School us on engines...
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LaserRed01GT
Banned
Maybe you missed the title to the thread.....here let me quote it for you "School us on engines."
billfisher
Active Member
i decided to take the high road on this one suffice it to say buddy you told me nothing i don't know with the possible exception of flow numbers.
it isn't often i take the high road. chevy still sucks no matter what.
it isn't often i take the high road. chevy still sucks no matter what.
hotmustang331
Active Member
I was impressed at first that you displayed maturity and were willing to admit that your input on this subject was your simply your opinion (billfisher -“i can only base my information on reading others findings”) and that you did not have any discernable experience on the subject of cylinder head development. Then, you couldn’t leave well enough alone, and your desire for an attempt at self-admiration took over and led you to make your last post in a desperate attempt to impress your piers here. And of course, you again, felt the need to end your post with an arbitrarily negative and unnecessary comment towards Chevy (GM).
I am going to delve deep into my psychic abilities and go out on a limb here that you probably spent most of the day yesterday scouring the internet searching for some sort of relevant information that you could copy and paste, then fumble over and change up the wording (and proper spelling) that might give you the opportunity to make a last ditch effort to sound as if you actually had experience with cylinder head design and development.
I was again impressed by your last post…..that is….until I got about 9 words into it when I read stuff like this: “velicity chart”, “useless to lift to .600 if velocity and filling drop off at .580”, and “the net loss of filling negates a meaningless flow bench number.”
Mr. billfisher, allow me to share with you the reality of cylinder head D&D. Perhaps you should listen closely, because it sounds like you need it.
Before any flow testing can be performed, the flow bench must be calibrated for that day's air conditions. Then you set the cylinder head on top of a bore fixture with the appropriate bore for the particular application. A dial indicator is then placed on the valve. We then use a threaded actuator to push open and hold the valve at the target lift being tested. Some people will use lighter rate valve springs in order to make the valve actuation easier, but the lighter springs, specifically the opposing spring from the one being tested, can be sucked open and skew the results. This is more common than you can imagine. I use the actual spring that will be used in the application. Once you record and “sync” the flow data, then you can plug the lift/flow data into FlowCom and/or a data analysis program. V = 1096.7*Sqrt(H/d). Once velocity has been calculated, the volume can be calculated by multiplying the velocity by the orifice area times its flow coefficient.
A cylinder head with a relatively small intake runner and high velocity characteristic can be a good or bad thing. Contrary to the popularly perpetuated internet myth, if you work a cylinder head so that it shows an exceptionally high velocity profile which results in sacrificing even moderate amounts of low lift and mid lift airflow (CFM), you'll lose power. Even if it shows gains at the upper lift range. That’s just the nature of the beast. Conversely, high flow (CFM) capability is very important at upper and peak valve lift, but not at the expense of the low lift velocity that initially gets the intake charge moving and keeps it moving even as the valve closes. Increased velocity or flow will not necessarily get you more charge after IVC if the motor is not tuned for that specific point in RPM, but with some careful intake runner pulse tuning we can optimize the velocity/flow to IVC relationship. The speed at which flow begins as the valve begins to lift is critically important. That speed creates gas inertia that helps fill (or empty on overlap) the cylinder as thoroughly as possible. A thoroughly stuffed cylinder normally equates to power, but the proper runner volume for a given application that has a relatively small cross section and a relatively high flow, will produce good results on a street/strip motor. Maximum effort drag race heads are given a slightly different approach and will typically require a larger runner volume. For instance on the LS2, the stock 211cc intake runner’s cross section works well for a street/strip low cube (under 350”) motor, but for a high HP motor or a maximum effort drag race head, you can focus more or your time in the runner to increase it’s volume. This can be done by changing the geometry of the entire port….SSR (short side radius), ceiling radius, SSR apex, strategic removal of material, etc. The right combination of runner volume and flow will lend itself to increased port airspeed. This will help to eliminate fuel separation, reversion, promote swirl, and increase the air/fuel intake charge. All which equates to performance and power. There are little tricks to manipulating flow characteristics. You can partly control the lift to flow characteristics by way of valve grinding. A inner radius cut (back-cut) can lend itself to improve the effect on low lift and mid lift performance, whereas valves without a back-cut tend to accentuate the very high-lift numbers. It all boils down to the motor combination and its purpose.
