MORE POWER WITH SMALLER EXHAUST VALVES? 

Watching and trying to absorb the teachings of Ben Alimeda and David Vizard gives an incredible amount of wisdom. Their teachings generally compliment eachother. What one does not get to explaining, the other catches.

It takes a hardcore scientist to figure this stuff out and a great person to share it with the layman. Great work Ben!

Oh Ben, this video brought me great joy today! When my Uncle got back from 'Nam' (he was a Tank Mechanic), he got a '65 Mustang and after he worked his magic it was an incredible Street Racer. He had the 289 Engine apart one day and I noticed he fitted the largest Intake Valves he could fit, 1.84 or 1.88", but was using the smallest factory Valves, 1.46" if I remember correctly. Tri-angle on the Intakes, 45 degrees on the Exhausts. Lots of beautiful porting on the Intakes, just cleaning up on the Exhausts. Even with a high lift ratty Cam, that thing would Idle well and flat out launch. I always thought that was counter-intuitive, he would tell me Shhhh, it's one of my secrets. He just passed away last year. Thank you Ben for explaining this in a way that is completely understandable, as you always do in your videos. Vindication is a wonderful thing... Mabuhay, from The Philippines 🇵🇭

There is no substitute for wisdom derived from successful practices. Thank you Sir. Very Respectfully, SKWID Rider’s Shipmate ET1(SS/SW/MTS) US Navy, Ret. Killmonger: 2020 Fat Boy (Stage II+ by Blockhead) SilverBAK: 2021 Road Glide (S&S 129ci/Fueling Race Kit by Rider’s Shipmate)

Blessings Mr.Alameda, I truly appreciate your sharing of your life's experiences. I wish for your health to return to full maximal power!

There is no better teacher than the race track 👍❤

There is a guy in Louisiana back in the 80s. I can't remember his name. He ran Big block Chevys. He would weld up the lower part of his exhaust ports cause he said it made way more mid range torque and power. His old Redneck backwoods home built car hurt alot of feelings. He was whooping alot of high end cars with his old orange 3rd Gen. I think his name was Jimmy something. I want to try and port the intake ports on my 4.6l 2v and leave the exhaust alone. You are the second one I've heard with this way of thinking. And seeing how this guy was woopin high end cars with his back yard built car. I thank you again.

The single angle on the exhaust valve becomes a relative Venturi which accelerates velocity!!! Ben you are a physics genius!

I have experienced it with the FE. 2.19 intake 1.6 exhaust. Exhaust just wants out. And a small valve will get it out, the time is the key. The FE overachieved because it was ahead of its time. Especially the softened pocket intake side to the plug. I agree on the 5th stroke! The EGR effect helps cool the chamber and creates a resonance wave that brings it back.

A lower lift and shorter duration of the smaller exhaust valve works well. I had a custom cam made with a .500 inch intake lift and a .300 exhaust lift and it has serious low end torque and top end power.

Growing up it was all about exhaust, today, if you can't get it in. Don't worry about getting it out. Awesome tutoring Ben💯👍

Between you and Darin Morgan us wannabes actually learn a few things. Thank for being who you are sir!

Port flow and hogging out the port volume to get more flow on a flow bench may be shooting yourself in the foot. You also need to consider flow velocity which combined with the flow volume equates to port energy. A larger port volume that reduces the velocity reduces the port energy, which reduces cylinder filling. With modern heads designs that are very efficient, yes a smaller exhaust valve with possibly the 52° seat as Ben explains, can be used. David Vizard with his Polyquad 4 valve conversion sinks the exhaust valves a bit so the incoming air/fuel during overlap skips over the almost closed exhaust valve instead of getting pulled out the exhaust.

Ben I build a lot of 2bbl low lift rule engines and found exhaust was more efficient on blow down and did improvements on intake side and ground camshaft to help intake won many races with Engines I build . Great video's thank you for sharing .

Nice explanation on the exhaust. I think of it as building a check valve on the exhaust to promote anti reversion or one way flow.

You are absolutely correct smaller exhaust valve sink it does precisely what you said but dont tell anyone

This is why honda made 3 valve heads. My 400 came on at 6000 rpm until 10000rpm redline. 4 valve bikes are had similar hp but no midrange. 40 years later I learn why. Thank you.

