Couple of Motor Questions

[Jr_]

Timing Issue,
Turns out there was no timing issue. I thought there might be a problem because it was so hard to start. I have set the valves and timed to the BB for now. Also adjusted the carb to highest steady vacum at 800 rpm.

Now I am working on the carb (Carter). Seems like there is some play in the connection to the accelerator rod that does not let it go full closed. I can jingle the accelerator and it will idle down to 550 real smooth. Looks like the problem is the accelerator rod connector on the carb is loose where it goes into the carb body. Have not had time to study in depth yet. If I get this figured out I am hoping to get my mileage up from 9mpg.

 

[Bill Hanlon]

What

Timing Issue,
Turns out there was no timing issue. I thought there might be a problem because it was so hard to start. I have set the valves and timed to the BB for now. Also adjusted the carb to highest steady vacum at 800 rpm.

Now I am working on the carb (Carter). Seems like there is some play in the connection to the accelerator rod that does not let it go full closed. I can jingle the accelerator and it will idle down to 550 real smooth. Looks like the problem is the accelerator rod connector on the carb is loose where it goes into the carb body. Have not had time to study in depth yet. If I get this figured out I am hoping to get my mileage up from 9mpg.

Once you get all the bugs worked it should idle at about 400-450 RPM. In the winter I set my GMC 228 to idle at 425 RPM like the book says. In the summer I take it up to 450 to make up for the slow down that occurs when the A/C compressor kicks in. Only thing you have to get used to with these low idle speeds is the low oil pressure that goes along with them. I was so freaked out I bought a 4" 270 degree sweep 60 PSI +- 2% pressure gauge because the 60 degree swing on the small stock 60 PSI gauge made it look like I had no oil pressure at all at a hot idle. Turns out I had 8.5 PSI at 425 RPM after a 10 mile run at 65 MPH on a 95 degree day with the A/C on, then coming to an idle waiting for a light to change. Today (temp in the mid 40s) idle pressure was over 20 PSI. GMC manual calls for a minimum of 40 PSI at 2750 RPM and 5 PSI at idle on a new or newly rebuilt engine. Service limits are a minimum of 25 PSI at 2750 RPM and 2 PSI at idle on a worn engine.

 

[Jr_]

Update on Carb, Carter YF on a 54 Chevy 235 Truck Motor with 5,000 miles on rebuild. Carter Carb installed about 400 miles ago.
Initially I had a problem with some slop at the Throttle Shaft Lever Assembly and the accelerator rod connects. I was able to correct that by slightly bending the accelerator rod. (Problem was when let off the accelerator the Throttle Shaft Lever Assembly did not completely close. The accelerator rod would not pull fully closed).
2nd problem was trying to idle the truck down to 400-450 rpm. This turned out to be operator (me) error. The meter I was using was multiply the RPM by 2 and I did not realize this. (Mainly due to not reading the meter instructions). Once I put the Adv Timing light on and realized I was trying to set idle speed to low things got better. Truck now idles at 450 rpm. I adjusted the idle mixture screw to show a steady 22" vacuum. This turned out to be about 1.25 turns from full close.
Now I just need to run a tank of gas and see what kind of mileage I get. Hopefully it will be better than the 9 mpg I was getting at 60 - 65 mph.

 

[Bill Hanlon]

Update on Carb, Carter YF on a 54 Chevy 235 Truck Motor with 5,000 miles on rebuild. Carter Carb installed about 400 miles ago.
Initially I had a problem with some slop at the Throttle Shaft Lever Assembly and the accelerator rod connects. I was able to correct that by slightly bending the accelerator rod. (Problem was when let off the accelerator the Throttle Shaft Lever Assembly did not completely close. The accelerator rod would not pull fully closed).
2nd problem was trying to idle the truck down to 400-450 rpm. This turned out to be operator (me) error. The meter I was using was multiply the RPM by 2 and I did not realize this. (Mainly due to not reading the meter instructions). Once I put the Adv Timing light on and realized I was trying to set idle speed to low things got better. Truck now idles at 450 rpm. I adjusted the idle mixture screw to show a steady 22" vacuum. This turned out to be about 1.25 turns from full close.
Now I just need to run a tank of gas and see what kind of mileage I get. Hopefully it will be better than the 9 mpg I was getting at 60 - 65 mph.

9 MPG at 60-65 isn't too far from what I'd expect if the rear gear is stock. That speed is winding the engine pretty tight with stock gearing, especially if the rear tires aren't real tall.

My 228 GMC with a Carter YF carb, 3.55 rear gear and 31" tall tires gets around 13-14 MPG suburban driving. It had one tank at about 19 MPG during a leisurely 45 MPH country cruise and one at 16.5 MPG at 60-65 MPH with a 15 MPH tail wind.

 

[vwnate1]

Okey-Doke .

FWIW, ' Motors ' are tethered like Gensets, APUs and trash pumps etc. .

' Engines ' are used to move vehicles .

 

[Bilbo]

Okey-Doke .

FWIW, ' Motors ' are tethered like Gensets, APUs and trash pumps etc. .

' Engines ' are used to move vehicles .

I've not commented on this before, but Electricians work on "motors", and Mechanics work on "engines". To me, a motor has always run on electricity...