The Secret Life Of Your Engines Cylinder Heads - How Combustion Chamber Shapes Make Power

When we talk combustion chambers we usually think in terms of compression, CCs, plug placement, valve size and shrouding. But, there is an important element to every four cycle engine's camshaft profile called overlap and the relationship between the intake and exhaust valves, as well as the rest of the chamber, dictates how effective that overlap is on initiating intake flow into the cylinder.
#engines #tuning #camshaft
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[@brocluno01]

So now you need to have an episode on Bob Glidden and welding iron heads to get dual quench areas and small "heart shaped" chambers. A lot of pioneering work was done in his shop. And he never showed his heads to anyone. They were always covered. 10 Pro Stock championships with 5 in a row tells you that he knew what he was doing. Many aftermarket heads emulate Glidden's pioneering work. 👍

[@contraband1543]

If no one ever saw the heads then how did they even know he was legal to race? I hear stories like this all the time and I dont see how that makes sense. Dont they see the engine bay during inspection? Do they just take his word it's a legal size engine? I dont get it.

[@artsomniacv-logcitybydanie1249]

@@contraband1543 It's possible that if the heads are just meeting the requirements of what getting the requirements of what metal they are, That they wouldn't have to see anything. I would assume they are allowed larger valve size and port work the port work but probably they do inspect the cylinder diameter and the piston compression And the intakeAnd feel delivery system... Outside of that I don't think they care too much about the rest because you really can't cheat any other way with heads unless you change the metal? ... Especially if it's a stock Sized cubic inch class, Heads might not even matter at all.

[@Jubr123]

Bob gliddens clevelands ran like a Big block 😎

[@fustyblatherskite2142]

When the Ford Cleveland heads came out, they had real good combustion chambers. Then to meet emissions Ford adopted a lousy open chamber. The worst thing wrong with the Cleveland heads were the exhaust ports. Every one of the racers spent a lot of time trying to improve them.

[@artsomniacv-logcitybydanie1249]

@@fustyblatherskite2142 I think I know what you're talking about because I Opened up those exhaust ports... It's almost like for a mission's reasons they just close closed up the exhaust hole and recast the head the same with smaller ports... It's almost like you could see how much to take off off by the casting marks

[@jseal21]

This is why I watch your videos religiously. You didn't say ANYTHING that I didn't already know, BUT I still learn extremely valuable lessons. Thanks for reminding to look beyond the nuts and bolts and remember to look at the effects on the WHOLE system.

[@smokecrackhailsatan]

I don't have a project car, never have, not really any plans to ever build one. I just love how Tony explains the (frankly pretty complex) physics of what's going on in a way that's easy to visualize. Find these videos super interesting.

[@darrellclark8112]

I have only heard one other person talk about this subject. Smokey Yunick talked about this back when he was doing a column in Circle Track Magazine.

[@UncleTonysGarage]

And that's exactly where I learned about this 40 years ago

[@daverosinski3663]

I wish Uncle Tony would have been my shop teacher in High School.('67-'71) I learned, yes , but nothing like what he teaches in these videos. Thanks for doing these.

[@dadalebreton184]

I just commented the same "I learn from his contents and teachings". He uses details that no others eather skip or don't know themselves. Your looking for specific detail and can't find it in 2022 on the web? I just hate it. Hehe

[@DwayneRouthierJr]

I'm 31 years old and I've never heard this talked about anywhere! The visualization using slaghammer was excellent! The yearning I have for knowledge like this is worse than trying to quit smoking..... I NEED IT. I was going to say " this is what I subscribed for" but I found out I wasn't subbed anymore...

[@williamstamper442]

Best way to achieve what you yearn is to get in there, get your hands dirty and just start doing it. I know life, family comes first but try to leave yourself some time for you. Don't take from the family budget but put a little aside for projects and buy, sell, barter parts and services to pay for go fast stuff on a real world budget. It can be done! Just don't wait too late to get started. There is no such thing as waiting too late, the only reason I said that is you are missing out if you don't start now!

