Tired of cracked pipes and leaking exhaust manifolds?

Andre Eriksen

I had an R4 pipe that cracked within minutes of use (despite everything was spring mounted) and I got it TIG welded. Shortly thereafter it cracked just next to the repair weld.

On top I find that the O-rings on the manifold wear out in no time and there is black oil running down the motor as well as exhaust gas/pressure is leaking out.

So I made a new manifold out of an old Rotax exhaust manifold and used an old Rotax exhaust pipe to modify the pipe.

I will be making a number of manifolds from grounds up on a CNC machine. In the rules it is stated that the manifold is open and that you cannot change the length of the exhaust (which I didn't do). I actually think that you can just heat up the R4 pipe and use the manifold to form the the crown.

I do not run SKUSA but I will try to get this legalized in the Molecule Karting Series as this is a much more reliable, cheaper and proven design.

_________________
2012 Formula Car Challenge Vice Champion (Pro Formula Mazda)
2011 Rotax DD2 Masters National Points Champion
2011 NorCal DD2 Masters Vice Champion
2010 NorCal Rotax Masters Champion
www.viking-racing.com
http://www.facebook.com/VikingRacing

Chris Hegar · Posted: Tue Jan 15, 2013 11:19 am Post subject:

I'd like to see your pipe mounts.
_________________
www.Hegar4.com

Jeff DeMello · Posted: Tue Jan 15, 2013 11:27 am Post subject:

Andre Eriksen · Posted: Tue Jan 15, 2013 12:35 pm Post subject:

The mounts are the standard hegar mounts I beliveve. Both mounted on the engine with a rubber mounted crate holding the pipe/muffler. Pipe mounted with springs muffler mounted with hose clamps.
_________________
2012 Formula Car Challenge Vice Champion (Pro Formula Mazda)
2011 Rotax DD2 Masters National Points Champion
2011 NorCal DD2 Masters Vice Champion
2010 NorCal Rotax Masters Champion
www.viking-racing.com
http://www.facebook.com/VikingRacing

Chris Hegar · Posted: Tue Jan 15, 2013 1:00 pm Post subject:

Again I'd like to see a pic if possible. What motor/cylinder is that, 01? Breaking in one run is a new one to most of us. I will also add that I rarely sell the 01 setup, it takes a different rear mount height than the 99. It is very important to make it perfect.
_________________
www.Hegar4.com

Andre Eriksen · Posted: Tue Jan 15, 2013 1:23 pm Post subject:

I will post some pics tonight or tomorrow but you will not learn anything from that:

1. As already stated it is a 100% standard setup.

2. It has only been run on a '99 setup (the one on the picture is a 01 that I just built and it has never even been fired yet. With this setup it fits just fine.

3. I have two R4 pipes. In the SAME setup one pipe was cracking but the other one ran for an entire season without problems. IOW it is a pipe issue and not a mount issue.

4. The O-rings on the manifold are still wearing out and the pipes are still leaking.
_________________
2012 Formula Car Challenge Vice Champion (Pro Formula Mazda)
2011 Rotax DD2 Masters National Points Champion
2011 NorCal DD2 Masters Vice Champion
2010 NorCal Rotax Masters Champion
www.viking-racing.com
http://www.facebook.com/VikingRacing

Chris Hegar · Posted: Tue Jan 15, 2013 3:05 pm Post subject:

Hmm strange.

In our experience all headers are gonna leak some with little to no real HP loss but that's just an observation. I doubt any body is gonna allow the mod you have made to the R4 and let it pass tech. They get all over a guy for polishing it let alone anything like you have done.

I'd go talk to RLV, they're pretty good with customer service.
_________________
www.Hegar4.com

joseph hollinger · Posted: Tue Jan 15, 2013 3:13 pm Post subject:

Plus it looks like RLV will be coming out with a new R4 anyway.
_________________
A lie gets halfway around the world before the truth has a chance to get its pants on. -- Winston Churchill.

Andre Eriksen · Posted: Tue Jan 15, 2013 4:12 pm Post subject:

My Rotax never leaked oil all over the engine from the manifold. Whether it means lost HP or not it is still annoying.

You are right SKUSA will probably not allow and I do not care since I do not run there... If the local series will allow it still to be seen. To me it is still better because I can have a practice engine with this solution, O-ringed head etc. that is ultra reliable that I can just throw hours on so I am happy about my mods no matter what.

I know a new R4 is coming out - to my knowledge it is the same poor manifold/header design.
_________________
2012 Formula Car Challenge Vice Champion (Pro Formula Mazda)
2011 Rotax DD2 Masters National Points Champion
2011 NorCal DD2 Masters Vice Champion
2010 NorCal Rotax Masters Champion
www.viking-racing.com
http://www.facebook.com/VikingRacing

Mike Goebel · Posted: Tue Jan 15, 2013 6:18 pm Post subject:

I think that what you have is definitely going in the right direction. Let us know after 10 - 20 hours of durability testing how it works out. There is another possibility that the cracking could be just from heat stress cycling and also contributing to the cracking could be stretching of the material in that section a bit too much.

Mike G.
_________________
Closet KZ Lover!!!
mfg Technology Centre
So Cal’s #1 Non Profit Engine Builder

Andre Eriksen · Posted: Tue Jan 15, 2013 6:23 pm Post subject:

Agree on all points. I will let you know after a lot of testing.
_________________
2012 Formula Car Challenge Vice Champion (Pro Formula Mazda)
2011 Rotax DD2 Masters National Points Champion
2011 NorCal DD2 Masters Vice Champion
2010 NorCal Rotax Masters Champion
www.viking-racing.com
http://www.facebook.com/VikingRacing

Jason Berry · Advertiser Joined: 29 Dec 2001 Posts: 298

Andre

You are addressing a very common problem that is currently known among the stock honda drivers.

We have been told that the O-ring manifolds are the cause of the cracked pipes. Customers switched to OEM manifolds with same results.

RLV is very aware of this issue and they have been diligently testing a new pipe to eliminate premature cracking.

They ran the new pipes at Lancaster and have been testing in the off season.

The new pipe seems to be the right fix.

Only sharing if you want to choose your projects to tackle.

Rotax design, not a bad idea at all.
_________________
916 687 3980
www.shopswedetech.com
www.swedetechracing.com
www.swedetechracing.com/news-events-blog/
www.facebook.com/Swedetech

Larry Andrews · Posted: Tue Jan 15, 2013 7:47 pm Post subject:

<blushing>

http://www.ekartingnews.com/viewtopic.php?t=105841&postdays=0&postorder=asc&highlight=manifold&start=50

<shrug> Mad MSPaint skillzzz, yo!

joseph hollinger · Posted: Tue Jan 15, 2013 8:16 pm Post subject:

Andre Eriksen · Posted: Tue Jan 15, 2013 10:05 pm Post subject:

Thanks Jason,

I cracked one pipe, had it repaired, cracked again - put it on the shelf bought a new one and has not seen any issue with that for a full season.

To me the leaking oil thing is almost the worst. I like to have my stuff clean and I hate having to spend an hour cleaning the engine or install new O-rings constantly.

If they have fixed that I will switch - if they have not I will stick to my "own" design and I am convinced it will work both in terms of reliability as well as getting a proper seal.
_________________
2012 Formula Car Challenge Vice Champion (Pro Formula Mazda)
2011 Rotax DD2 Masters National Points Champion
2011 NorCal DD2 Masters Vice Champion
2010 NorCal Rotax Masters Champion
www.viking-racing.com
http://www.facebook.com/VikingRacing