I performed all this work and polished the chamber however I ended having to mill 1mm off the head to reduce comb chamber volume to regain comp ratio 10:1
@frankaudi003 сағат бұрын
Thank you for the knowledge.
@nitrousshovelhead4 сағат бұрын
thank you
@owenludolph4 сағат бұрын
mushroom valve.
@donaldhalls21896 сағат бұрын
Knowing this information 30 year's ago would have helped 😂, interesting information, thanks for sharing, all the best to you and your loved ones
@JohnH.-qp6fb7 сағат бұрын
I had been talked into a spherical dished piston long ago from a known tech man at JE at the time. The feedback they had was the reason it was used at the time. I haven't yet built that engine however, another friend has used this with great power. No, outstanding power. Never hear about them now. Randy was the man at JE at the time.
@timpieske66399 сағат бұрын
Thanks DV 🏁
@ezkempinkemp346710 сағат бұрын
I understand what he means by grinding out the quench plateau, but how much does that lower the compression?
@user-zu2ed6ye5w10 сағат бұрын
I have had great luck with WIX ..51061 oil filters on SBCs ..truck pullers,drag racers, and street racers , useing straight 30 wt. Oil with .003 on mains, .002 on rods !
@timmcooper29410 сағат бұрын
Another great one, can't wait to see the one covering combustion chamber and piston crown shapes. Back in the dark days, playing with small block Chevys, I was always amazed at how much better the approx 1970 and older cylinder heads ran on otherwise the same basic combination. No better flow, just a better combustion cavity / quench situation.
@daviddroescher16 сағат бұрын
Detention vs burning. As you said the total charge is at/above flash point ge phase change from lquid to gas is completed allowing temperature to spike above ignition. Atomised fuel is the making of small droplets of fuel that are phase changing on there surfaces. Vapor pressure is responsible for restricted rate of evaporation keeping flame rate below supper sonic ( above is explosive below is burn, speed of sound is dramatically affected by pressure and density).Lquid fuel dose not burn due to insufficient O² infusion, phase change is absorbing massave amounts of heat and allowing the vapor to mix with O² then burn at a controlled rate based on temperature. Detonation happens when the cooling effects of phase change is used up, causing the temp to spike the liquid is now all gas at spontaneous combustion temperature where all is consumed at or above the speed of sound. I think the rattles are sonic booms in cylinder. MSD is 20° of spark shrinking volume from idle to 3000 ( if i remember correctly its been 20yrs) 20°becomes too short of time at higher rpms for multiple sparks ( coil saturation time limmits i think) so it is a continuous spark for 20° above the set point.
@Pegleg30217 сағат бұрын
That was outstanding, keep it coming!!!
@daleolson350617 сағат бұрын
I found that the head gasket had to match the bore exactly,the thinnest possible. This helped detonation problems
@savagefabrication79517 сағат бұрын
Darren’s videos are amazing. Still learning from them each time I re listen.
@superstockamx906418 сағат бұрын
Tried to make a nice payment but there is no option other than “save card info” which I refuse to do. Can this be fixed to “do not save card info” or use PayPal?
@tahustvedt19 сағат бұрын
A lot of heavy road car parts have race car parts inside them. You just have to dig them out.
@TaylorJensen-ys2cv19 сағат бұрын
Darin Morgan is a fantastic guy...Needs more video on his channel, which could explain why his subscriber count is in the toilet, got to catch him on Dragboss's channel.
@diegodecasasmora283820 сағат бұрын
I have built a cosworth yb turbo engine, running,_7.9:1 CV compresión with minimum quench clearance and its more responsive and fuel efficient than with std quench, running 1.9 bar boost no problem with detonation.Big respect to D V👏👏👏👍
@professionalhuman442920 сағат бұрын
Watching this to learn how to adapt my system on a VFR800 V4 VTEC Honda motorcycle. Any suggestions people? I will also be looking at adding stepped 4-2-1 system with Davids advice from this and other videos.