[@williamstamper442]

Instead of an Edit I just wanted to add this comment... Find some like minded people near you and try to hang out with them. Sometimes one can satisfy their car guy yearnings thru others projects and then you are not even on the hook for the overall cost! It's at least one way to "get into it". Of course I still think you need something of your own as well. Good luck bro. Wish you the best.

[@DwayneRouthierJr]

@@williamstamper442 Thank you for the kind and inspiring words! I gotta tell ya though, I was born into the "sickness".... Literally. My grandfathers were hot rodders in the 50's, one with cars the other with OTR trucks. One passed when I was 5 the other when I was 9. The majority of what I've learned I've learned by doing what you've stated and through books. I'm a lot like uncle Tony.... Junk everywhere.... Cars everywhere... But it's these little tidd bits of info I wouldn't otherwise think about that I long for. There's only so much that can be learned from a book.

[@williamstamper442]

@@DwayneRouthierJr drag strip is another good place to hang out and talk and learn info and maybe a new crew to hang with. If we lived nearby I'd get fired up by your enthusiasm and before you know it we could be knee deep into a project. Try car shows and local shops. Find like minded people to hang out with

[@williamstamper442]

@@DwayneRouthierJr I'm 53 and live in Detroit. I'm half hillbilly from eastern Kentucky too. There are like minded people all over our beautiful country called America! Seek and ye shall find!

[@vernrosenburg5410]

That concept of exhaust scavenging to help fill the combustion chamber has been used on two stroke diesel’s from conception. Never thought of it in gasoline engines. It makes sense. Thank you for bringing that information to the forefront.

[@jamesgeorge4874]

In the 2 stroke Detroit diesel a blower does all the scavenging, there is no "exhaust stroke" all the "intake timing" is in the port size and location. There is one camshaft for the exhaust valves.

[@matttravers5764]

Uncle Tone's mechanical talks are the ultimate mental health therapy!...😎

[@alexgillies4183]

I always figured the quench parts of the head were to raise the compression without having a big flame-front blocking mountain on the piston as well as getting some swirl; I've never heard of the concept of it influencing the overlap but as soon as I heard it explained it made perfect sense! Thanks for giving us gear-heads something new to ponder!

[@texasmopar5557]

Im doing the same thing with a hi output 318. I put 1.88 valves and ported 302 heads. Fun winter project.

[@arthurrose6473]

Interesting to see what you configure with the combustion chambers- Dave Vizard would be the perfect brain to pick for insights. He also has an appreciation for classic Mopar engineering from those days, and rightly so!

[@ogt92fromthe1step9]

He has several videos out on quench pads, swirl port, valve unshrouding and different degree valve angles with a flow bench numbers to back it up. He has some really in-depth videos where he cut cylinder heads in half and shows you how to port and polish and open up heart-shaped cylinder heads. The man is a wealth of knowledge. 💪

[@Sam-zp5rd]

I wish somebody would have explained this to me like you just did 30 years ago! Would have saved so much trial and error. Thanks

[@uurkr9581]

Nobody talks about how awesome you are. Thank you for another mind opening video.

[@UcantBeSerious03]

Why do you have a traffic cone on the work bench. I'll see myself out!

[@rustybritches6747]

LOLOLOL HAHAHAHA 😆

[@lilmike2710]

Can't you see? That's clearly a Tennessee Vols megaphone.

[@buckley94thmp]

Orange you guys going to be serious?

[@mpetersen6]

That's not a traffic cone! It's a Turboencapulator!

[@ctsingletrack]

It's for autocross later

[@craigiefconcert6493]

I’ve never taken an engine apart or done any of this stuff but I love UTG! I’m just a home noodles trying to learn. I changed my timing belt on my 99 CRV and now I realized I got my intake cam off by one tooth. It runs but uses too much gas. Now I understand the importance of the intake and exhaust valve timing.

