OK,
Here it goes... I'm doing a JL pipe mod 'How To' to fix the stupid design flaw these crappy headpipe seal are with just a single pipe with a silicone red/orange high temp o-ring that lays in a cut groove are too small and just chaffe themselves in a very short time, then start leaking so bad that our high performance RD run like crap and puke oil all over.
Major issue is the loose fit in order to be able to run a o-ring squished in there when installed.
I even glued the spigot joint with Ultra black and let dry for 2 days, was solid as can be.
Pic #1... it only took about 125 miles on Mikes RD350 to burn out joint and o-ring completely.
This is the byproduct of making power....
(https://photos.imageevent.com/supertune/mikemrd350/large/20191115_164939.jpg)
So my brain went to work and hurt a bit thinking what to do.
Do I cut out the headpipe flange sleeve, bore the flange, then machine a new sleeve a lot closer the the spigot size on the pipe and delete the o-ring?
(way too loose and the pipes wiggle and wear out the o-ring)
Do I just get a new silicone o-ring and glue it up again and then make a tail support back at the silencer up to the frame with a motocross pipe hanger to keep the pipe from dog tail wiggling?
Now wait a minute...let's look at other pipes that don't have this problem.
What do they have different?
Oh, they have a double pipe flange that Gary uses at Spec 2, my old Bassani set has and my custom Steve Turner pipe have...
like this:
(https://photos.imageevent.com/supertune/mikemrd350/large/20191115_172812.jpg)
(https://photos.imageevent.com/supertune/mikemrd350/large/20191115_172912.jpg)
So that will work!
I got a "2 thick wall pipe and measured the tube on the pipe chamber and determined I needed 1.125in length.
Chopped it in a cold wet saw then left it just a bit long to face off to the 1.125 after I bored the id to fit the od of the chamber pipe.
It measured 1.753in. Then put in lathe and I bored it to 1.757 then faced it off to the 1.125 length.
(https://photos.imageevent.com/supertune/mikemrd350/large/20191115_173021.jpg)
(https://photos.imageevent.com/supertune/mikemrd350/large/20191115_181958.jpg)
(https://photos.imageevent.com/supertune/mikemrd350/large/20191115_182015.jpg)
(https://photos.imageevent.com/supertune/mikemrd350/large/20191115_184308.jpg)
(https://photos.imageevent.com/supertune/mikemrd350/large/20191115_185916_001.jpg)
(https://photos.imageevent.com/supertune/mikemrd350/large/20191115_201255.jpg)
(https://photos.imageevent.com/supertune/mikemrd350/large/20191115_201446.jpg)
Then I had to grind off the plating to have clean metal to weld new sleeve on.
(https://photos.imageevent.com/supertune/mikemrd350/large/20191115_182115.jpg)
Now wrapped 6 turns of masking tape so the inner stock tube fit snug to center the flange to the chamber and I'll hold it all together and then tack weld it in place then do a final weld of the new collar tomorrow...
NOTE: DON'T wrap the spigot like I did! Once I tacked the collars on, it was a pain to get the tape out! :busey:
Next time I'll tape the inside of the pipe for much easier removal of the tape...
I'll just paint them with some epoxy black paint when done.
I'll post up the finishing steps as soon as I have it all welded up.
Chuck
(https://photos.imageevent.com/supertune/mikemrd350/large/20191115_202142.jpg)
(https://photos.imageevent.com/supertune/mikemrd350/large/20191115_203825_001.jpg)
(https://photos.imageevent.com/supertune/mikemrd350/large/20191115_203915.jpg)
Awesome work chuck! This is exactly why I'm offering up the manifold upgrade. Much thicker 3/8 flange and machined tolerances with a squished high temp silicone o ring. People paid good money for that pipe only to get a crappy thin flange with a groove cut in it by what looks like a grinder.
You came up with a great solution though.
GRA
Thanks Garrett!
So here it goes...I was in a hurry and forgot that RD350 exhaust stud location spread is smaller...I know that but didn't think about it until I went to put them on today... :bang:
Here's a vid "of why" I did this...
https://imageevent.com/supertune/mikemrd350?p=143&n=1&m=-1&c=3&l=0&w=4&s=0&z=3 (https://imageevent.com/supertune/mikemrd350?p=143&n=1&m=-1&c=3&l=0&w=4&s=0&z=3)
Here the exhaust stud spreads of the 3 RD's.
RD 350 = 62mm
RD 400 = 68mm
U.S RD 400F = 72mm
(https://photos.imageevent.com/supertune/mikemrd350/large/20191116_202320.jpg)
(https://photos.imageevent.com/supertune/mikemrd350/large/20191116_202452.jpg)
(https://photos.imageevent.com/supertune/mikemrd350/large/20191116_202644.jpg)
Welded up the new collar sleeves on the flanges. (note: I didn't push them all the way on yet)
(https://photos.imageevent.com/supertune/mikemrd350/large/20191116_154305.jpg)
(https://photos.imageevent.com/supertune/mikemrd350/large/20191116_154258.jpg)
With semi high heat paint.