@jamest.500122 сағат бұрын
I just had a crazy idea. Of building a injector like a annualar booster, that fits between the intake and head. Similar to the ZEX® brand nitrous plate systems. Only using tiny holes all around the port walls in about a 1/8". Ring or semi circle. Or even a 1/4"-1/2" on the top side ,with a couple dozen .020" holes with a internal feed to the holes being about 0.5-1mm thick by the width of the injection patch. It could be a primary fuel injector or a secondary system. Or even a water methanol injection. To a Nitrous injection point. With the holes being at different angles and shaped like a rocket nozzle. A .020" inner diameter, with s .040" outer exit diameter the fuel will cool the port wall. Also having them angled to the head from 15°-45°. Using a injector like solenoid valve to be fired just as the intake valve opens. Possibly experiment with start timing to allow air only for a short time in the start to cool the exhaust but only while hot when cold it needs to be opposite. And using a relatively high fuel pressure. 80-120psi to get the required fuel through the somewhat small orifices. The intake can be milled out to fit the ring in and epoxy it in place. It can be made from copper, brass, aluminum, cast stainless would probably be best, with the inner wall thickest to allow porting to fit. Have a groove milled into the ring. When porting if the groove is gone, there is less than so much thickens remaining, and having approximately 5mm to start and allows down to 1.25mm hopefully the 24-36 nozzles per sq inch. (A off the wall number) It wouldn't be the cheapest injector but for high performance street, land speed and road race, nascar, where engines run hard for long durations. Engines getting heat soaked. It could be that little bit that makes the difference. May not make any more power when cold , but could either prevent power drop-off due to heat. Or possibly gain power due to cooling of the intake charge, along with superior atomization. I would love to test it , or see this tested. It is crazy, but we never know until ee know! Have a awesome day...🎉
@kimeldiin193023 сағат бұрын
I was taught by my turbo friends , i.e.Peter of Andersson Turbo systems, a ten C. lower in gas temp , result ins 100 C lower exhaust temp.... hence INTERCOOL !! (Building 600 hp , 1300cc Hayabusas ..)
@KristoffKucheКүн бұрын
I just built a propane fueled SBC engine in 2023 . It is a 12.1 CR with a set of Vortec heads with as tight a quench area as possible . With propane not needing to be vaporized , vortec head swirl mixing and tight quench I'm expecting good performance . It is unfortunate that I could not get sodium cooled exhaust valves for this build . Good thing propane has good detonation resistance but some better valves would have been nice . Your episode has verified that I am the right track . Thank You Sir !
@billymanilliКүн бұрын
www.youtube.com/@darinmorgan3520
@gregorymarch91Күн бұрын
You've been on a roll. Great stuff. Can't wait for more. Much thanks.
@bobgyetvai9444Күн бұрын
DV fine details removes our misakes . WE WANT MORE !!
@theodavies8754Күн бұрын
KZread dumped a ridiculous number of ads into this video. Good luck with your channel. I only run NA. Torque and efficiency for the sum of the parts. Started out with air cooled 2 strokes 40+ years ago, melted pistons were always from insufficient squish clearance and lean mixture at full throttle. Before the days of rev limiters, mapping and unleaded. Often see porting being done with the intention of directing the mixture towards the spark plug so not sure where it all went wrong. Buddy, that valve has been closed for best part of a stroke before the spark. Swirl with maximum micro turbulence will get the best economy. Too rich will reduce the header temperature but it's better than aluminium paste in the crankcase. Happy days.
@JohnH.-qp6fbКүн бұрын
During my engineering studies, I recall the study material from Chrysler about combustion duration. Eleven to seventeen maximum degrees of rotation drop on the various engine bores, strokes was that determination. These were flat or decompressed pistons. The workup was one of comparatives of decks, timing and temperatures etc. The fuels used were taken into account for control etc. The studies are now old, however showed production capabilites without the fine tuning good engine builders would provide. The surprising part of the study was the time verses completed combustion. -- Your video was a good partner to that. Thank you David.
@user-hu1um2xk5hКүн бұрын
Wow. I had no idea David Vizard was on here. Wish I would've known this guy 25 years ago when I was digging deep into building high horse power engines. I had so many questions I needed to know about volumetric efficiency and I heard you were the man to see. Dude, youre a legend, up there with the best of them like Shelby and other true original greats. I just cannot believe that youre on here and somehow got suggested to me. Well, cheers to you, sir!