[@gordocarbo]

experience is more valuable then reading info imo. Keep at it

[@douglasmcroberts9586]

A natural instructor! Could give training lectures on any scale to any audience! World class !! A snazzy suit or casual, he could teach surfing ! A very- very interesting instructor. He makes learning fun!!!

[@dongeorge4037]

I always learn something (that I consider to be) important when I watch your presentations.

[@billjones9292]

Fascinating. I learned of the importance of overlap in air cooled aviation engines but it was to cool the exhaust valve, thank you Tony. PS I thought pointing the spark plug towards the exhaust valve gave it the most boom.

[@billybradyjr6008]

I heard that to. I remember guys indexing the plugs back in the day.

[@WildDisaster]

Pointing it towards the exhaust valve was to prevent pre-ignition. That's pretty much when the incoming charge gets ignited before it has filled up the combustion chamber. By pointing to the exhaust, the intake charge fills up the cc and is fully ignited, but the rate by which it ignites also becomes a factor. Igniting a full intake charge and the rate by which it burns is directly affected by overlap.

[@lautburns4829]

I was 12 and loving engines for the first time. I ran a little Clinton engine with various exhaust pipes and noticed that the thing wouldn’t run without some kind of pipe. My dad built houses so I had piles of copper pipe to play with so I would hammer out pipes that looked Kool and fasten them it the little Clinton engine. What I found was a piece of 3/4 inch ran the best. But if I held a pices if pipe about 1/8 inch from the exhaust port it would run but moving farther away the engine would sputter and quit. Later in college physics class I learned why. Interesting you bring this up today. Boy I love high performance engines! Can’t wait to see your development on those heads.

[@grantsgalaxy687]

The new gen hemi has quench pads and the straight through flow and the engine does not like tones of overlap in the cam. And as a small block chevy guy we pay big attention to combustion chambers . Lots of old pistons for mopars had a quench dome ,it was for closing that open style chamber up

[@humblestate5737]

I'm only 5:57 into the video, and I had to stop and commnt, to say this guy is spittin knowledge hard. I've talked the talk, walked the walk, and burned through a few engines, transmissions, and tires, but I never knew some of these details like I know now. Buddy is building an L72 for his '66 Vette and I'm piecing together an LS7. This info will go far and I know I will never forget it.

[@russwilkerson2741]

Now ya just blew my mind. I always thought overlap was the delay between the exhaust valve closing and the intake opening. I still can’t picture this yet. Piston traveling down = intake Piston traveling up = exhaust

[@frank3RV4]

Uncle Tony, your explanation makes total sense to me! I have read a lot of textbooks, articles and always seek good information. This video of yours is an out of the park home run! I have learned a lot from you. Thank you for sharing such good information!

[@MichaelBrown1432]

Tony, What a great way to explain how engines work!

[@needmoreboost6369]

I’m glad you brought forced induction into the vid it’s often assumed it’s exactly the same as n/a but it’s definitely not, my own gm v6 had a closed chamber but with dished pistons with a detonation prone large squish point so I’ve been developing and trying different chambers and the most recent are completely open and it’s got excellent off boost drivability and response and it’s almost detonation proof with 9.3:1 comp running under 30psi of boost on 98octane

[@ewconway]

Excellent educational video on combustion chamber dynamics, flow, overlap etc. I really learned something new watching this video. Thank you for your lecture and knowledge. 👍

[@alxf66]

This was super informative and well explained. Thank you!

[@curtisanderson9984]

Great explanation Tony. I was always curious as to the differences in the Boss 429 and the Hemi. Maybe you can do a video on static compression, dynamic compression, and cylinder pressure. There seems to be a lot of confusion in this area. Thanks, and keep it up!

[@duanebiesterfeld4719]

I know about the pulses but putting that together with the overlap was something new to me. Thanks!