In spite of the perceived limitations of a flow bench, in skilled hands it still provides an excellent source of information in order to guide the engine designer/builder in deciding how to go about modifying the head and other engine components. Head flow data is also essential to provide accurate port flow coefficient data that is required for the use of data analysis software. With that data analysis software and flow data teamed together, it provides a powerful way to finitely understand a running motor and it's unique characteristics. Details which are just about impossible to view any other way. A flow bench is a valuable tool if used for what it is that can help fine tune a combination, but obviously it is not the ultimate authority.
My opinion has been countered by other Chevy experts huh? I cordially invite them to come aboard in this thread and participate in a discussion of cylinder head technology.
I have to wonder though...if you have access to this stuff, and have this much knowledge, WHY are you driving a 2V gt????? Muchless a stock headed one.
With what you know, you should have a custom designed intake on the market for us!
billfisher
Active Member
what we have here is a difference of opinion. i have a "small as necessary" attitude. i like high velocity torque producing ports with moderate flow and usable powerband for the street. 211cc port or larger likes power in the range his presentation shows for a smallish motor. 7100 rpms. that's great forhim. i like the following:
for 5.0 l a 185cc port like an afr or twisted wedge. killer flow with just the right velocity for low end and top end.
for 5.8l 200cc is a good size. now i'm not advocating a particular size "rule", but rather keeping the area under the curve in a reasonable range.
the 225cc AFR ls replacement is an amazing piece. but why spend a bazillion dollars for a factory part that is hogged to flow some number when cheap aftermarket parts are available? TFS heads, AFR, or any other part will work better IMO. i shied away from the "B" heads i have for that reason. too big for a usable band. my usable band.
this is in fact a good and necessary discussion. these mustang guys need to know that the dreaded LS is not to be feared. at least not in a 4000lb car.
4000 lb GTO 400hp = 10:1
3452lb stang 350hp = > than the LS powered car.
3200lb stang 320rwhp = LS car.
my `83 2500lb stripped racing notch and 425hp = faster than all of those.
i still think the LS boys fear an 6.1L 425hp hemi in a light car. i do.
ok factory flow number as he sees them
ls-1 = 230cfm AFR says that
ls-2 = 263cfm he says that
ls-7 ? too much
3v ~230-240
4v~240
GT = 300 - 310 cfm?
hemi 260cfm?
6.1l hemi = ?
i used to have to numbers for all of the LS with vaious intakes installed. i lost them. that's another area to work on. tunnel port intake to gain on them there. i am fibreglassing my tapered runner insert as we speak . we will dyno this spring. i'm going to take the best MPH version to the dyno. no excuses this time.
cam timing set for max hp
intake
A/F right.
open exhaust.
no excuses. then the heads come off for my "you don't know anything like i do" machining, deshrouding, and pocket port. hopefully i wont destroy them. maybe if i look in enough books i will do ok. or maybe the last 15 years of doing my own and taking them by to a local expert for his opinion will do me ok. i need to reread his passage so i can get it right.
i submit to anyones expertise on this matter. my 5.4 is weak and has little going for it. but it does make 340 rwtq SAE. that's somewhere to start. i need credentials to just buy "words on a page". sorry. i am not a badguy. i just think chevy sucks.
for 5.0 l a 185cc port like an afr or twisted wedge. killer flow with just the right velocity for low end and top end.
for 5.8l 200cc is a good size. now i'm not advocating a particular size "rule", but rather keeping the area under the curve in a reasonable range.
the 225cc AFR ls replacement is an amazing piece. but why spend a bazillion dollars for a factory part that is hogged to flow some number when cheap aftermarket parts are available? TFS heads, AFR, or any other part will work better IMO. i shied away from the "B" heads i have for that reason. too big for a usable band. my usable band.
this is in fact a good and necessary discussion. these mustang guys need to know that the dreaded LS is not to be feared. at least not in a 4000lb car.
4000 lb GTO 400hp = 10:1
3452lb stang 350hp = > than the LS powered car.
3200lb stang 320rwhp = LS car.
my `83 2500lb stripped racing notch and 425hp = faster than all of those.
i still think the LS boys fear an 6.1L 425hp hemi in a light car. i do.
ok factory flow number as he sees them
ls-1 = 230cfm AFR says that
ls-2 = 263cfm he says that
ls-7 ? too much
3v ~230-240
4v~240
GT = 300 - 310 cfm?
hemi 260cfm?