@davidphillips3953Күн бұрын
I always fully polish the head of the exhaust valve till i can see my reflection any time I'm close to pushing the limits of detonation. It slightly reduces the surface area and the valves ability to absorb heat from the exhaust. It also makes it harder for carbon and ash to build up on it. It is not hard, if it is a used valve i tape up the stem with electrical tape then sand blast the head to remove carbon and ash, after that just chuck it in the drill press and start off with around 220 grit and work my way in several stages up to 2000 or even 3000 grit. If I'm sending it to get coated I just do the sand it to round off edges then blast to clean it and help the stuff grip better.
@davidphillips3953Күн бұрын
On the intake valve I do the opposite, make sure to leave nice sharp edges, especially the margin to the face on the chamber side to sheer the fuel and reduce reversion during overlap. I try to get em as sharp as possible there at that 90 degree angle.
@ThomasELeClairКүн бұрын
,,,,,,,,thanks David ,,,,,,,,,,,,,,,,,,,,,after the prior weeks of doubters ; you are working stronger than ever ; putting out high tech topics ,,,,,,,,,,,,,,,,we all need to know.............
@timothyfalkowski6007Күн бұрын
would a "dykes" style ring that is L shaped, reduce the volume at the ring ???
@robertenglish5313Күн бұрын
Hi, I find your videos very informative... Just a question... What's your view on the big split duration cams like the thumpr series and the bootlegger series cams. While the have a tighter LSA are they overdoing the exhaust duration? Thanks
@douglash3129Күн бұрын
Thank You David!
@WilliamMunny-d8sКүн бұрын
HEY DAVID, there seems to be alot of , lets say misled people on youtube and here in canada. Every body puts Dual 2.5 or even dual 3 inch exhausts on everything from stock 4.8 L Ls, 1995 366 bus engines to stock 325 2004 truck engines. Seems to me a SINGLE 3 inch mandrel bent system should suffice for most these lower power stock engines. I seen a chart somewhere saying about 1 inch of mandrel bent pipe /100hp is a good ballpark estimate and only a dyno will rweally tell you if you need more BUT common sense should dctate a relatively stock engine thats run 99%on the strreet should be good with a single 3 inch AM i CORRECT or are they actually benefitting from DUAL 3 INCH[besides their egos]
@WilliamMunny-d8sКүн бұрын
the reason i ask is im considering buy the old 1960 apache with 1995 bus engine in it. its stock engine with less than130,000 miles BUT he has dual 2.5 mufflers on there/ He also says theres a header flange problem that needs fixing so while i am it fixing that , should i just delete an entire muffler and tailpipe and just ypipe them together? Stock power is about 230 Hp, 385 Tq
@isaaccoonsКүн бұрын
Hello David I would like to purchase the IOP The pay button does not work I am building a 383ci I have a goal of 1.42 lb-ft per 1 ci or better. I have been following you for many many years. Now is the time to put together all of the knowledge.
@patrickwendling6759Күн бұрын
Thank you for your knowledge and videos USA 🇺🇸 TRUMP 2024
@joeacosta2542Күн бұрын
Hi David, thank you so much for the information you’re giving us wish. I knew this a long time ago the video that you did on the quench I’m interested to know just you don’t have to make a big deal out of it. Just answer the question if you could did Pont Pontiac have a better grasp on the combustion chamber shape because it was milled verses cast chambers and if so, why don’t any of the new aluminum head guys machine, the valve pockets and combustion chamber like Pontiac did and using the 30° angles on the seat just something fellow engine builders were talking about the other day in the shop. We tend to meet once twice a week and discuss these horsepower gains that have been lost overtime or maybe just not shared with the public. We very much enjoy your show and look forward to more videos on educating us on the foundation stones that we all need to have to build the best engine possible and then look for more. It’s a way of life at least for me and my buddies. Thank you for your time and I hope that your throat surgery ends up healing faster than it’s been going, thank you from the gang at the machine shop/Dyno/oh and we have one of the older super flows benches. Thanks Dave again best wishes, Joe.