[@Trikekid84]

Great video, I keep applying v8 head knowledge to my 3 wheeler. It's like your Harley head, hemi shaped, canted valves, I raised the compression and it definitely helped.

[@fc3sboy1]

Uncle Tony. The absolute best example of overlap and collector design is the rotary engine. If you talk just overlap 2 stroke is where you look. There can be 100% plus change in power out put along with rpm of said power out put by the over lap and collector and header design in a rotary and 2 stroke

[@rong4189]

A couple other things you don’t hear much about the SBM is that the plug is about as centrally located in the chamber as you can get for a wedge head, and the valves open closer to the centerline (max width) of the bore for less valve shrouding. But the factory ports aren’t ‘great’ so they need all the help they can get, as in, swap ported 360s on! lol

[@vipottaja]

One way to evaluate the effectiveness of a combustion chamber is the spark advance needed for best power. According to mopar performance, best for SB mopar is 35, Hemi 36 and BB 38 degrees total. In a Magnum it's about 32.

[@ChrisTheBmxGuy]

@@vipottaja good points but it also depends on bore size. Typically bigger bore you need more advance all else being equal.

[@albertgaspar627]

@@vipottaja like Chevy Vortec heads versus anything they made before them.

[@donmcindoo2304]

Please continue to shoot videos on your progress I am very interested in this sounds like a really cool project

[@UncleTonysGarage]

I'm planning on a full build for this coming spring

[@griffittsgarage]

Ohh my favorite topic! Cylinder heads and intakes. Cheers Tony 🏁

[@c-man5679]

I love how much information you give thank you.! I translated to my Volkswagens and it is extremely helpful. VW has a long intake manifold and everyone says get dual carbs but I didn't listen and got a single two barrel.. so I need a strong signal to pull the fuel from the center carburetor and now I know how to fix my problem you're a genius

[@electronicengineer]

You are an absolute plethora of ICE knowledge Tony. I continue to be impressed by the information that you share. I always learn something from watching and listening to you. Thank You for sharing your absolute wealth of knowledge with us for free. You are a good human Tony.

[@michaelmartinez1345]

This is a very good episode Tony!!! The movement of exhaust gas through the exhaust system, causing a vacuum behind each pulse that helps to initiate the flow of the fresh air/fuel mix into that cylinder, because of the breif moment of both valves being slightly open at the same time - aka- valve overlap.... When I was going through A&P school, the instructors explained that valve overlap was an event that took place to cool the exhaust valves... Looking back at that training, I remember that everything was to emphasize the reliability of airplane equipment.. A very small emphasis of how to tune for more power and speed was being taught in those schools... But I now tend to believe the reasoning that You give here Tony... The overlap is a function to improve responsiveness and performance of 4-stroke reciprocating engines...

[@JoshTolbertUrbana]

That definitely explains the pent-roof chamber thing...They wanted the benefits of the hemi's canted-valve setup with the more-direct intake signaling, but they wanted the non-valve areas closed down as much as they can. Hadn't thought about it like that before.

[@williamstamper442]

Tony I'm not a mopar guy and not a chevrolet guy, but always been a fan of closed chambers, compression and cam timing with intake closing being the most important event. And testing is the only way to find the sweet spot on the cam design. I haven't bought an off the shelf camshaft for my own projects in over 30 years. Yet with all I said, I know there is much more to be learned about combustion chambers design. Ok I'll let the cat out of the bag, I'm a lowly oldsmobile guy. I have a stock stroke .030 bore 455 that makes 625hp/640tq on the pump with a single carb single plane. Currently running a custom crane hyd roller with a standard iron distributor drive gear on the billet shaft so I didn't have to worry about bronze gears. The cam is based on LS chevrolet lobes, it's .620ish lift 255/260ish @ .050 duration on a 110 lobe sep. I know there is more power if I tweak the grind but I'm tired of juice lifters and wanna go solid roller next. Goal is 700hp normally aspirated all Olds, and I'm on my way. The info in this vid is just part of the answer but well done presentation and I hope others pick up on what you are throwing down!

