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Fri Mar 24, 2017 7:04 am

Working my list of things to do to the engine bay cleanup/tune project that I'll be diving into in the next while and came up with a couple more questions.

1. The bubble gum weld

The previous owner hacksawed the manifold to eliminate the heat risers. I will be replacing this but I'm confused by this act. If it was plugged, why not just leave it plugged and attached as opposed to cutting the riser off and welding the muffler opening shut. I don't know/get that.

So my first question is; is my muffler f$#%ed or can I grind off the weld evenly and drill a hole back out to accommodate a new functioning manifold? The muffler doesn't leak at this time and if I can save a couple of bucks by not having to buy a new one that would be great. Is it possible?

2. The mystery line.

I already know that the throttle positioner is connected as it should be but isn't working properly at this time (I will try and repair it) but I'm at a loss as to what that second line (the one with the nut plugging it off) just below it is for. I looked for another vacuum line/connection elsewhere and there is nothing (not even on manifold as with two stage positioners).

So my second questions is; What the heck is it? Haha Any help would be awesome on this one. I have no idea.

Cheers as always!

Fri Mar 24, 2017 12:15 pm

Anyone?

Fri Mar 24, 2017 12:38 pm

New2me69 wrote: Working my list of things to do to the engine bay cleanup/tune project that I'll be diving into in the next while and came up with a couple more questions.

1. The bubble gum weld

The previous owner hacksawed the manifold to eliminate the heat risers. I will be replacing this but I'm confused by this act. If it was plugged, why not just leave it plugged and attached as opposed to cutting the riser off and welding the muffler opening shut. I don't know/get that.

So my first question is; is my muffler f$#%ed or can I grind off the weld evenly and drill a hole back out to accommodate a new functioning manifold? The muffler doesn't leak at this time and if I can save a couple of bucks by not having to buy a new one that would be great. Is it possible?

!
You need to take the insulator off (and maybe the rear tin) and see what's going on under it. It is just a few screws. Maybe the heat riser flange is still bolted to the muffler?

Sat Mar 25, 2017 12:40 am

#2 to me certainly looks like one of those aftermarket EGR add-ons that were popular in the '70s and '80s. My other guess is that its a manifold vacuum nipple added under the carb to fit the engine into an auto-stick with an intake manifold that doesn't have the right vacuum fittings for it. You may safely remove it.

--

As far as the throttle positioner goes, at idle:
- loosen small lock screw
- turn big screw clockwise until you get movement from the arm
- rev engine to 3,000-ish RPM
- let off throttle and count seconds to idle
- adjust big screw until you get 3-6 seconds at 3,600 RPM
- tighten small locking screw

The throttle positioners on these cars are VERY fickle. 1/16th of a turn is often all it takes to upset the adjustment. On the plus side, once it's set, it's pretty much set for the life of your engine's vacuum signal. I swapped camshafts in my engine last year and had to do half a turn, which is a big adjustment. I have only seen one bad single-piece positioner in my years of collecting and restoring them.

Before that, perhaps hold the throttle positioner arm back so you get the "throttle positioner fast idle" and set the secondary screw/arm assembly to 1,200-1,400 RPM. I forget which order of operations Bentley requests.

Good luck, and let us know how it goes.
Robbie

Sat Mar 25, 2017 9:24 am

#2 Might have gone to an Altitude compensator. The Altitude compensator would have been mounted on the upper part of the engine compartment fire wall driver's side.

Sat Mar 25, 2017 9:47 am

beetlenut wrote: #2 Might have gone to an Altitude compensator. The Altitude compensator would have been mounted on the upper part of the engine compartment fire wall driver's side.

Not until 1970 did they become two piece. On 69 they were one piece units like in that picture.

Sat Mar 25, 2017 9:51 am

asiab3 wrote: #2 to me certainly looks like one of those aftermarket EGR add-ons . . .
I think that Robbie called it.
That might also explain yer missing heat riser.
The rest of the NoX device installation required a hole to be drilled and tapped into the heat-riser tube.
A short pipe nipple then connected an E.G.R. valve to the heat-riser.

Most of them ended up in the garbage can!

Sun Mar 26, 2017 3:01 pm

57BLITZ wrote: asiab3 wrote: #2 to me certainly looks like one of those aftermarket EGR add-ons . . .
I think that Robbie called it.
That might also explain yer missing heat riser.
The rest of the NoX device installation required a hole to be drilled and tapped into the heat-riser tube.
A short pipe nipple then connected an E.G.R. valve to the heat-riser.

Most of them ended up in the garbage can!

Fantastic! I researched a bit and I think you guys nailed it. Makes sense to me. I'll be removing it once I get going on the cleanup and sorting of all this stuff.

Thanks again. Really appreciate the help.

Steve