My ongoing project car
 

All right, this month I'm redoing my HBP engine.
I'm actually going to tear down both motors I have and build up one good one.

First off is the original S5 NA motor that was in this car.
Some history about this motor:
I did a rebuild on this motor back in 2005 with the help of a builder. I did this cause I was totally new to rotaries. I wont mention or bad mouth the builder cause he kinda taught me what I know about doing rebuilds.
This motor ran really well till I swapped in the S4 bridge-port.
Ive put about 55k miles on this motor.
It drank a 1/4 qt of oil every 1500 miles it seemed.
I had it dynoed once, and it only made 131rwhp.
I raced a stock na subaru impreza wagon once and was even.
Toward the end of the last few thousand miles I put on this motor, I revved the hell out of it and I bounced it off the rev limiter a couple of times.

Well today I tore it down, and this is what I found.

http://i184.photobucket.com/albums/x...DSC_0001-1.jpg

http://i184.photobucket.com/albums/x...DSC_0002-2.jpg

If you look carefully, you'll notice that there are no corner seal plugs in this side of the rotor!?
http://i184.photobucket.com/albums/x...DSC_0003-2.jpg

http://i184.photobucket.com/albums/x...DSC_0008-3.jpg

All the other corner seal plugs have been located. So 3 were not installed.

Build up of ? junk.
http://i184.photobucket.com/albums/x...h/DSC_0007.jpg

The porting on the center iron.
http://i184.photobucket.com/albums/x...DSC_0010-4.jpg

http://i184.photobucket.com/albums/x...DSC_0011-4.jpg

Im going to use this center iron and the stationary gears from this motor cause the bearings look better than the ones in the S4 motor.

That's it for today.

The ports are shiny, the rotors look to be ok (you will need to check clearance to be sure).

I don't like the shape of that port. This design is giving up significant low end without making any improvements in the high end because that port has about a 15 degree later port close, but it is at such an awkward angle that it will not help chamber charging at high speeds.

For what it is worth, I made 138 WHp on a bone-stock s4 6-port block, factory ECU, modified AFM (lean the mix up a little) and stock exhaust. Stock intake manifold too. This doesn't bode well for the porting on your engine that made 14 Hp more stock than mine. (What I am thinking is that the port design is actually hurting your power.)

If I were you, I would start with a new stock center plate and port it yourself.

Otherwise, it looks like you got an excellent starting point.

Ports are...OK.
They are not the best, but I've seen a lot worse...

There are some builders who refuse to use the stock corner seal plugs.
So those will tell you it isn't a big deal yours are missing.
It's weird that only one side is missing...
hmmm

Gunk in the water passages are normal.
Never did a coolant flush recently, right?
It's aluminum oxide from galvanization of the rotor housings from dissimilar metals and an electrolyte (i.e. the coolant).
You can't really prevent it; you just gotta deal with it.
This is why coolant system flushing is recommended as maintenance.


-Ted

My stock port 12A makes 134 rwhp, so its a good thing you swapped in that
bridge port later.

Looks like a fun project.

Nice text-book reply.
Nice.
I suppose that this porting might be hurting the performance.

Let me just say this: with the S5 motor I had in there, It pulled from 3.5k-6.5k rpm but just runs out right at 7k.
Redlines at 8k. Buzzer at 8500. Rev limiter at 9k.

With the HBP motor I have in there, it really opens up around 5.5k rpm and wants to keep going at 7k rpm. But some of the last times I drove it, it bogs down after 7k rpm, probably for some reason being with the stock ecu.

I just know there was and is a big difference in performance with this HBP motor compared with the S5 motor. I can feel it.

I love this HBP motor and wouldn't go back.

Now for the decision of if I should stick with the stock port center iron that's in the HBP motor, or if I should swap with this ported S5 center iron.
It would probably depend on the whole debate of if ported center irons increase or decrease power, etc.
Stock ported center irons would probably be better, but I'm going with the ported iron just to see what happens.
Ive already experienced the stock center iron with this HBP motor.
Why not see what its like with a ported center iron.
This is a bridge ported motor, so I'm not really too concerned with the low-end performance anyway.

