Could you live with the engine having to run under a load way below where it starts to come on the cam?

I wish my engine had some compression, you can just tell when something fires up when it’s got done squeeze to it! You can feel it !

I don't admire that at all. I don't get it

It's all a perspective, and the intended purpose of the build. One man's idea of a "small" cam may be gigantic to others and vice versa. What do you classify as a small cam ?

Those guys hang turbos.

Was is static or dynamic compression?

That was 30 years ago. I don't remember getting into that. But it explained perfectly to me why diesels are so much more efficient. My classic car has around 10 to 1 (Static CR) vs my wife's VW New Beetle with a diesel engine at 19.5 to 1.

@@BarrySCrawford dynamic CR is always less than static (since your intake valve usually isn’t fully closed at the start of the compression stroke and some air gets bled off). Regardless, I just finished to book, “the Mysterious Case of Rudolf Diesel.” It’s about the guy who invented the Diesel motor, it wasn’t as technical as I thought it would be, but quite the twist ending. You should give it a read, I feel like any car guy (even one not into Diesels like myself) owes it to Diesel for his invention. The book explains why he was kind of erased from history, even though he was right there in the mix with Edison, Nobel and other big inventors.

yeah oval port vs rec id pick the rec ones too if i have a big block like that. i guess it about which heads youd go faster with. but if youre not seriously racing yeah, id go with the cheaper promaxx too. i might do the 180's on my 302 windsor that i want to stroke

Agreed

That is a term that has been carried on for years, and shouldn't be used as such a blanket comparison. Port dimensions are relative to a targeted rpm and power level. To blanketly say Small ports make more torque down low and large ports are for higher rpm but kill torque down low is completely inaccurate. The CORRECT port design will make more power EVERYWHERE in the curve. So to assume a smaller port will make more torque down low is relative to what it is being compared to. Since a "smaller" cross sectional area will ALWAYS make LESS power than the correct port with the correct CSA for any given application. It is also true going the other direction with a larger csa port. The port design and size is only too large or too small when compared to the correct port. To say a small port makes more low end and a larger port kills the low but makes it up higher is NOT always the case. It's all relative.

The 5 angle valve job

They are not new. Hot rod magazine had them in a sbc the 1990-2000.

I look at small port heads as a governor, all they do is limit the top end. I used to believe it but look at modern manufacturers are doing... 6.4 hemi truck head is huge and makes great tq, LS3 is really big and still makes great tq, 5.7 hemi eagle head flows 330 cfm and makes great low end tq. People will point to the 351 Cleveland 4v but the port had other problems not related to size as well as the big head was also combined with big cams usually that killed low end more than the big port did.

@@davidphillips3953 Yes, the newer manufacture designs, especially the LS series and the gen 3 Hemis lead me to believe it might have something to do with the pushrod pinch, as those engines don't have near as much as the SBC. My theory is that the head porters of yesteryear designing bad ports and I will explain it below utilizing the SBC, as it's the most common street/strip and race engine. On a SBC, the pushrod pinch is very narrow. In order to gain area, porters want to make the port taller (Think cathedral port LS heads). However, there is only so much area that can be gained due to needing material to seal the intake manifold gasket. Why is the push rod pinch the tightest area? for both SBC and BBC, two ports are trying to fit between the same two pushrods in order to keep the intake runner length similar up to the carburetor plenum. This isn't a problem on the LS series, Gen 3 hemi, or old school SBF. The LS and Gen3 Hemi run Port Fuel Injection. thus no need to bend the end four intake runners to one central location. The runners run relevantly straight to a long plenum. For the SBF, runner length varies dramatically relative to the SBC. The same runner variance can also be seen on carburetor versions of the LS and Gen3 Hemi. Okay, So GM decided to cram two intake runners between two pushrods and created a problem while solving another. How does this perpetuate to idea that smaller runners make more torque? The answer doesn't have to do with the pushrod pinch but the area after the pushrod pinch. In a time before the cheap aluminum castings and CNC porting, ported cylinder heads were mostly stock cast iron heads ported by hand. To gain area, grinders would grind the area after the pinch, creating a large cavity. This looked great on advertising the CC of a ported head, but in reality, slowed air velocity. Grinders would also drop the short side to gain CC's, but due to the steep valve angle of the SBC, would cause air to detach from the intake floor and "jump" the short side instead of following the short side to the back of the valve. I doubt that many old school porters worked the pushrod pinch much for fear of breaking through to the pushrod and costing a small fortune to fix correctly or sourcing another head and starting over, both cost time and money. I have a theory that these porting "tricks" led to soggy bottom end performance due to the poor shape of the intake tract in the head. As the RPMs climbed, air would be skipping over part of the large cavity and flow would increase some. And as SBC is the most common performance engine, the legend was born that big heads produce less torque, because ported cast iron heads had bad intake ports. Therefor the idea became a wives tale that hasn't left yet, even if it has been disproven with good designed intake ports on modern heads.

No

MLS same thickness for all testing.

Or a Pro Systems SV-1

Hard? It's impossible, and shouldn't be done. The day they make a flowbench that mimics a running engine, then maybe. Engines don't run at a steady state of 28"...

No. The actual lift is .630. The cam lobe would be .370

@WeingartnerRacing Thanks bud. I have never heard the rocker mentioned from any head/flow person.

Dyno proves the combo. One nuance to take from this is an odd look at the same thing: compression ratio. Where am I going? The combustion chamber serves as a cross connect device between exhaust and intake systems during overlap, and looked at from a scavenging perspective [meaning negative signal to the intake]... its an accumulator. Anyone ever dealt with hydraulics before has dealt with a positive signal end, but principal is the same: the smaller it is, the sooner pressures equalize/faster response time. VE should improve as chamber size decreases. When people say a bbc is undervalved, maybe thats true because the chamber is pretty big? [I include piston features as part of effective chamber size at tdc]. I wonder if anyone did work detailing bore/chamber ratio behavior... I don't recall reading that anywhere.

Yes. It did bad.

The same for both

Yes

I don’t think that made much of any difference. And you can make what you want to see happen. Just look back at the previous dyno session when the head wasn’t milled and the head wasn’t ported. You could buy the pdf and book and see it better.

Yes.

I don’t know if you have seen my face but I have a face for radio not tv.

Yes, I have. I ain't saying you're pretty but you ain't ugly. haha. Have a great day.@@WeingartnerRacing

@@lollipop84858 Smart folks then

I guess you could invest your own time and money to test. A couple of things one of if I did what you said the modification to the chamber would have changed the flow figures as much or even more than just going to 50degree seat. So in the end same scenario. It would also have altered quench area more than just milling. Not smart. Second it would have made less power than what they are now. People want more power not less. The reason most didn’t say what you did is not because they don’t have stones it’s because they listen, learn, and move on. Not complain because they wanted something different then contradict. A chihuahua doesn’t have more balls than a Saint Bernard. They just bark more.

​@@WeingartnerRacingI learned valuable info that backed up my theory on head choice. I'm using the same camshaft with a 110cc chamber head. I'm using the track as a performance meter though. Once I'm satisfied that I've gotten the best out of it, I'm switching to a set of 330 cfm intake runner heads with 130cc chambers. I'm having fun already! Thanks for a great channel Eric