Holley Twins Question

[Thumperbird]

All,

I am wanting to buy a second set of carburetors for my dual quad 445 in the heavy 65 Thunderbird.
Currently have a set of bj/bk's on it and tweaking those but would like a spare set so I can always have something in operating condition and also have the ability to compare one set to the other.
Dual quad so they have to be single side feed, also feeling like 4 corner idle adjust might be a good fit for the Edelbrock dual quad air gap with custom offset spacers, not sure yet.

Considering a generic set of Holley 01850SA's or Quick Fuel SL-1957E's or ?

Looking for suggestions on best way to go?

Thanks.

[Falcon67]

Why not Ed 600s.  I bolted a pair on a 302 tunnel ram and they did fine.  One I had, the other was a $100 eBay purchase.  Set both to box stock and they had decent AFR readings and basically drove out the door.  I did do tweaking with pump shots and calibrate to get best launch and MPH at the drag strip, but I was pretty impressed for just throwing two carbs on a mild 302 and lighting it off. 

That said, I have a pair of decent older 1850s and the plan would be to use Drew's calibration data to set those up for test.  But that would be tested on a not-so-mild 351C with a tunnel ram, 4.56 gear and 4800 stall converter.  Without Drews data, I would have torn down one of the Eds and used some measures for a baseline start.  Basically, the Eds ended up 4% fatter primary/secondary on both the get best MPH on the track so I would have taken the base 1850 setup and looked for 4%, or maybe start one jet size all around which can be as much as 3%, depending. 

One big difference is that the Eds have a very efficient primary booster system and a smaller primary bore/venturi.  "Spreadbore" like. The 1850s, not so much.  So idle and drive-away for a street car would be where you'd likely need most tweaking.

[Drew Pojedinec]

Thanks Chris. I didn’t want to be the guy to suggest edelbrocks.
I mean, yeah I could build some 1850’s, but that isn’t gonna solve the distribution issues.

[e philpott]

Someone like Keith Craft or FE Specialties ( can't remember who ) just posted a dyno result from the EBrock intake with EBrock carbs and were pleasantly surprised how well they did on Wes's Face book a few weeks ago

[Drew Pojedinec]

Yup was Lance Smith of Craft Performance engines.
600hp out of a 462 I think.

[Thumperbird]

Not sure how bad the distribution is just yet.  One data point, i.e. bj/bk makes it tough as I do not have experience or other reference for jsut how smooth or strong the combo can/should be.
I get a decent idle around 700, not too bad for the combo I believe, but a tad rough cold.

Currently working on moderate and hard acceleration lean out.

Not a bad idea to try Ed's, no custom spacers of course, will have to check out that article.
Not that I really care too much but they just do not have the same look one expects on a Ford.  Kind of still want to stay somewhat close to real 1960's ford world.  If I want to stray more I would go EFI for fun I think.

I have found a couple used 600 vacuum secondary Holleys I can pick up for $50 a piece, might just play with them as well.

Are the Quick Fuels worth the extra $'s in my application if I decide to go with a new set of carbs?
Other models?

Thanks

[Drew Pojedinec]

If ya want....  send me the repro bj/bk’s. I’ll record the calibration and test them out on my 2x4 setup.
Won’t cost you anything but shipping.

If they don’t run right for me, we can make some changes as you see fit.

[Thumperbird]

Thanks for the offer Drew, might take you up on that this winter.
I have not tested and tweaked enough yet myself, part of the reason is that it is too much fun to drive so I don't want any down time.  With the duals, it takes extra effort to make internal carb changes.  Having another set would at least enable me to swap and go more or less.

I will track all of my changes as I go here, heck i haven't even played with it using a single carb yet.
I need to get my final exhaust in place and a pvc in the mix, getting a bit of oil out of the breathers at higher RPM's.
I also think I need to lower converter stall by 3 to 400 rpm's, too soft down low for my taste but not sure how much of that might be tune.
Thanks

[Pentroof]

Holley Twins? Never heard it put that way. Maybe that's why I started thinking about Holly Sonders.






Now every one of you is going to Google that.....admit it!

[Heo]

I did

[My427stang]

Thumpr, I'd consider Drew's offer because assuming your carbs are good, they are likely the best running carbs for your application (assuming the adapters aren't causing the issue)

It'd be real nice to see what a sharp carb guy with a dialed in engine sees with yours, then you can either have him fix yours, or you can rule out the carbs. 

I don't remember what your adapters look like, but it wouldn't take much cause some turbulence around the corners.  You likely posted before, but do you have any pics?

[machoneman]

Holly Twins?

Here you go!


https://www.youtube.com/watch?v=noYmDgLZfYI

[Barry_R]

Let Drew check the carbs.  I suspect that - if the carbs are OK - you are fighting that manifold spacer deal.

[Thumperbird]

I will probably send to Drew this winter if I don't feel good enough about things.

Current state:

Rich at idle, rich at tip in, I think as soon as the second carb comes on just a tiny bit things get lean, get into it a little more and not bad, then moderate to heavy acceleration goes quite lean.
What is good is that I can sit at a light for several minutes or more in 95 degree heat and it just keeps chugging along, no overheat, very minor changes in rpm occasionally, but rich.
As I said earlier, getting exhaust done soon and a few other things so the platform is more stable for tuning.

Have not had them off yet to give a once over, too many not so fun summer obligations.

Thanks for input.  Will post spacer picture again when I find it.

[Thumperbird]

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