RV Exhaust History

f-1rocket · #1 04-02-2012, 12:03 PM

Recently, I read a negative comment about Vetterman exhaust systems in the forum that requires a closer look. In hope of a little creditability, let me say that I have been flying for over 50 years to include F-106s, F-4s, F-15s and F-16s. I have been flying Van's aircraft for over 25 years, built the first F-1 Rocket to fly back in 2000, helped build two others, bought/sold and helped build over 15 RVs, and all but one have utilized Vetterman exhaust. I have never experienced a crack or any form of malfunction of these systems.

I think it useful to newer builders to hear about the evolution of the RV exhaust systems. Early on, when I began this journey with Vans aircraft there was only one source of exhaust, built by Allan Tolle. My first RV-4 had the Tolle system and after sending it back the fourth time for welding cracks, I included the prop for balance. The prop was OK, and I discarded the exhaust system as many others had already done. Problem was the only other option at the time was to have a local shop weld up something that would work. I heard through the grapevine that a guy by the name of Larry Vetterman, who was a RV builder, was thinking of marketing exhaust for the RV. I called and ordered a set of his four-pipe system for my O-320, and the result was a system that fit, never cracked and gave me a 100+ RPM increase on the top end. Twenty five sets of Vetterman exhausts later, I can say I have never had to return a set for repair.

Larry Vetterman is an icon in the RV community at the same shoulder-level as Van himself. He provided a product that allowed Vans to grow, and solved one of the major problems facing RV builders many years ago. Most other exhaust system builders today learned their trade from Vetterman.

Bottom line to this diatribe is that it dismays old time RV builders and flyers like me to see or hear negative comments from individuals who have built one aircraft and now have all the answers. Going negative on someone like Larry who have given so much to our sport shows a severe lack of knowledge.

If someone out there has a better idea about mounting brackets for RV exhaust, please step forward. I guarantee the idea will be incorporated in the Vetterman system. From personal experience I know this Vetterman fellow pretty well. No one is more intent on improving the sport of RV flying and making it safer than Larry. Nor short of Van, no one has given more time and effort to advancement of the sport than Larry Vetterman. Jim Cash

DanH · #2 04-02-2012, 12:56 PM

Awww, come on Jim, cut the nonsense. I made the negative comment and stand behind it.....which was very specific to the flattened-and-bent tube mounting system, not the pipes, and certainly not Larry..

Let's not confuse engineering and design with personal goodness, please.

panhandler1956 · #3 04-02-2012, 12:58 PM

I for one completely take for granted things like the vetterman exhaust (it bolted on easy and works great!) - that is testimate to it's design and manufacture.

Thanks for the history lesson! Good stuff!

Sam Buchanan · #4 04-02-2012, 01:25 PM

Quote:

Originally Posted by DanH

Awww, come on Jim, cut the nonsense. I made the negative comment and stand behind it.....which was very specific to the flattened-and-bent tube mounting system, not the pipes, and certainly not Larry..

Let's not confuse engineering and design with personal goodness, please.

While the cowl was off last week for an oil change, I rearranged the exhaust hanger clamps, etc so all the hangers would be straight with no bends needed. I also replaced the steel tubing with solid rod but retained the original rubber hoses as shock mounts. I suspect this mod will work for many years.

I've only had to replace two or three of the flattened/bent tubes over the past 13 years. Yep, they are kinda inelegant but have worked quite well. I always carried a length of 3/8" steel brake line in the plane's kit in case a hangar needed to be fabricated on the road. Never needed it, however.

The hangars have been a source of considerable discussion and modification in the RV community over the years because nobody seems to have found the final solution. But the quality of the exhaust system itself is above reproach and has flown on thousands of RVs.

fixnflyguy · #5 04-02-2012, 01:42 PM

I have the 4 pipe Vettermans on my RV-4, and now have just over 100hrs. on it, so my alternative hangers are still in "testing stage". In lieu of the tube/hose system, I fabricated 3/8" diameter stainless tubes with a 1/4" rod end threaded in each end, and made a Stainless tab bent approximately 45 degrees that is installed on a sump/intake bolt each side of the engine, and a similar tab on the clamp for the pipes near the cowl exit. The system is rigid, yet flexible for engine shake,ect. I dont have anything that is tied to the engine mounts, so the exhaust and hangers move with the engine...Time will tell how they hold up, but they look neat and are fairly simple...

f-1rocket · #6 04-02-2012, 02:15 PM

Hi Dan. Good to hear from you. To complain without suggested solution is not engineer-like to me, and I am an engineer. If you have a better idea that will fit all modes of airframe and engine combination from RV-3 to RV-10, be easy to install and affordable please forward it to Larry Vetterman. That would be of benefit to the whole RV-community, and that is what we should all be about. Right? Jim

F1Boss · #7 04-02-2012, 02:28 PM

Quote:

Originally Posted by DanH

Awww, come on Jim, cut the nonsense. I made the negative comment and stand behind it.....which was very specific to the flattened-and-bent tube mounting system, not the pipes, and certainly not Larry..

Let's not confuse engineering and design with personal goodness, please.

What happened, Dan? Does your system not use the two-donut-rubber dohickey in the hangar system? Std auto stuff - lasts forever; way longer than the formed SS clamps/fuel line/tubing/clamp arrangement.

BTW still need those inlets.

Carry on!
Mark

scsmith · #8 04-02-2012, 02:34 PM

I think a key detail in the mounting system is whether the hanger tubes are attached to the engine mount, airframe, or to the engine itself. I think I recall that Vetterman's installation instructions show both options - to the rear engine sump bolts or to the engine mount.

I have mounted mine, using his sketch and hardware, to the back of the engine at the rear sump bolts. I expect this arrangement to be very durable.

I think if you mount to the engine mount, the hanger tubes, or the adel clamps, will fatigue and fail eventually. If you use solid rods instead of the hanger tubes, I think something in the attachment will still eventually fail.

ccsmith51 · #9 04-02-2012, 02:49 PM

I have a Vetterman exhaust and steel brake line tubes to secure the exhaust to the rear sump bolts. The plane has about 100 hours on it and both have broken at the sump. There is no connection between the exhaust and anything other than the engine.

Is there another material that I can use to make hangars that is more durable?

F1Boss · #10 04-03-2012, 07:57 AM

Quote:

Originally Posted by ccsmith51

I have a Vetterman exhaust and steel brake line tubes to secure the exhaust to the rear sump bolts. The plane has about 100 hours on it and both have broken at the sump. There is no connection between the exhaust and anything other than the engine.

Is there another material that I can use to make hangars that is more durable?

Did the brackets break at the bend where you squashed the tubing & formed it into a bend? I suspect that is Dan's complaint, as it is a fairly obvious weak point. Better to use a formed steel bracket at the pan bolt, and attach a straight length of tubing, or a rubber strap, to the bracket instead of bending the flattened tubing. You can cut a rubber strap out of an old tire, or get one at an auto parts store.

I, too, have danced this dance.

Carry on!
Mark