We have M311’s on our LS427 built by Thompson Motorsports. I wanted a high torque engine that could if need spin to 7,500. These heads are so efficient they do both. The engine makes 542 wheel hp and 539 wheel torque. The dyno guy ran extra runs and recalibrated his dyno because the engine pulled so hard he thought it was a mistake. Frankensteins are the best imo.
Cylinder head manufacturers rarely if ever provide anything other than port volume and flow numbers. What else are people supposed to argue about? I’d love to see intake flange CSA, min CSA, port length, location of MCSA, throat diameter etc all published but it’s not even out there for OEM heads. Love the idea for this series and can’t wait for the other videos
A SBC Gen 1 vs Gen 3 & 4 is a perfect example. Put 240 cc heads on the same CID engine with the same cam specs and exact same intake manifold design and the Gen 3 & 4 will make more power across the board, every single time. And I'm a SBC guy though and through. I just know there's a huge difference. The primary one being valve angle.
I hear y’all, that’s what I try to look for when looking at heads. I learned that from Eric weingartner. But the only problem is, barely anyone will advertise their csa, or port design, and therefore the only thing to go off of is the port volume. Which I take with a grain of salt.
I wish people would just stop with cylinder head port volume. There is no such thing as cylinder head port volume. There is only intake track runner volume.
Do you ever run into a factory head that is harder to improve upon vs when you make your own castings and design your own port? For example the factory ls7 head likely has a larger cross sectional measurement than your custom ls7 head. Have you found any factory heads that seem to go backwards by messing with the ports?
All those No's are surly aimed at retail sales for the guy who likes playing with a hobby car. Surly it's the same with cam shaft cards. Gives a reasonable idea of what it does, but if it makes 50 hp less or 20 hp more than what Joe Bloggs offers for $200 less; does it make any difference?
All I understand, is a 350 CC BBC head will feed 500 cubic inches to a certain RPM 7500 approx & a 215 CC Pontiac head might support a 474 CID engine to 6300 RPM before it chokes. Shape impacts the ports performance, but I'd much rather have room for a larger volume than be undersized. Small ports can only feed so many cubes for so many rpm. Bigger ports have better chance at making higher HP & Torque at a higher RPM and may not give-up anything down low. The heads are the lungs of the engine and control the ultimate RPM capability, no matter how much cam you have, or short-block modifications. The smallest port that moves the most air generally wins, but Pontiac & Mopar to a slightly less degree are under valved & port volume stinks! You can buy off the shelf SBC heads that have larger port volume & flow more air than any off the shelf Pontiac head. Most everyone building Pontiscs build large cubic inch motors, otherwise they can not compete.
95+ % of people in the comments section do not know much and have never even ran a 12 second pass in a 1/4 mile… and they are also the ones offering the most advice and talking the most shit
Sbf heads always seem to have less port volume than sbc.. I’ve wondered how much of that is because of port geometry, valve angle etc?? How do sbf and sbc heads compare that way?
Port or runner volumes were not even on the list of required figures for Dave Crower when he spec'd out a cam for me. CUI and head Flow numbers from .100 - .700 at every .100 increment was the largest thing he required.
This video wasn’t referring to all camshaft companies. There has been a trend lately from several different so called Camshaft experts telling people how to choose the correct cylinder head based on port CC. There are several very talented Camshaft experts who have my respect, but those that are ignorant enough to try and talk on a cylinder head topic in which they have no experience are just idiots.
If I’m being honest here, I bought your M311 heads based on port volume… 🤣 But in all seriousness, you can’t find information like this very easily. Great video!
Hi, A great video. I think the biggest problem you have- with LS customers AND they are your biggest critics? They are the dumbest/ cheapest racers on the market.Dumber than mopar guys, cheaper the pontiac guys.. So you are faced with dumb cheap guys who know how to work the internet. Good luck. You will need it.
Your attention to detail is making it all too difficult....simply design a cylinder head with an intake port the size of a 55 gallon drum and it will produce huge port volumes and crazy good flow rates. Therefore, it should make the most HP across the broadest RPM range for a given engine size, right? BTW, I am a certified internet expert! ☺
NA talk.. Turbocharge your vehicle if you want more time with your kids because all this information doesn't amount to a few pounds of boost If you have spare coin by no means do what he says-for the majority of us this don't mean shyte this is just another industry turbos are taking away from the NA boys
You missed the entire purpose of the video. CC has a lot to do with turbos and this video had zero NA only information. You are the exact person who should be watching so you can understand the differences. Port CC effects all combos NA, turbo, blower, nitrous. If you step back and listen and grasp the topic, you’ll then learn this was a generic video on the fact that port cc is not the way to judge a good or bad cylinder head.
This is the reason people need to be educated more on cylinder heads. Flow numbers are just a reference number, and most of our competition fake big numbers to sell cylinder heads to guys like yourself who don’t know any better. Sadly, flow number are just a by product of design and application. Keep watching and I’ll dive into flow numbers in a later video, and I’ll show how those numbers can be misleading.
@frankensteinenginedynamics1380 - for me, it's not just about peak power... it's about area under the curve. That's the reason why I've always preferred Edelbrock street heads over others. In every dyno comparison I've seen, they get more flow with less volume and valve diameter than their competitors. For years people swore 2.02 valves were the only way to go for power... but I've seen Edelbrock 1.96 heads beat more 2.02 valve heads than I care to count. Volume does make a difference when you get up over 7,000rpm, and can keep enough pressure fill them (also knocks back reversion)... but in most street applications (save for a max cubic inch builds), it's all about flow+velocity. You need both. Flow is always important. I think the major difference you're seeing to your competitors, is the engine beneath the heads. You can have the highest flowing heads in the world... but if you don't have enough bottom end to take advantage, it's pointless.
Hard to find knowledgeable folks that deal with forced induction heads, Such a tremendous void exists for a HUGE Market, Somebody will make Millions off the right formula. Coast to Coast Diesel Enthusiasts will continue advancing in the diesel industry, Such a Fantastic Community!
I just saw a video where someone said the description of an expert is someone who has done it for 40 hours a week for 5 years i think. Some of these people are couch potatoes experts that can run a key board lol. I love these type of videos, love learning. I’ve learned the volume is nothing unless it’s the same brand and type cylinder heads. Glad I found this though. Kings already knew what you were saying, but would love to hear more, like taper rate, wet flow, stuff like that.