RV4 fuel line firewall exit ?
 

The firewall is angled down for rudder peddle travel. The fuel line wants to be parrallel with the floor. Does any one have suggestions on how the fuel line exits the firewall ?
I can use a ?Dan Horton? steel tube weldment to pass an aluminum tube or a ?TS Flightlines teflon hose and pot it in with firebarrier 2000. It would be nice to transtion from AL to Flex with a bulkhead fitting at the firewall. The implied resulting angle just seems undesirable.

What's so bad about having the fuel line angle down ever so slightly, I am wondering?

No Worries?
 

Larry,
The angle isn't that big of a deal, bend your aluminum fuel feed line behind the firewall accordingly. Most Jurassic RV4 builders (like me) used a steel firewall through fuel fitting: https://www.ebay.com/i/263367384932?chn=ps
From there to the gascolator and routed via flexible fuel line with aeroquip firesleeve from there to the engine driven fuel pump.

Steve Sampson, builder of one of my favorite RV4's G-IKON blogged his progress with great photos. http://gikonfwf.blogspot.com/
Also, you might get a few ideas here:
https://www.google.com/search?q=RV4+...kHAi9rFC7a-uM:
V/R
Smokey

Larry,

I dealt with this myself. Wanted to keep the fuel line and fitting straight thru the tunnel and firewall. Cut a bushing out of 304 stainless on my lathe, marked a line on top then split it on the bandsaw at the same angle as the firewall to get two thick washers out of it.

Thanks much for the help !
 

Bob's washers are clever. Angling down looks fine after some reflection on pump/mounting. Smokey's link to the RV4 was very informative.....Larry

Bob, that sounds like a Jim Winnings solution. I think of him often. Good work.

Jim certainly influenced me in the direction of fixing things that weren't ideal with simple solutions that usually involved welding or machining. I sure miss him.

no issues.

Very helpful Axle
 

This raises another question:
Does the red cube on the suction side of the engine pump raise the bubble risk for FI systems ?
Similarly, can the selector valve and filter use 90* AN elbows without bubble probability ?

Larry,
I can't specifically answer those questions as I have not tested for those scenarios. What I can say is this:

I have not had any major issues with my installation. I do get different reading for fuel used depending on if I do a long flight or numerous short flights out of one tank. That may be due to the location of the red cube but my theory is that it is due to using my purge vale before startups and circulating fuel through the fuel system (including the red cube). I see approx. .3 gal used every time I do the fuel purging.

Below is the current set up.

I did more or less the same but it was 2 stainless wedges so that the fitting came straight out. I have a mill so it was easy but an enthusiastic person could have got there with a band saw and a file. In the olden days people built Baby Aces with a bench vice, hack saw, some files and if they were high class maybe a drill press. We are all spoiled. Me especially.