June 23, 2018, 10:32:04 AM

Author Topic: 8v71 fuel line size  (Read 1375 times)

Offline Kitt

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8v71 fuel line size
« on: November 06, 2013, 06:21:23 PM »
I'm replacing some of the fuel lines in our Model 5 and some I want to make sure they are sized right for the flow required.

What are the fuel line ID sizes supposed to be feeding the primary filter and primary filter to fuel pump?

The lines from the fuel pump to the secondary filter and then to the block are all AN-6 hose with the 1/4" NPT to AN-6 adapters. Those are fairly new and won't replace them if they're big enough - are they?

Thanks for the info - I couldn't find anything in the 71 series book or the Eagle manual I have.
1977 Eagle model 05
8v71, Allison HT740D

Offline luvrbus

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Re: 8v71 fuel line size
« Reply #1 on: November 06, 2013, 07:20:57 PM »
1/2 inch on the suction side to the fuel pump 3/8 out from the pump to the secondary filter and 3/8 to the heads 
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Offline bevans6

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  • 1980 MCI MC-5C
Re: 8v71 fuel line size
« Reply #2 on: November 06, 2013, 07:54:59 PM »
Just a warning when buying hose ends.  You mention AN-6 hose fittings, which are 3/8" as Clifford states.  AN fittings are 37 degree flare.  JIC fittings come in both 37 degree flare and 45 degree flare.  All of the hose fittings on my 8V-71 are 45 degree flare, in fact most of the fuel lines are 45 degree inverse flare fittings.  It completely possible that your bus has been plumbed with AN fittings (I prefer them) but it may also have the 45 degree flare fittings.

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Spicer 8844 4 speed Zen meditation device
Tatamagouche, Nova Scotia

Offline Kitt

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Re: 8v71 fuel line size
« Reply #3 on: November 06, 2013, 08:08:32 PM »
Thank you both - that helps a lot. I'll keep the -6 hoses where they are and use -8 to/from the primary filter.

Brian - I plan on replacing the NPT-to-AN adapters, so I'll make sure they match. Yes, I'm liking the AN fittings too.
1977 Eagle model 05
8v71, Allison HT740D