Did you cut back the chamber wall to unshroud the intake valves. That 2.19” is even more shrouded than the factory 2.06”. You can plunge cut it or mark a radius and remove material with a cylindrical carbide bit. I had my 702’s plunge cut at the shop for about 0.300” valve to wall clearance. It made a big difference across the entire rpm range, but especially the top end!
At what point does the increasing valve size have a diminished return or even loss for increased shrouding. Would think the low lift numbers would be affected most…
I had to change an intake on a very old dart head to 2.35s because they were sunk so much. Hopefully you’ll be getting them for a critique soon and flow them and then beat me up for my chamber work😂
For a street/strip 461 turbo motor >15 psi would the 290 head be better or would it choke it? Thinking it would have good cruising velocity at low rpm and be more efficient.
I wonder if opening the chamber adjacent to the intake would help low lift flow with the larger valve. I realize these heads will get returned, but maybe that and an adjustment in seat angles could help. Thanks for the videos.
@@v8packard Yes that was the 396 and the 402 . they were basically 402 was a. .30 396.but the chamber is still wider than the 427 or454 with their 4.250 bore I Mark the block and bevel the top of the block, that is what Ford did with the Cleveland. The air is already passing between the valve and the chamber and sure doesn't need to hit a ledge that is bad news. I noticed when I put my LS together it presents a ledge to the air, I'm either going to jog the heads or bevel the bore which I can because my top rings are down. 300. It's a turbo engine
@@davidreed6070 The 4.25 bore high performance blocks (427 and 454) were also notched. Not all, truck stuff and smaller valve passenger car were not. But anything with a 2.19 intake valve from the factory was notched, for sure.
On a engine with more cam I'd like to see a dyno comparison of normal valve, then ridge cut in the face for anti reversion (think it was Vizard who talked about that). And then radius of that modified intake valve. A does the face cut help with reversion and if so can you radius the intake thereafter kinda thing.
@@WeingartnerRacing yeah I've never seen it done, have you? Would think reversion would be more of a pressure wave out of time thing than flow towards the face of the valve so I have a hard time picturing the conformation groove doing anything. As far as the margin radius I'd think it could help on the intake (not just the exhaust). I read the intake margin to face should be sharp and that's the norm. But as far as flow separation and unwanted turbulence from a sharp edge I'd think flow may improve. And perhaps in applications with a very rough burr finish that sharp edge induced turbulence would be less ideal if the fuel staying more in suspension is now less of a concern vs just filling the cylinder. Not sure if the flowbench pressure drop would translate. Or maybe it does nothing lol. Guess that's why we test.
Eric can u tell us why Vizard is the only one doing the conformation groove? What I gather from his book is the groove helps the valve and seat seal better when the intake valve seat is thermally distorted from the heat on the side closest to the exhaust seat side and used with a 30* seat which is harder to seal when distorted compared to a 45* 50* seat... plus a 30* seat presents more thru flow area (better low lift flow) than a 45* seat at low lift... the groove helping with reverse flow makes sense because as the piston nears TDC and is doing its part to expel exhaust gas the intake valve begins to open while the exhaust valve is still open (overlap) there is an opportunity for reverse flow to take place around the intake valve if the groove is there it could help restrict reverse flow which would help flow into the cylinder easier and produce more TQ/HP. Now I realize this greatly depends if you have the correct size port, velocity LSA and a whole host of other factors correct for that particular application but I think the opportunity exists ...idk please tell me what you think I know it has to be tested on a running engine on a dyno ... how much testing have you done on this ... great videos I appreciate all you do
The idea of enormous valves, and ports to match, always means big numbers on a flow bench, but unless the head is for a race only engine, which is operated WFO pretty much all the time, the results on road vehicle are likely to be disappointing. Venturi type porting, when the intake ducts are actually made smaller, is likely to work better for the road.
@@Ws6Ms Its OLD thinking now! Overly large ports, and enormous valves, mean big numbers on a flow bench, but due to slower gas speed at low to medium engine speeds, will always be slower on the road.
@@humourless682nah I still doubt that... then why do big port ls3/lt1 make more power than a smaller head ls2 and drive just as well ? Or the old hipo ford 302 with huge ports and smaller cam had a better power curve than chevy dz 302 with small heads and huge cam.... big port heads with correct cam and compression will always outperform in daily/racing sorry
@@Ws6Ms The laws of physics cannot be changed. If the port size is smaller, the gas speed will be higher, through that port. Increase the size of the valve and it will increase even more. In the US the idea that bigger is better, sells, but for quite a while smaller ducts have been being used in some very serious engines. The idea of making intake ports smaller, even though its FAR more effective, is never likely to sell, hence the large number of videos like this one, which equate big numbers on a flow bench, to more power (at a far higher cost). Essentially, this is the reason why a 4 valve, DOHC, head, is a good deal more effective than a 2 valve pushrod head, with enormous ports, and gas moving at a snails pace.
