What about the air velocity on the AFR heads? David Vizard talks about this on his Channel in episode 9. The combustion cambers receive more air when a higher velocity air column rams more are into the chambers as the rpms increase.
This is a comment because I like comments. It's a really good demo. There is probably lots of guys thinking about getting a gen6 and wondering what a proper head will do.
I've been running a similar combo for almost 20 years with AFR 305 rectangle port heads, they didn't have ovals back then. Compression the same, and similar 242/248 hydraulic roller but custom grind from Comp with .638 lift, 110 lsa. I use the RPM air gap on it with a 1" open spacer. I liked the curve better than the Victor Jr. since it's primarily street driven and the spacer helped a pinch up top. This combo makes a very fun street engine and has gone a best of 11.38 @ 118 in a 4100 lbs chevelle through a full exhaust system and DOT tire.
I remember an old mechanic telling me about the problems with the 409 dropping valves. Must've been pretty common, apparently whenever they revved the engine to around 6000 rpm. I learned later that the valve springs were the weak link in the 409 and better springs became available. I have no experience, just a lot of useless second-hand knowledge, but that's the story I heard..
Can't get over how well the engine responded to the AFR oval port heads. They absolutely blew the big rec port heads into the weeds. I would take that 468 combination with the dual-plane manifold. It gained 30 hp at 4000 rpm, and lost 20 hp at 6500. I think the average power advantage would go to the dual-plane manifold in that case.
It would feel better driving around on the street with the dual-plane, but that single plane will win at the drag strip every time. If you shift around 6500 rpm, it will probably drop down to 4700 or higher on the gear change. The single plane is already matching the dual-plane there.
dang GOOD video!... ALL things I've been thinkin about lately...as I'm planning a bbc 454 big oval assembly. BIG THX 💗 richard...you been readin my mind.
I've found on the BBC a weak link is the stand-alone rocker stands themselves. Increasing spring pressures substantially I think requires the use of a stud girdle.
I agree on higher spring pressure with HR cams. I'm running 150 closed and 420 at .6 on sbc with 1.7 rockers. PAC 1.275" duals so light weight. Also need to remember if your springs are a little soft your lifter wheel will come off the cam, causing damage and wear. There think there was evidence of this at lower rpm with the softer springs.
Hard to beat those AFR oval ports for the street. Just for grins overlay a 6.2 LS3 with a 469 cam over the iron rec port head dyno curve. I always thought comparing the LS to a BBC was nonsense, but in some cases not. Once you put the good heads on it it certainly IS nonsense, though!
I've seen that ugly curve drop on the dyno more than once, and with a worse drop off. Some times all that was needed was a .060" shim under the springs to fix it. Some of the worse flat tappet cams are the small Extreme Energy since you wouldn't typically put a big spring on such a mild cam that is intended to peak at 5200.
Could you take the cylinder head flow test data and put it on a graph, with valve lift on the x axis and air flow on the y? It would be really interesting seeing head-to-head (haha) tests done.
Yea let’s see the difference when you throw a proper cam in that motor to match that head. If you put a cam in it that’s got .800 lift, I’d be curious which head makes more power then. It’s not just a set of heads, you gotta have the other parts to match what those heads are good at. This cam was engineered better for the afr heads. With a higher flowing head, you’ll make more power with a bigger cam and at higher rpm.
Really enjoying seeing info on how to keep the Old Skool relevant with modern engines. Curious...did the AFR heads want the same amount of timing as the rec ports?
Perfect timing Richard. I’m trying to guess my spring pressures. 5500 red line so I can use much softer springs than recommended. Have you tried LS style small beehives on a 454?
@richardholdener1727 say even in higher boost applications? 25+ psi? Just hard to separate fact from fiction when looking through forums. Ideally the concepts make sense but who knows. Example Some bring up the positive pressure on intake side can help initiate valve float, some go into valve size so square inch vs pressure applied (increase valve spring by math given), then there is exhaust back pressure which is usually higher than boost pressure and that keeping the exhaust valve open. So many things.
@richardholdener1727 😅🤣 I know sounds dumb but we see it a lot in the bike world. Most will degree cams and leave them. One reason is cost. a set of cams for bikes can cost 1000-1600. Add in valve train parts and you could be up 1500-2000.
