455rkt

Thought I would share my experience, maybe someone has done this already. I have been a long time ROP member, but am finding more info and traffic here now.

Replacing my Edelbrock 3711 (SBO Performer EGR) with the Edelbrock 2711 (SBO Performer Non-EGR). Needed to eliminate that EGR boss for a couple of reasons.

At any rate, was struggling to find a fitting to replace the heater valve fitting at the Passenger side rear of the manifold. I knew I would not replace with another Heater Valve. I had seen some standard heater hose fittings, but I would have to use a brass reducer in the manifold to make them work. A steel factory style, non-ac heater hose fitting would work, but is kind of expensive. I happened upon this at Summit, fits exactly as needed!

https://www.summitracing.com/parts/icb-f750np625ba

Made in USA, billet aluminum, no reducer fitting needed, and fits the standard hose size. Made for a clean, low profile install. 7 bucks. I went with Anodized Black to offset the Gold engine paint. A lot cheaper than the factory style, non-ac steel hose fittings sold through a few resto places. Anyone updating to an Edelbrock intake, or want to clean up their engine bay, this looks like an inexpensive solution.

Fun71

Nice find. Be aware that there needs to be a restrictor in the fitting or else the heater core will balloon and burst at higher RPM. Did that more than once over the years before I figured this out. The factory parts (hose nipple for non-AC and vacuum control valve for AC) have a 1/4" hole in the fitting.

76olds

I used the same fitting on my 2711 , I bought the blue anodised one.
Certainly does look better than the heater control valve sticking out of the intake.

danktx

I went a different way as I wanted the hose horizontal when it left the engine. I found this one on *bay for $10.

Fun71

I like it. It still needs a 1/4" restriction or else the heater core will blow out at higher RPM.

76olds

Kenneth, How high RPM were you running when your heater core expanded? Did it blow the tank off the core or expand the core itself?

Eric

Fun71

One heater core ballooned and leaked after the first 5000 RPM pull.
The core expanded. The heater core tubes are wide, flat, and thin. With too much coolant flow the tubes sort of inflate and try to become round, which causes them to split at the edge.

bccan

I had the same thing happen right after a track day, kind of ballooned. My radiator guy thought it had frozen but no way that ever happened. I welded a washer onto the manifold fitting to reduce it down to appx a 1/4” opening as I learned from Olds forum. Never a problem since.

olds 307 and 403

I so far have been lucky, probably jinxed myself. I just used a hardware store 3/4" hose barb and have done a few 5000 rpm runs in my 70. It is probably the 7 psi rad cap I run, at 13 to16 psi my old cars want to leak somewhere.

Tuffnut

I put a similar brass hose hose fitting in my new eddy 3711. I have a high flow water pump as well. Now I am a little concerned I may blow the heater core based on previous comments. Not that my rev's ever get to 5000 rpm... never know though. . The old fitting I took out was pretty corroded. Almost need a flow control in the heater hose to reduce the flow or get the right fitting.

Jeff

danktx

After comments here I think I will just put a cup plug with a 1/4" hole in the heater hose with a clamp to hold it in place. Any reason that wouldn't work?

76olds

Thanks for the info Kenneth, I'm surprised hearing of this.
The reason being, I worked in a rad shop back in the early 80's after school, Saturdays and summer vacations. Did many re cored rads and heater cores. These were the the original copper core single tube inlet/outet with the 1" X .1875 thin tube style you mentioned, a little hard water build up back in the day caused the expansion.
I know the heater cores had larger tube separation in the mid 70's , they were changed to .250 in which eliminated this at higher RPM's.
In fact,
We tested the new heater cores at 40PSI after complete, yet they could handle 60PSI before expansion began. The tank was the first expand over 60PSI.
If guys are running high flow water pumps and T-stats, I don't think, downsizing to 1/4 restriction would be a good idea to restrict the flow like the old days.

Eric

Fun71

I recall one heater core that I bought from Summit in the mid 90s made a roaring noise during normal driving that changed with engine speed. Then of course it blew out after some 5000 RPM pulls.