Engine Control Cables - Try Again

[pvalovich]

I posted this query earlier but failed to get a response. Unfortunately, my understanding of the issue hasn't improved since the original post, so i'm trying again with different wording.

For you -8/-8A folks out there, how did you determine the final location for the firewall engine control cable holes? Vans instructions are really vague - and after my experience strictly following their fuel system instructions (placed the fuel boost pump IAW their fus plans; drilled the fuel line firewall hole IAW their firewall forward plans - and discovered I needed a tight "S" tube bend to get 'em aligned - shoulda caught it before drilling, but life is harder when you're stupid) - I'm hesitant to use their "Typical" measurements shown on drawing 21.

[Rick6a]

Before I received the engine, I made all the penetrations and routed the engine cables per the firewall forward drawings. But then I knew I was going to install an engine ordered thru Van's. The only problem I experienced was the too long FWF kit mixture cable and even Van's was at a loss to explain why a 60" cable was normally included in the FWF kit. I'm told the have since changed the mixture cable length to 55" conforming the the factory RV-8A. Still, 52-1/2" worked much better for me and Van's made an even exchange.....except for my costs for shipping. Of course, none of this means anything to you if you are not going to install an OEM Lycoming.

http://www.vansairforce.com/communit...ad.php?t=21453

[tonyjohnson]

Like pvalovich I am about ready to hang my engine and I am trying to determine the place to penetrate the firewall for my throttle and mixture cables on my 8A. Of course, that issue may be affected by the engine setup you are running.

I will be using a vertical draft Superior O-360 with precision fuel injection on my 8A. I understand that there is an issue with the attachment of the cable to the fuel injection system, unless you have a "special" arrangement that places the lever on the fuel injection on the opposite side of the normal setup. I have the standard precision fuel injection.

If anyone has the same setup that I have and has installed the throttle and mixture cables I would very much appreciate information about where to put the holes in the firewall. Any other information about what cables to use, gottchas etc would also be welcome.

[grover]

I used the locations called out on the dwg. the cables make pretty tight turns fwf (throttle [carb] and mix, no prop) so were I doing it over, I might look at a way to reduce the bend radius (radii?) by moving the holes a little. the controls work fine. just would like to see less stress on the cable assy's.

[westwinds]

I too posted these same questions only for an 8 with a vertical induction carbed 0360 engine about two months ago. I don't recall getting any replies. I don't mean to hijack this thread but i too would be interested in knowing if the drawing locations called out worked ok or would be better if slight adjustments were made. C'mon guys there are a lot of flying 8s &8As out there. Can any of you remember if the factory locations worked good or if a slight adjustment would be helpful. I,m not going to have an engine for a long time but plan to punch the firewall and install the cables in a couple of weeks. Even if you could look at the penetration locations at the next oil change or cowling off it may help some of us. Thanks, Tony

[Ironflight]

I used the FWF drawing locatins for all penetrations on my carbed O-360 installation, and everythgin worked out just fine. (RV-8)

Paul

[robertahegy]

I also used the Van's specified locations for my 0-360 A1A and they were all fine. I did order the engine from Van's, who has Lycoming build them to Van's specifications. Other engine manufacturers do not always have the same configuration as Van's, and that creates some fit problems using Van's parts.

Van's parts will fit when using them on their specific engines and the holes they specify will also work in conjuction with the whole assembly. Using other engines may or may not always work as Van's has no way of knowing how each and every engine manufacturer spec's their engines and they do not produce variations to accomodate these differences. If you stray away from the Van's spec'd engines, you may find yourself reinventing the wheel, so to speak.

Roberta

[Bob Axsom]

There were no recommendations in the RV-6A except to mound things what had to be mounted in specific locations first the work toward the items that were completely location independent. The constraints on the controls were that they mount at a specific location for the pilot; attach to specific points on the engine, governor and airbox at an angle where the full range of motion can be exercised; and penetrate the firewall where the first two requirements can easily be met without interference with the less position flexible items on the firewall. I have a LASAR ignition control box with a fairly large footprint and cabin heat penetration that Van has no way of knowing where I put them so some airplane specific visualization is not a bad idea before blindly drilling holes - always! The firewall is more demanding of individual thought than most areas of the airplanes but if they give you a recommended location that is the best starting point. I often used pieces of coat hanger wire to to simulate tubes and cables to check routing and lengths. My mixture, throttle and carb heat cables penetrate the firewall in the center relieved section and the prop cable penetrates on the upper left side. The excess length is distributed where it provides freedom of motion at the engine end and where it can't be seen behind the panel. I used butterfly clamping a lot in the engine area to contain the routing.

Bob Axsom

[westwinds]

Paul and Roberta, Thanks for the replys. Based on your info i feel fairly safe using Vans plans dimensions called out. Paul. was your engine from Vans or was it a Lyclone. Even so, on a simple vertical induction carbed engine i cannot see the differences in sumps making that big of a difference in carb and controls location. Thanks, Tony

[Ironflight]

My engine was a Mattituck TMX-360 - I have not found any external differences between it and the Lycoming version.

Paul