'67 L-79 Holley Questions...

[Timothy B.]

Re: '67 L-79 Holley Questions...

I will double check the vent tube test today and try to detirmine if the power valve is bad. I may have also fouled a plug but it's not common for this car to be a bad girl.

[Clem Z.]

Re: '67 L-79 Holley Questions...

when you put your finger over the bowl vent pressure builds up in the float bowl. it will cause the fuel level to rise and in a short period of time fuel will be forced out of the booster nozzles. if the power valve is blown the fuel will forced thru the power valve vacuum port which is at the bottom of the carb and it will flood the engine quickly. make sure the engine is off of fast idle before you try this.

[Timothy B.]

Re: '67 L-79 Holley Questions...

I will let you know tonight or tomorrow if the car stalls. I understand now how the test works. Thanks for the explanation, Tim

How do you straighten the metering bodies with the block in your picture, vise, etc.?? Thanks,

[Clem Z.]

Re: '67 L-79 Holley Questions...

I will let you know tonight or tomorrow if the car stalls. I understand now how the test works. Thanks for the explanation, Tim

How do you straighten the metering bodies with the block in your picture, vise, etc.?? Thanks,

you could use a vice i use a arbor press

[Mike M.]

Re: '67 L-79 Holley Questions...

This is a darn fine thread.
Why hasn't someone added the "Stars"?
I would, but, haven't figured that one out.
HaND

[Bob S.]

Re: Here's what I ran into on the Throttle Shafts,

Bob:



The shaft on the bottom is the original one from my 3810. (it was replated in zinc but I never got around to coloring the spring and the lever)

The curly tape were the shaft seals I took off when I disassembled it. The tape is about 2" long, quite different from the white plastic or nylon strips you get today. Was thinking that maybe someone improvised these seals, as the carb is not my original but a correctly dated carb for my car. The secondary had 4 similar tape seals but narrower.

The upper one is a replacement throttle shaft for a 3810 and other 67 carbs, which I acquired last year. Note the grooves in the shafts where the seals should be. Here's a close-up:



Doesn't that look to you that the replacement one is set up for O-ring seals.

So, I'm scratching my head over the seals, while the replacement throttle assembly is working great on the car.

Jerry - I agree with you the new shaft looks like it's designed for O-rings instead of the old style "strip seals". You haven't been able to find replacement O-rings for that shaft?? .....if so, does the supplier say that 6 seals are required for one carb??

After spending nearly 20 years in product engineering for a manufacturer of diesel fuel injection pumps/injectors/etc., I find it hard to imagine why they would design the shaft with 3 seal grooves on each side......Could one shaft p/n offered for service be configured to fit different baseplates requiring 3 different seal positions? (Possible, but doesn't seem very likely to me in this case.) ....Or did the designers somehow consider the redundancy of having 3 seals / grooves necessary? (Such a design wouldn't inspire a lot of confidence for me.) I'm aware of similar throttle arrangements in mechanical diesel fuel pumps that use only one seal, but the differences are they are pressurized, seal diesel fuel rather than air, and they have shafts that ride in either a bronze or steel bushing rather than cast aluminum as the Holley does.

Bob

[Clem Z.]

Re: '67 L-79 Holley Questions...

those teflon pieces are not seals they are there to make the throttle move smoother. if you try to put "O" rings on the other shaft you will not be able to move it. i have only seen them on OEM carbs and not all. never saw them on a after market carb