TMX O360 and Vans FWF kit

drill_and_buck · #1 11-16-2006, 07:59 PM

I am installing a TMX O360 CS on my RV-8 and using Vans FWF kit. I was connecting the fuel system this evening and was disappointed to find out that I could not make the connection between the gascolator and the engine driven fuel pump.

The plans call for installing KBO45 fitting, which is a 45 degree fitting, on the right side of the fuel pump. The problem is that you can not screw in the 45 degree fitting. It hits the case where the prop governor gets installed.

My plans are to return the fitting and the VA-129 fuel line and use a straight fitting and order a fuel line with a 45 degree end. I have to believe that there are a lot of other O360s being installed. I am not sure why Vans includes these in the kit if people end up returning them. If you are planning to install a O360 CS, save yourself the aggravation and delete the above two items from your FWF kit.

Anyone else install a O360 CS and run into this? If so, what was your solution?

-Mke
RV-8
Finish

Davepar · #2 11-17-2006, 10:02 AM

Unfortunately, a common problem. I installed a 90 degree fitting in the pump. The fuel line from the firewall to the engine driven pump (fuel injection--no gascolator) then ended up being too long. I'm paying $50 to get it cut down. Actually more than that because one of the ends was screwed up by Vans (or whoever makes their hoses) and couldn't be re-used.

Using a 90 degree fitting in the pump will probably be cheaper than a 90 degree hose end. Those things are expensive.

Dave

mburch · #3 11-17-2006, 10:20 AM

Hope I'm not hijacking the thread too bad, but I swear it's germane to the discussion of firewall forward issues with the TMX IO-360.

Dave - How did you end up making out with your throttle quadrant? Is it worth it in the end? I just ordered my engine (same basic M1B setup as yours) and I'm wondering which way to go.

thanks,
mcb

drill_and_buck · #4 11-17-2006, 11:05 AM

Dave:

Great idea.

Glad to hear that the 90 degree fitting fits. Yes, that is a lot less expensive than a 45 or 90 degree hose fitting.

Thanks!

-Mike

Davepar · #5 11-17-2006, 11:16 AM

Don't ask me if it's worth it yet. So far I've only been able to make airplane sounds with it. Maybe once I'm flying it'll seem worth it. Of course, I'd probably be flying by now if I skipped it.

It is working well now. One of the levers is a bit stiff, but that's only because one of the dust boots is a bit tight. With some lube on there, it works well and will hopefully break in over time.

The additional complications with the throttle quadrant that I found:

1. Custom cables required. If needed, I can provide the lengths I used. The cables from Vans are the only ones I found that will work with their engine mount points, unless you want to spend hundreds at Spruce and wait a few months. The primary drawback to the Vans cables are that they are too fat to work with the non-aluminum firewall eyeballs. Also, the Vans custom cables say "not for use in aircraft." Comforting. They try to cover this up with their part number tag, but the wording was still visible on one of mine.

2. Difficult cable angle. The quadrant wants the cables to enter at about 2:00 looking from the side. However, the cables actually enter at 3:00. The cables have a swivel end, but not enough to make up the difference. You have to kind of mount the cables high and angle them in. Also, altered or special clevis ends (see Bill Repucci's site) are needed. Standard clevis ends will hit the lever arm.

3. Throw adjustment. With knobs, you don't need to worry too much about throw. As long as the mixture/throttle/prop arm moves from stop to stop, you're good. With the quadrant, it looks kind of goofy if the levers don't all hit the bottom or top of the arc. This involves drilling new holes in the lever arms to tweak the throw.

4. Lever arms close together. Even if you don't care about the lever arm throw, the clevis pins will interfere with each other using the stock mount location in the arms. The arms are just too close together.

5. Bulkhead mount point. Mounting the quadrant was fairly simple, but figuring out how to make a bulkhead for the cable bulkhead nuts was tricky. In retrospect, I wish I would have spaced them further apart.

Ok. Now we've really hijacked this thread.

frankh · #6 11-17-2006, 11:52 AM

Remember your local hydraulics shoppe!

I had them shorten an Aeroquip hose by lopping off the end, shortening the firesleeve and crimping a new fitting on the end which they keep in stock.

Total cost about $8 I think.

They can also make new hoses but they probably won't have any firesleeve...WAAY cheaper than so called proper airplane hoses and they look exactly the same and have the same or better temp/pressure ratings.

Very useful place and they love a challenge.

Frank

mahlon_r · #7 11-17-2006, 01:05 PM

Could you remove the prop gov drive assembly, from the accessory housing and install the fuel pump fitting in the fuel pump and then reinstall the prop gov drive on the engine?
There is nothing different there, as compared to an engine from Lycoming, so I would think the problem is universal to any 360 engine with a prop gov drive on it, regardless of the source.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."

rgbewley · #8 11-17-2006, 01:20 PM

Be careful about putting a 90 degree fitting on your fuel pump. The fuel will aspirate on the sharp 90 degree curve and could result in insufficient fuel flow. Better to put in a straight fitting with a sweep, although more expensive (probably about $40.)

Captain Avgas · #9 11-17-2006, 01:46 PM

Quote:

Originally Posted by frankh

Remember your local hydraulics shoppe!
They can also make new hoses but they probably won't have any firesleeve...WAAY cheaper than so called proper airplane hoses and they look exactly the same and have the same or better temp/pressure ratings.
Frank

The problem is they "look" the same...but they're probably not. You're most likely getting hose fittings produced in China without any QA control.

There's absolutely no redundancy on fuel lines FWF. One strike and you're out. It's one of the places on the plane where aviation quality components are a very good investment.

And coming down suddenly might not be the worst scenario....there's always the prospect of a fuel fed fire to contemplate.

Incidentally, many builders believe that swaged end fittings are the best. However this is a misconception....Aviaquip reuseable hose fittings are in fact more reliable than swaged fittings.

In short, it's the Experimental Category.... but I wouldn't be too experimental with fuel lines.

Davepar · #10 11-17-2006, 02:20 PM

I know next to nothing about fuel hoses, so went conservative with a reputable local aviation shop for the modifications.

That's an interesting point about the 90 degree fittings before the pump. I think you mean vaporize, not aspirate. However, there are at least a few other 90 fittings in the fuel line before the pump on the standard setup from Van's, although all aft of the firewall. I could wrap it in firesleeve as added insurance.