Carb adapter /351 4V

[73inNH]

Hi,

Can anyone point me to an adapter that will allow me to mount an Edelbrock spread bore carburetor on my factory intake? I removed the EGR plate and would like to bolt the carb direct to the intake.

I have a typical spread bore to square bore adapter, but it doesn't cover the weird (EGR?) channel in the intake.

Kurt

 

[Don C]

That's a common problem, you can read more here:

Carburetor recommendations, please! - 351C, 4BBL - Engine, Transmission, Drive Line, Etc - 7173Mustangs.com

 

[73inNH]

If I go this route (Edelbrock.com: RPM Air-Gap Small Block Ford 351C Intake Manifold) am I losing power? Manifold is designed for 2V, but will work on 4V. What's the consensus, is this an improvement over stock?

 

[Don C]

I would say that it is not an improvement over the stock manifold, other than the cooling from the air gap, which may not overcome the smaller runners and port mismatch. You can use the "turkey pan" intake gasket to keep hot oil off the bottom of the manifold.

IMO if you want to change manifolds the Blue Thunder 4V would be a better choice.

 

[73inNH]

Looking into the Blue Thunder. Since they are no longer made, this is going to be an $800 swap, when all is said and done.

I'll report back.

 

[Don C]

They definitely are not cheap:

DSC Motorsports - Part Details

If you don't want to go that route, my next choice would be a 4V Edelbrock Performer, only $425 from Summit.

 

[73inNH]

Ordered a BT. Will let you know how it goes.

 

[Omie01]

I have run both the Air-Gap and the BT, I lost a considerable amount of power swapping to the BT. The Air-Gap pulls way harder. I will say though that I port matched the Air Gap as close to the 4V size as I could. Now this could be the cam profile being better suited to the AG. The other problem I had with the BT was float bowl heat. I had warm engine start issues. I had to install a phenolic spacer to soak up some heat. Just my experience. I am running 4v CC heads and a lunati voodoo roller cam set. Good luck!!

 

[73inNH]

So, after giving this some additional thought, I cancelled the BT and bought this: https://www.edelbrock.com/performer-351-intake-manifold-for-ford-351-4v-cleveland-2665.html

I found a new one on eBay for $350. I couldn't justify the premium for the BT. Parts should be in next week.

I'm also removing my valve covers to change gaskets. Should I do anything else while I'm in there? Any easy improvements to make on the rocker arms etc. for a DIYer?

 

[Don C]

If your engine still has the umbrella style valve seals they are likely hard and brittle and may be failing. Check around the lower side of the heads and the oil drains for chunks of them. When they start coming apart they can plug the screen on the oil pump pickup. Replacing them with the heads on the engine is doable, but requires a valve spring compressor and a way to keep the cylinders pressurized to keep the valves closed while removing and reinstalling the seals and keepers.

Also, if they are sludged up clean them as much as possible, pulling the oil drain plug and letting everything run out of the bottom is the easiest way. Visually check for any sign of broken valve springs or anything else that doesn't look right.

 

[Ryunker]

Hi,

Can anyone point me to an adapter that will allow me to mount an Edelbrock spread bore carburetor on my factory intake? I removed the EGR plate and would like to bolt the carb direct to the intake.

I have a typical spread bore to square bore adapter, but it doesn't cover the weird (EGR?) channel in the intake.

Kurt

View attachment 54215

I went to a local machine shop, had them "create" one for me that allows standard Holley 4160 stuff bolt on with zero issues.

 

[boilermaster]

Don C,

Funny thing on valve seals,

I have been working on cars for 40 plus years and the only time I ever saw anyone drop a valve was a young guy using an air hold set and his quick connect failed.

I have a air hold set as well as a leakdown tool but never use them for valve seals, would rather have the piston at TDC of the cylinder than have air pressure drive the piston to the bottom of the bore.

Boilermaster

 

[Don C]

I've done it both ways, and when using air pressure it's critical to have the piston at TDC, and I crank the pressure regulator way down, doesn't take much air to hold the valves in place, and less likely to send the piston to the bottom. A 2" valve has a surface area of about 3 square inches, 5 psi puts 15 pounds of pressure on the valve.

 

[73inNH]

Just an update . . . Installed the Edelbrock Performer 4V intake and an 800 cfm avs thunder carb. The car started great, and ran excellent (slight off idle hesitation to work out), but after driving for a few miles and inspecting, there is a significant leak from the rear seal of the intake. Grrr. :/    I retorqued the bolts today and we'll give it another test, but it's likely that I will be reinstalling the intake again. But, I'm glad it ran well!

More to come.

 

[Don C]

Did you use the gasket that runs across the top of the block? They are hard to keep in place and get to seal.

A better option is to run a 1/4" bead of good silicone sealant across the sealing area. The one that is best is called 'The Right Stuff'

It comes in a squeeze tube, caulking gun tube, or pressurized can and is available at most auto parts stores and Amazon

Permatex® the Right Stuff® Gasket Maker – BLACK – Permatex

 

[73inNH]

I used RTV Black and no cork gasket across the front/rear.

I clearly did something wrong. 

I cleaned the metal face with degreaser, but I'm wondering if there was still some oil residue on there.

Per your recommendation, I will order some "Right Stuff" for attempt #2.

 

[Don C]

Some silicone sealers don't do a very good job of adhering to surfaces, The Right Stuff is very sticky. Ford came out with it in the '70s, was somewhat expensive, but worth it. Permatex followed with their version, still a little more expensive than the other not so right stuff, but definitely worth it.

 

[73inNH]

Don,

They sell black and red in this product. I believe red is a little higher temperature. Is the black okay to use (500 degrees)? Black is available near me, I'll need to order red.

 

[Don C]

Yes, black is fine for that, and is what I use.