[@williamstamper442]

Instead of doing an Edit on my own comment thought I would just throw out another one. All this combustion chamber talk revitalizes my desire to build a custom head for the brand of my choice, which is Oldsmobile, and what I want to achieve is a canted valve, a la big block chev (the porcupine) and fit them within the space given. Reason is this cross flow theory/dynamics Tony is talking about in the video, but doing so by unshrouding the flow around the outer sides of the valves. Valve shrouding kills more power than many other things when the inherit design is a 10 degree head with the valves in the same plane. I believe a canted valve in an aftermarket aluminum rough casting cyl head for Olds may finally achieve the 400+cfm mark to make this engine more competitive. I could be wrong with this but sure hope to try it before I die. Around 1969 Olds engineers designed a near "hemi" design based on a standard 455 short block. I'm a die hard Olds guy and forget the freaking designation they gave this engine. Maybe it was called a W-43? I don't know I gotta look it up... But they actually built a running version decked out with stock accessories of the time to actually go into production. But 1971 and emissions kinda killed it. I believe they only built 2 or 3 of them. One is on display in the GM car show trailer showing innovations and different engines the company built over the years. Far as I know there are no running examples out there in the real world as of 2022. Thing is I wanna make a cyl head out of aftermarket aluminum to kinda achieve the same thing. I'm not gonna set the world on fire but if I can bring a new found respect for the Olds name then I'll be happy.

[@Dakiraun]

I love the details of stuff like this - learn so much from your videos Tony!

[@matthewbakker8113]

David Visard discusses this in his books and on his channel. It is sometimes called scavenging, a term more often associated with 2 strokes. Thats also why cleaning up the intake valve bole and a 5 angle valve job has disproportionate increases in performance than one may expect.

[@donaldhill2775]

Love your engine stuff ! Often thought provoking and achievable without remortgaging the house 👍

[@tobygathergood4990]

Most interesting Tony. It's almost like listening to my grandfather explain the very same things years ago to me, (I'm almost 69 now). About 20 years ago I created a set of 400M heads with "squish" areas like a 460, but built for the 531/400M engines. They ended up working very well. I have a set off, and if you would like I will dig them out and take a few pics and send them to you for any sort of reference that they might be good for.

[@douglasmcroberts9586]

I think tony is genius! Down to earth and truly caught up in his presentation. If he taught math i would probably learn math- and enjoy it, Impossible!!!

[@jamesblair9614]

Welding and modifying a cast iron head combustion chamber, you know I’m going to be following this series closely.

[@benjamintresham9649]

There’s some good videos on KZbin that shows intake and exhaust flow on engine’s with clear cylinder heads

[@nickcinalli6145]

Great tutorial Tony love to see how you weld those heads to get the desired results thanks mate

[@TinkerKing209]

You are literally the uncle I wish I had. Love you brotha. Thanks for the time you take to teach us.

[@robflammia4716]

That's the content I need to feed my head. None of the ev bashing . Just motor stuff

[@tabbott429]

Very informative and helpful. On My '68 396 BBC (bored to 402) short block Im running some late 70's open chamber large OVAL port heads from a dump truck 366 bbc w/ SMALL valves ( 1.92 intake /1.64 Exhaust). The small valves give REALLY nice low end torque for taking off from a stop but arent designed for much above 4500 RPM. I found a set of 68 closed chamber Heads with the 2.08 int/1.75 exh more suited the the original 396 power levels which i may swap at some point. In a 58 Chevy Bel Air low RPM is just fine though...w/ 5000 RPM roller cam

[@butziporsche8646]