@@humourless682 the only way what you're describing would be more effective is like 500rpm to like 2500rpm... but from 2000 to let's say 7000rpm the whole curve the big head will make more power its been done numerous times... have you seen the intake ports on a 4 banger Honda? There huge
could you use/ try thin MLS gaskets to get the compression up that ridge AS opposed to sinking the valves to kill low lift flow to make a big cam into a shorter cam on the larger valve you get a new higher seat which can help unless you have the too early intake opening where you sink the valve (and/or go to steeper seat) cheers how many cuts on the chamber side?
Still lovin and apreciate what you do. Thank you for your efforts Eric. But the number of ads in this one are a little heavy. Atleast from my perspective. Anyway, Thanks. Great vid as usual. 👍
@@chippyjohn1what’s your largest 4 valve engine in a vehicle. A large 2valve engine makes more mostly due to size. Point being there are not big 4valve engines besides diesel engines
@@WeingartnerRacing Okay, but you acknowledge that you make power due to displacement. Because people don't require massive engines is not an argument to say 2 valve is better. Multivalve has been common since WW2, look at the DB605, the best engine back then. Any decent race engine uses multivalve, except where valve number is limited by rules to make it harder to make power.
I had the 2.19 1.88 valves put in my 68 Camaro with closed chamber oval Port head's made a very noticeable improvement, great video keep them coming
Did you cut back the chamber wall to unshroud the intake valves. That 2.19” is even more shrouded than the factory 2.06”. You can plunge cut it or mark a radius and remove material with a cylindrical carbide bit. I had my 702’s plunge cut at the shop for about 0.300” valve to wall clearance. It made a big difference across the entire rpm range, but especially the top end!
At what point does the increasing valve size have a diminished return or even loss for increased shrouding. Would think the low lift numbers would be affected most…
FloTek 290 is the same head, but comes with the 2.300 valve standard
I had to change an intake on a very old dart head to 2.35s because they were sunk so much. Hopefully you’ll be getting them for a critique soon and flow them and then beat me up for my chamber work😂
Right on
Id love to see how much the AFR 265s would pick up with a bigger intake valve and your valve job . Did you do a set with a 0.225 intake valve ?
Thanks
Yeah . 6:30 ish . Sometimes laying back the short turn will stuff flow up. The large, gradual curve is what you need to make the port work
For a street/strip 461 turbo motor >15 psi would the 290 head be better or would it choke it? Thinking it would have good cruising velocity at low rpm and be more efficient.
OLÁ. Olhando a instalação da nova séde de válvulas percebe-se seu parcial conhecimento do assunto que tratas. ABRAÇOS... Roberto Udo Krapf
Thank you for your knowledge and videos USA 🇺🇸 USA 🇺🇸 USA 🇺🇸
did you ever flow these after you took that ridge off?
Do you to a shallow top cut to get rid of the ridge or blend by hand?
Eric, do you believe these results are exclusive to this head? Or will all BBC heads behave similar with a larger valve installed? Awesome video!
Every head is a different situation.
I’d like to see the peak flows under boost for this head.
I really want to see what happens. How the two compare.
I wonder if opening the chamber adjacent to the intake would help low lift flow with the larger valve. I realize these heads will get returned, but maybe that and an adjustment in seat angles could help.
Thanks for the videos.
People jog the heads because the heads chamber is wider than the bore. I sometimes bevel the top of the block but have never tested that on the dyno
@@davidreed6070 some big blocks came with the notch at the top of the bore from the factory. You can see where it would be on a head gasket.
@@v8packard Yes that was the 396 and the 402 . they were basically 402 was a. .30 396.but the chamber is still wider than the 427 or454 with their 4.250 bore I Mark the block and bevel the top of the block, that is what Ford did with the Cleveland. The air is already passing between the valve and the chamber and sure doesn't need to hit a ledge that is bad news. I noticed when I put my LS together it presents a ledge to the air, I'm either going to jog the heads or bevel the bore which I can because my top rings are down. 300. It's a turbo engine
@@davidreed6070 The 4.25 bore high performance blocks (427 and 454) were also notched. Not all, truck stuff and smaller valve passenger car were not. But anything with a 2.19 intake valve from the factory was notched, for sure.
On a engine with more cam I'd like to see a dyno comparison of normal valve, then ridge cut in the face for anti reversion (think it was Vizard who talked about that). And then radius of that modified intake valve. A does the face cut help with reversion and if so can you radius the intake thereafter kinda thing.