Anyway this is what the end irons already look like.
http://i184.photobucket.com/albums/x...h/DSC_0019.jpg
http://i184.photobucket.com/albums/x...DSC_0026-1.jpg

With this rebuild I'm just going to clean up the ports.
But mainly this rebuild is about putting new o-rings and gaskets in.

Is that a gouge in the face of that last plate?

ha ha, yep.
That's a mistake I made the 1st time I ported it years ago.
I don't think it affects any thing major.
Maybe some carbon will build up there.
Look at it this way, Its an experiment to see how gouges in the surface of an iron effect performance / longevity of a rotary motor. :D

Hahaha and clean them ports up man!

Those ports are U-G-L-Y.... I wanna see how they clean up when you're done.

I got the engine out of the car this morning. Only took 4 hours.

Next:
Take engine apart.
Clean parts & do a little port work.
Check out rotors and compare them.
Get every thing ready to be put back together.

Gasket kit should be arriving Wednesday, so it will be going back together after that day.

So I just took off all the things attached to the block, (manifolds, omp & lines, water-pump, etc.)

Well after I took the exhaust manifold off I looked into the ports and saw a puddle of coolant in the front rotor chamber. Confirms bad coolant seals, or reused ones, lol.

That's all I have to report.

Wow! I didn't see the secondary ports when I made my comment. The way you have opened up the secondaries, that later closing on the primaries won't make any difference. You might as well leave it alone (what is the point of closing the primaries when the secondaries are still open).

I thought this was more of a daily driver, my apologies (I should have seen the HBP in the title - I thought this was a ported S5 NA).

Good luck with the build.

Get some dyno numbers, I would be curious if you can get 200WHp out of this build.

If anyone is confused,
I have two motors,
one is a street-ported S5 na, mainly the primaries are ported.
the other is my Bridge-ported S4 na, mainly the secondaries are ported.

Im planing to use the S5 center plate in the S4 engine.
I also plan to use the 9.7 compression rotors from the S5 engine, if that's what they are.
Also plan to use the stationary gears from the S5 engine because there in better condition. And will probably use the oil pump too.

This afternoon I'm going to take apart the S4 bridge-port motor.


Dyno & performance?
When I ran this HBP engine before, according to my butt-dyno I could spin the tires around the top of 1st and cherp 2nd, this is with an open diff.
Im going to swap in a LSD along with this build.
I heard from someone, that with an LSD if you can spin or cherp the tires, you might have around 200hp.

With this build, this time around, its not really all about the porting or the center plate and its porting.
Its first about replacing the O-rings and gaskets with new ones, second its about the porting.


Any other bits of info are...
I'm thinking about...
Going with the S4 intake manifolds.
And stock ecu for now.
Getting a exhaust header.
Going with out power steering, taking the bracket and pump out, since the original pump went bad.
And thinking of aux oil injection.


Peace.

A HBP w/ S4 manifolds and stock ecu? What's the point? If you have the S5 manifolds, why don't you want to use them? Also... I highly recommend an aftermarket ECU or at least a retuned stock one. The stock ECU doesn't perform well with a BP motor.

Of course, you can run the engine and putt around until you get that ECU squared away, but it's kinda like having a super model girlfriend who's still "saving herself".... :)

Good luck with the build.

Stock ecu is just temporary.

S4 intake manifold is just simple. I don't want to mess with the vdi.
Sure, I've heard that you get an additional 5-10-15 HP with the S5 vdi, but is that with it still functional? Or can you get away with it wired open?
The S4 manifold eliminates that uncertainty. lol.

Can you please tell us who this person is so that I can take a baseball bat to his head...


-Ted

Maybe they were talking about a turbo?
Maybe I heard wrong.
Anyway I'm going to see if it can be done. :)

Classic. Rebuild has come to a fork in the road.

I just tore down the bridge ported S4 engine.

The front iron of the bridge ported motor has a coolant-seal-tract to coolant-passageway break / rust through.

What should I do about this?