I know these are basic setups! But normally today, spring companies want the spring setup within a certain distance from coil bind! 50 thou, 100 thou, whatever they tell you! Unless you’re using a 30yr old spring design! I guess it worked fine on puppy cams. But we rarely setup springs on seat pressure anymore! I’m also wondering why you never mention about cylinder head material grade? If it’s going on a basic rebuild, it probably doesn’t matter! But normally people looking to your channel are looking for the most power possible, not just a rebuild! Also probably worth mentioning about the rocker box of the head! If it’s a rebuild with low power/puppy cam, it doesn’t matter, but put a big shot of nitrous or boost on the engine & some heads will rip the roof of the intake port completely out! This stuff is probably worth mentioning even to the guys doing basic stuff! So he doesn’t have to upgrade head again when he gets bored with the power! Who doesn’t? Thanks for trying to point all the morons straight! I love how you make a video on something, back to back, whatever, than they say, oh I wish you tested with this head/cam/intake! I very surprised you have not said, why don’t you go test it you lazy couch potato mtherfker! 😜😜😜😜😜😂😂😂😂😂👍🏻👍🏻👍🏻👍🏻👍🏻👍🏻
coil bind clearance set up is not nearly as critical as seat and open pressure for 90% of the street/strip applications, we use it for wilder combos with more rpm
in your opinion...do you feel the AFR oval preformance heads would be a significant amount more representative to what the 049 stock ovals would do... when compared to those rec port head? do you feel the 049 heads w/some port smoothing would work well and adequate to a solid roller 255@.50/ .680 lift (7000 rpm range) ???
I wonder if AFR uses less spring rate since they use lighter valves? NOT MUCH... PAC Racing Springs #1940 Street Hydraulic Roller Spring 1.550 O.D. 175 lbs. on seat .725” max lift Max RPM 6500-6700
OHC engines use valve springs like the OHV engines. Yet, they don't suffer from valve float until much higher in the RPM range. Why is this? The OHV has the lifter and pushrod linking the cam to the rockers unlike that of the OHC. Obviously those components are the real issue that needs addressed. Placing higher pressure valve springs is just a bandaid on a bullet wound. And, you CANNOT "cure valve float." You can defer it later in the RPM band.
I contend that flow values at low, mid or high lift, or even average flow fail to express meaningful information given they don’t provide total cfm flow per valve actuation cycle.
That's true, but you can still make more power by picking the head that has the best average flow through the range of valve lift. In order to get the total flow over a valve actuation cycle, you would need to have the full valve lift curve and do degree-by-degree calculations using a curve fit of the cylinder head flow data. I have done that sort of thing in Excel to compare the power potential of different heads on a given valve lift profile.
@@andyharman3022 I fully understand all the contributing factors that you detail, and others. I contend one simply bench measure total flow on a fully outfitted engine via electric motor at the entire operating range, over a given time frame as the the absolute, accurate measure of flow.
@@richardholdener1727 on a hot day, on a race course? That's what I'm curious about. The dyno offers ideal scenarios, wouldn't it be wise to go conservative once its into vehicle? I know locked timing will ping a motor to death without an educated throttle pedal foot...
Flow testing heads with just some playdough around the port, I still can't get past that. I'd rather see an intake / exhaust manifold bolted on as there has to be some sort of influence no? .
@@ks_1111 Given an engine runs with an intake and exhaust, these would matter if they influence head flow. Say a head flows 300 and the intake 250 , you could have a 500 head and still only get 250.
I would like to no what a 4 7 swap firing order cam and a4hole super sucker 1inch spacer on single plane intake would make I believe the cam will load and unload the cylinders more efficiently more power with the. A. F. R head thank you I watch all the time
The lighter the spring the better. The hydraulic roller is heavier than a mechanical flat tappet and the mechanical has faster lift possible, So if you want to rev it real high forget the roller and go with a flat tappet.
Technically speaking, higher spring rate does not cost power, this is a fallacy, it can actually increase power duo to proper closing without seat bounce. Remember one thing, there are the same number of valves opening as well as closing and as any spring is closing the energy is returned, this was a proven factor at Reher-Morrison racing engines.
John, I know you like Richard and you probably want him to succeed. Comments can help with that regard but the all seeing eye starts to ignore repetitive comments with the understanding that they are spam and ignores any like or dislike that you provide if it's submitted in the first ten seconds if you don't watch the whole video. There is a reason why your comments show up at the very bottom of the list. The bits think they are spam and youre being filtered.
@@timothybayliss6680 🐿🐿🐿🐿🐿 lol you think I don't watch the videos ok .........I'm amazed at the level of knowledge you figure you have on the subject. It's still a comment, it gets other comments added ( like this one ) I'm kinda sure I watch the videos, if not now later . But ether way don't worry about what I do just focus on what you do instead . It's not a competition .