I can tell you nobody does it besides vizard for a reason.
@@WeingartnerRacing yeah I've never seen it done, have you?
Would think reversion would be more of a pressure wave out of time thing than flow towards the face of the valve so I have a hard time picturing the conformation groove doing anything.
As far as the margin radius I'd think it could help on the intake (not just the exhaust). I read the intake margin to face should be sharp and that's the norm. But as far as flow separation and unwanted turbulence from a sharp edge I'd think flow may improve. And perhaps in applications with a very rough burr finish that sharp edge induced turbulence would be less ideal if the fuel staying more in suspension is now less of a concern vs just filling the cylinder.
Not sure if the flowbench pressure drop would translate.
Or maybe it does nothing lol. Guess that's why we test.
Eric can u tell us why Vizard is the only one doing the conformation groove? What I gather from his book is the groove helps the valve and seat seal better when the intake valve seat is thermally distorted from the heat on the side closest to the exhaust seat side and used with a 30* seat which is harder to seal when distorted compared to a 45* 50* seat... plus a 30* seat presents more thru flow area (better low lift flow) than a 45* seat at low lift... the groove helping with reverse flow makes sense because as the piston nears TDC and is doing its part to expel exhaust gas the intake valve begins to open while the exhaust valve is still open (overlap) there is an opportunity for reverse flow to take place around the intake valve if the groove is there it could help restrict reverse flow which would help flow into the cylinder easier and produce more TQ/HP. Now I realize this greatly depends if you have the correct size port, velocity LSA and a whole host of other factors correct for that particular application but I think the opportunity exists ...idk please tell me what you think I know it has to be tested on a running engine on a dyno ... how much testing have you done on this ... great videos I appreciate all you do
The idea of enormous valves, and ports to match, always means big numbers on a flow bench, but unless the head is for a race only engine, which is operated WFO pretty much all the time, the results on road vehicle are likely to be disappointing. Venturi type porting, when the intake ducts are actually made smaller, is likely to work better for the road.
I don't believe that to be true... not when matched with a small cam.... the big head and small cam is a proven combo
@@Ws6Ms Its OLD thinking now! Overly large ports, and enormous valves, mean big numbers on a flow bench, but due to slower gas speed at low to medium engine speeds, will always be slower on the road.
@@humourless682nah I still doubt that... then why do big port ls3/lt1 make more power than a smaller head ls2 and drive just as well ? Or the old hipo ford 302 with huge ports and smaller cam had a better power curve than chevy dz 302 with small heads and huge cam.... big port heads with correct cam and compression will always outperform in daily/racing sorry
@@Ws6Ms The laws of physics cannot be changed. If the port size is smaller, the gas speed will be higher, through that port. Increase the size of the valve and it will increase even more.
In the US the idea that bigger is better, sells, but for quite a while smaller ducts have been being used in some very serious engines.
The idea of making intake ports smaller, even though its FAR more effective, is never likely to sell, hence the large number of videos like this one, which equate big numbers on a flow bench, to more power (at a far higher cost).
Essentially, this is the reason why a 4 valve, DOHC, head, is a good deal more effective than a 2 valve pushrod head, with enormous ports, and gas moving at a snails pace.
@@humourless682 the only way what you're describing would be more effective is like 500rpm to like 2500rpm... but from 2000 to let's say 7000rpm the whole curve the big head will make more power its been done numerous times... have you seen the intake ports on a 4 banger Honda? There huge
could you use/ try thin MLS gaskets to get the compression up that ridge
AS opposed to sinking the valves to kill low lift flow to make a big cam into a shorter cam
on the larger valve you get a new higher seat which can help unless you have the too early intake opening where you sink the valve (and/or go to steeper seat) cheers how many cuts on the chamber side?
Still lovin and apreciate what you do.
Thank you for your efforts Eric. But the number of ads in this one are a little heavy. Atleast from my perspective. Anyway, Thanks. Great vid as usual. 👍
Why are people in the US obsessed with old technology? We have had multivalve heads for a long time now.
Because we want to make more power than small 4valve engines.
@@WeingartnerRacing that doesn't make any sense.
@@chippyjohn1what’s your largest 4 valve engine in a vehicle. A large 2valve engine makes more mostly due to size. Point being there are not big 4valve engines besides diesel engines
@@WeingartnerRacing Okay, but you acknowledge that you make power due to displacement. Because people don't require massive engines is not an argument to say 2 valve is better. Multivalve has been common since WW2, look at the DB605, the best engine back then. Any decent race engine uses multivalve, except where valve number is limited by rules to make it harder to make power.
@@WeingartnerRacing Mercedes M159 was a 6.3 liter 4-valve.
Made 622 HP with small cams, 11.3:1 on pump gas a warranty