6.1l hemi = ?
i used to have to numbers for all of the LS with vaious intakes installed. i lost them. that's another area to work on. tunnel port intake to gain on them there. i am fibreglassing my tapered runner insert as we speak . we will dyno this spring. i'm going to take the best MPH version to the dyno. no excuses this time.
cam timing set for max hp
intake
A/F right.
open exhaust.
no excuses. then the heads come off for my "you don't know anything like i do" machining, deshrouding, and pocket port. hopefully i wont destroy them. maybe if i look in enough books i will do ok. or maybe the last 15 years of doing my own and taking them by to a local expert for his opinion will do me ok. i need to reread his passage so i can get it right.
i submit to anyones expertise on this matter. my 5.4 is weak and has little going for it. but it does make 340 rwtq SAE. that's somewhere to start. i need credentials to just buy "words on a page". sorry. i am not a badguy. i just think chevy sucks.
hotmustang331
Active Member
Oh yea Bill...Ported Ford GT heads flow around 370CFM. Stock your right...around 300-310 stock.
That seriously owns stock ported LS7 heads....remeber guys LS7 heads are P&Pd FROM THE FACTORY!
That seriously owns stock ported LS7 heads....remeber guys LS7 heads are P&Pd FROM THE FACTORY!
LaserRed01GT
Banned
I have to wonder though...if you have access to this stuff, and have this much knowledge, WHY are you driving a 2V gt????? Muchless a stock headed one.
With what you know, you should have a custom designed intake on the market for us!
I don't ever remember saying that was my only car....do you?
As far as the intake, I have tossed around the idea. R&D'ing stuff like that is VERY expensive. Maybe this summer. I am still in the hole from all this "stuff" I have access to. It ain't cheap.
LaserRed01GT
Banned
Interesting......and your opinion is based on what personal experience. Please enlighten us Bill.
billfisher
Active Member
i started on VW's in 1984 and stangs. i owned a vw that i baha'd. i then began adding different parts until i ran into a problem with the stock case. we then bushed it to handle more cylinder pressure. the case did ok, but we needed more cubes, so we added them. stock heads but stroked and bored. etc etc etc. we were buying and making merged cone headers using the vacuum for free case vacuum and power. 8 dowel crank. it broke. then God created swaged cranks. 6 degree cut on the crank and flywheel. etc etc etc. fast as hell but unstable. that was the end of vw's and cars until got back from europe. and by the way i have references here. but really i don't answer to you.
John Larocca. heard of him? probably not. but i built his motor and others here. he was my boss at the weld/muffler/fab/engine building shop i worked at. his words would be "bill's an ace mechanic. "
my first heads were 6 cyl ford 200cui in. you ask how can you port 200 I-6 ford heads. well if you know it all you know the answer to that. you can't poert the intake on 200 cuin. I-6 ford heads.... aHHH but i can. because i carefully cut the outer intake off, ported the inside, ported the intake ports and cast iron stick welded the outer back on. how you say? I am a friggin certified welder also. all positions carbon,cast iron,SS including schedule 80 all positions. you know what schedule 80 is right. i'm sure you do. everybody does. i spent years at the local experts shop. his name is Donny, and he worked at Lone Star for Danny here in clarksville. you know none of these people. so how the hell do you expect me to explain my resume here. it would take forever. i port heads conservative. i am certainly not Al Papito, and my guess is you are not Robert Yates, so until you magically become one of those guys, or you are on an edition of NASCAR today, your opinion mean no more than mine. it simple physics.
port X has a taper of Y. there are bosses and pinch points that other structures in a head necessitate. anywhere that a structure pinches the port it causes a laminar interruption. laminar airflow is the only way to have a perfect head. there is no perfect port. guide bosses(which crappy ports remove) are a source of gain. raising the roof and cutting the short side in an attemt to
a) allow laminar flow parallel to the margin or
b) achieve airflow perpendicular to the margin.
a requires high lift as in your LS heads and any parallel arrangment of valves.
b) requires canting of valves in the 8 degree range to one side and i forget the range toward the oncoming air. or a hemi arrangement or 4V.
hence the issue with tumble port ford heads ALA 99-04. the floor is flat and the angle to the valves requires a sharp turn right at the valve. the air column over shoots the valve and has to redirect.
3v had a very tall roof. the anlge is shallow and very good in fact. but the small 35mm aftermarket valves are too small, so 282 cfm is max until someone figures out how to get 37mm in there.
fordGT heads and Gt500 heads have a near perfect approach to the valves. and good low lift mid lift and high lift flow stock.
i have an opinion on almost everything. i have enough of a pysics back ground to comprehend.
more later dinner....
