A bit off point, but what is the latest buzz with Mummert & Edelbrock re: new alum. intakes?

While I understand modern gas is more volatile, I'm not convinced SOME riser heat wouldn't come in handy in sub-freezing weather, plus I prefer the no-logo/OEM type markings/configuration of the Blue Thunder. And yet, I'm more interested in the better lower rpm throttle response of John's version, and will definitely want to upgrade my carb. eventually, and lose all that excess iron manifold weight.

6 VOLTS/POS. GRD. NW INDIANA

Brad - I bought mine in March this year price was $420, CA gov Jerry Brown got $33.68, and shipping was $29.  I'm a consumer and only offer this as info, bought it from DSC Motorsport, in SoCal, at the time he had an auction add on epay, I called and bought it.  The pricing was high but the Y-block parts market is like that.  If running an MSD 8383 you will have machine work expenses to shave the rear of the intake, can't remember what I paid, not to bad as I recall. You can Google DSC for more info he's a Ford guy who knows what a Y is.

Paul - I totally agree, put up a webpage offer headers you don't have and haven't made but know people want, what is that other than an annoying waste of time. 

Ted, Redding, CA

Some of the problems with the internet is that search engines do not delete links.

I constantly get requests for B-T intakes of all varieties even though they have been deleted from our site for 3 years.

RE: Headers. I think the reason they are not available has been thrashed out on this site.

Regarding our intake: We have 21 samples that look good.

Ordered the production run Tuesday so should have quantity in 4-6 weeks

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

It just occurred to me that a standard intake gasket would likely expose the part of John's manifold that blocks the riser port to enough direct exhaust heat to warm up the entire intake considerably. The stock '55 configuration I'm running now has 5 gaskets under the carb, and the restricted truck-type intake gasket plus deleting the flapper valve likely has my '55 manifold not a lot hotter (?).

6 VOLTS/POS. GRD. NW INDIANA

Daniel.  The nice thing about John’s intake is the exhaust port does not need to be blocked.  The blocked port is built into the manifold casting so don’t look for any heat from the crossover port at the heads being significant with either a blocked or open gasket.  I’ve welded the ports in the Blue Thunder intakes ‘shut’ so the same could be accomplished.  Without a flow path under the manifold, there’s not much exhaust heat at the intake gasket actually heating the intake manifold itself.  Once an engine is fully heated, the crossover port can be considered a detriment but in cool weather, it does reduce the propensity for carburetor icing while the engine itself is transitioning from cold to hot.  And that's assuming the flapper valve on the exhaust pipe is working correctly to force additional exhaust across the engine through the exhaust passage in the intake manifold.

If you'll look at the Edelbrock Air Gap dual plane intake lineup, there are no heat risers on those either.  And there are none on most single plane intakes regardless of manufacturer.  Eliminating the heat riser passages is a standard item on performance orientated intake manifolds.

Lorena, Texas (South of Waco)

Ted,



Pardon my ignorance, but I'm curious whether most all more modern cylinder heads (and the performance-oriented manifolds made for them) are missing the Y-Block's heat riser system? If this is something that was found to be non-essential and thus phased out over the years, I can certainly understand why it was not incorporated into John's design. I had only assumed that the restricted, non-flowing riser passage in my '55 manifold was still providing just enough heat to enable good cold weather performance, as I do routinely drive in sub-freezing dry weather without any hint of warmup stumble.

Still, it would seem to me that bare aluminum directly exposed to super-heated exhaust would likely conduct more heat to the manifold body than when the riser port is blocked (with steel shim material) under the gasket, and thus insulated from the manifold (routine/typical performance setup). Though a very minor issue, it would still be interesting to see a back-to-back dyno HP comparison between blocked & unblocked risers using John's manifold, assuming a small difference in fuel charge temp. would register?

6 VOLTS/POS. GRD. NW INDIANA

Most modern engines have multi-port fuel injection which do not require the additional heat.

I know for a fact that TBI GM vehicles still used a heat passage into the early 90s and when modifying those particular engines, retaining that feature is generally desirable for street performance. Though since they are still efi, much of the ill effect can be tuned out pretty easily.


Lawrenceville, GA

From a performance standpoint on a fully heated engine, any additional heating of the intake manifold is a detriment.  For a carbureted engine that only gets driven 5-10 miles at a time, then the exhaust crossover within the intake manifold has its place in the grand scheme of things.  For an engine that sees a majority of miles each time it runs, the exhaust crossover is not needed.

 

The oem’s went out of their way to reduce carburetor icing and hesitation issues as the engine was transitioning from cold to hot.  Once the engine is fully heat soaked, then any additional heating of the manifold under the carburetor tends to create other problems and was cause for some additional ignition controls to further retard the ignition timing under high heat situations.  The Seventies saw a variety of thermostatically controlled valves and a myriad of vacuum lines to work out the warm-up issues with carburetors.

 

The crossover exhaust ports in the intake manifolds along with the temperature controlled flapper valves in the exhaust were the early fix for carb icing and cold carburetor choke/hesitation issues.  In the late Sixties and thru the Seventies, duct work from the outside of the exhaust manifold to the air cleaner inlet in conjunction with vacuum controlled flapper valves supplemented the exhaust crossovers.  This allowed warm or heated air to actually flow into the top side of the carb in addition to the heating that was taking place in the intake manifold below the carburetor.  All this was done to solve that icing issue at the carb just during the warmup period.  Once fuel injection went from throttle body design to port injection, then the additional heat from the exhaust during engine warmup was able to be removed from the engines.

 

And that’s the short version.

Lorena, Texas (South of Waco)

Carb or intake heat is still a good idea in the frozen North when it's 20 degrees or less. But then nobody I know is driving his or her 55 year old Y-block in the winter. EXCEPT Hoosier's Ranchero, and he runs a "B" intake with heat in that. He does, however, Disable the blower for snow and ice. Mine stays in the garage.

Frank/Rebop

Bristol, In ( by Elkhart) 

This discussion hasn't even touched on the heat issue for the choke itself. In cold situations, the choke will not open properly without a heat source. The only alternative is to convert to a manual choke or an electric choke setup. Some like the electrics, others don't. I realize that in Texas or California this isn't an issue, but up North it is..

Paul