@daddyschainsjewelryКүн бұрын
Thats why you dont spray water on a grease fire
@bill2178Күн бұрын
darin is awesome
@davidreed6070Күн бұрын
Dv on a turbo engine do you recommend widening the ex seat to about .0.60 to pull more heat from the ex valve?
@The0utmodeКүн бұрын
I would like to debate on this one David. You do bring up a good point of the cotton fibers acting like the hair found in a human lung, and while it is true that an engine pulses so it is not constantly pulling on the filter at idle and low rpm. But What about high rpm? Where the time between the engine pulses is very short. Or how about a vehicle where the air filter is sticking out of the hood and you are going 170 mph down a racetrack or a drag strip? Surely the filter can not properly filter the incoming air because the cotton fibers are being blown back and can't catch the dirt or pollen partials. Not to mention a barbaric test I have done. Place a dry cotton towel over your face and try to breath now take that same towel and wet it with oil and try to breath through it. It's much easier to breath through the dry towel believe me. I love your videos and think you are highly intelligent, But I think your wrong on this one. If you have a way to disprove my rebuttal please reply I'm always learning and would like to know more, Thanks.
@lancasterjim2441Күн бұрын
Wow thank you for sharing . I remember reading one of your books or watching a seminar way back in mid 2000s and you mentioned 4 v heads tumble the air and they weren’t figured out yet. It’s good to here the progress you’ve made . I will be implementing your ideas on a 4v Harley .
@lesgaal4017Күн бұрын
I was wondering David if you have done much work on Fords Cleveland heads, here in Australia 2v+4v heads are still extremely popular. The Ford Australia heads from standard were much better than their American counterparts , i think if you have time to do a video on them it would be greatly appreciated by all. Cheers Australia.
@TeedeckКүн бұрын
Ben Alameda spoke of this crevice gap in one of his videos but he warned going too small especially in a boosted application can actually crack a piston easily. This is great stuff.
@ThomasELeClairКүн бұрын
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,he and charley serverdo are highly educated in the engine science......................few are.......
@user-wc3fb4qs2wКүн бұрын
The question for me is how far can you go with a ceramic coating at the top of the piston to cut down on the crevice volume and still utilize a gas ported ring like total seals? As in how much can you limit the growth of the piston with the thermal barriers at the top? The Line2 Line abradable coating looks awesome for the skirts of the piston.
@user-wc3fb4qs2wКүн бұрын
I’m pretty sure you meant to use Line2Line’s ceramic coating from the top ring groove up. Don’t think there powder coating would last up there?
@seancollins9745Күн бұрын
If you build a tight quench pump gas engine it'll knock in the quench zones and it'll suffer from lspi. Pentaroof engine's have zero quench, and make phenomenal power per ci
@lancasterjim2441Күн бұрын
Here’s my argument based on my dyno data on late model fuel injected Harley’s using throttle by wire. port velocity on such a short intake runner length using electronic throttle is no longer a concern as the throttle blade or velocity valve as I like to call it can be mapped to maintain peak air speeds at all accelerator positions or torque requests. As for the 170 port vs 195 port , for that specific cam timing the 170 was better, but change the cam timing to take better advantage of the 195 and my bet is you will make even more power correct ? the more we increase flow the less time we need to hold the valves open so the piston does more work .
Пікірлер
I performed all this work and polished the chamber however I ended having to mill 1mm off the head to reduce comb chamber volume to regain comp ratio 10:1
Thank you for the knowledge.
thank you
mushroom valve.
Knowing this information 30 year's ago would have helped 😂, interesting information, thanks for sharing, all the best to you and your loved ones
I had been talked into a spherical dished piston long ago from a known tech man at JE at the time. The feedback they had was the reason it was used at the time. I haven't yet built that engine however, another friend has used this with great power. No, outstanding power. Never hear about them now. Randy was the man at JE at the time.
Thanks DV 🏁
I understand what he means by grinding out the quench plateau, but how much does that lower the compression?
I have had great luck with WIX ..51061 oil filters on SBCs ..truck pullers,drag racers, and street racers , useing straight 30 wt. Oil with .003 on mains, .002 on rods !
Another great one, can't wait to see the one covering combustion chamber and piston crown shapes. Back in the dark days, playing with small block Chevys, I was always amazed at how much better the approx 1970 and older cylinder heads ran on otherwise the same basic combination. No better flow, just a better combustion cavity / quench situation.