Like an expansion chamber on a 2-stroke but without the reverse cone to force the fuel/air mixture back into the cylinder. Hey Tony, a great thing to add to this would be an explanation on how motorcycles have smaller combustion chambers (and hence shorter heat path) allowing higher compression ratios on pump gas. Another interesting thing would be an explanation of Anti-Reversion headers. There were some really good ones for VW/Porsche Type 4s in the early 80s that outperformed standard headers (there were rotary scavenge designs as well). These anti-reversion headers had a sort of cone with small aperture facing away from the port so if gas tried to revert back to the cylinder it blocked reverse flow. This is done sometimes now by having header ports a bit larger than cylinder head exhaust ports creating a sharp edge. But this tech changes. When I was a kid racing go karts we didn't use expansion chambers but just exhaust megaphones. So, we fabbed up port plates with semi-circular protrusions into the crankcase to decrease its internal volume thereby raising scavenge pressure to the intake port. These were referred to as "Rabbit Ear Stuffers". When chambers started showing up these seem to have gone away as the chamber was used to suck the fuel/air mixture out of the crankcase (via the transfer/intake and then exhaust port) and tuned to length to push the mixture back into the cylinder after the intake port closes. It was/is effectively a form of supercharging as it can fill the cylinder with more than a cylinder's volume of fuel/air mixture. It is so long ago now that my Power Products, Westbend, and McCullough engines (MC10) are actually antiques. Ha Ha

[@roadrunner4404]

Great video. The primary header tube length and diameter in conjunction with the sizings of the collector create a low pressure pulse. Plus the column of hot air racing away from the exh port draws or sucks the initial incoming intake charge into the cylinder. Yes small amounts of raw fuel air are siphoned away but it kick starts the int charge moving. Add that to ram tuning the arrival of the fresh int charge pooling up behind the intake valve and you gain serious horsepower. Ram tuning both int and exh to certain rpm ranges. Extra compression almost always adds more power too across the rpm range. The gigantic amount of deep scientific variables is a key reason I love drag racing so much

[@timsprojectcar1875]

I milled a pair of 360 heads till the combustion chamber is nearly closed. Maybe not wise, but they didn't crack. They work great on my 318.

[@robertdouglas3456]

I love the idea of welding the combustion chamber! Rock on UTG! 🤩🤩🤩🤩

[@RaulNatera]

Great explanation Tony, I learn a lot for free, thanks!

[@davidpaul5465]

No joke, your best video yet!

[@slantfish65sd]

Excellent information. Really great to bring this up and mind people about the combustion chamber valve placement valves, valve sizing ports. All of that stuff. The cylinder head truly is one of the best places to make power from

[@donk363]

I'm running a Cleveland with 2v heads and wanting to figure out how to "close" them. Wish I could afford to change over to 4v closed or , in my happy dreams , Aus 3v heads. I e thought about filling with weld but then came to my senses when I thought about the weld breaking off and trashing a rare engine! I hope UT can make those open chambers into closed and even chamber cc across the bank! Cant wait to see how its done!!!

[@Thunderstruck951]

kzbin.info/www/bejne/p3bZk6Wvl9mnbJI watch this to see how Bob Glidden modified those heads.

[@nicholasagnew2792]

I'm surprised you haven't done this video till now, good stuff man, really good stuff.

[@terrencebuller7676]

Thanks for all the information and sharing it with everyone. Take care 👍

[@W.Khairi]

Valve timing and overlap, Love it.

[@galeclay8907]

Still need more uncle Cathy 👍👍

[@Robs-Garage-experiments]

Wow! That was a really good video Tony. Job well done! Your dead on right about most people don’t pay attention much less know a whole lot about that chamber and gas flowing issue during overlap. Big power in the overlap and if the chamber is a good one, in your own words, the magic happens.