A new video from Ben makes my day 🙂

Amen, that's exactly how I do it too.

Ben thanks again. When Ford made the valves smaller on the 4v open chamber Cleveland everyone thought they were nuts. I’ve used these heads numerous times and had excellent returns in power. Now you have me thinking about the 2.19 valve and 1.65 exh 🤔

Another great presentation Ben! I recall an article authored by none other than Ed Iskenderian speaking on this cross contamination problem maybe 10 years ago. Ed said the cylinder heads are becoming so efficient that we have to be careful about overloading on the exhaust duration which is how we had to cam cars in the old days due to their inefficient designs back in the day. Obviously from the information you're sharing we have arrived at that point when the standard go to camshafts will be much more symmetrical in duration instead of seeing a 10 degree difference between intake and exhaust duration. The wide 114-118 LSA is going to supply much more total torque throughout the power band than we've ever seen because of the technological advancements in cylinder head development. The information is learned at such a rapid rate now. Seems like new theories are tested, proven and available to us in months now instead of years. Gone are the days of guessing what's happening in our engines and bigger ports must be better. Thanks again.

Excellent analysis Ben! 👍👊

I always try to make engines better weather it's a weed wacker or a small block Chevy. Take example the 4.0 Ford sohc. Replacing the intake and porting the heads made a huge difference. Tom marana is one of the only ones who works those.

This was extremely informative. I just didn't think of any of this. The other day watching your other video on exhaust valve spring pressure bring to high also blew my mind🎉

I love your videos Ben. I am the one that texted you last week. I am going to setup a call with you in a week ish. You told me when I do to send you my plenum and throttle body. I want to try this setup on my heads. I am running a 4.6l 2v in my 03' Crown Vic P71. We will talk soon. Keep these videos coming. We really enjoy them brother.

I agree Nolan and Billy I probably the best. As long as they are going to get involved in what you are doing.

This video was amazing. The more I watch your videos the more I learn. Now when I see ads for heads and when so called experts talk I truly listen with a very questioning attitude. I am truly greatfull for the knowlege you have given me.

Hello BEN,I hope that your days and health are much more important roles for yourself and FAMILY, friends, fans,. New subscriber ,and I am currently catching up on POV of the channel, and you seem so humble about the knowledge, experiences of your own racing career, and I can only imagine what you don't share with everyone, sure wouldn't like to pull up to the staging lights beside you,YOU MY NEW FRIEND ARE A LEGEND,,thank you ben for the channel, and the info that YOU DO SHARE, keep info and videos coming, thank you very much

Engineering knowledge is just that, the brand name means very little, thanks for sharing yours.

More power? Probably 😀 But when the engine makes a lot of torque, it also has a good chance of accelerating on the track. Thanks for video and cheers, -juhana

Wow, this was one of my favorites. Thx for the ever expanding experience!

Excellent insight Larry Widmer from Endyne developed parallel thoughts long ago

Your amazing

Another eye opener. It's greatly appreciated.

Very interesting stuff Ben. People say that an engine is simply an air pump, but I disagree. I think that it is a delta P device, and anything but simple. As you were talking I was thinking about how we are trying to maximise cylinder depression during the overlap period, but at the same time, trying to limit charge overshoot, and exhaust reversion. You make many very good points. Certainly in NA engines the greatest challenge is getting the intake charge in. Many thanks to you for sharing this. Regards Greg

Amazing video 🎉

It's very nice to watch your videos! They are not only informative, but also fun. Thank you!

Thanks for the videos..A interesting watch .

I'm building an engine using 351 Cleveland heads. I want to raise the exhaust ports which will cause more low lift flow. This would mean that I should open up the LSA. You and Vizard agree on this. With his calculation poly angle valves with a twisted wedge like the Cleveland, the LSA needs to be opened up for optimization. I can see what is going on by your explanation. Sinking the exhaust valve is a good idea as the intake charge doesn't like to change direction. I need to look at my exhaust valve size as well. Thanks for the great video.

Wow Ben another mind boggling video. I can't get enough of this shit.

Thanks for taking the time to make the videos and sharing your knowledge. We really appreciate it more than we can ever tell you !!

very intresting about the LSA and new style performance heads

Many thanks 👍🙏🔥 great information 👌

Lots of great info as always 👍thanks for posting this great video

Great video Mr Alameda !!!