Detention vs burning. As you said the total charge is at/above flash point ge phase change from lquid to gas is completed allowing temperature to spike above ignition. Atomised fuel is the making of small droplets of fuel that are phase changing on there surfaces. Vapor pressure is responsible for restricted rate of evaporation keeping flame rate below supper sonic ( above is explosive below is burn, speed of sound is dramatically affected by pressure and density).Lquid fuel dose not burn due to insufficient O² infusion, phase change is absorbing massave amounts of heat and allowing the vapor to mix with O² then burn at a controlled rate based on temperature. Detonation happens when the cooling effects of phase change is used up, causing the temp to spike the liquid is now all gas at spontaneous combustion temperature where all is consumed at or above the speed of sound. I think the rattles are sonic booms in cylinder. MSD is 20° of spark shrinking volume from idle to 3000 ( if i remember correctly its been 20yrs) 20°becomes too short of time at higher rpms for multiple sparks ( coil saturation time limmits i think) so it is a continuous spark for 20° above the set point.
That was outstanding, keep it coming!!!
I found that the head gasket had to match the bore exactly,the thinnest possible. This helped detonation problems
Darren’s videos are amazing. Still learning from them each time I re listen.
Tried to make a nice payment but there is no option other than “save card info” which I refuse to do. Can this be fixed to “do not save card info” or use PayPal?
A lot of heavy road car parts have race car parts inside them. You just have to dig them out.
Darin Morgan is a fantastic guy...Needs more video on his channel, which could explain why his subscriber count is in the toilet, got to catch him on Dragboss's channel.
I have built a cosworth yb turbo engine, running,_7.9:1 CV compresión with minimum quench clearance and its more responsive and fuel efficient than with std quench, running 1.9 bar boost no problem with detonation.Big respect to D V👏👏👏👍
Watching this to learn how to adapt my system on a VFR800 V4 VTEC Honda motorcycle. Any suggestions people? I will also be looking at adding stepped 4-2-1 system with Davids advice from this and other videos.
I just had a crazy idea. Of building a injector like a annualar booster, that fits between the intake and head. Similar to the ZEX® brand nitrous plate systems. Only using tiny holes all around the port walls in about a 1/8". Ring or semi circle. Or even a 1/4"-1/2" on the top side ,with a couple dozen .020" holes with a internal feed to the holes being about 0.5-1mm thick by the width of the injection patch. It could be a primary fuel injector or a secondary system. Or even a water methanol injection. To a Nitrous injection point. With the holes being at different angles and shaped like a rocket nozzle. A .020" inner diameter, with s .040" outer exit diameter the fuel will cool the port wall. Also having them angled to the head from 15°-45°. Using a injector like solenoid valve to be fired just as the intake valve opens. Possibly experiment with start timing to allow air only for a short time in the start to cool the exhaust but only while hot when cold it needs to be opposite. And using a relatively high fuel pressure. 80-120psi to get the required fuel through the somewhat small orifices. The intake can be milled out to fit the ring in and epoxy it in place. It can be made from copper, brass, aluminum, cast stainless would probably be best, with the inner wall thickest to allow porting to fit. Have a groove milled into the ring. When porting if the groove is gone, there is less than so much thickens remaining, and having approximately 5mm to start and allows down to 1.25mm hopefully the 24-36 nozzles per sq inch. (A off the wall number) It wouldn't be the cheapest injector but for high performance street, land speed and road race, nascar, where engines run hard for long durations. Engines getting heat soaked. It could be that little bit that makes the difference. May not make any more power when cold , but could either prevent power drop-off due to heat. Or possibly gain power due to cooling of the intake charge, along with superior atomization. I would love to test it , or see this tested. It is crazy, but we never know until ee know! Have a awesome day...🎉
I was taught by my turbo friends , i.e.Peter of Andersson Turbo systems, a ten C. lower in gas temp , result ins 100 C lower exhaust temp.... hence INTERCOOL !! (Building 600 hp , 1300cc Hayabusas ..)
