Text and Photography by Jim Langley and Chirag Asaravala

There is no doubt our hobby is an expensive one. Most of us save our project receipts but cringe at the thought of ever actually tallying up the expenses. Many of us have spent a paycheck on car parts, and most have done so well before actually receiving the paycheck!

So when an opportunity is presented to get a good deal on an otherwise big-ticket performance part, you can't help but take advantage. One such company is making a business out of this very concept. Professional Products has taken perhaps the un-admirable role of making "knock offs" of popular "E" brand intake manifolds. By taking advantage of lower

It's no secret where the manifolds are produced.
materials and labor costs overseas, Pro Products can bring to market versions of Edelbrock's popular "Performer", "RPM", and "Victor Jr." intakes for less than two-thirds the cost (The satin "Typhoon" EFI intake runs around $300, compared to $500 for the Edelbrock RPM. Shown is the polished version, which is around $400.)

 Now we're well aware of the sociopolitical flood gates we're opening regarding supporting companies that use cheap foreign labor. We're not concerning ourselves with that debate, it's your decision. In this article we are strictly focusing on reviewing the product and whether or not it's worth the dollars. Or yuan. Or whatever.

Pro Products sent us their Typhoon Power-Plus 5.0L EFI manifold for evaluation. The kit consists of a lower and upper manifold, available in polished or satin. There is no hiding the fact that this is a virtual replica of Edelbrock's proven Performer RPM design. We felt at a price tag of under $400 (compared to nearly $600 for the real thing) this may be a popular option for budget-minded enthusiasts who are not sure if an intake

The Cobra intake plenum was cut off to allow porting the runners, then welded back together.
upgrade will net any more power on their existing combo. This is precisely the position we were in with our Project Green Machine II, Tech Editor Jim Langley's 1992 5.0L Mustang. The car has been down to consistent 12.2x ET's at 113 mph with a heavily-ported Cobra intake manifold. Jim wasn't convinced that spending half-a-grand on an Edelbrock intake would yield significant gains over the hogged out Cobra. Yet he acknowledged that without trying he'd always wonder if the ported Trick Flow heads and stealth custom cam were being held back. So one afternoon off came the Cobra and on went the Typhoon.

Inspection of the Typhoon reveals the cost savings. The intake is nowhere near as cleaned up as its Edelbrock counterpart. The port openings are irregular and inconsistent in size, and there is considerable casting flash in the runners. Visually it appears the mating surfaces are square, but we wouldn't be surprised if they run wider tolerances than domestic product. Nevertheless the problems are not insurmountable. Most guys may be willing to sacrifice a couple hours of cleanup time with a die grinder for $200 in the bank. We spent a little time gasket matching the port openings (see below), and cleaning up excessive flash.

On the plus side the polished intake looks decent and claims to be hand polished. All the appropriate ports comes tapped and cleaned, and the box includes the correct fittings and hardware. We had no issues installing it, and it sealed up as would any new intake. We've detailed the installation on the next few pages.

Gasket Matching
Typically intake manifolds are manufactured with port dimensions slightly to grossly smaller than the port on the cylinder head. This ensures that a smaller cross section is feeding into a larger one, a fairly safe transition and easy way to increase velocity through the intake tract. Of course this

Porting entails reshaping the entire runner, as was done on our Cobra intake.
comes at a cost of less volume than may be optimal for the motor. Intake porting is a procedure to address this. Like cylinder head porting, it is an end-to-end methodical hogging out of the runner and ports. The end goal with an intake port job is to complement the cylinder heads, in flow and volume but also in transition fron the intake to the head. Gasket matching on the otherhand is simply the latter- opening up the port entries or exits to the size of the gasket or head. The objective being to ensure there is a good even transition between the intake and head, without steps or ledges obstructing flow. With gasket matching we are not concerning ourselves with changing the volume or flow path inside the runners.

The Typhoon intake clearly needs to be gasket matched. It is obvious that the foundry does a minimal clean up of the ports and runners before shipping. This way labor costs are kept down, as are costs for sophisticated CNC machinery. This is how the intake can be priced so low. Yet this is not necessarily bad. If you are serious about power, you should be checking the port transitions on any intake, Edelbrock or otherwise. In our experience we've found that you end up gasket matching most of the time, as your head port work or milling work varies from stock. The procedure is not that tough as detailed here by Jim Langley.

