Project 1977 F100 - New radiator + electric fan!

[bobo333]

Hi guys

try running the heater hoses to the LPG system and put the thermostat back in, then you will have the best of both worlds and a control valve on the LPG system

The heater hoses are already running though the LPG system but for some reason there wasnt enough flow with the thermostat closed which caused the vaporizer to freeze up. After doing some more research im starting to think that it may have just been a coincidence and the actual cause of the freezing was a vapor lock from when i replaced the coolant.

I am going to try putting the thermostat back in and being more careful to fill the coolant right up and bleed all of the air out. If that doesn't work then i will re run the heater hoses through the gas system and see how it goes.

After reading through these posts, one thing is clear. You definitely need to fix the suspension, alignment, brakes and tires. This is where you'll currently see the most gains. Perhaps invest in some lower springs that can also help carry a load.

All of those things are on my to do list, unfortunately funds are short currently so they will only get done as i can afford them

Over the last couple of days i have been tidying up the dash wiring, after adding bits and bobs along the way it was getting a bit messy, ive also added in more factory style connectors to make servicing easier and provisions for more accessories later on

Thanks for looking

[RCB]

Have you considered raising compression? My 66 F100 got right at 20mpg with the 4spd/granny. Mostly this is due to compression. Probably the easier would be decking the head, but I've never dealt with a dual fuel system and not sure about compression and LPG.

Another thought is if you can run a smaller alternator. Not sure what it's running currently, but something smaller might create a bit less pull.


And while I think your bed cover came out great, have you considered the same shape, but removing the tailgate and bring the slope to the bottom of the bed? While you would get some drag from the bed sides, it will reduce dead air behind it. If you make it a hatch, your bed is still accessible. However, if you need all of your bed capacity, then it wouldn't be very helpful.

Something else that can also help, but not sure it's application for LPG is installing an oxygen sensor and gauge. On a gas motor, it will give you an idea of how rich or lean you are running... on an LPG engine... no idea.

Don't know if any of that is helpful, but thought I'd offer it up.

[Beau]

Someone on this forum used a small oil or transmission cooler and ran water through it as a source of heat for his WAI. Perhaps something like this adjacent to/boxed around your LPG system might help.

[ron]

I think the vapor lock Or low fill in the radiator makes the most since to me, and I think the heater should have priority (first heat available) and a small flow all the time back to the radiator.Please correct me if Im incorrect

[oil pan 4]

Propane has an octane of over 100.

[320touring]

Originally Posted by bobo333

Hi guys

The heater hoses are already running though the LPG system but for some reason there wasnt enough flow with the thermostat closed which caused the vaporizer to freeze up. After doing some more research im starting to think that it may have just been a coincidence and the actual cause of the freezing was a vapor lock from when i replaced the coolant.

I am going to try putting the thermostat back in and being more careful to fill the coolant right up and bleed all of the air out. If that doesn't work then i will re run the heater hoses through the gas system and see how it goes.

Out of interest, where do the coolant hoses to the vapourisor come from? on my 328, they a t-eed off from the heater inlet and outlet.

this means that when the thermostat is shut they're on the loop that the coolant is pumped round (i.e. the engine side of the coolant circuit)

jsut a thought as the closed thermostat= frozen LPG makes me think the coolant supply to the vapourisor is coming from the Radiator siide of the thermostat (i.e. only works when thermostat open?)

[bobo333]

Hi guys,

After much reading and researching and looking and checking i think it may have just been a coincidence that it froze up after i put the thermostat in and it was actually caused by a vapor lock from when i replaced the coolant, doesn't explain why there wasn't one in there in the first place though. On that note im gonna try putting it back in and carefully bleeding the coolant to make sure there are no air bubbles.

In other news i pulled the dash facia off the other day to give the wiring a quick tidy up as it had gotten messy from adding in the speakers, amp, thermofans and other bits and bobs... i got a lil carried away though and ended up with the whole loom out again but its much tidier now and everything is almost where it should be:


The wires hanging out on the left are for the HU, wiper switch and heater switch, just need to extend the wiper and heater wires and add a factory style plug in before i tape it all up nice and neat.
Then in the middle (the white plug) is the loom for the guage cluster, all finished, 1 plug to get everything in/out.
On the right is the wiring for the headlights and thermos (the bundle with the green wires in it) same again a factory style plug will be added to the end then all taped up to make servicing the switch panel nice and easy.
Above that are the factory green/white plugs that have all of the wires coming in from the engine bay, and next to them (just out of the pic) is another factory style plug i added to bring in the thermofan wires, the LPG system wires and a couple of spares (spotties?) from the engine bay... and this is where we cross over to the other side of the firewall:


The LPG wiring used to go over the top of the engine then through a hole in the firewall but i wanted all of the wiring running long the same place so i redid it, this loom now contains the LPG wires, the tacho signal, the thermofan signals and 2 spares.

All taped up and run to the appropriate places:


Now all of the wiring comes though the firewall in the same place and i just have 3 plugs to disconnect the engine bay side from the dash side.

Have you considered raising compression? My 66 F100 got right at 20mpg with the 4spd/granny. Mostly this is due to compression. Probably the easier would be decking the head, but I've never dealt with a dual fuel system and not sure about compression and LPG.

Another thought is if you can run a smaller alternator. Not sure what it's running currently, but something smaller might create a bit less pull.

20mpg :O thats amazing! is that with hypermiling? and not on the highway im guessing?
rebuilding the heads is on the cards eventually, i wanna put in hardened valves/seats to help with wear from the LPG so raising the compression might be a goer then too.

it currently has an old school generator still so replacement with an alt will happen soon, it wont be small though as i will be using this as a demo truck for my car audio business, i will have a switch on the alt though so it only charges the 2 big deep cycle batteries i have when it needs to.

I need all of my bed for lugging around MDF so the lower bed cover wont work for me.

I think the vapor lock Or low fill in the radiator makes the most since to me, and I think the heater should have priority (first heat available) and a small flow all the time back to the radiator.Please correct me if Im incorrect

Yeah thats what im thinking too, im going to try putting the thermostat back in today and bleed it properly to make sure there are no air bubbles

Wow epic long post... Thanks for lookin

[ron]

double check the web but I think a 77 has hardened valves already,unless you still had leaded fuel back then in Australia

[bobo333]

Yeah we didnt go off leaded until the mid 80s im pretty sure

[ron]

ford started to convert to hardened seats in 73-4 over here we went to unleaded about 82 . was your rig built in the states.