Fuel System: Edelbrock, 289, and spacers.

[Quentin]

Hi, greetings from Oz.
Just about ready to install a very impressive looking engine - (currently bare metal, and looks so good I am loathe to paint it!). R1, oversize valves and headers, so as it will breathe significantly better I am subsequently using the Edelbrock 1406 600cfm. In terms of actual size of the carby there appears to be no difference from a 1403 ? Which brings me to my query - installation of 289 is into a Hawk using stock engine mounts and stock hood, which is not on the car at present. I want to put some spacers between carb and manifold. Can I get away with using a 1 inch spacer without running into clearance issues?? (aftermarket air cleaner is 3".) Cheers, Quentin

[3rdGenStude]

That's what's in my GT, except maybe the air cleaner. I'm not sure if mine is 3" or 2", but probably three. I do have a 1" metal spacer between the 1406 and my manifold. Pretty sure my engine has never been out of the car, so I think it's stock motor mounts.

Paul

[Skybolt]

There are air cleaner bases that drop the assembly down. This way if you raise the carb you can drop the top of the filter.

http://www.mdperfspec.com/eddrba14airc.html

Len

[DEEPNHOCK]

Yes and no.
The secondary throttle bores, and the GM part of the throttle shaft are the two things you will need to address.

First... The throttle link.
The a/t kickdown tab will hit the intake manifold heat crossover part of the intake manifold in the stock configuration.
As long as you are not using a GM a/t (P/G, TH350, TH400, or 200R4, 9r 700R4), then this small portion of the throttle arm is not needed.
What I do is trim the lower part of the throttle arm off right where the bend seam is below the throttle shaft.
(see pic)


Next....

The secondary throttle bore on the stock Studebaker WCFB intake manifold are smaller than the AFB secondary throttle butterflies.
This will cause the butterflies to hang up in the bore and the secondaries won't open up.

You can do one of four things here.

(a) Find a late Studebaker AFB intake that already has the larger throttle bores
(then the AFB is a bolt on after you remove the kickdown tab)

(b) Install a WCFB intake that has been modified to accept an AFB carb.
(Several people have them available for sale, but shipping cast iron can be expensive)

(c) Install an AFB to WCFB adapter plate.
This is easy, but it adds 3/4"+ to the intake/carb stack height, and makes air cleaner choices a bit harder, due to hood clearance issues.
A 'straight' AFB riser plate will make for an awful 'shelf' at both the primary and secondary opening at the intake manifold.
The carb will bolt up, but your performance will not be optimal.

(d) Put a stack of AFB carb mount gaskets...Or a heat isolater AFB carb mount gasket set on there.
The heat isolator set is a stack of alternating aluminum plates and gaskets.
What this does is raise the carb up high enough so the secondary butterflies will open and not hit the intake secondary throttle bore openings.
This is the least desireable method, as it leaves a 'step' under the carb going into the intake.
This causes a lot of unwanted turbulence and affects optimal performance.
Yes, it will work, but it is less than ideal.

(e) Grind or machine the throttle bore size larger to allow the secondary throttle butterflies to fully open.
(This is the preferred method for best performance)
You will need to remove the intake to do this to keep grit and cast iron out of the intake ports on the engine.

IMOHO....
Easiest is to buy one that is prepped (yeah, I know... I am one of the guys that preps them)...
Second is to buy an AFB intake, but that is also the most expensive.
Third would be to spend a couple hours with a carbide burr and grind your WCFB intake to fit, and trim your AFB.
No adapters, lowest height, best performance.
I would avoid adapter plates and gasket stacks, if getting the best performance is important to you.

HTIH (hope the info helps)

[Mike Van Veghten]

Quentin -

Question 1. Why so large a carburetor ?
Question 2. Do you know that a spacer will make the "combination" seem like the carburetor is larger than it actually is ? IF, you need a spacer for linkage clearance, a four hole, 1/2" will provide the best overall option. Read up on what spacers (four hole and open) actually do. Spacers add plenum volume. Adding plenum volume slows the incoming air/fuel speed. This is not good for overall engine efficiency.

I have a similar combination going into my 54 wagon. A 570cfm Holley and no spacer. And the intake manifold I have will probably (Im guessing here) flow more than the manifold you are using. It's a custom, aftermarket manifold.
I'm using the Holley only because I like the design better than the Carter/Edelbrock design. In any case if you check the volumetric efficiency of a 289 with an rpm capability 6000rpm, the carburetor size is smaller than 500cfm..!
Yes, 570 is large, but 600 plus a 1" spacer is way overkill.

All this is to say, keep a 500cfm carb. around, give it a try some day soon. You may be surprised.

The visual difference between the 500 and the 600 Edelbrock carburetor...is the primary booster ventury. Very easy to spot, the 500 carb. booster is very large to effectively plug up the main ventury.