[@herbferguson]

I've learned what Uncle T is talking about over many years of going to Bonneville... As Gray Baskerville called it, The Great White Dyno. Dollar per Hp, the recycled blown fuel Hemis that guys use have the most bang for the buck. The two fastest Blown Fuel Roadsters at Bonneville are nitro powered Hemis... one is naturally aspirated on nitro and actually went faster than the blown car. The N/A gas classes are ruled by wedge type engines. Blown gas powerplants seem to do slightly better with non Hemi designs as well. One friend of ours ran a 500 inch TFX nitro fuel Hemi on 4 cylinders on one bank and the car went just as fast as the full configuration. They estimated it had to be making 500-600hp per cylinder to go the speed it did with 250cu. in (E record 303mph). Car number 125 has blown fuel competition coupe records starting at AA 305.241mph A 305.607mph B 311.149mph C 300.022mph D 296.278mph E 303.231mph Keep in mind these engines are de-tuned from a drag racing setup... they have to last up to about 80 seconds under load each pass and it takes 2 pass average to set a record. Also Bonneville is around 4000ft above sea level.

[@mattmorrison6958]

Excellent video and valuable insights. Love how it was all explained! Supercharged applications I totally agree that there is always a high pressure gradient available to move things in the right direction but turbocharged comes with inherent drive/backpressure that varies greatly with the setup and across the operating range- making scavenging, or residual exhaust gas which is what's left if you don't scavenge the rest of the chamber, displacing what would otherwise be filled in the following intake stroke. What you're describing is what we've attributed to some significant changes in power psi and response in turbo applications with an exhaust manifold change alone. That effect scales well with the valve overlap and whether the overlap phase is a good thing or a bad thing

[@joesantiso6495]

Not a Chrysler guy here - don’t watch your site much - but David Vizard commented on the piston pin offset thing - and he has found a consistently positive power gain in his Dyno experience - ( sometimes big; sometimes small) by reversing offset pistons -so- yes- here is confirmation

[@rossriley3818]

Kevin Cameron writes about this beautifully. In his writing you will understand why a high performance engine develops that staccato scream as the combustion chamber “supercharges” due to an aggressive cam overlap. The sound of a motor “coming” into its cam. When you know you know.

[@markcarter78]

Great video. The problem is knowing how much overlap to use

[@marccres6619]

Very good video, when I was in school my teacher tought us ,cam profile, overlap are your starting points ,and your video like he did explaining why. Thanks for the video.

[@CODA-Improvements]

When I have to watch it twice in a row to follow, that’s a great video!

[@cheatingiscompeting3647]

Hope next Sunday's live goes better. Definitely enjoy the sit down Q and A type video.

[@dakotastimein6561]

Great video, this is definitely a variable I’ve never thought about or heard of.

[@Texasmule]

YES, I thought I was the only 1 who got the idea to weld and wedge the combustion chambers down to about 60cc from 64. kicked my sbc up to like 10.2:1

[@vaughngordon1095]

When I listen to you talk cars and mechanic stuff I harken back to the days when I went to school to learn the trade. Bill Pfeifer was my instructor. Real cool old school no nonsense kinda guy who could explain the whole lesson in basic words. The only difference between him and these videos is you never mention "Joe Blow's Garage down the street".

[@garyr9185]

Hi Tony Great video, I love in depth engine tuning, and have been playing with engines about 30 years now. To be fair though David Vizard does also talk all about this stuff and is also a wealth of knowledge . Great Video, loved it. 👍👍👍👍

[@UncleTonysGarage]

David is a friend of mine, and we've done a couple of shows together. He's been under the weather lately, but I hope to do something with him again soon.

[@garyr9185]

That would be gold..

[@nicholasagnew2792]

Yes! Lets see how much gusto a 318 can have!

[@NoWr2Run]

GREAT EXPLANATION OF COMBUSTION CHAMBERS.

[@georgeduarte3240]

Thank you. All very good information when building an engine for power. Only wish i new this 20 years ago. Great channel.

[@Zchef85]

One of your best videos Tony.

[@elebeu]

The tunnel ram and fenderwell headers were worth the price of admission.