As far as staying with the bridge port way, I'm thinking either,
A: block up that coolant passageway and just run with it that way, or,
B: take the other stock front plate I have and bridge port it the same as the other plate.

But I'm thinking of totally reconsidering the entire build. Maybe go a different way. I have my reasons.

What other way are you referring to? P-port or a simple street port?

Well I've decided what I'm going to do, and its not going to be bridge ported.
So that kinda defeats the title of this thread.

But I will post up a little more of what I found with the original S5 motor, as a kinda proof of a build to judge upon.

The end irons.
It looks like they were ported mostly outward. The aux ports look a little different from each other.

http://i184.photobucket.com/albums/x...DSC_0012-3.jpg

The plastic is a crappy template I made a few years ago to resemble stock ports.
You can see the difference.
http://i184.photobucket.com/albums/x...DSC_0016-1.jpg

http://i184.photobucket.com/albums/x...DSC_0010-5.jpg
http://i184.photobucket.com/albums/x...DSC_0019-1.jpg

I found a very slight wear on the ends of the side seals. And found very slight wear on the top edges of the ports. Maybe that porting caused this?

Anyway, I'm going to slightly bevel those ports.

I also found spots on the rotor that were really clean, instead of having the oil and carbon residue. These spots are on the sides and on the faces of each rotor.
Kinda find that weird.

BTW: This motor only has 55k miles on it since its first rebuild.

Nice conservative porting, I like. I am guessing that you have figured out how far you can go out without losing a side seal.

What do you intend to do with the intake manifold? I think you will find your biggest power gains from modifying the manifold. I don't know if you intend to keep the stock ECU or not.

Do you have a dyno curve from the HBP?

EDIT; By the way, my bone stock 6-port in complete stock trim (146 Hp) would squack the tires going into second. The tire squacking is mostly due to engine inertia, not power.

The 4-port will light the tires up from standing on the gas (between 2,500 and 4,500 RPM in first gear) while traveling in a straight line on dry pavement. It is making about 200 WHp. I have 245/40/R17s on it. A 6-port will probably never do that because it can't make the torque (Ports close way too late). You will probably have more high end than I have though (less torque X higher RPM = same horsepower).

I didn't port those ports.
Not yet anyway.

Imo, the lower ports look fine, but the aux ports are uneven, a little shloppy.

I looks like the corner seals might be about 1/3rd supported.


The bridge port motor.
I'm thinking I'm not just going to forget that motor.
I have a plan to sometime, put it back together, reusing the o-rings and other seals, and block off that one coolant passageway, then do an engine swap, maybe for just a few weeks, run it, take it for a mtn run, and get it dynoed, then swap the good motor back in.
Cause I still like that motor.


But for now, Im going with this street port motor.

:hurray:waiting for the finish ,great start!!!

Ok this is a classic question but, when I was cleaning the rotors, I lost track of which was the front and which was the rear rotor.
They are S4 n/a rotors.
So does it matter?
Is there anyway to tell which is the front and rear?
What should I do?

Usually I'm pretty careful to keep track of them, but not this time, oops.

It dosnt really matter. Just look at the letters on the rotor, as long as they are within one letter of eachother, up or down, then your good. And if these are the original rotors you were already using. Your good to go.

like he said, front and rear and interchangable. carry on.

Cool, thats what I thought too, thanks.

Here's one for ya...
When I was going through the rotors, I decided to use some of the comp. seals from the S5 rotors, cause they had less mileage on them. I used the side seals and corner seals.
The question is, does it matter if I lost track of the exact place that each seal went on the rotor?
Imo, this used to be a big no-no. And I did used to keep track of them in previous builds.
This time I purposely lost track of where they go, I found it easier to just take em off and put em on.
Imo, it might matter in the case of the side seals and corner seals, since the side seals have been trimmed to fit.
So in my case, when I put it back together, I guess will it be a "best clearance" issue with each side to corner seal.