I live for the big block Chevy content he drops
What about the air velocity on the AFR heads? David Vizard talks about this on his Channel in episode 9. The combustion cambers receive more air when a higher velocity air column rams more are into the chambers as the rpms increase.
This is a comment because I like comments. It's a really good demo. There is probably lots of guys thinking about getting a gen6 and wondering what a proper head will do.
I've been running a similar combo for almost 20 years with AFR 305 rectangle port heads, they didn't have ovals back then. Compression the same, and similar 242/248 hydraulic roller but custom grind from Comp with .638 lift, 110 lsa. I use the RPM air gap on it with a 1" open spacer. I liked the curve better than the Victor Jr. since it's primarily street driven and the spacer helped a pinch up top. This combo makes a very fun street engine and has gone a best of 11.38 @ 118 in a 4100 lbs chevelle through a full exhaust system and DOT tire.
I love what you do man I love how specific you are great practical testing ideas wonderful information for all the shade mechanics
ABSOLUTELY correct
We had a 396 on the Dyno that was in trouble at 5600.
Swapped the Comp steel retainers for the Comp titanium versions. Picked up 400 rpm and 30 hp.
I’ll take the air gap any day, that long flat torque curve is what I’m after. 👍🏻
I remember an old mechanic telling me about the problems with the 409 dropping valves. Must've been pretty common, apparently whenever they revved the engine to around 6000 rpm. I learned later that the valve springs were the weak link in the 409 and better springs became available. I have no experience, just a lot of useless second-hand knowledge, but that's the story I heard..
Man, does anyone else think that Richard's office is the best green screen background ever?
Great test and comparison Richard !!!!
Even if you're not into big blocks, some of this info is still helpful.
Exhaust is a big key
If you can't get the exhaust out
You're screwed
1.75 exhaust valves on 406 ford heads
Woke my 428 ci up back in the 70s
I will never own a BB Chevy, but I love these videos. Thanks
Alot of Area over 500hp after tuning with pedestrian heads and a 541 peak. Good job, Right Cam ...
Can't get over how well the engine responded to the AFR oval port heads. They absolutely blew the big rec port heads into the weeds. I would take that 468 combination with the dual-plane manifold. It gained 30 hp at 4000 rpm, and lost 20 hp at 6500. I think the average power advantage would go to the dual-plane manifold in that case.
It would feel better driving around on the street with the dual-plane, but that single plane will win at the drag strip every time. If you shift around 6500 rpm, it will probably drop down to 4700 or higher on the gear change. The single plane is already matching the dual-plane there.
Great explanation as usal
dang GOOD video!... ALL things I've been thinkin about lately...as I'm planning a bbc 454 big oval assembly. BIG THX 💗 richard...you been readin my mind.
🔥🔥Great Info for my Gen VI L29 K2500 EFI motor, Awesomeness Richard 🔥🔥
I've found on the BBC a weak link is the stand-alone rocker stands themselves. Increasing spring pressures substantially I think requires the use of a stud girdle.
Great test, that’s the heads what I want for my 502 for my Motorhome, everything is out of stock now
I agree on higher spring pressure with HR cams.
I'm running 150 closed and 420 at .6 on sbc with 1.7 rockers. PAC 1.275" duals so light weight.
Also need to remember if your springs are a little soft your lifter wheel will come off the cam, causing damage and wear. There think there was evidence of this at lower rpm with the softer springs.
Hard to beat those AFR oval ports for the street. Just for grins overlay a 6.2 LS3 with a 469 cam over the iron rec port head dyno curve. I always thought comparing the LS to a BBC was nonsense, but in some cases not. Once you put the good heads on it it certainly IS nonsense, though!
I've seen that ugly curve drop on the dyno more than once, and with a worse drop off. Some times all that was needed was a .060" shim under the springs to fix it. Some of the worse flat tappet cams are the small Extreme Energy since you wouldn't typically put a big spring on such a mild cam that is intended to peak at 5200.
Could you take the cylinder head flow test data and put it on a graph, with valve lift on the x axis and air flow on the y? It would be really interesting seeing head-to-head (haha) tests done.
Yea let’s see the difference when you throw a proper cam in that motor to match that head. If you put a cam in it that’s got .800 lift, I’d be curious which head makes more power then. It’s not just a set of heads, you gotta have the other parts to match what those heads are good at. This cam was engineered better for the afr heads. With a higher flowing head, you’ll make more power with a bigger cam and at higher rpm.
Put an air hat on that 5.9l magnum, i'd like to see the actual cfm that engine is pulling at the various levels of modification.
