Best carburetor for 86' 460 7.5L

[ArdWrknTrk]

Today I changed plugs, wires, cap, rotor. Set timing at 8 btdc. Found a slight leak at the fuel line inlet.

I pulled it apart and the brass filter looked new. I put a bit of antisieze on the threads and snugged it all back up. Thanks for the advice there Jim.

I need to check fuel pressure, but I set the choke and cranked it a bit and it eventually fired up and ran at a fast idle. I wanted to try this per procedure before starting to diag things.

After a few revs the truck stumbled and shut off. I’m planning to check the vacuum at idle and adjust the idle.

This truck came from Washington near Seattle and I’m at about 1200 above sea level. I’m thinking fuel needs backed off. Exhaust is sooty. Old plugs were black and dry.

I know, I know get it out and drive it.

Gary, a few pictures for you and the site.

Your image exceeds the upload file size.

If it is really smokey I would check for a blown Powervalve.

Try slowly closing both idle mixture screws completely.

If it will run better (or still run) then it's likely the Powervalve diaphragm is ruptured.

1,200' elevation change is not enough to make a real difference.

If you were in Mexico City or even Denver, it might.

 

[Fryeken]

Your image exceeds the upload file size.

If it is really smokey I would check for a blown Powervalve.

Try slowly closing both idle mixture screws completely.

If it will run better (or still run) then it's likely the Powervalve diaphragm is ruptured.

1,200' elevation change is not enough to make a real difference.

If you were in Mexico City or even Denver, it might.

Thanks Jim,

I’ll work on the file sizes and work on the idle mixture to check the power valve.

Should I also check the float levels per the factory adjustment manual next?

 

[ArdWrknTrk]

Thanks Jim,

I’ll work on the file sizes and work on the idle mixture to check the power valve.

Should I also check the float levels per the factory adjustment manual next?

You can simply use the resizing tool in the right column when inserting an image.

You could check the float levels if you like.

Note that the adjuster works opposite of what you might expect WRT screw and nut.

Plugs shouldn't be that sooty.

Also check that the EGR is closing all the way.

If it sticks it will kill the engine at idle.

But black plugs + won't idle = power valve or timing chain to me.

 

[Fryeken]

You can simply use the resizing tool in the right column when inserting an image.

You could check the float levels if you like.

Note that the adjuster works opposite of what you might expect WRT screw and nut.

Plugs shouldn't be that sooty.

Also check that the EGR is closing all the way.

If it sticks it will kill the engine at idle.

But black plugs + won't idle = power valve or timing chain to me.

Yeah, on a cold start it shoots like my old powerstroke.

Unfortunate part is the former owner replaced the timing cover and water pump. No mention about the timing set. I hate to assume that the old nylon gears and chain were still fine.

Jim, I’m with you. Not a bad idea to put a double roller in to save picking out the junk.

Any issues with the Edelbrock/cloyes piece?

https://www.edelbrock.com/performer-link-adjustable-true-roller-timing-chain-set-7830.html

Working on getting a donor carb from a 351 to learn rebuilding.

 

[ArdWrknTrk]

Yeah, on a cold start it shoots like my old powerstroke.

Unfortunate part is the former owner replaced the timing cover and water pump. No mention about the timing set. I hate to assume that the old nylon gears and chain were still fine.

Jim, I’m with you. Not a bad idea to put a double roller in to save picking out the junk.

Any issues with the Edelbrock/cloyes piece?

https://www.edelbrock.com/performer-link-adjustable-true-roller-timing-chain-set-7830.html

Working on getting a donor carb from a 351 to learn rebuilding.

I can't speak to the Edelbrock/Cloyes adjustable.

I use their regular $42 Street True Double Roller set straight up.

My RV cam and Performer intake have plenty of bottom end. I don't need the cam advanced.

[ArdWrknTrk]

Yeah, on a cold start it shoots like my old powerstroke.

Unfortunate part is the former owner replaced the timing cover and water pump. No mention about the timing set. I hate to assume that the old nylon gears and chain were still fine.

Jim, I’m with you. Not a bad idea to put a double roller in to save picking out the junk.

Any issues with the Edelbrock/cloyes piece?

https://www.edelbrock.com/performer-link-adjustable-true-roller-timing-chain-set-7830.html

Working on getting a donor carb from a 351 to learn rebuilding.

There's not much to rebuilding a carb.

Remove the bowls and clean the heck out of it.

Lay out a white towel so little parts like e clips and check balls don't roll away and vanish.

Have a way to keep parts sorted (like a muffin pan)

I will put all the clutch screws from say the rear metering plate, and everything else under that rear bowl in one compartment, everything from the choke in another, etc..

Wear safety glasses when spraying carb cleaner through the passages.

(Be glad Gumout doesn't crackle like it did when these trucks were new! )

 

[Fryeken]

I can't speak to the Edelbrock/Cloyes adjustable.

I use their regular $42 Street True Double Roller set straight up.

My RV cam and Performer intake have plenty of bottom end. I don't need the cam advanced.

I’ll get one of those 3079-x double rollers on the way then.

[Fryeken]

I’ll get one of those 3079-x double rollers on the way then.

Well I finally found time to get back into this project. I picked up a 80457-s and found a pothole between the vapor recovery unit and the carb inlet. This truck has the hot fuel option and had a 5/16” hard line from the vapor unit to the carb. Not sure if that was factory or not, but I believe the fuel filter was deleted.

Anyway, I’m looking at running a Holley fuel fitting #26-71 to go from the bowl threads to the 1/2-20 on the line, but need to get a filter in their somewhere, and was also looking to add a fuel block to add a pressure gauge.

Do you know if anyone makes a 1/2-20 in/out filter- or do I need to go to and from -6an filters, which could get spendy?

I checked Wix and had no luck.

I’m not looking to run rubber line either unless it’s the only option.

 

[85lebaront2]

Well I finally found time to get back into this project. I picked up a 80457-s and found a pothole between the vapor recovery unit and the carb inlet. This truck has the hot fuel option and had a 5/16” hard line from the vapor unit to the carb. Not sure if that was factory or not, but I believe the fuel filter was deleted.

Anyway, I’m looking at running a Holley fuel fitting #26-71 to go from the bowl threads to the 1/2-20 on the line, but need to get a filter in their somewhere, and was also looking to add a fuel block to add a pressure gauge.

Do you know if anyone makes a 1/2-20 in/out filter- or do I need to go to and from -6an filters, which could get spendy?

I checked Wix and had no luck.

I’m not looking to run rubber line either unless it’s the only option.

The inlet fitting, if it is the long one seen here in the red circle is a filter, not a paper one, but a fine mesh screen.

[Fryeken]

The inlet fitting, if it is the long one seen here in the red circle is a filter, not a paper one, but a fine mesh screen.

Bill, close.

Here is my setup

And the wix filter that looks to tie it together