Technical Buick str8 manifold suggestions

I'm sure this has been covered but I haven't ran across a definitive answer yet across the web. If someone has any any insight or can point me in the right thread. Currently built a header for my 263 cubic inch Buick straight-8 and started running across some threads mentioning that you do not want to separate the header from the intake because the car run like **** for lack of intake Heat... haven't decided on the carb configuration yet nor even the intake layout but wanting to do multiple carbs does anyone have any insight on to what to stay away from or should I rethink separating the two manifolds thank you

 

You can separate them and use hot water to help heat the intake.

 

There are at least two ways to deal with manifold heat...exhaust or water circulation. The advantage of exhaust heat is the immediacy of it, in my opinion, compared to water requiring engine warm up before heat is applied. On the other hand, the water temp is more consistent and a lower temp than exhaust. The heat riser valves/flaps tended to minimize that problem for exhaust heat.

Perhaps the inclusion of a manifold heat valve in one of the header outlets, combined with a 'crossover' tube that is attached along an intake runner would solve that. Or, a similar arrange for water circulation would do the job. With the water style heat, the circulation probably should utilize the by-p*** hose connections to get immediate circulation to the manifold, but when the thermostat opens upon engine warm up, the manifold heat will be reduced somewhat. I have a couple of 263's and will be addressing these same issues.

Ray

 

Thanks fellas. My flap had stuck open when we took a long trip one day last summer. Exhaust manifold was all cracked maybe from that day maybe it was just previously never noticed it. I figured I would Fab up a header and make a custom intake and it'll be the end of that and then I started getting nervous when I was reading stories about the carburetors needing heat. In your opinion is this something that's needed just for initial start up until engine gets warm or is it something that will affect the performance no matter how long it runs. I'll try to search around for pics and find guys to put water to intakes before I'm not familiar with the setup. A couple tubes off a couple header pipes up to the intake sounds more my speed. Simple minded lol

 

I've got to figure that one out for the 4 barrel intake and Landgon cast headers on my 292 six in my 48 Truck. I figure to do it with water and fit some sort of aluminum block to the bottom side of the intake to heat it.
Take a look at setup for a stock Chevy six intake or Offy inake set up to run with stock exhaust. A plate with in and out fittings to run the heater hose to and from. It might give you and idea of how to fab one and use the stock heat chamber on the intake and a stock intake to exhaust gasket or fiber gasket made to match that. https://www.12bolt.com/store/p155/Offenhauser_Heat_Plate.html It won't work on my intake as I don't have that chamber on the bottom side for the water (or exhaust) to flow though.

 

I have headers on mine. Homemade intake. Intake is basically two "u" bends connected to the head with another "u" connecting them with the carb mounted in the middle of it. Water heat on the base beneath the carb.

Ben

 

It has been my experience that once the engine warms up, it runs fine without heat. But I live in a pretty warm place

 

I agree with Rich Fox. If you are planning on building headers for your car there will be plenty of under hood heat for the intake. Of greater importance in Illinois would be the possibility of carb icing during warm up on days with temps between 45*F and 32*F, so you may want to consider some sort of ducted heat into the air cleaner.

 

Its just a warm weather cruiser. Occasionally I'll drive it to work and the early spring & in late fall when it might be 40 degrees in the morning but no less than that. Ill sacrifice a little bit just to look cool. Lol

 

If its warm weather ,install a choke and adjust to your tune.

 

the only time you may have a problem is on the cold mornings. the lack of hot air may cause some carb icing until you build some heat into the eng and under the hood. it will be worse on cool damp days or days with a lot of fog. no problems in warm weather if you warm up the eng first.

 

I'm just in infancy planning stages for what I will be using on my Buick 320 straight 8 in my '37, but with exception of the Edmunds dual carb intakes that look like they have bungs for water to run through, the few aftermarket, (really theres only the Howard 6 carb) and homebrew intakes seem to disregard using a heat source. I was planning on going with something like this, (but with a different style header) for the four separate intake runners and carbs, with some sort of equalizer tube connecting them. perhaps depending on what material is used for the intake runners themselves and their close proximity to the exhaust header runners, could aid in adding a bit of heat without having to add a water pipe.

 

Stooge - that is a beautiful piece of work!

I have just about wore out my eyeballs staring.

One thought: I believe with four carbs on an inline eight, it will be easier to tune WITHOUT the interconnection pipe. With the interconnection pipe, the four central cylinders (two center carbs) will run richer than the outer four because of the pulsing of the interconnection pipe.

Jon.

 

I did one on a 300 6 cyl with a fabbed 4 barrel manifold made an exhaust p***age on the bottom of the plenum and dual exhaust and a heat riser valve like a v8 used to run exhaust from one exhaust side to the other until it warmed up

 

The only two issues at least the two main issues with not having some sort of direct heat to the manifold Are rough running until the actual engine heat from the head or block heats the intake sufficiently to help atomize the fuel in cold weather conditons and carb icing. The potential for carb icing normally goes away as soon as the engine it's self is up to operating temp. Both usually mean that you have to spend a few minutes warming up the engine before taking off in real cold weather.
A lot of us at one time or another have run what was intended for race only intake on the street and had to adjust our cold weather or even starting out with a cold engine driving habits to deal with it. The heat to the intake would make life with the car a lot easier but it isn't a total necessity unless the setup shows that it is a necessity if you want to drive it without having to deal with a few issues when you start out.