Thank you for your knowledge and videos.. USA 🇺🇸 USA 🇺🇸 USA 🇺🇸

I hear ya buddy, im ocd i always clean up my shop before i start workn on something. LOL. Its prolly a military thing...talk to ya soon buddy. Enjoyed the video, great info and direction.

Tyank you sir.

Thanks for knowledge!

Thank you for sharing your knowledge

"different level of ignorance"... Yes, I resemble that: there's always something to learn, so today was a good day. The intake/exhaust thing falls back to basic testing in as much as finding out if something works [and maybe why it works] is best done one change at a time. And I know: we're not always eager to pull/install heads a half dozen times.

Another great thought provoking video thank you. Did you see a big difference in idle A/F ratio comparing the modern heads with overlap (wasting the intake charge) versus the old heads with overlap (capturing intake charge and maintaining dynamic compression) ?

Mr. Ben, first I wish your health improves soon. Very informative video as are all of the others you have gifted us. How well would this work for a boosted application, specifically 306 small block Ford with tfs wedge heads 2.02/1.60 valves out of the box and 114 cam?

BEN! 😊 stock gen2 F body. Th350, 2500 stall, 3.23 gears. Daily driver with a little power. ? Pizza Delivery Car. CAM PROPOSED: 282/282 118LSA 118 ILC 11.5:1 static compression, 355 c.i. sbc. dart iron eagle 200cc or tfs super 23, or brodix. Performer EPS intake, roughly 8:1 dynamic and 6" rods. PUMP GAS pizza delivery car. Welding for money, making pizzas, and fully sending them.

an engine is simply an air compressor. it takes in air, heats it, and hot air returns more work than it takes to compress. for every 249C, you get twice the work. its really convenient to simply spray a combustible liquid into that air, have it combust rapidly, and produce the required heat and subsequent pressure rise that way. it wastes alot of the energy, but its a far better use of the energy than heat exchangers and phase changes (ie, steam). so. the valves are areas that are misunderstood. the whole theory of airflow tends to get overlooked in an engine... a fundamental rule is that air flow is limited to a certain speed, regardless of the pressure differential. iirc, its roughly 0.577 pressure differential. no matter how hard you try, you wont get air to exceed a certain speed. IN the nozzle. in the restriction. but you CAN use the HEAT in the gas to create a condition where the gas continues to accelerate as it leaves teh choke point, expanding as it cools down... it can flow down the PIPE far faster than it can flow through the valve. this doesnt happen with plain normal compressed air at ambient temperatures. it has to be HOT to expand MORE than the pressure suggests it would. delaval nozzles and rocket cones... getting the exhaust velocity up in a smooth, laminar flow... better scavenging. stronger pressure waves, better flow overall. turbulence is ENERGY being consumed. the more of the heat that is wasted in an engine that you can use to your advantage, the better. my personal area of improvement is throttle valves at the moment. think about it. if you understand bernoullis, a venturi, aerodynamics... you might see the major issue. in the venturi air speed is highest, but pressure is LOWEST. it is then expected to slow down, and rise in pressure before entering the cylinder. because the engine is an air pump drawing the air in, the system works. it consumes a lot of energy though, overcoming that inherent pressure gradient. its then expected to speed up AGAIN as it passes the valve into the cylinder itself. those pressure gradients choke flow, reduce VE. if you strap a plank of wood to an airplanes wing, it has the same effect... hard, if not impossible to fly, and if it does fly, it takes a LOT of power to force it through the air. a venturi is basically a wing wrapped into a ring... but still, 150 odd years of carb design, and ive never seen the issue addressed. not just maintain a constant velocity, but also a laminar flow. completely different to the rough surface effect which produces an effect known as the longest word in any language...500+ letters in german? "the amount of fuel that falls out of suspension inside the intake manifold"....

just food for thought ,how about the McGee brothers from Aussie with their Quad cam rotary valve v8's.mmmmm they went fast.

