Teague On Tech: Q & A with Bob Teague April 2023

As seen in Speedboat Magazine’s
April 2023 Issue.

B&M SuperChiller

Dear Bob:

Q. I purchased a SuperChiller Intercooler to
put under my B&M 250 supercharger. Now
I’m having the oil from the supercharger’s
front gear case blow out the pinhole vent in
the fill plug on the top. I don’t believe I had
that problem last year when I ran just the
supercharger. The boost pressure went from 11psi down to 6psi (I expected a drop). Does the B&M supercharger need the vented fill plug? Or do you think there is an issue with the seals in the front of the supercharger?

Thanks for your time.

Thomas Stevenson
LeClaire, IA


First of all, 11 psi of boost is unusually high for a B&M 250, unless your engine’s cubic-inch displacement is very low. Usually, you can expect a pound or two lower boost pressure with the SuperChiller primarily because the air becomes denser as it is cooled, and slightly due to the flow restriction through the core. If the oil is at the proper level in the blower and it is blowing oil out of the vent, it is likely that the seals are passing boost pressure into the gear case. Most all of the B&M blowers were designed to have a small hole drilled in the fill plug. There is a deflector cast into the front case to control the windage created by the gears which helps to keep the oil from coming out of the vent hole.

I know this sounds weird, but is it possible that you taped off the intake manifold or something before installing the SuperChiller and forgot to remove the tape? This would account for the higher pressure in the blower and the lower pressure in the intake manifold. It is also possible that your belt tensioner is not correct. When the tensioner is in the right position on the 16 primarily because the air becomes denser as it is cooled, and slightly due to the flow restriction through the core. If the oil is at the proper level in the blower and it is blowing oil out of the vent, it is likely that the seals are passing boost pressure into the gear case. Most all of the B&M blowers were designed to have a small hole drilled in the fill plug. There is a deflector cast into the front case to control the windage created by the gears which helps to keep the oil from coming out of the vent hole. I know this sounds weird, but is it possible that you taped off the intake manifold or something before installing the SuperChiller and forgot to remove the tape? This would account for the higher pressure in the blower and the lower pressure in the intake manifold. It is also possible that your belt tensioner is not correct. When the tensioner is in the right position on the 16 SuperChiller B&M Belt Tensioner.
rib belt setup, the yoke that holds the pulley should be about one-half inch from the aluminum housing that it slides in. Also, the nut on the stud that is used to pull the ten-sioner pulley back needs to be completely backed off so it cannot contact the housing. If the belt is not tensioned properly, it will slip and cause the boost pressure to be low. If these items check out, it might be time to rebuild the blower.


Carburetor Fuel Supply System

Dear Bob:

Q. I have a 1997 Eliminator 25′ Daytona with a Mercury Racing 600 SCi in it. It has the original blower but has a different cam, heads, and valve train. I also added a SuperChiller and some other odds and ends. Weldon fuel regulator. I’m currently getting a set of 800 Holley carburetors built for it and have a fuel supply question. The boat has had quite a bit of Teague parts installed by other owners over the years along with a Platinum shaft XR drive, so I figured I’d contact you for an opinion. I would like to get the Aeromotive part number 11211 14 psi 140-gph marine T-style fuel pump and a dead head regulator to replace my A1000 with a bypass regulator because it just supplies way more fuel than I need and is constantly returning, making it hard to balance the fuel tanks. Do you think the T-style pump and deadhead regulator will supply enough volume to consistently feed both Holley carburetors?

Thanks for your time.

Kyle Oeder
Morrow, OH

If you wanted to continue to use your current by-pass system, it can easily be done by installing an IMCO 6-port fuel valve. This valve allows you to return fuel to the tank that you are drawing fuel from.

The Aeromotive part number 11211 T-style marine fuel pump is a good part but has maximum power limitations. If your engine power is above 750 horsepower, then the 11211 pump will be on the edge of being able to supply the volume needed. I recommend the Weldon A2046 dead head regulator for reliability and stability. Another nice feature is that it has four outlet ports which would allow you to run four separate fuel lines to your fuel bowls.

We have found that in order to maintain 7-psi fuel pressure with the 11211 pump on a 700-horsepower engine, the regulator needs to be set close to 8.75 psi at idle speeds.

When you install the pump, install a fused relay to make sure there is an adequate and safe power supply to the pump.

For your chance to be featured in Teague On Tech, email your questions for Bob Teague to Ray@speedboat.com.

Check out the Teague Tech Library for diagrams and schematics of how to correctly install and perform various repair and upgrade projects. At Teague Custom Marine, we don’t ‘just sell parts’, we know how to install everything we sell. When it’s time to tackle a project, count on Teague Custom Marine to have the part and the answer.