[@flinch622]

You made good sense. Shape of combustion chamber may be a bit nuanced to some, but volume will be the biggest factor. This vid is insight as to why volumetric efficiency is not a fixed number on any engine over its full rpm range. A higher revving engine having less time [milliseconds] of overlap for the same cam needs a smaller chamber for the negative signal created by outgoing exhaust to begin intake charge movement. I had to deal with a few hydraulic systems over the years, and accumulators behave similarly except the pressure is positive: the bigger the accumulator, the longer it takes for the pump to bring it up to pressure. More interesting is how much influence does combustion chamber size tilt the spread on dual pattern cams? Maybe that's a good part two.

[@blackcoffeegarage]

Hotdamn I love engine theory on a tuesday night.

[@waynebuzzell2483]

Thanks Tony, that was a revelation for sure.

[@xxxxrock32xxxx]

To call some of the individuals I encountered at college Professors when watching this makes me laugh! Tony is a Real Professor in my humble opinion.

[@topenddean]

When my mentor Clif Kolostow worked at Ed Miller's in the late 60's early 70's they would take brand new 340's and mill the heads .060" That turned the open chamber head into a closed chamber head. I think they were more interested in upping the compression, but what you are talking about here was no doubt a part of why they were doing that. One thing is for sure. Their 340's ran better than most. Like MoPar said, "340...the Big Bore Hunter"

[@kenleppek]

BBC tall deck " peanut" heads came to mind when watching this video. The old dump truck motors.

[@richardlincoln8438]

Very good information Tony. Thanks for sharing.

[@owenhunt6796]

this video is pretty good but theres a few things id add, im not suprised that anyone would be lacking knowledge on this stuff becase of how sparce the info is and how hard it is to find. the hemi chamber bolth has the least serface aria for a given volume whitch helps retain heat in the combustion charge whitch ofc is responsable for the power you make and due to this it wont form hotspots adding to the spark plug point you made. the performince also has to do with the fact you can fit massive valves to the engine whitch allows large flow along with the geomitry advantage you mentioned. open combustion chabers came about becase the lack of high octane gas so they wanted to decrease surface aria and compression whitch also aids in emmisions kinda. high surface aria reduces the temp of combustion whitch does decrease nox emmisions. though the increased swirl and turbulace also helps with emmisions due to having a more homogonus and complete combustion. this also aids in high rpm performince sence you have alot less time to complete the combustion event so any added turbulince helps. though high rpm induces turbulance due to the increased flow whitch is one of the reasons why why we see hemis perform pretty well at high rpms. its always intresting to me that designs like the hemi and the rotary whitch i conciter to be on opposite sides of the spectrum due to the rotarys large surface aria per volume making combustion happen very slowly. bolth of them suffer from a large lack of turbulace.

[@stevelemmen7048]

Yes, this is the first time I've heard this info. Thank you.

[@grantlee2975]

Fantastic explanation Tony

[@donaldhalls2189]

Thanks for your information, all the best to yous and your loved ones

[@ericuncapher9922]

This is a great video..I think it's going to be a fine line. Might be a little advance detention situation.. Can't wait to see this happen.

[@kevinclancy.]

I love the explanation and I totally get what you are saying, great job.

[@philchambers188]

best...or one of the top ten tech episodes...love it...i wish you were a big block chevy man....

[@UncleTonysGarage]

I absolutely adore the Big Block Chevy, but my investment in time and parts is all centered around Mopars

[@Kowalskithegreat]

the more i learn about engines the more i notice the effort honda put into the 90s dohc vtec engines. the super tight quench pads on the b18c come to mind

[@generovinsky7228]

messed my head up thanks tony i have some things to re think some things i will need to watch this again.

[@stevengamsby8376]

Great video. Tony I’m going to look into it more for my diesel engine thank you Tony

[@bcbloc02]

Most all diesels have no overlap so this does not apply.

[@petermontagnon4440]

Good video Tony!!!!

[@craigbarrett2278]

Very intriguing concept!

[@joshreynolds729]

Excellent video tony, thank you. 👍