Interresting dyno test comparison

A customer brought me an older FRPP B460 crate motor to be refreshed because he was installing it into a different car and wanted to keep the stock hood so, a change of the intake to a Torquer II from a Victor G429 intake manifold was in order.

For information; this engine came with modified Federal Mogul H612P hyper pistons, a C460 FRPP hydraulic lifter camshaft and B429 heads. A homemade "cloverleaf" spacer 1" thick, (made from a 4 hole with the center cut-away), and his Quick Fuel Q-950 carburetor was a constant.

He wanted to dyno test his intake with port matched runners, (just to run the engine and get a number), but, wanted to do it in stages.

For the initial test, I ported just the #1, #3, #6 and #8 runners of the manifold. (Those runners are WAY off as to their initial location to the Cobra Jet ports).

565 lb/ft of torque @4,500 RPM
519 horsepower @5,900 RPM

Took the intake off and port matched the remaining runners;

543 lb/ft of torque @4,600 RPM
532 horsepower @6,200 RPM
It gained some RPM and 13 horsepower but, LOST 22 lb/ft of peak torque from the first test.

I wish we would have tested a totally unmodified Torquer II because it seems that the 4 runners "off" the most are much more important.

Always nice to see back to back tests. Thx for sharing.

reason for the torque loss, is the port match. The runner is now backwards shaped, instead of a linear or tapering cone into the head, the runner expands as it leaves the plenum, lower RPM air velocity is lost. As the RPM comes up, and the "shortage" of air volume is imparted, the increased runner size has a greater air charge available than the small runner as per valve open dwell time.

Reverse taper...it seems.

This certainly is not any "big shakes" to a lot of people however, I found these results to be interesting, to say the least.

There was some but not much taper either way in the finished intake manifold ports as the "match" went up 3 inches or more into the manifold.

Question for Randy? Have you ever tested a SCJ factory intake to say DOVE unmatched intake ports, and then port matched them, and dyno tested both ways. My SCJ intake is semi portmated on all 8 cylinders, but they are not fully enlarged to the intake runners. I have away heard a litte air fuel disrution is a good thing, in some cases. Ford used to claim 25HP gain by bolting an SCJ intake on unmatched to standard port heads. Instead of the reverse taper Torker intake deal, mine with the SCJ intake is opposite, and I think of it as the funnel prinicple. It would seem to increase low RPM air fuel velocity, is this correct?

supervel45 wrote:Question for Randy? Have you ever tested a SCJ factory intake to say DOVE unmatched intake ports, and then port matched them, and dyno tested both ways. My SCJ intake is semi portmated on all 8 cylinders, but they are not fully enlarged to the intake runners. I have away heard a litte air fuel disrution is a good thing, in some cases. Ford used to claim 25HP gain by bolting an SCJ intake on unmatched to standard port heads. Instead of the reverse taper Torker intake deal, mine with the SCJ intake is opposite, and I think of it as the funnel prinicple. It would seem to increase low RPM air fuel velocity, is this correct?

Actually, YES I have - kinda... about 30 years ago with a D3VE head.
As I remember, port matching the intake ports of the head did absolutely NOTHING, (or very, very little one way or the other), for torque or horsepower on a mild performance marine engine.

It looked better though, LOL.

Rand, I'm glad you are 'playing' with the Torker II.....it's very much underestimated for several applications i.m.o.

does this mean in some applications Port to port matching is somtimes hurting more than helping

5pointslow wrote: does this mean in some applications Port to port matching is somtimes hurting more than helping

Not really worse OR better but, definitely DIFFERENT in most cases.
It will depend upon WHERE you want an improvement and where you can afford to accept a decline.

BUMP ... for the recent phone call I got.

Interesting info. on this type of topic over on Speedtalk. Many engine builders have discovered that on BBC builds when using a mismatch intake to head port i.e. rectangular port versus oval port they make MORE power with the mismatch as opposed to rect./rect. or oval/oval intake and head ports. The general consensus was the flow distribution/disruption contributing to a more dense air/fuel charge. Almost like the old "swirl" debate. Interesting stuff. Much, of course like every other build, depends on parts combination. What you thought you knew...