Top speed of f145?

[6f40j9]

I seem to remember my old 72 not struggling this much on the freeway or attempting 55 mph.

Yes I know that motor is bigger but still…

So far I’ve done new plugs, new head, new gear oil in rear end, rebuilt (the oddball 2 barrel 6 month only) carburetor, new oil in motor, turning 30x9.5 mud tires on stock wheels.

It will max out at 50 on flat ground. It struggles to keep 35-40 up a short grade. I don’t want to downshift and go 20…

Any ideas what to look for, improve, etc. ?

 

[charliemeyer007]

Have you like check your actual speed with a GPS or a stop watch? My 72 will easily scream along at 55, it will go faster but I don't think its worth it.

 

[6f40j9]

Have you like check your actual speed with a GPS or a stop watch? My 72 will easily scream along at 55, it will go faster but I don't think its worth it.

The speed camera things on the side of the road seem to fall in line with the speedometer.

 

[shawnfj40]

Things to check. Timing, compression, dwell, vacuum advance/retard distributor and lobe condition. If you are properly tuned that motor will go faster than you want to. It’s not a speed demon or anything but it should not max out at 50 on flat ground.

 

[65swb45]

Stock 1969 Vacuum retard dizzy?

 

[6f40j9]

Stock 1969 Vacuum retard dizzy?

It’s capped off but yes. I assume so anyway.

 

[6f40j9]

Things to check. Timing, compression, dwell, vacuum advance/retard distributor and lobe condition. If you are properly tuned that motor will go faster than you want to. It’s not a speed demon or anything but it should not max out at 50 on flat ground.

I never have checked compression. Vacuum on the distributor is capped off. I can double check timing, I think we just set it by ear last time.
It seems to run fine (doesn’t miss or smoke), it’s just slow

 

[Mark W]

Your engine got no balls... at all. It ain't because it is an F rather than a 2F. Sumthin be wrong.

So... you have a new head but have not checked compression? You have not really set the timing? Do that.

What else have you not done? Points/dwell? Inspected the distributor for signs of slop/wear? Valve adjustment? Verified that the secondary is actually opening? (I'd actually put that at the top of the list.) Checked the vacuum? Do all that too.

BTW, that intake manifold is wasted on that engine. Sell it to one of the guys wanting to warm their 2F up a bit and just toss a regular one on there. You'll never know the difference.


Mark...

 

[65swb45]

Somebody’s got some homework to do! Thank you Mark for the list. My patience has waned over the last year or so.

 

[6f40j9]

Your engine got no balls... at all. It ain't because it is an F rather than a 2F. Sumthin be wrong.

So... you have a new head but have not checked compression? You have not really set the timing? Do that.

What else have you not done? Points/dwell? Inspected the distributor for signs of slop/wear? Valve adjustment? Verified that the secondary is actually opening? (I'd actually put that at the top of the list.) Checked the vacuum? Do all that too.

BTW, that intake manifold is wasted on that engine. Sell it to one of the guys wanting to warm their 2F up a bit and just toss a regular one on there. You'll never know the difference.


Mark...

Will set the timing with a light.
Did cold valve adjustment but not hot yet.
Distributor seemed fine when it was out but I’ll check the points and dwell.
I have no idea if the secondaries are opening, I don’t know how to check that.
I don’t care if the intake manifold is a waste, I’m not taking it off again.
Thank you for the tips, I do appreciate it!

 

[mrboatman]

Remember to keep your rpms at or below 3000 and you will be okay

 

[6f40j9]

So I checked out the carburetor a little more.
Primary is opening a smidge, secondary not at all. I guess I need to figure out how it gets activated.
I won’t be able to mess with the distributor for a couple weeks unless I get a day off.

 

[Mark W]

The primary is not opening completely when the linkage is actuated? Definite problem there.

Do realize that the secondary is vacuum actuated. It only opens with the engine running and under load manipulating it by hand does not really tell you what you want to know.

One simple field test is to put a tell tale on the actuating rod from the vacuum module and see if it has been displaced by the movement of the arm after a test drive.


Mark...

 

[Mark W]

Remember to keep your rpms at or below 3000 and you will be okay

If his engine is in nominal condition, he can turn it to 4000 on every shift, every day forever. In spite of what some will tell you, it really really is not a diesel tractor motor that has learned to swallow gasoline.


Mark...

 

[6f40j9]

The primary is not opening completely when the linkage is actuated? Definite problem there.

Do realize that the secondary is vacuum actuated. It only opens with the engine running and under load manipulating it by hand does not really tell you what you want to know.

One simple field test is to put a tell tale on the actuating rod from the vacuum module and see if it has been displaced by the movement of the arm after a test drive.


Mark...

Does it matter that I don’t have #1 in the pic? Mine didn’t come with it. I will look for the secondary rod in the daylight. I don’t remember seeing one on any of that back square apparatus but it gets busy in the back with all the linkage stuff.

 

[6f40j9]

There is no external rod for the secondary that I can see.
Poor quality pic but I tried to get a shot of the primary at wot. I can’t see how to get it to open more. I haven’t adjusted anything on it since it was rebuilt but I did have to take the top off a couple times to clean it out. Maybe I messed something up in the process?

 

[6f40j9]

Found some more linkage stuff on the front that looks like it’s binding up on the tube from the spacer, and a new leak.

 

[6f40j9]

Can anyone tell me how these are supposed to go? I’ve not touched them since I got the carburetor.

 

[6f40j9]

What I like to see on a rebuilt carburetor. Wonder if this has anything to do with why it’s not working correctly.

 

[charliemeyer007]

Seems to me the OEM manuals have really good pic's of the arrangement.