Holley 94 Rebuild - Secondary Carb
 

Decided to create a thread on the rebuilding of a Holley 94 as the secondary carb for my 2 x 2 Edmunds vintage intake. Rebuilt another 94 many years back and it was used last fall on my C69A to get it running on a Ford vintage aluminum intake. Had the parts glass bead blasted, and previously soaked in vinegar overnight. Here it is as it looks presently.

Re: Holley 94 Rebuild - Secondary Carb
 

The pics…

Re: Holley 94 Rebuild - Secondary Carb
 

One pic at time. Down to one bar… lol!

Re: Holley 94 Rebuild - Secondary Carb
 

Another pic.

Re: Holley 94 Rebuild - Secondary Carb
 

Another pic of the carb.

Re: Holley 94 Rebuild - Secondary Carb
 

DupliColor paint used.

Re: Holley 94 Rebuild - Secondary Carb
 

Deleted

Re: Holley 94 Rebuild - Secondary Carb
 

Parts that I had in my vibratory tumbler overnight a few days back.

Re: Holley 94 Rebuild - Secondary Carb
 

My vibratory tumbler. Have had it forever, but don’t use it often. Had to modify it by adding a stack of wooden cylindrical pieces to keep the lid from “collapsing” when tightening down the wing nut. Even then, the threaded stud wore a bigger hole through the lid. Ending up adding a rubber grommet through that hole, a rubber washer with a SS flat washer. Also switched to a nylon wingnut. This seems to have done the trick.

Re: Holley 94 Rebuild - Secondary Carb
 

Parts I ordered from Vintage Speed.

Re: Holley 94 Rebuild - Secondary Carb
 

Most of the parts I ordered. Missing are the Edmunds air cleaners and washable filters.

Re: Holley 94 Rebuild - Secondary Carb
 

New throttle shafts were “standard” size IIRC, but are about 0.003” larger in dia. than the stk shaft. Will put them in my lathe and polish them down to the correct size. Definitely too large to fit into the bore at only 0.003” over.

Re: Holley 94 Rebuild - Secondary Carb
 

Close up of the new shafts.

Re: Holley 94 Rebuild - Secondary Carb
 

Took forever to get it turned down. Decided to use my drill using 220, 400 & 600 grit paper. Measured old shaft again and it came in at 0.277” and new shaft around 0.287”. Not sure what’s going on. For sure dirt/grime buildup in the base shaft bores was hindering the fit. Cleaned them out with a bit of PB Blaster. Also added a bit of machine (3 in 1) oil to help as shaft would get jammed up. Thought I might end up bending it like I did to an original one when working on the first rebuild. They are fragile.

Re: Holley 94 Rebuild - Secondary Carb
 

Having issues with the new throttle plates. Not dealing very well. Had a hell of time getting them installed initially. Took me a few attempts to figure out their orientation.
They are stamped with two “dots”. Seems they are supposed to point down. The edges are beveled, but they do not have the two flat spots where the shaft passes through. Compared to a stk untouched base, and it seals much better. Before tearing into all these carbs, there was a base that sealed almost perfectly. Maybe I should have kept it aside. Maybe U shouldn’t have media blasted the throat surfaces. Most are slightly pitted. This is going to take a bit to solve, but have to head to Montreal now, so it will have to wait until tomorrow.

Re: Holley 94 Rebuild - Secondary Carb
 

Pic of the one base that sealed almost perfectly.

Re: Holley 94 Rebuild - Secondary Carb
 

Quite the process, hope the end product works great.

Re: Holley 94 Rebuild - Secondary Carb
 

Never heard of a secondary carb on a 2x2 setup. All the ones I’ve had and worked on the carbs had to be synchronized to run together

Re: Holley 94 Rebuild - Secondary Carb
 

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

Re: Holley 94 Rebuild - Secondary Carb
 

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!

Re: Holley 94 Rebuild - Secondary Carb
 

Good luck !

Re: Holley 94 Rebuild - Secondary Carb
 

The Edmund intake.

Re: Holley 94 Rebuild - Secondary Carb
 

Re: Holley 94 Rebuild - Secondary Carb
 

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.

Re: Holley 94 Rebuild - Secondary Carb
 

Re: Holley 94 Rebuild - Secondary Carb
 

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/

Re: Holley 94 Rebuild - Secondary Carb
 

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!

Re: Holley 94 Rebuild - Secondary Carb
 

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.

Re: Holley 94 Rebuild - Secondary Carb
 

https://www.fordbarn.com/forum/attac...2&d=1767918023

https://www.fordbarn.com/forum/attac...3&d=1767918023

Re: Holley 94 Rebuild - Secondary Carb
 

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

Re: Holley 94 Rebuild - Secondary Carb
 

Would you share contact information for vintage speed?

Re: Holley 94 Rebuild - Secondary Carb
 

Be careful of what you ask for.

Re: Holley 94 Rebuild - Secondary Carb
 

After the clear.

Re: Holley 94 Rebuild - Secondary Carb
 

Link to their site.

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

Screen shot of same.

Charlie Pride.

Re: Holley 94 Rebuild - Secondary Carb
 

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.

Re: Holley 94 Rebuild - Secondary Carb
 

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

Re: Holley 94 Rebuild - Secondary Carb
 

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.

Re: Holley 94 Rebuild - Secondary Carb
 

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.

Re: Holley 94 Rebuild - Secondary Carb
 

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

Re: Holley 94 Rebuild - Secondary Carb
 

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.