Ford Performance Cylinder Heads - Courtesy Of Kaase - Tech

What can be said for sure is that this Kaase head design, as cast, has flow capabilities that approach the figures seen from some conven-tional parallel valve heads after they have been CNC ported.

On the intake, things are looking really good. But how about the exhaust? Remember, this has been pushed much closer to the cylinder wall than is often deemed wise. Also, unlike the intake, the exhaust valve has no inward cant. It appears, for all practical purposes, about as conventional an exhaust port as you might see in any number of other aftermarket heads. With 184 cfm at 0.600 and 188 cfm at 0.700, the exhaust flow did not appear to have suffered one iota by the move toward the cylinder wall. In fact, the good news here is that exhaust-flow numbers were typically up, if only marginally, over most of the as-cast heads tested.

In all, as a customer would receive these heads, we can say they flowed exceptionally well. The next move was to see what they would do when given a basic porting job. Basic, in the context meant here, is a porting job that can be done over a weekend by a complete beginner.

Ported Results - Our test porting job was done by T&L's chief head porter, L.J. McCleary. McCleary is well known for his porting skills, so we can hardly call him a beginner. That said, the instructions given were to clean it up and smooth it out only. No reshaping, just make it the way Kaase intended by following the existing casting form. When you are a pro porter, it is difficult to ignore all you have learned from experience, but inspec-tion of the heads after McCleary finished looked like he had followed our instructions pretty well although workmanship was probably a few hundred percent better than some first-timer's.

So how much extra flow did we see from this simple porting exercise? Usually, the better the heads are coming out of the gate, the harder it is to make much of a gain. The flow bench showed that the expected small increase just did not happen. Instead, a relatively big increase was seen, not just on the intake, but also on the exhaust side. Check out the flow curves in Fig 1. For the intake, this Kaase head with just basic porting came within a whisker of 340 cfm at the relatively low lift of 0.600. That is solidly in CNC-ported-head territory, and the exhaust was equally impressive with 237 cfm at 0.700 lift.

Dyno Time - We would like to have had a dedicated big-inch engine to determine exactly what these heads may be capable of in terms of power output. With the airflow they delivered, they certainly promised a lot, but, as we all know, promises do not always equate to horsepower. What we needed to really put these heads to the test was a big-inch, high-compression, big-cammed, big-carb (Dominator size), and big-intake-equipped engine. What we had was a T&L customer engine that, had it been equipped with conventional parallel (inline) valve heads with basic porting, would have cranked out about 625 lb-ft and 620 hp. It has to be said that these numbers are based on dyno testing similar engines in all respects other than the heads. However, dyno tests from other engines is hardly a true back-to-back test, so all we can do with the results here is make no more than a rough comparison.

Well, the dyno test did give more than an inkling of what these heads might deliver under ideal circumstance by producing, in the less-than-ideal circumstance here, 630 lb-ft and 632 hp from our temporary mule motor. How much less than ideal are we talking of here? Enough that any more manifold vacuum at wide-open throttle and the engine would have inhaled the entire carb.

One thing's for sure: For a cost of about $1,400 a pair from Jeg's or Kaase, these heads look to be among the most cost effective on the market today. We can hardly wait to try a set out on one of our own motors. If you want a ported set from T&L (and this includes porting and the seat job that goes with it), it will cost you $2,450. For this, you will get a pro porting job that will produce in excess of 345 cfm on the intake and 245 cfm on the exhaust