Thank you so much, Mr Alameda. Very thought provoking and admittedly, never on my radar before. I think everything you've presented here "holds water" as presented. In my circle of friends, we refer to this as "over scavenging". Getting scavenging just right is a very big undertaking. With that, may I add another effect that may be happening simultaneously? So, at the moment that the exhaust valve separates from the seat, the "exhaust blow down" sequence begins. Cylinder pressure to that point is decending rapidly relative to time and piston position. At the point that blow down begins, the decreasing cylinder pressure now accelerates rapidly but not instantaneously back toward atmospheric. If you slow down this pressure drop for a few degrees of crank rotation, say 10 or 12 degrees or so, could it it increase BMEP enough to be worth a few extra horsepower, along with the fine tuning of the scavenging? I might be off base here but would love to hear your thoughts. Thank you again so much for this.

Nice video Ben!!!!!

Hope your health turns up if it hasn't already. Agree on less overlap required as the induction gets better. I'd be playing with the header, testing less duration, faster closing ramp of the exhaust (not looking to get rid of the sunken exhaust valve though) or a combination of all 3... in other words keep improve flow everywhere and see if there is some orher things in the combination that can make it better than what you've found works well. Don't dissagree with smaller valve than what's thought as necessary. Just think there's gotta be something left there. I hear 14k hp? And perhaps it's more of a break shit factor there on top fuel? Good stuff. Wish I could just do R&D all the time

I agree with you, a 45 and radius on the ex and do not back cut the valve. 30 45 60 on the intake and back cut the valve so the seat and the back cut are the same width. Do you agree

Thanks for this informative video im currently thinking of a cam swap in my 351 W I currently have a mild 112 centerline cam with ported stock valve 351 W heads 184s 154s this currently runs 8 .22 in the 1/8 mile in a 3700 lb car going to a 110 cam with just over .5oo lift would take this combo in to the 7 s thanks for this video also porting a set of y block heads food for thought

This has me thinkin now lol. Im doing an engine w a buddy of mine, 351w based engine with a old set of Canfields we got used. I had picked out a stage 4 or 5 tfs cam originally due to it was suppossed to be a 302 engine, but now i wanna go bigger but the lobe seperation and compression issue like you just mentioned has me contemplating what id like to see in the engine. The ports on the Canfields dont seem to have very high port locations like the yates heads youre speaking of but since his pistons are higher compression im wondering if keeping that LSA tighter may help it when its upwards of 8000 8500 rpm esp since he has a good amount of gear and is stickshift.

On Nitrous injection motors Mr. David Vizards says we need more exhaust flow to scavenging burned nitrogen pressure, Is that True or what's ur take??😳💥🌋

Very interesting knowledge tell me what to do on my 2jz head

I wanna get a set of LS heads built by you. Which casting number do you recommend I start with. I’m wanting a hot street motor, high commission, looking for around 650hp

i always wonder about intake runner length after carb before crank case reeds. reed throw a curve ball. and like thicker gaskets probably not thick enough to make a drastic chage.. on a 125 iame x30

@Ben Alameda Racing, Which category would a set of AFR185 Renegade heads fall into? Would limiting low lift exhaust flow still be beneficial? If it matters, its a 408w going into a F350 4x4 truck. For this combination, would you have a recommendation for compression ratio and the ideal amount of quench? (It will get a custom ground Hyd.Roller cam match when everything else is done). Im getting different answers everywhere i look, and I would trust your input over anyone elses. And thank you for all the valuable information in your videos. It is much appreciated.

Question... since you know about cams... Is it Overlap or LSA that causes the rumpity rumpity idle? Hypothetical scenario: 408W street with decent street heads at 10.8 compression, and all supporting parts. All three "mild" cams with 0 advance ground in. What would be the difference in idle and street manners between these three single pattern cams? (Two share intake valve closing for theoretical cranking pressure. Two share Overlap. Two share LSA.) Cam 1: 270adv 106LSA 58° Overlap 220 @ .050 (190 cranking pressure, 61° valve close) Cam 2: 262adv 110LSA 42° Overlap 212 @ .050 (190 cranking pressure, 61° valve close) Cam 3: 278adv 110LSA 58° Overlap 228 @ .050 (175 cranking pressure, 69° valve close) Thank you for this video!

I was called an idiot for doing the same thing. It blows my mind what some people think

I like your P51-D

A question regarding hot rodding small block Chevy for the street. Would cutting a 1.94/1.5 64cc chamber for a 2.02/1.5 make power or make junk? Thank you, I like building SBC at "Hillbilly Garage" and I'm looking for unusual upgrades.

