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fuel pump and tires

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69tr

Jedi Trainee
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I posted a question about my fuel pump a few days ago. The car is running fine now so I guess I will leave well enough alone.

I am going to get an electric fuel pump to carry as a spare. I need to know what the fuel pressure is on the stock pump so that I can get the right electric pump.

Does anyone know what the tire diameter of the original tires on the '69 TR6? I would like to get as close to the original size as possible.

I hope to get the car on the road in a few weeks.

Thanks again, Pete
 
Pete,

I'm not one of the wrenches here at BCF but I have
a 1969 TR6 and I stayed at a Holliday Inn last night.

I think the original tires were R15/185
I think the fuel pressure is around 3 psi

I installed an emergency electric fuel pump that is
hard wired with an on/off switch. I carry two lengths
of precut fuel hose so I can make a quick change over
on the side of the road and get home.

I also carry two additional mechanical pumps, should
they be required to get me home. Soon, I will have a third.

I also have unfused emergency driving lights connected to the battery
I also have three backup hood release devices.

backupsystems.jpg
 
Dale, do I sense a little Felix Unger in there some where?
 
TR6oldtimer said:
Dale, do I sense a little Felix Unger in there some where?
Click to expand...

Nope, Ray- past experience with the Crypt Car.

Remember that up until very recently ,this car averaged 7 miles driving
between breakdowns. A minimum tow for me costs $150. $500 possible.

I built redundancy into those components that I know from experience
are not reliable and tend to fail on a routine basis.

You seen my trunk photos and know what it takes to safely drive this
vehicle!!

d :thumbsup:

repairKit.jpg
 
I, too will be carrying some spare parts and I am trying to fabricate a backup hood release.

I will probably hard wire the electric fuel pump to a switch or run the wire and leave out the fuse. I would hate for the switch to be turned on accidently.

I have the tire size, but I was wondering if anyone knows what the diameter of these tires were. I cannot find the information on any of the tire websites. I want to get as close as possible so the speedometer will be correct.

Thanks again, Pete
 
69tr said:
I will probably hard wire the electric fuel pump to a switch or run the wire and leave out the fuse. I would hate for the switch to be turned on accidently.

I want to get as close as possible so the speedometer will be correct.

Thanks again, Pete
Click to expand...



Pete,

My emergency fuel pump is hard wired and ready to go. The
on/off switch is the black button, directly above the pump
in my photo. I have to push it in for the pump to begin running.
Plus, it makes quite a clatter when running. I'd hear it if it
cranked up by accident.

My speedo is probably only accurate to within 5 miles per hour.
I'm runnng R15/205 tires on my car.

There are several methods for hood latch opener backup.
All are easy to fabricate at home.

best wishes but remember- I ain't a wrench, so my suggestions are
always suspect, at best. :crazyeyes:

dale
 
69tr said:
I want to get as close as possible so the speedometer will be correct.
Click to expand...
In that case, you should be buying tires to match the speedo, rather than the original tires. The speedos weren't matched all that well to the tires even when the cars were new.

There is a calibration number on the face of the speedo, giving cable turns per mile (or per kilometer for a kph speedo). If you multiply that number by 2.5 (the speedo drive ratio for TR2-early TR6) then divide by your rear axle ratio (normally 3.7 carbureted, 3.45 for PI models), it will give you the matching turns per mile (or km) for the tires. So, for example, most US models have a calibration number of 1180 and a rear axle of 3.7; so 1180 * 2.5 / 3.7 = 797 turns per mile.

But of course whether your speedo actually matches it's calibration number is a different question.

I don't have one handy, but the information on the original tires can be found in the owner's manual; in the form of a table giving rpm @ 10 mph in various gears. Find the entry for 4th gear direct (no OD), multiply it by 6 to get rpm @ 60 mph (which is also driveshaft tpm) then divide by the rear axle ratio to get tire tpm.
 
Dale: our local NAPA store is all out of 1/4-28 left-handed, cheese-head screws. Oh, and they need them in SS. Do you mind if they ring you and check your stock?

:smirk:
 
angelfj said:
Dale: our local NAPA store is all out of 1/4-28 left-handed, cheese-head screws. Oh, and they need them in SS. Do you mind if they ring you and check your stock?

:smirk:
Click to expand...

I've converted the car back to Pedro original metric, since you saw it last time.
I have several boxes of screws I removed. I'll check my suply of cheese-heads
and see what I can find!!

If I don't have any, I'll grind a hex head down the middle for ya!

d
 
69tr said:
I am going to get an electric fuel pump to carry as a spare. I need to know what the fuel pressure is on the stock pump so that I can get the right electric pump.
Click to expand...
I didn't see an answer to this in with the tomfoolery ... as I recall, original pressure spec was 2.5 to 3.5 psi, but a "2-4 psi" electric will work fine.

I heartily recommend the little Facet 40105 :
https://www.aircraftspruce.com/catalog/eppages/facetpumps.php

Although they recommend it be mounted near the tank, my experience has been that it will work just fine mounted next to the original pump. And switching over by the side of the road is fairly easy : Tie wrap the Facet to something, then pull the lines off the old pump, run them to the new pump (using your "Kentuckey credit card" as necessary). Now hook up the wires using your emergency "clip leads", getting power from a green wire at the fuse block and ground wherever you can find it. Took me all of 10 minutes when the stock SU (electric) on the Stag crapped out ... the TR3A has never let me down.

Sometimes (not often) you can find used Facets on eBay for about 1/2 the AS price. I've bought several that way and never found a bad one ... knock on wood. Look for the ones that say they are for VW bugs, as the bug also used the low pressure version.

PS, unlike the SU (and others), the Facet clicks all the time even when fuel is not flowing. This is perfectly normal although it can be a bit annoying sometimes. For limping home it shouldn't matter, but for a permanent installation (the Stag is still using the Facet), some sort of vibration mount is a Good Idea.
 
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