quote:

Originally posted by ccctimtation:
My nearly new Q-jet is still available. By now you could have had it mounted and running, 300 hour running take off from new engine.

My carb seems to be good it is all the other stuff now...36 year old controls seem to fail...lol

I still may need yours let you know when I can do a road check//

I like your $10 donation idea too!!!

Mine is off a 350 so probably 650 t0 750 cfm, need to check bolt pattern first but I bet it works. It has extra holes (plugged) in the carb body but not set up for anything from or to the carb other than fuel.
Tim

Geez I see from my old pictures someone actually had the choke heat source hooked to a vacuum port, I see Dorman has a replacement kit, but where shall I pick up the heat source??

While thumbing through the service manual, I came across a graph showing oil consumption vrs MPG, to my surprise a gas engine getting 9mpg can use a quart of oil anywhere from 600 to 700 miles, I always thought my consumption was high, but it fits some where in the center of that range.

Ordered the choke heater kit from Dorman, looks like it just straps to the exhaust manifold with a hose clamp. Probably be there about as long as it takes me to install it..oh well!!!!

I am really surprised that I did not see all this before I got into rebuilding the carburetor. I guess the timing advance semi-worked because the check valve was kerplunk even though the PVS did not open, the choke was probably slow to open, but it was hot enough under the dog house to open it sometime. I have yet to see where the timing is set, I have to do it from underneath and use cylinder no.5 or 8??? I guess,,, it is all caked with road grime so it needs to be cleaned before I can read it.

With a working carburetor, adjustments and new components I do hope to see improvements in performance and gas mileage. Should have all my new stuff by weeks end. O'le!!!

If I can get even 0.5 MPG improvement, payback will be fast.

You should have timing marks down low on driver's side.



You can use cylinder 8 (rear pass side) or 5 (3rd from front on driver side) with these marks. good luck.

My Qjet had an electric choke. Here is photo of the disconnected valve and EGR with vacuum lines.



Front left line went to the vacuum advance.

That is the vacuum line port I was going to use glad to see we are on the same page. That timing spot looks similar to mine also.

Because my radiator is mounted as an up and down flow rather than cross flow the PVC is in an entirely different area, mine is on the opposite side of the engine. I am going to use it to take the secondary lock-out off when the engine warms only because I bought a new one, and a new vacuum motor too. If I had been at the stage I am now I would not have sprung the $100 for the new vacuum motor and PVS. I would just eliminate the lock-out.

The parts I am waiting on all pertain to the lock-out and the choke heat, so I could just hook it up like you did and give it a test ride.

Steve you did not by chance save that old engine and transmission did you? What is that extra fuel line you have teed into the carb inlet? I was thinking of running an extra electric fuel pump direct like that to help with the vapor lock.

One final thought, on the way home from Memphis last fall I think the fuel lines and tanks got clear of crap, now with these changes I expect the Nose to be a traveling machine, always jealous of DannyZ able to go anywhere in his Euro.

The choke heat kit has yet to arrive from Rock Auto, and today we got a pretty good snow fall, so I have some time before a road test can be completed, if the parts ever get here.

My old engine went to Mary Ray! She got it installed in her 33 ft tag axle Barth a while ago.

The trans had over 100K miles of hauling my 33ft. It was howling pretty loud. I gave it to the guy who gets me auto parts and machine work done. He did some freebie scrounging for boat engine parts for me and had an old truck that needed a trans.

The extra line teed into the fuel line was for a pressure gauge. There was some controversy about its' safety but it was really valuable figuring out the problems with fuel pumps, filters, tank selector valves, and vapor lock. When I converted to the fuel injection system I plumbed it in with metal line. It remained the most valuable gauge for troubleshooting for that vehicle, since many of the problems I had were fuel delivery related. I used it to tell when I needed to change the element in my big cartridge filters.

If I were you I would install huge filters back at the tank, and an electric pusher pump. I would bypass the mechanical fuel pump entirely. Use a pressure regulator right at the carb with a recirculating fuel system. The pusher pump keeps the fuel under pressure all the way forward. The regulator keep the carb inlet at constant pressure and allows the excess fuel to head back to the tank, maintaining constant flow rather than a dead end fuel line running through the hot engine fuel pump. Also allows any vapor to purge back to the tank. This was essentially what I had just before the change to fuel injection and I never had vapor lock.

Steve I took your advice on the electric fuel pump and filters last summer so I have that already, the fuel pump pressure gage seems like a good Idea, I am still using the mechanical fuel pump in series because it does have a fuel return line. Without the engine running it does have fuel pressure at the carburetor and I suspect but have not proved that fuel is circulating back to the tank through the mechanical fuel return line as long as the ignition is on, not the safest if in an accident I know.

So with all that said I did have vapor lock on my way to Memphis last fall, it was like 100 degrees, and happened when I slowed down to fill up with gas. My debate is: I was going to install a line directly from the electric fuel pump and tee it into the carburetor by-passing the mechanical fuel pump and hot front of the engine, I will put an on and off electric valve in this line and fuel pressure gage on the carburetor side of the valve. So if it started to miss and the fuel pressure got erratic I could flip the switch and get fuel directly from the electric fuel pump while still supplying the mechanical fuel pump and its return line, I think.

I used a fuel pump with about 10 psi output, ran it through an adjustable 3 port pressure regulator set at about 5psi, the excess ran back to the tank.

Holley bypass style regulator:

https://www.holley.com/product...ators/parts/12-803BP

As you suggested I ran the fuel lines away from the exhaust and up to the top back of the engine as far from engine heat as possible.

Steve. you used better quality parts than I, and I think your recirculation system is a better way to go. GM for safety, recommends I use an oil pressure switch that turns the fuel pump on and off, I did not because I was afraid if it did not start or the carburetor filler bowl was empty, there would not be any fuel to start the engine. I guess I could put in a by-pass switch to turn the pump on if I had a problem starting. I am sure I would forget to turn it off during normal run, maybe a momentary switch

I am going to give the system I have one more trial if it does not work I will spring for your better system.

Duane, a number of friends have the setup like yours and include a momentary switch for the electric pump to fill the bowl before starting. Not unlike an RV a boat may not be restarted for a week or more.

Duane, on the Euro I ran my electric fuel pump hot when the key was on, but switched by a red toggle on the dash that lit up when it was on. That way I knew if the pump was running when the engine wasn't, and could switch it off. Crude, but it worked for me.

I too ran a switch for priming the carb after sitting. It really cut down on cranking time waiting for fuel to fill the carb. When primed, it started almost immediately.

The oil pressure switch is recommended because in the event of a crash, rollover, etc it will stop fuel flow after the event. Only problem was the oil pressure switch was normally closed and opened when running. I had the pump connected to the ignition circuit.

I intended to put a switch in like Danny's but never got around to it because I installed the fuel injection system which could sense when the engine was running and took care of that.

Danny, I think your 79 needs a prime pump too. Probably would start quicker.

Geez I thank everyone for the help on this, better safe so now along with the carb rebuild and parts, I am going to install a pressure switch fuel shut off( hope I can find the right off/on set-up) and a switch probably momentary to fill the carb bowl.

We got 6 inches of a "light dusting" so I have some time to order parts, my heater kit for the choke is not here yet either.