What do you think about this?

i usually draw diagrams of each rotor when i disassemble an engine. it helps me keep track of things: front, rear and the positions of all the seal. then i put the seals in place on the drawing, clean them one at a time and replace them to the drawing.

that said, at the end of the day, clearances are what matter, so if they're all mixed up, there's nothing you can do about it now but to sit and measure everything, then keep track of it all until assembly. at least that's what i'd do.

Actually, on high mileage engines, the triangle-shaped part of the apex seal will wear into the rotor. I had good success with switching rotors, as that allowed the triangle an un-worn part of the groove to seal in.

I don't know if that was better or worse, but it worked.

Make sure that you get the three piece seals in correctly. The triangle piece should always touch the rear plate for the rotor (towards the back of the engine). The reason that I am telling you this is that I wore a housing out prematurely (significant wear in 350 miles) using a backwards-installed 3-piece seal. It doesn't matter with the 2-piece seals.

As said before, as long as the seal fit in the groove within the tolerance, you should be Ok.

You can sometimes tell on subtle wear on the rotor gear and apex seal groove area.
The rotor spins only one way, so those areas wear a certain way.

If you never brushed off the carbon, it's more obvious from the carbon patches.
This is true of the side seal area by the tips, cause of reversion going in and out of the intake ports.


-Ted

Everything's fairly clean and ready to go back together.

http://i184.photobucket.com/albums/x...DSC_0003-3.jpg

So I want to go with the S4 manifolds.
I took em apart and cleaned them this afternoon.
This is what I found inside.

http://i184.photobucket.com/albums/x...DSC_0004-1.jpg

http://i184.photobucket.com/albums/x...DSC_0007-1.jpg

http://i184.photobucket.com/albums/x...DSC_0009-2.jpg

This is a manifold that was in my gray rx7, I only drove it around for 10 miles.
The car had been sitting in a junk yard for 3 years before I got it.

It freaks me out that I dove it with the manifolds in that condition.

to get all of that stuff out go and get some gasket remover form advance it comes in a spray can make sure you wear some gloves using it shit burns like hell but takes all that carbon out of there.

So after weeks of not touching the engine because of Christmas vaca and then a week of being sick, I finally got back to it this week.

Engine is all back together and actually sitting in the engine bay.

Whats next is a whole bunch of little things I've got to get together.

Not much pictures taken yet. Seems Im more concerned with it going back together around this time of the rebuild process. But ill try to get some.

So the engine is all back together with manifolds and such. Just need to charge the battery.
It should be running by the end of today.
Some pix of some things I did coming soon.

Alright. Some pictures.

Engine bay as it is for now.
http://i184.photobucket.com/albums/x...DSC_0001-2.jpg
Old Miata batt on the charger.
In front of that, power steering lines simply joined together.
Around the same area, Oil temp cable loosely in engine bay.
Near fire wall, a clear hose going from the BAC valve to the intake pipe. (Might redo that sometime.)
Next to the air filter, the S5 OMP set aside but still hooked up to its wires so it don't throw a code. Using a S4 OMP instead.

Secondary throttle plates removed.
http://i184.photobucket.com/albums/x...DSC_0004-2.jpg

The new oil filter pedestal I won at DGRR'09.
http://i184.photobucket.com/albums/x...DSC_0005-2.jpg

Oil temp cable and where it leads to.
http://i184.photobucket.com/albums/x...DSC_0008-4.jpg

Gauges I bought from advanced auto parts years ago, with light switch.
http://i184.photobucket.com/albums/x...DSC_0010-7.jpg

So its basically an S4 na engine with street ported S5 end irons and S5 throttle body in a S5 RX7.

Nothing really special in the motor, just FD corner seal springs, and the apex seals are RA classics. That besides the porting in which I added chamfer edges to all the ports.

It Lives!!
Got it running around noon.

I have a few bugs to work out.
Like the oil pressure line leaks at both ends.
A coolant hose on the TB was leaking, its now fixed.
I redid the clear hose for the BAC with better hoses.

I installed a new lawn mower battery.

I need to run wires for the volt gauge.
Need to install the charger/cigarette lighter.
Need to relocate & install air/fuel ratio gauge.
And the list goes on.

Fixed.
Done.
& Done.