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Fuel / Oil Line Routing (Carb Engine)

T

tx_jayhawk

Well Known Member
Hi All,

I'm trying to finish up the last few firewall forward connections and am in need of some feedback on the general fuel/oil line routing and how much "slack" to provide between the fixed point and the engine. I am planning to support both the fuel and oil lines at some point mid-span between the firewall and the engine (it seems prudent?). Maybe Mel can offer some input here?

1) Fuel - This is from transducer to mechanical fuel pump. I am going to adel clamp the line to the engine mount at the mid-point.

fuellinehx6.jpg


For reference, this is the other side of the transducer. I used 5052 tubing for the "U", as that should be a little stronger than the 3003 cheapie stuff that vans uses. Also, although it looks like the primer nipple is touching the nutplate, there is actually 0.5" of clearance.

fuelflowss8.jpg


2) Oil - The oil cooler lines are obviously the temporary clear ones until I get the hoses made. Do these lines have sufficient slack? I am planning to support the one from the engine (to lower port of cooler) with an adel clamp on the engine mount

oillinesvm3.jpg


This one just goes from the top of the cooler to the engine (a little hard to see).

oillines2im2.jpg


Thanks
Scott
7A 0-360
 
Comments are in red for each pic.
tx_jayhawk said:
1) Fuel - This is from transducer to mechanical fuel pump. I am going to adel clamp the line to the engine mount at the mid-point.

fuellinehx6.jpg

Looks good to me.
I would consider putting a washer between the Adel clamps securing the primer line to the engine mount tube above the cabin heat muff. The line is passing over another Adel, and could wear through the backside of the cushion and rub on the metal band of the clamp. This would cause a fuel leak in a BAD place...
Additionally, I'd consider some heat-reflective tape or sleeving on the transducer-to-fuel pump line where it passes over the exhaust pipe, for additional insurance against vapor lock and heat damage to the firesleeve.

For reference, this is the other side of the transducer. I used 5052 tubing for the "U", as that should be a little stronger than the 3003 cheapie stuff that vans uses. Also, although it looks like the primer nipple is touching the nutplate, there is actually 0.5" of clearance.

fuelflowss8.jpg

Again, looks good. I see torque stripe on some fittings and hardware - this is a GOOD THING!

2) Oil - The oil cooler lines are obviously the temporary clear ones until I get the hoses made. Do these lines have sufficient slack? I am planning to support the one from the engine (to lower port of cooler) with an adel clamp on the engine mount

oillinesvm3.jpg

Hard for me to tell, but from this angle it might not be a bad idea to add an extra inch or so to the engine-lower port line. A standoff bracket to the cooler flange, and an Adel clamp on the line (just FWD of the SCAT tube lower clamp in the pic) would be a good idea as well IMO.
Same comment about heat-reflective tape for the fuel pump-to-carb line (I do see the heatshield on the pipe).

This one just goes from the top of the cooler to the engine (a little hard to see).

oillines2im2.jpg
Click to expand...
Looks good.
 
no fuel line clamp

I'm not Mel nor do I play him on TV. I'm thinking a clamp on the fuel line is not a good idea because it would restrict the amount of flex the fuel line needs when the engine is running. The carburetor "rotates" away from the gascolator during engine operation causing the fuel line to straighten out.

Steve
 
Thanks all for the feedback. On a somewhat related note, does anyone have a source for a good price on some quality SS oil hoses that can be made to length if I just give them the dimensions?

Or, are most people making them themselves...any input on hose type to order, recommended fittings, and means to pressure test?
 
Thanks Rad.

Next question for the group...what type of hose? Seems there are a half-dozen or so different hose part numbers. I'm guessing I want a SS braided hose of some type for oil, but is there a commonly accepted part number and mfgr?
 
All,

I've been doing research to assess what hose type. I did find a good link that compares the aeroquip to stratoflex part numbers:

http://www.sacskyranch.com/h_cross.htm

As far as aviation hoses, it seems strato 124 / aeroquip 666 (teflon w/ ss braid) is the preferred hose of choice for oil applications, as the teflon hoses supposedly last much longer than rubber. Strato 193 / aeroquip 306 are a lower cost solution for lower pressures (vaccum, manifold, etc.), while strato 111 / aeroquip 303 seem to be a middle of the road solution (cost and performance wise). Van's uses aeroquip 701, which I understand is similar to 666 but has an elastomer as opposed to teflon inner tube.

Question for the group...does anyone know how the different SS teflon "racing" models (like aeroquip 2807) compare to the 666?

Thanks,
Scott 7A
 
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