John Larocca. heard of him? probably not. but i built his motor and others here. he was my boss at the weld/muffler/fab/engine building shop i worked at. his words would be "bill's an ace mechanic. "
my first heads were 6 cyl ford 200cui in. you ask how can you port 200 I-6 ford heads. well if you know it all you know the answer to that. you can't poert the intake on 200 cuin. I-6 ford heads.... aHHH but i can. because i carefully cut the outer intake off, ported the inside, ported the intake ports and cast iron stick welded the outer back on. how you say? I am a friggin certified welder also. all positions carbon,cast iron,SS including schedule 80 all positions. you know what schedule 80 is right. i'm sure you do. everybody does. i spent years at the local experts shop. his name is Donny, and he worked at Lone Star for Danny here in clarksville. you know none of these people. so how the hell do you expect me to explain my resume here. it would take forever. i port heads conservative. i am certainly not Al Papito, and my guess is you are not Robert Yates, so until you magically become one of those guys, or you are on an edition of NASCAR today, your opinion mean no more than mine. it simple physics.
port X has a taper of Y. there are bosses and pinch points that other structures in a head necessitate. anywhere that a structure pinches the port it causes a laminar interruption. laminar airflow is the only way to have a perfect head. there is no perfect port. guide bosses(which crappy ports remove) are a source of gain. raising the roof and cutting the short side in an attemt to
a) allow laminar flow parallel to the margin or
b) achieve airflow perpendicular to the margin.
a requires high lift as in your LS heads and any parallel arrangment of valves.
b) requires canting of valves in the 8 degree range to one side and i forget the range toward the oncoming air. or a hemi arrangement or 4V.
hence the issue with tumble port ford heads ALA 99-04. the floor is flat and the angle to the valves requires a sharp turn right at the valve. the air column over shoots the valve and has to redirect.
3v had a very tall roof. the anlge is shallow and very good in fact. but the small 35mm aftermarket valves are too small, so 282 cfm is max until someone figures out how to get 37mm in there.
fordGT heads and Gt500 heads have a near perfect approach to the valves. and good low lift mid lift and high lift flow stock.
i have an opinion on almost everything. i have enough of a pysics back ground to comprehend.
more later dinner....
billfisher
Active Member
as a matter of fact the first thing i ever did on a stang was replace the engine. i did it with no manuals and no experience. i did it from common sense and my background growing up with a father that has a masters degree in mechanical engineering. all of the men in my fathers family are 30-50 jouneymen machinists. you learn things around them.
i swapped the motor and it firesd on the first hit. i rebuilt my first motor. a 69 firebird witha 400 cuin ram air motor. with a manual and common sense. it rocks to this day. that was 1989 maybe. all of my motors last for years. i have lost contact with most or they have sold the cars, but they were fine workmenship. all quality and hand fit everything. i don't have to answer to you. but there is the smallest saml[ple of hunders of cars both chevy,dodge,ford, and import i have built or done major work on.
you were 11 and picking you nose when i started this crap.
i swapped the motor and it firesd on the first hit. i rebuilt my first motor. a 69 firebird witha 400 cuin ram air motor. with a manual and common sense. it rocks to this day. that was 1989 maybe. all of my motors last for years. i have lost contact with most or they have sold the cars, but they were fine workmenship. all quality and hand fit everything. i don't have to answer to you. but there is the smallest saml[ple of hunders of cars both chevy,dodge,ford, and import i have built or done major work on.
you were 11 and picking you nose when i started this crap.
billfisher
Active Member
you fail to understand..... if the Ls2 was a ford it would be the ****. because it's a chevy it's useless and crap. that's all there is to it. it isn't like in trying to be reasonable. (use reason) not me.
billfisher
Active Member
i would like to take this time to thank the moderators for their silence.
it is golden.
as are my rediculous opinions. you guys may hate me, but this is fun no?
it is golden.
as are my rediculous opinions. you guys may hate me, but this is fun no?
no, not really
although it is a good thing we have members like this on stangnet to offer such deep, unbiased enlightening insight (sarcasm)
hotmustang331
Active Member
Bill blood runs blue...thats all. I understand where hes coming from, im no chevy lover....but I do know that GM does a heck of a job with their engines. Bill ofcourse knows this, GMs LS1/2/6/7 linup are awsome motors....but I think whats going on here is that everyone thinks they are touched by God and completely OWN Ford. Bill wants to show that what GM is doing is not rocket science, its nothing special....they are just taking a different approach than Ford.
