I got impatient and ordered the BT. Haha. Thanks everyone for your time.

I have never had an issue with either the fit or finish with the Blue Thunder or Mummert manifolds.  Each has its own advantages depending on the exact engine combination they are being used on.  Both are U.S.A. made and machined.

Having talked with the owner of Blue Thunder, material, foundry, and machining costs have all increased significantly over the last couple of years.  Conversations with some of the other aluminum parts suppliers indicates that this is a problem that is industry wide.  I suspect the quality issues being referred to are in reference to the influx of offshore manifolds that are coming into the U.S...  Porosity issues would appear to be at the top of the list for those.

Lorena, Texas (South of Waco)

My Mummert intake is great - I have had 0 issues...

https://www.hotrodreverend.com/post/update-on-the-55-ford-fast-fords-and-the-hot-rod-reverend


Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com

I just re-read the description on ebay for the Blue Thunder intake. I'm not sure which intake they're referring to, but they mention seeing other intakes leaking. They mention quality control issues among other aftermarket manufacturers. They note this as being the reason why their intake is so much more expensive. Theirs are shot peened and pressure tested up to 60psi. They state their intakes are free of any kind of casting marks and are inspected by multiple people before being shipped. Has anyone ever noted any quality control issue with a mummert intake?

In this case, the answer would be NO.  To be able to move or clock the wires one hole from where they were so the distributor would rest at the point you would like the timing to be, you would ideally need at least 22½° of available distributor movement.  The low-profile TSP/CRT distributors for the Y when used with an unmodified Blue Thunder intake has much less than 5° of movement when installing when the vacuum advance chamber is pointing to the left bank of cylinders.  Modifying or machining the BT intake where the clearance issue resides is a potential fix but that clearance problem typically shows up only after the intake manifold is fully bolted in place.

The clearance issue with the low-profile TSP/CRT distributors when used with the BT intakes originates with the placement of the distributor cap hold down clamps.  If they were clocked similar to the Ford or MSD distributors in relation to the vacuum advance chamber, those particular distributors would work okay with the BT intake manifolds.  In looking at the low-profile TSP/CRT distributors, it is possible to re-clock the distributor cap with just a little bit of machine work to the distributor housing.  My work around for that particular clearance issue when not using an OEM or MSD distributor with the BT intake has been to just use the Thunderbird TSP/CRT distributors which have the distributor caps in a higher position.

Another consideration when selecting the intake manifold is if there is a slot in the plenum divider or not.  While the slotted plenum dividers do help the top end horsepower numbers, they do cost you some low-end torque numbers.  The carburetor signal is also reduced when that slotted divider is present and you can figure on at least a 1½” Hg reduction of manifold vacuum at idle when that slot is present.

Lorena, Texas (South of Waco)

Here is a ECZ-B with stock flow figures and ported.  This intake made 439 hp on the 303Y and the ported Mummert made 454hp.  Joe-JDC

JDC

On that distributor issue with the Blue Thunder...Could you just "name" a different #1 terminal on the cap?  I had a "scrub" engine that had a real BEAR of a time getting the dizzy to drop down into place.  It took me a lot longer than it should have one night to get it in and it ran well enough to idle and drive around but (the short story is) the total timing was WAYYY off.   When I went to advance it to the correct total timing the vacuum port on the distributor hit the intake and wouldn't get me close to what I needed...so I spun it back around 45 degrees and put each wire one terminal over and it worked perfectly. 

Not sure if that would fix it, but it looks like the answer is to wait a few weeks for Mummert's and save some coin.  

How does a ported 57 "B" intake compare to off-the-shelf Mummert & BT manifolds under 6,000 rpm?

The BT and Mummert aluminum intakes are very similar in performance as cast.  I have ported probably 40 or more over the last 13 years for forum members and local guys.  Here is a picture of the as cast flow figures for both of them.  I have seen 585 hp on Ted's dyno with both after porting on high performance builds.  Joe-JDC

JDC

Daniel has touched on this but I’ll give more detail.  Factory (OEM) and MSD distributors work okay on the Blue Thunder intake manifolds.  I do not recall having an issue with the Pertronix distributors with the Blue Thunder intakes in the past but there’s not a Pertronix distributor here right now to verify that.

The TSP and CRT distributors without the Thunderbird tach drive do sit lower than the TSP/CRT models with the tach drive.  Only on the Blue Thunder intakes does this create a problem in that the TSP/CRT distributor cap hold down clamps are positioned such that the distributor has difficulty in having adequate rotational movement for timing purposes if positioning the distributor so that the vacuum advance chamber is not turned towards the fire wall or rear bulk head.  The Thunderbird versions of this distributor with the tach drive have a higher positioned cap and clear that rear boss on the Blue Thunder intake manifold just fine.

I do get requests for the Blue Thunder intake instead of the Mummert intake due to the BT intakes having an appearance that will pass for ‘stock’.  A majority of Thunderbird owners are pro-Blue Thunder intake for this reason and especially when the intakes are painted to match the engine color. And Charlie has also brought up the heated crossover in the Blue Thunder intakes which is a plus for those who drive their Ys in cooler weather.

Lorena, Texas (South of Waco)