Holley 94 Rebuild - Secondary Carb

[Ken/Alabama]

Originally Posted by Ziggster

Going with progressive linkage. My Edmunds intake is rearwards biased on account that I’m keeping the stk generator in its stk location. The forward carb is in the exact same position as one on a single carb intake. As such, I want to run that carb only all the time and the secondary will open when primary carb is 65% open. This makes engineering sense to me at least as an engineer. lol!

Good luck !

[Ziggster]

The Edmund intake.

[petehoovie]

Originally Posted by Ziggster

The Edmund intake.

[Ziggster]

Originally Posted by KiWinUS

Exactly. Hope it’s an open plenum intake (which most Edmunds aren’t) or it’s going to idle on 4 cylinders.

I mapped out the runners of the Edmunds intake. It was a month or two ago, and IIRC, it was an “open” intake, but your comment caught my attention. Geeze! Here’s a coloured coded diagram of the runners from each carb throat/opening. Let me know what you think. I’m on the road so can’t do much checking.

[petehoovie]

Originally Posted by Ziggster

I mapped out the runners of the Edmunds intake. It was a month or two ago, and IIRC, it was an “open” intake, but your comment caught my attention. Geeze! Here’s a coloured coded diagram of the runners from each carb throat/opening. Let me know what you think. I’m on the road so can’t do much checking.

[Ziggster]

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Doing a little digging into throttle plates and discovered they’re not round. lol! Another rabbit hole. Just trying to understand how I can get a better seal between the throttle plate and body/throat. Interesting tech info in this link. Not sure how accurate the info is, but still interesting. Will measure both the old and new throttle plates tomorrow.

https://www.xs650.com/threads/the-my...numbers.43752/

[Ziggster]

With the new plates installed in the base and comparing that with the untouched stk base with stk throttle plates, when closed, the angle of the plates are very different between the new and old plates. The base with the new plates has a steeper angle when closed compared to the stk setup (distance between arrows). Not sure why that is, and not sure if that is good, bad or ugly. Was hoping with all the new parts it was just going to be a simple “rebuild”. Haha!

[1952henry]

Speedway does, or did sell throttle plates for secondary carbs. They have a different bevel than stock.

A trick to sealing the plates is to get some GM DAG 213 sealant for throttle plates. Paint it around closed throttle plates, wait for it to set, then pop open plates. My understanding is this was done at the factory on the tripower setups.

[petehoovie]

Originally Posted by Ziggster

With the new plates installed in the base and comparing that with the untouched stk base with stk throttle plates, when closed, the angle of the plates are very different between the new and old plates. The base with the new plates has a steeper angle when closed compared to the stk setup (distance between arrows). Not sure why that is, and not sure if that is good, bad or ugly. Was hoping with all the new parts it was just going to be a simple “rebuild”. Haha!

[Ernstudet22]

Your carb body looks really nice. Are the pics before or after the clear?

[Ernstudet22]

Would you share contact information for vintage speed?

[tubman]

Be careful of what you ask for.

[Ziggster]

Originally Posted by Ernstudet22

Your carb body looks really nice. Are the pics before or after the clear?

After the clear.

[Ziggster]

Originally Posted by Ernstudet22

Would you share contact information for vintage speed?

Link to their site.

https://www.vintagespeed.com/aboutus/

Screen shot of same.

Charlie Pride.

[Ziggster]

Went back and checked their catalogue info on those throttle plates, and indeed the bevel angle on the edge is 12 degrees vs the 5 degrees for the stk ones. So, that at least would explain the difference in the angles when closed. Will try to speak with Charlie today or on Monday.

[Ziggster]

Originally Posted by 1952henry

Speedway does, or did sell throttle plates for secondary carbs. They have a different bevel than stock.

A trick to sealing the plates is to get some GM DAG 213 sealant for throttle plates. Paint it around closed throttle plates, wait for it to set, then pop open plates. My understanding is this was done at the factory on the tripower setups.

Thanks for sharing. I had forgotten about that product as someone had mentioned it my HAMB thread on dual carbs (link below). I even found a vendor it. Believe it was around $20. Will order some for sure. Thanks for the reminder. Haha!

https://www.jalopyjournal.com/forum/...1343799/page-2

[Ziggster]

After much fiddling, decided for now, to go with these two stk plates that I gave a quick cleaning with some sponge sanding blocks. Not sure of the grit of each, but guessing maybe 180 and 220.
It’s not as good as the remaining stk base in terms of sealing, but when trying to blow through each throat, there is a lot of resistance compared to the new aluminum 12 degree plates. The bottom plate in the pic seals a bit better than the top plate.
I have some Permatex bearing sleeve retaining liquid, and wonder if a coat of that might help. Will look into that separately. Now to continue with the rebuild.

[Ziggster]

Will have to come up with a washer of some sort for the end of the shaft. Not got to remove a stk linage from a stk shaft as there is no need for that linkage.

[Ziggster]

Pic of base with plates installed showing length of new extended shaft. Not sure if I’ll need that much.

[Ziggster]

Went to install the new hex head idle mixture screws with the new springs. Both were hard to install. One in particular was really bad. Checked and then noticed there were practically no threads left in that one bore. Re-tapped both, and new screws installed easily.