I just built a propane fueled SBC engine in 2023 . It is a 12.1 CR with a set of Vortec heads with as tight a quench area as possible . With propane not needing to be vaporized , vortec head swirl mixing and tight quench I'm expecting good performance . It is unfortunate that I could not get sodium cooled exhaust valves for this build . Good thing propane has good detonation resistance but some better valves would have been nice . Your episode has verified that I am the right track . Thank You Sir !
www.youtube.com/@darinmorgan3520
You've been on a roll. Great stuff. Can't wait for more. Much thanks.
DV fine details removes our misakes . WE WANT MORE !!
KZread dumped a ridiculous number of ads into this video. Good luck with your channel. I only run NA. Torque and efficiency for the sum of the parts. Started out with air cooled 2 strokes 40+ years ago, melted pistons were always from insufficient squish clearance and lean mixture at full throttle. Before the days of rev limiters, mapping and unleaded. Often see porting being done with the intention of directing the mixture towards the spark plug so not sure where it all went wrong. Buddy, that valve has been closed for best part of a stroke before the spark. Swirl with maximum micro turbulence will get the best economy. Too rich will reduce the header temperature but it's better than aluminium paste in the crankcase. Happy days.
During my engineering studies, I recall the study material from Chrysler about combustion duration. Eleven to seventeen maximum degrees of rotation drop on the various engine bores, strokes was that determination. These were flat or decompressed pistons. The workup was one of comparatives of decks, timing and temperatures etc. The fuels used were taken into account for control etc. The studies are now old, however showed production capabilites without the fine tuning good engine builders would provide. The surprising part of the study was the time verses completed combustion. -- Your video was a good partner to that. Thank you David.
Wow. I had no idea David Vizard was on here. Wish I would've known this guy 25 years ago when I was digging deep into building high horse power engines. I had so many questions I needed to know about volumetric efficiency and I heard you were the man to see. Dude, youre a legend, up there with the best of them like Shelby and other true original greats. I just cannot believe that youre on here and somehow got suggested to me. Well, cheers to you, sir!
I always fully polish the head of the exhaust valve till i can see my reflection any time I'm close to pushing the limits of detonation. It slightly reduces the surface area and the valves ability to absorb heat from the exhaust. It also makes it harder for carbon and ash to build up on it. It is not hard, if it is a used valve i tape up the stem with electrical tape then sand blast the head to remove carbon and ash, after that just chuck it in the drill press and start off with around 220 grit and work my way in several stages up to 2000 or even 3000 grit. If I'm sending it to get coated I just do the sand it to round off edges then blast to clean it and help the stuff grip better.
On the intake valve I do the opposite, make sure to leave nice sharp edges, especially the margin to the face on the chamber side to sheer the fuel and reduce reversion during overlap. I try to get em as sharp as possible there at that 90 degree angle.
,,,,,,,,thanks David ,,,,,,,,,,,,,,,,,,,,,after the prior weeks of doubters ; you are working stronger than ever ; putting out high tech topics ,,,,,,,,,,,,,,,,we all need to know.............
would a "dykes" style ring that is L shaped, reduce the volume at the ring ???
Hi, I find your videos very informative... Just a question... What's your view on the big split duration cams like the thumpr series and the bootlegger series cams. While the have a tighter LSA are they overdoing the exhaust duration? Thanks
Thank You David!
HEY DAVID, there seems to be alot of , lets say misled people on youtube and here in canada. Every body puts Dual 2.5 or even dual 3 inch exhausts on everything from stock 4.8 L Ls, 1995 366 bus engines to stock 325 2004 truck engines. Seems to me a SINGLE 3 inch mandrel bent system should suffice for most these lower power stock engines. I seen a chart somewhere saying about 1 inch of mandrel bent pipe /100hp is a good ballpark estimate and only a dyno will rweally tell you if you need more BUT common sense should dctate a relatively stock engine thats run 99%on the strreet should be good with a single 3 inch AM i CORRECT or are they actually benefitting from DUAL 3 INCH[besides their egos]
the reason i ask is im considering buy the old 1960 apache with 1995 bus engine in it. its stock engine with less than130,000 miles BUT he has dual 2.5 mufflers on there/ He also says theres a header flange problem that needs fixing so while i am it fixing that , should i just delete an entire muffler and tailpipe and just ypipe them together? Stock power is about 230 Hp, 385 Tq
Hello David I would like to purchase the IOP The pay button does not work I am building a 383ci I have a goal of 1.42 lb-ft per 1 ci or better. I have been following you for many many years. Now is the time to put together all of the knowledge.