(https://photos.imageevent.com/supertune/mikemrd350/large/20191116_172246.jpg)
(https://photos.imageevent.com/supertune/mikemrd350/large/20191116_172259.jpg)
I went to install them and the collar OD is 2" and is too big to get the washers and nuts on them for a 62mm spread of the 350 pattern... :eek:
So in the mill they went...
I cut them .060 on each using about a 5/8 endmill.
(https://photos.imageevent.com/supertune/mikemrd350/large/20191116_191703.jpg)
(https://photos.imageevent.com/supertune/mikemrd350/large/20191116_191730.jpg)
Due to no room for washers and normal 12/13mm nuts, I pulled the studs and replaced them from the 35mm stock ones to the 26mm ones I use for all my racebike builds for flat header pipe flanges.
I also use the special flanged BMW exhaust manifold nuts that use a 10mm head in a 8x1.25 thread size.
(https://photos.imageevent.com/supertune/mikemrd350/large/20191116_190100.jpg)
It was late when I got done and forgot to take a finished pic and will do that tomorrow as Mikes coming to get his Team Scream Racing built and tuned very rowdy RD350 with this HPI ignition.
Chuck
Final pics...
No leaks now.
I was told by my local turbo guy they said the Permatex Ultra gray work better for heat so used it instead of the ultra black as there is no o-rings now.
(https://photos.imageevent.com/supertune/mikemrd350/large/20191117_114326.jpg)
(https://photos.imageevent.com/supertune/mikemrd350/large/20191117_114236.jpg)
Final rip up the street...
https://imageevent.com/supertune/mikemrd350?p=164&n=1&m=-1&c=3&l=0&w=4&s=0&z=3 (https://imageevent.com/supertune/mikemrd350?p=164&n=1&m=-1&c=3&l=0&w=4&s=0&z=3)
Chuck
AWSOME! that bike sounds so good.
I noticed this issue right away with my own build, those seals are crap.
Now, is there any other solutions that dont require welding ? Just curious, cause it would be nice to have this problem fixed before it accours :)
You can buy Garrett's oringed flanges.
http://www.2strokeworld.net/forum/index.php?topic=1191.0
this might be less work, and cleaner. just fyi for you guys.
https://www.belmetric.com/allen-socket-nuts-c-563_578_1505/nskt8x16ss-allen-socket-nut-stainless-p-9432.html
what a great mod!
Quote from: m in sc on January 03, 2020, 01:27:15 PM
this might be less work, and cleaner. just fyi for you guys.
https://www.belmetric.com/allen-socket-nuts-c-563_578_1505/nskt8x16ss-allen-socket-nut-stainless-p-9432.html
Mark that is so cool AND inexpensive! I ordered 15 of them today. Postage was $5 bucks might as well order a bunch, not just a few.
The socket nuts were delivered today - two days after I ordered them. They look great. One thing to note - if your exhaust studs are long, washers or a spacer might be required. I installed a socket nut and it stopped several mm short of holding the flange down. Off the to the hardware store.
Otherwise, they are great and so much easier to install compared to regular hex nuts.
Why not just replace the studs with allen cap head bolts?
Quote from: pdxjim on February 22, 2020, 06:03:46 PM
Why not just replace the studs with allen cap head bolts?
Jim,
All aircooled RD350's and 400's have the top exhaust studs in the cylinders go into a open backside threaded hole and most don't come out from rust and corrosion. So the chances of the studs coming out and leaving good threads is really slim.
I have to drill them out 90% of the time.
If I do get them out...I'll use the new shorter studs.
C
Quote from: SUPERTUNE on February 24, 2020, 10:57:30 AM
Quote from: pdxjim on February 22, 2020, 06:03:46 PM
Why not just replace the studs with allen cap head bolts?
Jim,
All aircooled RD350's and 400's have the top exhaust studs in the cylinders go into a open backside threaded hole and most don't come out from rust and corrosion. So the chances of the studs coming out and leaving good threads is really slim.
I have to drill them out 90% of the time.
If I do get them out...I'll use the new shorter studs.
C
Thx for that Chuck. Been awhile since I messed with aircooled RD cyls. Last few bikes I've done, TDR, KH400, and LC I've had more trouble keeping the studs in than getting them out.
Great work, I knew spacing was different from having to slot flanges sometimes but did not know was that much.
Quote from: Hawaii-Mike on February 22, 2020, 05:32:35 PM
The socket nuts were delivered today - two days after I ordered them..
Are you in Hawaii if so that's impressive.
Yes I'm in Honolulu and I was shocked! Priority should only take 2-3 days however vendors seem to be allergic to mailing things here.
Chuck
This setup does not use an o ring?
Only the base gasket?
I did use a ring gasket on the base with Ultra gray gasket maker and no o-ring just glue into the spigot with the same Ultra gray gasket maker.
Chuck
Eric Heyman pointed me in the right direction with these brass 8mm nuts https://www.ebay.com/itm/BRASS-8MM-1-25-PITCH-11MM-HEAD-X8-INTAKE-EXHAUST-VW-BUG-BUGGY-GHIA-EMPI-43-6051/264156966757?epid=655454971&hash=item3d80fb6f65:g:N2YAAOSwTA9X7~Xv
They worked great on my spec II :)