Ford 4V design in the end >Chevys 2V design. 4V head techknology is just better IF designed correctly....and Ford is headed that way. Chevy is about at the limit of what they can do with their current heads....Ford is no where close to tapped out with 4Vs.
If im not mistaken, Top fuel cars have 4V heads, not worked small block chevy or Ford 2V style heads.
Ford 4V design in the end >Chevys 2V design. 4V head techknology is just better IF designed correctly....and Ford is headed that way. Chevy is about at the limit of what they can do with their current heads....Ford is no where close to tapped out with 4Vs.
If im not mistaken, Top fuel cars have 4V heads, not worked small block chevy or Ford 2V style heads.
LaserRed01GT
Banned
Bill I don't even know where to start on that last attempt at a cylinder head technical post. Clearly you do not have any real experience with cylinder head R&D as nothing in your post made any sense at all. It sounds like some more beat up copy and pasting. I am not sure where you got it from this time, but it obviously was not from any post by a competent cylinder head expert. In all honesty, this whole time I assumed that you were about 13-14 years old based on your spelling, grammar and punctuation. You made a comment saying that somebody was 11 and picking their nose when you were “doing this”, so maybe you are older than I thought……however my thinker tells me otherwise.
One piece of advice to you Bill “The Ace Mechanic” and I will let you go away quietly. I know you are young, but you would really benefit from putting aside the attitude and try to look at things from a different perspective. Instead of pretending to know all about cars, perhaps you should approach this with an open mind and listen to those who actually do this stuff for a living. Now I am no expert, but I have been around the block a few times. There are also plenty of others on here who seem to have a solid understanding of cars, and you would be wise to listen and learn.
BTW, fuel motors are based closely on the old Elephant (60’s 426 Hemi). They have some differences like a 4.8" bore pitch and a 5.4" camshaft height, but the cylinder heads still use a hemispherical combustion chamber and two valves per cylinder. The valves are just huge…..2.45x intake/1.92x. A close family friend of ours has a 1988 210” Top Fuel Altered car that we help maintain. He only runs it now for exhibition runs since the car is setup to run on 100% nitro methane still. NHRA only allows 85% nitro now on the fuel cars and they are considering going to 80% now. He runs a 2.450” intake valve and a 1.915” exhaust valve. It’s a 496 just like most of today’s fuel cars, except his only makes about 4500 HP as opposed to 7000 nowadays….I say “only.” Today’s fuel motors are getting around 50-55 lbs of boost. They are running about a 6.5:1 – 6.7:1 static compression ratio. I’ll quit rambling, I get fired up talking about fuel motors
One piece of advice to you Bill “The Ace Mechanic” and I will let you go away quietly. I know you are young, but you would really benefit from putting aside the attitude and try to look at things from a different perspective. Instead of pretending to know all about cars, perhaps you should approach this with an open mind and listen to those who actually do this stuff for a living. Now I am no expert, but I have been around the block a few times. There are also plenty of others on here who seem to have a solid understanding of cars, and you would be wise to listen and learn.
BTW, fuel motors are based closely on the old Elephant (60’s 426 Hemi). They have some differences like a 4.8" bore pitch and a 5.4" camshaft height, but the cylinder heads still use a hemispherical combustion chamber and two valves per cylinder. The valves are just huge…..2.45x intake/1.92x. A close family friend of ours has a 1988 210” Top Fuel Altered car that we help maintain. He only runs it now for exhibition runs since the car is setup to run on 100% nitro methane still. NHRA only allows 85% nitro now on the fuel cars and they are considering going to 80% now. He runs a 2.450” intake valve and a 1.915” exhaust valve. It’s a 496 just like most of today’s fuel cars, except his only makes about 4500 HP as opposed to 7000 nowadays….I say “only.”
Today’s fuel motors are getting around 50-55 lbs of boost. They are running about a 6.5:1 – 6.7:1 static compression ratio. I’ll quit rambling, I get fired up talking about fuel motors
billfisher
Active Member
billfisher
Active Member
hotmustang331
Active Member
Thats odd, I remember watching speed TV and the camera guys talking with the top fuel mechanics talking about the heads. What they had in hand were 4V heads....anywho, ill stop there. Thats why I said "if im not mistaken" I think Bill is retired Laserred
.
