primairy runners. After I found the right length measure it out and fabricate a normal header with the right dimensions. I'm glad I went to the trouble of getting my own steady state chassis dyno, should really come in handy on this one
But first things first, I'll continue on the stationairy gears tomorrow
If I fab up a simple cheap steel equal length manifold with all the primairy runners sticking out on the top like on a tractor, and slide a slip-on collector over it I can easily try different lengths by cutting a piece of the primairy runners. After I found the right length measure it out and fabricate a normal header with the right dimensions. I'm glad I went to the trouble of getting my own steady state chassis dyno, should really come in handy on this one
But first things first, I'll continue on the stationairy gears tomorrow