Really enjoying seeing info on how to keep the Old Skool relevant with modern engines. Curious...did the AFR heads want the same amount of timing as the rec ports?
less
Less timing, Richard mentioned.
Less……. Better combustion Chambers
Perfect timing Richard. I’m trying to guess my spring pressures. 5500 red line so I can use much softer springs than recommended. Have you tried LS style small beehives on a 454?
WE HAVE RUN BEEHIVES ON THE BBC-BOT NOT STOCK LS SPRINGS
I really wounder what the numbers would be with a stock ls gen 454 w the top end kits onnit.
What about valve springs and seat pressure for boosted engines. If cam was left stock and no increase of rpm was sought after.
we have run on stock springs with stock cams
@richardholdener1727 say even in higher boost applications? 25+ psi?
Just hard to separate fact from fiction when looking through forums. Ideally the concepts make sense but who knows.
Example Some bring up the positive pressure on intake side can help initiate valve float, some go into valve size so square inch vs pressure applied (increase valve spring by math given), then there is exhaust back pressure which is usually higher than boost pressure and that keeping the exhaust valve open. So many things.
WHY WOULD ANYONE TRY TO RUN 25 PSI ON A STOCK CAM APPLICATION
@richardholdener1727 😅🤣 I know sounds dumb but we see it a lot in the bike world. Most will degree cams and leave them. One reason is cost. a set of cams for bikes can cost 1000-1600. Add in valve train parts and you could be up 1500-2000.
Dont know about gm engines, did they overlook testing during development. This goes with that at susans.
Those 088 heads were designed more than 50 years ago. Much has been learned since then.
I know these are basic setups! But normally today, spring companies want the spring setup within a certain distance from coil bind! 50 thou, 100 thou, whatever they tell you! Unless you’re using a 30yr old spring design! I guess it worked fine on puppy cams. But we rarely setup springs on seat pressure anymore! I’m also wondering why you never mention about cylinder head material grade? If it’s going on a basic rebuild, it probably doesn’t matter! But normally people looking to your channel are looking for the most power possible, not just a rebuild! Also probably worth mentioning about the rocker box of the head! If it’s a rebuild with low power/puppy cam, it doesn’t matter, but put a big shot of nitrous or boost on the engine & some heads will rip the roof of the intake port completely out! This stuff is probably worth mentioning even to the guys doing basic stuff! So he doesn’t have to upgrade head again when he gets bored with the power! Who doesn’t? Thanks for trying to point all the morons straight! I love how you make a video on something, back to back, whatever, than they say, oh I wish you tested with this head/cam/intake! I very surprised you have not said, why don’t you go test it you lazy couch potato mtherfker! 😜😜😜😜😜😂😂😂😂😂👍🏻👍🏻👍🏻👍🏻👍🏻👍🏻
coil bind clearance set up is not nearly as critical as seat and open pressure for 90% of the street/strip applications, we use it for wilder combos with more rpm
Isn’t the purpose of a green screen to enhance a background? Silly Richard. You crack me up 😂
BABY STEPS
This is for when he puts Godzilla in the background. ( Maybe the Abominable Snowman too ,. . or the pink Bigfoot from Dirt Every Day vids. . )
A 1.8 ratio rocker would help the square port a lot.
My bell rang... That means a video posted by Richard.
Richard. Did ya'll use the rod bolts in the SpeedMaster connecting rods or did you upgrade to ARP's?
THEY HAD ARP IN THEM WHEN I GOT THEM
in your opinion...do you feel the AFR oval preformance heads would be a significant amount more representative to what the 049 stock ovals would do... when compared to those rec port head? do you feel the 049 heads w/some port smoothing would work well and adequate to a solid roller 255@.50/ .680 lift (7000 rpm range) ???
THE AFR IS A LOT BETTER THAN THE STOCK 049
I wonder if AFR uses less spring rate since they use lighter valves? NOT MUCH...
PAC Racing Springs #1940
Street Hydraulic Roller Spring 1.550 O.D.
175 lbs. on seat
.725” max lift
Max RPM 6500-6700
OHC engines use valve springs like the OHV engines. Yet, they don't suffer from valve float until much higher in the RPM range. Why is this? The OHV has the lifter and pushrod linking the cam to the rockers unlike that of the OHC. Obviously those components are the real issue that needs addressed. Placing higher pressure valve springs is just a bandaid on a bullet wound.
And, you CANNOT "cure valve float." You can defer it later in the RPM band.
Absolutely
What happened to project Nova?