Every time I listen to you I learn a lot. Do you advocate a flat valve on both sides but 3 angles intake and 1 angle exhaust?

Balancing the equation, yes. WORKS ...stronger pulse

@ 42:50 so the raised material between the valves serves as a "sunk in" effect? Along with the "machined ridge" around the exhaust valve....?

would you also use less exhaust duration? I see a lot of these dual pattern cams with 8 degrees more exhaust duration than intake, would you run something closer to a single pattern cam or maybe 2 degrees more exhaust duration than intake? But also the issue with the wider LSA is you are now opening the exhaust valve earlier? Which hurts low speed torque as it takes energy away from the power stroke. Instead of changing the LSA why dont you just lower the durations instead and keep the later opening exhaust?

From 41:00 to 42:00-ish....would a "flatter"(12° - 15°) exhaust valve be ideal here? Rather than let's say a 23° "tulip" valve? I've never felt real comfortable with the tulip exhaust valves I've been asked to use in GM cathedral or rectangle LS heads. In the early 2000's, fresh out of school, the flow bench numbers of the exhaust looked really good from 0.100" to max. When compared to a tulip in the same head and flow bench, same radius valve job, 0.100 - 0.400 jumped 10% to 20% but same results all the way to 1.000. 8 months prior to that, I learned to degree a camshaft. I saw the possible effects of the exhaust flow "evacuating", best way I could describe it at the time, too much intake charge, but i lacked the experience to support my thoughts to all but one person. He gave me a pat on my back and said, "Good job Arty." "Now let's talk about this 408 you're gonna build me for these heads." His name was Terry Smith. He was one of my Hotrod instructors. I haven't used a tulip valve in 22 years, and I can't remember thinking twice about it. If I'm understanding correctly, I think I made a good choice...

Funny, the tighter the lsa with the same duration, the intake valve closes sooner. This traps more air in the cylinder and is called effective stroke. This is What dictates dynamic compression ratio. Alot of good info but also alot of b.s

have you tryes to but a 4 inch stroke in a 305 chevy i was told that only a 3.750 stroke

HA! @ 46:47 I think you're about to get into what I asked about.....

Ben, just saw this video. Do you think your "secret" is why GM only improved the intake flow on sbc vortec heads and did little, if anything, to the exhaust port flow??

Ben i did about this sam thing on my bog block Chrysler i been building engines for 50 years i went with a 15 degree exhaust angle Pontiac theory more flow at low lift i gained low end on a 310 duration cam and rpm raised 2000

Ben, would not doing a back cut on exhaust valves help?

I'm gonna take a wild stab at it before watching the entire thing and guess you want a smaller exhaust for a longer duration of exhaust gas discharge and higher velocity for evacuation to take better advantage of overlap?

@ 20 min...my quirk is i need a lego puzzle .. to make it hard .. im the worse got breakfast mixed in with main caps joke not that bad .. i can sort it but.. i always read instruction for critical stuff.. i wont change. torques spec and pattern are useless information when it 5 second of instruction manual.. if u read instruction you wont make a mistake if you go off the fly well your risk... pride is prone to mistakes

The cam on my old school 355sbc with 10-1cr is 243in 257ex @50, 533in 519ex lift, 107lsa. The valves are 2.02in 1.6ex. Would more rocker ratio on the intake and more lash on the exhaust to reduce the duration be helpful? Thanks.

The Biden teleprompter comment had me dying

Velocity encourages inertia.

ic and a head scratcher but ñmakes sense. So if you had a 110 lsa cam you would degree it in on a 106?

Can this be applied to old 302 iron heads? Leave the 1.45 valve in, do not round the edge on the exhaust valve face? Just trying to get the best "yank" on a street motor.

No teleprompter needed.

wouldn't you be better off having your charge going out the exhaust on a turbo motor so u limit egr in combustion chamber .. like best chance for clean charge.. and just compensate with boost to have as cleanest charge on normal manifold injection. obviously f1 doesn't do this so it doesn't work and excessive fuel consumption.. although there direct inject well later pre combustion chamber stuff

Go figure....less is more

over-scavenging