Roee Kalinsky's RV-7A Project

Exhaust
Home Up News Specifications

 

Back Up Next

Exhaust

2011.08.18: My exhaust pipes are the standard crossover configuration for the vertical induction IO-360 as supplied in Van's firewall-forward kit.  While bolting these on should have been a quick and simple task, at this stage it seems that very few things are...  The crossover pipes for cylinders 1 and 2 fit perfectly onto the studs, but those for cylinders 3 and 4 did not.  It seemed that the one or both of the flanges on the pipes was ever so slightly rotated relative to the studs on the cylinders.  Long story short... called Van's, who redirected me to Larry Veterman, who actually makes the pipes.  I sent my pipes back to Larry, who found that they fit ok on his jig.  So... either the studs on my engine are a little off, or his jig is, or there is just more slop than tolerance between the two...  In any case, Larry offered a relatively simple solution of adding a ball joint in the riser for cylinder 4 to give the necessary freedom of rotation.  This he did for a very nominal fee that I gladly paid, and indeed it solved my problem.

The exhaust hangers also did not fit well, but that's a known design problem, not a manufacturing issue.  The problem is that with the -A model (i.e. tri-gear), the exhaust cross-brace, if installed as specified, interferes with the nose gear socket.  Larry's instructions also list an alternate method of supporting the exhaust, from the airframe instead of the engine.  But I didn't like that idea because of the relative motion.  So I kept the original plan (support by the engine sump bolts), but just moved the cross-brace a little further forward to clear the gear leg socket.  I also adjusted the tabs on the collars that attach the braces to the pipes.  I adjusted them such that the ends of all the brace tubes can be kept perfectly straight, thereby keeping them intirely in tension, no bending loads.  This should prevent breakage of the tube ends, which has been reported by some RV owners.

The right side pipe comes from clyinders 3 and 4, and also hosts the cabin heat muff:



The left side pipe comes from cylinders 1 and 2.  Also visible here is the ball joint that Larry Vetterman installed for me on the riser for cylinder 4:



Hard to get a good shot of them, but here are the exhaust pipe support braces:




Back Up Next

 

 

Send mail to roee@kalinskyconsulting.com with questions or comments about this web site.
Copyright © 2003 Roee Kalinsky
Last modified: October 30, 2011

Visit my consulting web site at www.kalinskyconsulting.com for your engineering needs.