IO-360 forward induction throttle linkage

[mburch]

Hi folks,

I have a Mattituck IO-360 (parallel valve) engine with a forward-facing sump, Precision fuel injection, and a Vetterman crossover exhaust. Probably not that unusual of a combination. I was having problems getting enough clearance between the throttle cable and the exhaust pipes, so I came up with a somewhat alternative routing. I re-bent the throttle bracket that's included in the Van's FWF kit and flipped it around on the mounting boss, so the throttle cable is moved about 2" outboard:



This gives plenty of clearance between the cable and the exhaust pipe:



However, it seems to work best with an offset arm and a long bolt plus spacer:



Closeup of the linkage:



This setup seems to work really well - there's enough travel to reach both stops on the fuel servo, and there's a ton of room between the cable and exhaust. I guess my question is, should I be concerned about the somewhat unusual use of an offset throttle arm and a long bolt? I've never seen this arrangement before.

thanks,
mcb

P.S. Please ignore the lack of safety wire, cotter pins, firesleeve, etc... I'm still test fitting.

[hgerhardt]

I had the same problem on my -6. I ended up making a new bracket from 1/8" aluminum Tee extrusion.

[Davepar]

Had the same problem as well. Ended up making up a custom bracket out of some aluminum angle. Borrowed the idea from someone else.

http://www.dualrudder.com/rv7/2006/08/26/1031

After bending the steel bracket from Vans a few times trying to make it fit, I started worrying about it just breaking off.

I also used firesleeve on the cable and a heat shield on the exhaust.

[Larco]

Many of us are using the spacer and long bolt, in some cases it is used on the mixture as well. It works ok but of course it's your decision. Larry

[roadrunner20]

Originally Posted by Davepar

Had the same problem as well. Ended up making up a custom bracket out of some aluminum angle. Borrowed the idea from someone else.

http://www.dualrudder.com/rv7/2006/08/26/1031

After bending the steel bracket from Vans a few times trying to make it fit, I started worrying about it just breaking off.

I also used firesleeve on the cable and a heat shield on the exhaust.

I also had to fabricate a new bracket. Mine was of steel, not sure of the type. Also used the firesleeve and heat shield for exhaust protection.

[mlwynn]

Hi Matt

I have exactly the same engine, FI and exhaust set up and am just starting to work on the linkage. The pictures that came with the AFP injection show rotating the injector 90 degrees so that the throttle and mixture arms come out of the bottom. I have not yet received the cables or brackets so I am not sure how this is all going to play out. Nice pictures. Thanks for posting them. I will keep you posted on how this all comes together. Anyone else rotated the injector?

Michael Wynn
RV 8 Finishing
San Ramon

[Rivethead]

You just did what I did about a month ago.

[mburch]

Originally Posted by mlwynn

I have exactly the same engine, FI and exhaust set up and am just starting to work on the linkage. The pictures that came with the AFP injection show rotating the injector 90 degrees so that the throttle and mixture arms come out of the bottom.

Oh, so on the AFP injector the arms are both on the same side of the servo? On the Bendix (Precision) injector they're on opposite sides. It's hard for me to say how that might work... you might be able to do it if you could find room for both cables to come forward, and you had enough clearance from the cowl...

mcb

[mburch]

Thanks for the feedback, guys. I think I will go with this setup, possibly using a shorter bolt and spacer if I can get the geometry to work out. I will of course firesleeve all the cables and use heatshields where they come close to the pipes.

Man, this firewall forward stuff can be frustrating... I'm also using a center mounted throttle quadrant, which presents its own special challenges. But if I built the canopy, I can probably figure this out too!

thanks again,
mcb

[Bob Brown]

That's almost the exact setup I'm using, except I have a slightly shorter bolt, I used a piece of steel tubing as the spacer instead of aluminum and I faced the spacer on either side with a large washer. Haven't seen any problems, but I'm using a slightly shorter bolt. I thoroughly inspect (and lube) all the control cable connection points every time I have the cowl off for an oil change. At condition inspection, I dissasemble this connection and replace the bolt...cheap insurance. FWIW, I've seen no wear on the bolt.