What's your experience with those stainless style rockers, are they better/worse than alloy ones?
aluminum is lighter
I contend that flow values at low, mid or high lift, or even average flow fail to express meaningful information given they don’t provide total cfm flow per valve actuation cycle.
That's true, but you can still make more power by picking the head that has the best average flow through the range of valve lift. In order to get the total flow over a valve actuation cycle, you would need to have the full valve lift curve and do degree-by-degree calculations using a curve fit of the cylinder head flow data. I have done that sort of thing in Excel to compare the power potential of different heads on a given valve lift profile.
@@andyharman3022
I fully understand all the contributing factors that you detail, and others.
I contend one simply bench measure total flow on a fully outfitted engine via electric motor at the entire operating range, over a given time frame as the the absolute, accurate measure of flow.
@@flyonbyya Or just do a fired dyno test with a good airflow meter. There is no substitute for the real thing.
What about lifters when changing spring pressure
no problem in this spring rate range
I thought going over 36 or 38 total was frowned upon? 41 total sounds nuts, but the dyno doesn't lie
they want what they want
Keep adding until it doesn't make power. His timing was locked, meaning it didn't change with rpm.
Most of the time 454s are gonna want 38-44 total
@@GJ-DT interesting to know
@@richardholdener1727 on a hot day, on a race course? That's what I'm curious about. The dyno offers ideal scenarios, wouldn't it be wise to go conservative once its into vehicle? I know locked timing will ping a motor to death without an educated throttle pedal foot...
Flow testing heads with just some playdough around the port, I still can't get past that. I'd rather see an intake / exhaust manifold bolted on as there has to be some sort of influence no? .
Well then you're not testing just the heads.....you're now testing an intake or header or both....
@@ks_1111 Given an engine runs with an intake and exhaust, these would matter if they influence head flow. Say a head flows 300 and the intake 250 , you could have a 500 head and still only get 250.
You can always buy a bench and some heads and intakes and do videos yourself if you want???
@@bobroberts2371 they have always been rated and tested as a seperate units
I would like to no what a 4 7 swap firing order cam and a4hole super sucker 1inch spacer on single plane intake would make I believe the cam will load and unload the cylinders more efficiently more power with the. A. F. R head thank you I watch all the time
The lighter the spring the better. The hydraulic roller is heavier than a mechanical flat tappet and the mechanical has faster lift possible, So if you want to rev it real high forget the roller and go with a flat tappet.
Would afr 305s run better on 454 over the 265s? Thankx.
not at this power level
I can’t find those valve covers anywhere.
we got them from AFR
@@richardholdener1727 I appreciate the reply but I don’t see these exact ones on their site.
My mrs says she loves BBC, strange she has never owned a Chevy
can it do the reverse..does a too high spring rate or too high rocker ratio make you loose power??
high spring rate does cost power
Technically speaking, higher spring rate does not cost power, this is a fallacy, it can actually increase power duo to proper closing without seat bounce. Remember one thing, there are the same number of valves opening as well as closing and as any spring is closing the energy is returned, this was a proven factor at Reher-Morrison racing engines.
High spring loads increase friction, so can lose a small amount of power. But power loss due to valve bounce on closing is worse.
Do you build engines or put together parts for certain up ranges for payment?
I do not-I can tell you how to get there-actually many videos up telling you combinations to reach power levels
have you tested the benefits of degreeing a cam?
YES
Richard what brand rocker arms
comp stainless
Oh snap,
Test don't guess. Cheers!
What did you guys do beat that poor engine for a week straight and port the dual plane and re run the test
i feel like this video was for me lol
Hit it with 200🍼 and you have a 9 second 3600lb street car
All srings matter
Personally I blame squirrels
Squirrels at my wife’s hibiscus 🌺 Personally, I despise squirrels.
John, I know you like Richard and you probably want him to succeed.
Comments can help with that regard but the all seeing eye starts to ignore repetitive comments with the understanding that they are spam and ignores any like or dislike that you provide if it's submitted in the first ten seconds if you don't watch the whole video.
There is a reason why your comments show up at the very bottom of the list. The bits think they are spam and youre being filtered.
@@timothybayliss6680 🐿🐿🐿🐿🐿 lol you think I don't watch the videos ok .........I'm amazed at the level of knowledge you figure you have on the subject. It's still a comment, it gets other comments added ( like this one ) I'm kinda sure I watch the videos, if not now later . But ether way don't worry about what I do just focus on what you do instead . It's not a competition .
@terry ch did you blame squirrels 😳
@terry ch lol perfect
BUILT!!! It was a built BBC!