Mixture Arm Interference with Starter

walkergp · #1 03-21-2016, 07:49 PM

I have installed Van's mixture bellcrank and bracket for an IO-360A1B Horizontal Induction. When I connect to the mixture arm I am unable to get full throw due to interference with starter (see pic). This engine installed in another aircraft was configured with the arm in the down position where there would be no interference. Van's said I either need a shorter starter or modify the arm to avoid the contact. Even if I use the lower hole and cut off the top portion it does not look like I will still get full throw.

Any suggestions?
Thanks,
Greg Walker
RV-8A

airguy · #2 03-22-2016, 08:44 AM

Reroute the cable?

Mike S · #3 03-22-2016, 08:57 AM

Can you turn the injector servo to a different position--------clock it 90* ???

Boyd Birchler · #4 03-22-2016, 07:39 PM

You have an offset arm, it appears that a straight arm would clear.

walkergp · #5 03-22-2016, 09:17 PM

Thanks for the ideas!

airguy - Rerouting the cable could be done from the bottom like the prior installation of this engine. I assume Van's had a reason for routing it above the sump. My exhaust is supposed to be delivered any day so that will give me a better chance to look for alternate routing.

Mike S - Not sure I understand clocking the injector servo?

Boyd - I think a straight arm would clear the starter. Might need a longer bellcrank as it appears the angle would be too oblique for the mechanical advantage. Do anyone have a source for these arms?

Thanks,
Greg

JanRV6UK · #6 03-23-2016, 06:11 AM

Hi,

May I ask what make and model starter you have fitted ?

RV7Guy · #7 03-23-2016, 06:18 AM

Hi Greg,

Just went through this last week. You'll notice the arm attached to the mixture is locked by teeth like a gear. Loosen the nut and move it forward one tooth at a time. I think I moved mine a tooth or two. Check the travel.

I am clear of the starter but only by 1/8," but it is clear and everything is smooth with full travel.

[quote=walkergp;1064119]I have installed Van's mixture bellcrank and bracket for an IO-360A1B Horizontal Induction. When I connect to the mixture arm I am unable to get full throw due to interference with starter (see pic). This engine installed in another aircraft was configured with the arm in the down position where there would be no interference. Van's said I either need a shorter starter or modify the arm to avoid the contact.

Bill Dicus · #8 03-23-2016, 07:26 AM

I did not use the Van's bracket. Flipped the arm down and made a simple bracket of bent steel, attaching by two bolts to a flange on the case of my IO-360M1B. This allowed direct movement with no reversal of action and has worked flawlessly for 50 hours. Will try to post pic. I believe others have done something similar. Good luck and please post your solution. Thanks.

JonJay · #9 03-23-2016, 08:47 AM

Remember, if you flip the arm the opposite way, you reverse the operation.

Toobuilder · #10 03-23-2016, 09:07 AM

Quote:

Originally Posted by JonJay

Remember, if you flip the arm the opposite way, you reverse the operation.

Yes, but when you dump the Rube Goldberg bellcrank, you "unreverse" the action, and it works fine.

I did this change on the -8 and it works great. With Van's focus on simple and light, I never could understand why he added the extra complication of a bellcrank.