Gasket matching an intake manifold begins with finding the relative position of the manifold and gasket to the head when installed. Temporarily bolt down the manifold with gaskets. Note where the top of the gasket sits in position to the intake and head (arrow.) Scribe a mark on the gasket to mark the position of the intake manifold edge.
With the manifold and gaskets removed from the head, position the gasket against the intake manifold using the marked scribed in step one. Then using a permanent marker, machinists dye, or a scratch awl trace the gasket port boundaries to the manifold. Note, we're using a Mr.Gasket #5833 intake gasket. This is equivalent to a Fel Pro #1250 (1.20" x 2.00")

Once all the gasket ports are traced onto the manifold we can clearly see how much material is required to be removed. Keep in mind you should only open the intake ports completely to the gasket size if the ports on the cylinder head are also opened to the same amount, or larger.
Using a die grinder makes quick work of removing the soft aluminum. It is good technique to slightly radius the edge as shown here, rather than leave a hard corner.

Periodically check your progress against the gasket. Once all the ports are completed be sure to properly clean the shavings out of the manifold.
Don't stop gasket matching at just the lower manifold-to-head junction. The transition between upper and lower manifolds is also a place to check for alignment as it the throttle body orifice. As shown, the Typhoons throttle body opening was severely out of round and well less than the 70mm diameter we needed.

The same technique can be applied to matching up the throttle body opening in the upper intake manifold. Use the correct sized throttle body gasket as the template and grind evenly, out to the scribed marks.
Trust us, spending a little bit of time gasket matching before installing intakes and heads will pay off. It is attention to detail that makes seemingly mundane engine combinations make that extra 10-15 horsepower, or run a tenth or two faster than everybody else.


Results
As embarrassed as we are to announce it, we figure it's our duty to let you know we are not immune to the occasional bout of automotive brain lapses. While attempting to fire up the motor with the new intake we heard an awkward noise followed by engine the engine cranking over way to easily, but not igniting. It became evident after a few more turns of the key that something wasn't right internally. Suspecting something timing related the dreaded tear down began. Soon enough it became clear that a nut had somehow found its way down the open distributor hole during the intake installation process, lodged itself between the chain and sprocket, and when the starter was bumped it resulted in a snapped timing chain. As if that wasn't bad enough, the salt in the wounds came upon reviewing the compression test results -we had bent some valves in the process. So off came the heads for repair.

Several weeks later the motor was reconstructed and we were able to obtain some track results. As mentioned earlier, our '92 5.0L Mustang had been running consistent 12.2 ET's at 113 mph with the ported Cobra intake. With the new Typhoon intake bolted up the car ran several 12.1X ET's in similar weather. While the gains are not overwhelming, they are positive, and inching the Green Machine closer to a 11 second timeslip - a remarkable task if you consider the short-block is stone stock with nearly 140,000 ticks on the odometer.
 
 
In This Article:
We gasket match and install a budget minded EFI intake manifold from Professional Products.
 

The Typhoon is based on Edelbrock's Performer RPM EFI manifold design. Advertised to operate in the 1500 - 6500rpm range, it is suitable for 5.0L motors with head and cam upgrades.
 

The upper intake features a removable plenum cover, allowing for easy access to the runners for porting. Note the vacuum ports are in the same positions as the Edelbrock intake.
 

The lower manifold is a nice piece. There is plenty of meat around the runners for extensive port work if desired. All mounting bosses were tapped and threaded properly, the injector bosses were free of burs or other potential problems.
 

Port sizing on the Typhoon is significantly smaller than a Fel Pro 1250 intake gasket. We measured as small as 1.08" x 1.78". The casting quality is not perfect either, sizes vary port to port as well as top to bottom. Gasket matching is highly recommended.
 

Comparing the Typhoon's lower maniflld to the Cobra (top) reveals the major design difference in runner arrangement. The sequential runners offers less restrictive bends and an opportunity to increase runner length.
 

Professional Products also makes high quality throttle bodies and spacers. Be sure to gasket match the the opening on the upper intake manifold.
Contacts:

Professional Products
12705 South Van Ness Avenue
Hawthorne, CA 90250
Ph: 323-779-2020