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Maybe one of the engine builders on here will jump in and answer. Personally I don’t see any upside to a larger gasket if your chamber is good with the smaller one.

I would not foresee any clearance issues with any 340 or 360 based motor. As far as shrouding, if the chamber can be taken to at least the bore line there are gains to be made. As Garrett said above, PBR liked to deshroud out to the fire ring on the gasket.

I get, and I totally agreed with that position until I tried it. Little to no negative effect in my bench testing, but i have no idea what the effect on wet flow would be. The bevel on the top of the bore helps a little as well. I’m not arguing a point at all, just throwing out some thoughts.

My preference on a max effort set of heads is the TF. I have one set that will be tested OOTB. Maybe the max effort set comes later???

There are so many things I would love to try. 45 vs 50 deg seats. 11/32 vs 8mm valves. Nail head vs tulip exhaust. But for me the big one is pushrod pinch area. If we run a test to isolate one parameter I would like that to be pinch area. But when pinch area is increased, other things...

I cannot disagree with the flow vs effort opinion on the TFs. They are impressive right OOTB. Such a tiny pushrod pinch though. As far as time estimates, I can only say I have a an hour or two each day over the course of 6 days in steps 1-14. But that includes a lot of flow test and...

Working on some heads for the @NC Engine Builder cylinder head dyno testing. Engine break in and first testing is with bone stock Speedmaster heads. We also have several other out of the box heads to test, but it would also be nice to test a few modified heads. There are several modifications...

BEST TOOL UPGRADES I added the foot pedal, metering valve and gun from this company. Big improvement over stock.

The radius of curvature can be anything you choose to grind.

I wish I had taken the time to investigate it more before porting the really good port. Your perspective is interesting, a bit different than mine. What I see is 4 ports that loose the short side flow at 0.550 lift and one that hangs on to the short side through 0.700 lift. Regardless of the...

Here's all I have on stock 190 CNC Trick Flow. I remember one of PBR's posts where he talked about spending 8-10 minutes on each port to get them to flow 300-305. He never said what he found but my guess is that it's short side related.

Tying up a few loose ends from yesterday. PRH asked about test/flow data on the TF head with the swirl vein removed. I do have a little bit of data, but it would be meaningless to post it. The port is so dissimilar from anything else that a comparison is pointless. I've just made too many...

That's what I'm betting on.

Agree. Then add to that the inner runner vs outer runner angle of approach.

I could not agree more. He put a lot of information out there, for which I am quite thankful. There are little clues posted throughout his writings, but rarely all in one place.

By the way, that TF port with the 2.08 valve is around 210-212 cc now. Most of that additional volume was needed to get flow past 0.550 back up to a respectable number. If the pinch was left smaller I think the port could be left smaller. I’m going on the assumption that the larger pinch is...

My experience so far is that any standard location pushrod, standard low port SBM head will get increasingly inefficient after 290-300 cfm. There are just too many tight turns and area changes to navigate. Gains above 300 are an exercise in compromise. You gotta give up something to get...

It sure is nice to see two mature individuals resolve a (small) conflict without insults and unnecessary language. Thanks guys.

I agree with what you are saying, but I like to see other data. PBR and I would share some data, sometimes publicly, sometimes privately. We compared stock Speedmaster, Edelbrock and Trick Flow flow numbers. My bench and his agreed quite well. That doesn’t mean either one was correct, but to...

Superflow 600. You?

Post away. It ain’t controversy if we’re learning.

The ‘tall apex’ is just to differentiate it from the short apex. Even the tall apex is a good bit shorter than stock. Once the 2.08 valve was in and the pushrod pinch was opened, speed in the center of the short turn was over 500 fps. The tall apex is still 440 fps in the center. The short...

Here's an interesting comparison of 4 tests on Trick Flow Ports. Two are with a 2.02 valve and two are with a 2.08 valve. There are many points to be made here, but I'll start with three. First, look at test 1231 in green, which is a totally stock port. This port at 308 cfm is the highest...

@Cuda416 is right on with the flow specs. My testing has a stock Speedmaster at high 240s/low 250s at 0.500 on the flow bench. Should be pretty good for a 340/360 on the street. Head would be a little small for a 400 ci+ motor. At a minimum I would clean/wash the heads good, check valve to...

Nice chamber.

I’m guessing they are a powdered metal. One or two seats will dull a new carbide cutter. Nicks/lines start showing up quickly. Chatter potential is much worse as well.

Largest gripe I have about the SM heads is the hard, hard seat material. Seats are a pleasure to cut on the ProMaxx and the TF compared to the Speedmaster.

ProMaxx casting on top. Speedmaster on the bottom.

Two different foundries. The ProMaxx is a Stephen Sun casting.

As I recall John liked the Speedmaster better than the Edelbrock, but he liked the ProMaxx better than the Speedmaster. In trying to get ready for the cylinder head challenge, I’ve run hundreds of tests on the SM, ProMaxx and TF. If ‘potential’ is the criteria, my ranking would be TF then...