Thank you for your knowledge and videos USA 🇺🇸 TRUMP 2024
Hi David, thank you so much for the information you’re giving us wish. I knew this a long time ago the video that you did on the quench I’m interested to know just you don’t have to make a big deal out of it. Just answer the question if you could did Pont Pontiac have a better grasp on the combustion chamber shape because it was milled verses cast chambers and if so, why don’t any of the new aluminum head guys machine, the valve pockets and combustion chamber like Pontiac did and using the 30° angles on the seat just something fellow engine builders were talking about the other day in the shop. We tend to meet once twice a week and discuss these horsepower gains that have been lost overtime or maybe just not shared with the public. We very much enjoy your show and look forward to more videos on educating us on the foundation stones that we all need to have to build the best engine possible and then look for more. It’s a way of life at least for me and my buddies. Thank you for your time and I hope that your throat surgery ends up healing faster than it’s been going, thank you from the gang at the machine shop/Dyno/oh and we have one of the older super flows benches. Thanks Dave again best wishes, Joe.
Thats why you dont spray water on a grease fire
darin is awesome
Dv on a turbo engine do you recommend widening the ex seat to about .0.60 to pull more heat from the ex valve?
I would like to debate on this one David. You do bring up a good point of the cotton fibers acting like the hair found in a human lung, and while it is true that an engine pulses so it is not constantly pulling on the filter at idle and low rpm. But What about high rpm? Where the time between the engine pulses is very short. Or how about a vehicle where the air filter is sticking out of the hood and you are going 170 mph down a racetrack or a drag strip? Surely the filter can not properly filter the incoming air because the cotton fibers are being blown back and can't catch the dirt or pollen partials. Not to mention a barbaric test I have done. Place a dry cotton towel over your face and try to breath now take that same towel and wet it with oil and try to breath through it. It's much easier to breath through the dry towel believe me. I love your videos and think you are highly intelligent, But I think your wrong on this one. If you have a way to disprove my rebuttal please reply I'm always learning and would like to know more, Thanks.
Wow thank you for sharing . I remember reading one of your books or watching a seminar way back in mid 2000s and you mentioned 4 v heads tumble the air and they weren’t figured out yet. It’s good to here the progress you’ve made . I will be implementing your ideas on a 4v Harley .
I was wondering David if you have done much work on Fords Cleveland heads, here in Australia 2v+4v heads are still extremely popular. The Ford Australia heads from standard were much better than their American counterparts , i think if you have time to do a video on them it would be greatly appreciated by all. Cheers Australia.
Ben Alameda spoke of this crevice gap in one of his videos but he warned going too small especially in a boosted application can actually crack a piston easily. This is great stuff.
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,he and charley serverdo are highly educated in the engine science......................few are.......
The question for me is how far can you go with a ceramic coating at the top of the piston to cut down on the crevice volume and still utilize a gas ported ring like total seals? As in how much can you limit the growth of the piston with the thermal barriers at the top? The Line2 Line abradable coating looks awesome for the skirts of the piston.
I’m pretty sure you meant to use Line2Line’s ceramic coating from the top ring groove up. Don’t think there powder coating would last up there?
If you build a tight quench pump gas engine it'll knock in the quench zones and it'll suffer from lspi. Pentaroof engine's have zero quench, and make phenomenal power per ci
Here’s my argument based on my dyno data on late model fuel injected Harley’s using throttle by wire. port velocity on such a short intake runner length using electronic throttle is no longer a concern as the throttle blade or velocity valve as I like to call it can be mapped to maintain peak air speeds at all accelerator positions or torque requests. As for the 170 port vs 195 port , for that specific cam timing the 170 was better, but change the cam timing to take better advantage of the 195 and my bet is you will make even more power correct ? the more we increase flow the less time we need to hold the valves open so the piston does more work .
Thanks David what about 4 valve heads?