Can you guys help me figure out this washer/spacer.
It was in my baggie for the "front cover".

Either the oil pump system, or the OMP (which I've removed from system). Or it's just a washer for 1 of the front cover bolts. Looking at the build docs, I can't see a washer needed anywhere.

In the picture, it's the OMP shaft next to the washer.

I had a quick dig through my photos - forgive me as it's been some time since I did mine but the only thing I can think of is the washer for the oil pump shaft. In this pic you can see it with associated nut just below the front pulley:

Attachment 210361


Except this is usually quite thin and wide as you dint it upwards to lock the nut. Yours looks a bit too thick and narrow for that :dunno:

Ya it's not the washer you smash to lock the oil housing nut in.

The oil pressure regulator or the front oil control valve, I don't see any washers on the workshop manual either. It's bugging me, I'm usually pretty good taking things apart and labeling / documenting how it all came apart. I don't have the OMP so I don't know if there is a washer in there or not.

I've read people put washers in there to increase the PSI. I have the RX7 pressure regulator (N3A1-14-230) I'll install. Do I need to do anything to the front oil control valve as-well?

The inside diameter of washer is 0.475inch (12.15mm). Close to the oil shaft and OMP. I've looked at the workshop manual and can't see any reference to a washer in those areas.

On the outside tension bolt that doesn't use an o-ring, is there a plain washer on there from factory? My rebuild kit had extra washers for the tension bolts, so I just put one there. (Without o-ring on ofcourse).

https://cimg3.ibsrv.net/gimg/www.rx8...b71c2b8ea9.png


It's not very clear from the illustrations I have access to, but what is the bit behind part number 19 of the oil pump?

That's the lock ring on the shaft. The picture is deceiving as it looks like a washer though.

Exhaust time.
I have 10 hours on the plane now, and the exhaust is bloody loud. I thought just exiting behind the rear of the plane would of been good enough.
So this has been talked about a long time ago on the airplane forums.

Outer pipe = 321 ss 0.050 thick. Flat plate bent to a 5" tube
Inner pipe = 321 ss 0.036 thick. 2.5" diameter
(I might use 302ss 0.065 since I already have it)

From my understanding, the area of the holes should be double the area of the inner pipe.

Does anyone know what the metal sleeve inside the OEM exhaust header is ?
https://cimg7.ibsrv.net/gimg/www.rx8...6fef88fd44.jpg
https://cimg3.ibsrv.net/gimg/www.rx8...d667015485.jpg
https://cimg4.ibsrv.net/gimg/www.rx8...054236a0f5.jpg
https://cimg5.ibsrv.net/gimg/www.rx8...e4614a3d3c.jpg
https://cimg6.ibsrv.net/gimg/www.rx8...e497ec38f5.jpg

If you’re using T321 then you need 347 wire. If standard stainless then 309 wire. If you’re not using T321 then you need to increase the wall thicknesses to account for the lower high temp yield strength.

Do you know what the inside metal sleeves of the manifold is? It's not Inconel is it?
I can barely weld a rake back together. lol. Have a good local welder here. He has ER347 rods and solar flux type B for the inside.

Have read your detailed post on exhaust headers. I'm a little worried about sticking with the 1.75" OD primaries & 2.5" exhaust now. I know the stock manifolds do a really good job in terms of holding up against the heat. One option is to weld the big 5" tube (Centrifugal Accumulator) to the stock manifold as in the picture above. Other is to cut up a stock header (or racing beat, have both) and switch to 2" primaries. Not sure which one is easier to weld too.

Where did you source your 321 from? To make a tube bigger then 4", the best I've found is to buy flat stock from McMaster-Carr and make my own size. Thinking 0.050 or 0.063 (18ga - 16ga) for the big CA. Haven't found a good source for the rest of the 2.5" though. We have plenty of 304 @ 0.083 which is heavy and thick enough.

I'm hoping by reducing the large shock waves into smaller ones, the energy should of a lot friendly on the rest of the exhaust system.

Sorry, I think it’s just low grade stainless, probably 400 series. I cut the flange off and welded 321 pipes to it using 347 wire. They never broke, but it did crack where those were welded to a 321 collector. They were all 18 Ga. The main issue was I had it to constricted and eventually the expansion/contraction stress took it’s toll. Had to weld up some minor cracks after each race season for the last few years. I don’t think you’ll have that issue, but it comes down to good materials, good fit up, and good purge welding. If you don’t have that skill you’d be better off letting someone who does handle it. I work for a stainless fab company though and one guy can hand weld 20 Ga on par with an orbital weld machine.

it was a race engine manifold, so the largest was 3” OD. I have some 4” OD on the new exhaust system, not cheap.

SPD Exhaust has 5” OD 0.063” wall T304. If you need T321 you might call and ask. Our company has suppliers who can provide short cut pieces, but you can expect to pay more obviously.

I can't help on the manifold front, but super impressed you have 10 flight hours on this build. Too many home builds never leave the hangar. If you're ever in Montreal or Hawkesbury, let me know. Think she can pull a glider? Our L-19s make less power than a renny ;)

TeamRX8, we have a great local welder that does all my work (and other planes). I can't weld worth a poop. I msg SPD Exhaust a few weeks ago, but they don't have anything bigger then 4" in 321. Will end up getting a flat plate from McMaster and roll it to shape. I'm surprised your 18 ga cracked, that is pretty thick stuff! I'm throwing around the idea of welding the middle pipe, and making the two outer pipes slip fit, to help with the expansion/contraction.

Loki, hopefully this summer I'll have the plane home in Ontario. I'm building it in FL during the winters, so it's taken a few years but I'm almost there.

Built the header muffler. Was tricky to get all the pieces cut and fitting, but happy with results. The harsh high pitch ear bleeding noise is gone and I can actually talk to my test pilot, even at full throttle. I'd say the noise is now comparable to a standard aircraft engine. I can actually start to hear the prop noise over top of the engine. I measured back pressure of the big can, and was getting 3.5psi at 7000rpm. I didn't get a before capture, but I put a spectrum analyzer on my phone and was coming up in the low Hz (under 300Hz).

All three primary tubes are 2", double slip joints.
The inside pipe is 2.75" and is welded to the front end cap, while slipped inside the flex bellow on the exit end cap. I'm hoping that will allow enough room/flex for expansion. I finally found a flex bellow in 321ss.

Sorry for the busy looking pictures. We pulled an all nighter welding, so didn't take any pictures along the way.
https://cimg2.ibsrv.net/gimg/www.rx8...ccbc6e835b.jpg
https://cimg6.ibsrv.net/gimg/www.rx8...28b05c93c5.jpg

Phase two will be adding a long pipe underneath the plane which I talked about here.
I temporary put it up in place, and the engine noise pretty much disappeared with the prop taking over all the noise, it was heaven to my ears. But I ran out of time and had to head back to Canada now for a few months.
https://www.rx8club.com/series-i-tec...5/#post4909265

Sorry, I could have told you where to get the bellows. Must have missed your post if it was discussed here.