An additional note, if you spend a lot of miles on fast highways/freeways, then the 600 "may" not be too bad (minus the large spacer). But if you spend more of your miles in more of an in-town setting...keep that 500cfm idea in mind.

Have fun with your new engine.

Mike

[Quentin]

(Sorry Jeff, should have mentioned it is a 63 Hawk with AFB manifold.)I have two intakes - a standard 1963 AFB, and a modified 2bbl to 4bbl from a vendor. I was going to use the modified one, mainly because I am lazy, and it doesn't need a clean. However, this is now an "open" 2 hole set up, and you would prefer the 4 hole AFB? Curses! 2 hours cleaning.....I wasn't really thinking of performance with the spacers - Given it is generally about 95 degrees here, the half inch edelbrock 4 hole wooden spacer is for insulation from heat, and to raise the carb slightly so as to avoid the well documented linkage clearance issues and I don't have to cut anything. I'll just go the half inch if you think I will create turbulence/inefficiency problems with anything higher. ( there is a simplistic blurb in the Summit catalog about spacers - 4 hole = minor bottom end gains vs open = top end?) I'll give the 1406 a go - again I invoke the laziness principle - the edelbrock is brand new off the shelf, and doesn't need a clean! plus I have the full rod and jet kit to muck around with at a later date for tuning. I can always go back to the standard Carters I have if it proves cantankerous. The heads are Dave T with R3 large valves and some minor work around the edges, so should perform significantly better (and possibly cope with 600 - after all, Mr T sticks twin 4bbls on them.......!!...)

[DEEPNHOCK]

Either of your manifolds will work just fine.
A single 'heat insulator' carb gasket will prevent heat transfer ok....

Since you are in a warm climate, I would advise blocking off your heat crossover passage to keep the heat off the carb.
You will need to either wire open your heat riser vlave, gut the heat riser valve, or replace it with a straight through dummy block.
This will put all the exhaust out your pipes without running it through the intake.

I use a thin stainless steel sheet metal plate and a good quality composite gasket.
The stainless keeps the exhaust heat and pressure pulse from burning through the gasket.
Contact me for more info, if you want.

[55 56 PREZ 4D]

Either of your manifolds will work just fine.
A single 'heat insulator' carb gasket will prevent heat transfer ok....

Since you are in a warm climate, I would advise blocking off your heat crossover passage to keep the heat off the carb.
You will need to either wire open your heat riser vlave, gut the heat riser valve, or replace it with a straight through dummy block.
This will put all the exhaust out your pipes without running it through the intake.

I use a thin stainless steel sheet metal plate and a good quality composite gasket.
The stainless keeps the exhaust heat and pressure pulse from burning through the gasket.
Contact me for more info, if you want.

Which side of the gasket do you suggest for the plate.

[DEEPNHOCK]

Which side of the gasket do you suggest for the plate.

Here's my routine.
Use Permatex Ultra Copper gasket maker (81878)
Use a dab of Permatex Ultra Copper on your fingertip and spead a small film on the cylinder head around the heat crossover port gasket flange surface.
Put the stainless steel blockoff plate in position and push around a bit to set it.
Make sure there are no blobs.
Let it set overnight.

Then, on the intake...
Flip it upside down and put a small film of Permatex Ultra Copper on the gasket surfaces of the intake port gasket flanges.
Install the intake gaskets. Work them around a little bit until they are in position.

Let it set overnight.

The next morning, put some white grease on the intake gaskets. Just a light film with your fingertip.
(You can do the same on the head intake gasket flange surfaces too. Just a film, though).
Install the intake manifold, and put in all the bolts...finger tight.
Using a circular pattern, starting at the center bolt, tighten each bolt to 10 foot pounds.
Using a circular pattern, starting at the center bolt, tighten each bolt to 20 foot pounds.
Using a circular pattern, starting at the center bolt, tighten each bolt to 30 foot pounds.
Thin enough so the gasket can crush and still allow the gasket to seal.

http://www.raylinrestoration.com/TechnicalPages/Torque/Torque.htm

[bensherb]

I have an AFB on my 62 GT on a stock manifold, with a 1" phenolic spacer and there are no steps to create turbulence. With a 14" round air filter having a recessed base of approximately 1 1/4", I still have well over an inch of hood clearance at the closest point.

With a spacer of 1/2" the kick down part of the carb link arm of all of the AFB's I've come across will clear the manifold without modification.

My carb is an original Carter of aprox 625 CFM. I also closed off the heat crossover ports in the manifold, in a slightly different way, I milled a small step into the port on the manifold to fit the plate into and sealed them with hi temp silicone, that way any gasket could be used without concern. Blocking the heat crossover disables the heat tube for the choke so I removed it and tapped the hole for a plug, then installed an electric choke coil. This set up works great for me.