The Truth on Cam Advertised Duration, Etc.

[spoolin ddub]

Okay you know more than Brian crower, the maker of the cam ,in what the did to their own cam design. I just can't wait to test them. Lol

Of course not . I'm just stating what I have always stated and what has been proven well before the AMS or Dsport article. Advertised duration and other numbers just aren't accurate. The old BC design duration @ .050 was already small compared to most cams. Way smaller. BC 272 is smaller than a damn FP2 . But now they are going even smaller than before... but adding more lift to make more power? Read Dsport article and look at the difference in what they claim to what the real numbers are Now seeing some are tested and shown @ 1.00mm and others @.050 makes it hard to compare. So Dsport even went as far to compare the claimed number vs the actual real numbers at both 1.0mm @.050 across the board for all the cams. That to make it an even playing field on every level. None of the cams numbers matched what they claimed. Some cams claimed to be smaller then a comparable cam but are actually bigger. In a earlier post I stated that exact scenario. I have no issues with BC and I am not saying BC new design won't make some damn good power. I think they will.. But more then any of the other companies I feel they should have been in the test.

 

[keltalon]

Of course not . I'm just stating what I have always stated and what has been proven well before the AMS or Dsport article. Advertised duration and other numbers just aren't accurate. The old BC design duration @ .050 was already small compared to most cams. Way smaller. BC 272 is smaller than a damn FP2 . But now they are going even smaller than before... but adding more lift to make more power? Read Dsport article and look at the difference in what they claim to what the real numbers are.... for all the cams. Now seeing some are tested and shown @ 1.00mm and others @.050 makes it hard to compare. So Dsport even went as far to show how accurate each cam is at whatever the company tested at @ 1.00mm or .050. Then they compared the claimed number vs the actual number !! None of the cams numbers matched. Then they show all the cams tested @.050 across the board to make it an even playing field. Some cams claimed to be smaller then a comparable cam but are actually bigger. In a earlier post I stated that exact scenario. I never said they won't make some damn good power. I think they are.

It's obvious you have no concept of the relationship of duration and lift. . If you want a tutorial session pm me I am not going to argue about it in your thread. I have one more dyno session with the bc 272 and I will retire them a few items is changing on my set up. I will break 700WHP with cyclone and bc 272s next dyno session.

 

[spoolin ddub]

It's obvious you have no concept of the relationship of duration and lift. . If you want a tutorial session pm me I am not going to argue about it in your thread. I have one more dyno session with the bc 272 and I will retire them a few items is changing on my set up. I will break 700WHP with cyclone and bc 272s next dyno session.

This is not argument. This is a discussion and what forums are for. To gain Information. I don't claim to know everything and I am still learning. But I learn fast . Bet most of the people on here never even heard of or understood the purpose of cam analyzer before I posted this. What I do know is the old BC 272 has basically the same lift as DSM HKS 272/delta 272. But on your cam test at 31psi degreed in BC 272 made 514whp and delta 272 made 536whp at the same boost. Then at 33psi BC 272 only made 529whp and BC may even a be little bigger on the "claimed duration". But you say they are now going smaller? I know the cam design does have an effect on performance but not more than duration and I also know more lift and shorter duration favors stokers more than it would on a plain 2.0L. Look at that cam test and see cams with more way more lift make less power than cams with less lift and that have slightly more "real" duration. I'm just saying a company can claim anything. put it in the cam analyzer and it will tell all to a tee. No guessing. I just don't understand why they wasn't in the test. You can over night the cams. But as I stated I'm not saying the cams wont make power. I truly do believe they will be bad ass. I know what BC on. I can see right thru it . I also feel people's mouths are going to drop when they see how well they perform..

 

[Archer Fabrications]

I can't wait to try the 276 /276 either. Kel! Those damn cam gears are stuck in customs and could be there as long as 15 days havnt gotten around to installing my "BC head" components yet due to fighting the single digit temperatures good info in here kel.

I have been sort of so so on my satisfaction with my BC272s currently, granted i pulled them from my friends wrecked talon, and i dont really know how used they were when i i stalled them... but they have been fine for me this far. I think the new design is gonna be a noticeable difference and hopefully move the power band up without sacrificing spool.

Carry on

 

[Seamus]

p considering turbo cars perform better with less overlap especially in high performance street applications!

As a blanket statement this is just wrong.

I bought bc 272's and I like them. But I did not buy them because they were the most powerful cam to run with my setup. I wanted the quickest spooling cam possible that wont fall on its face at 8k. The bc 272 will spool a turbo quicker than stock cams setup properly and still make power beyond the factory cam.

 

[keltalon]

As a blanket statement this is just wrong.

.

Oh Really. I am not the only one that thinks so read this article and enlighten yourself okay. thanks.

Cam tuning - Turbo and N/A *Sticky please?*

 

[keltalon]

I can't wait to try the 276 /276 either. Kel! Those damn cam gears are stuck in customs and could be there as long as 15 days havnt gotten around to installing my "BC head" components yet due to fighting the single digit temperatures good info in here kel.

I have been sort of so so on my satisfaction with my BC272s currently, granted i pulled them from my friends wrecked talon, and i dont really know how used they were when i i stalled them... but they have been fine for me this far. I think the new design is gonna be a noticeable difference and hopefully move the power band up without sacrificing spool.

Carry on

Okee

 

[spoolin ddub]

Just let me say this the new 276 276 design is an exact copy of the kelford 272s if you want to know how I know PM me

You prove my point of why I said you can't just go off the claimed specs. How is the duration going to be smaller when Kelford 272 has more duration than the BC 280's?

 

[keltalon]

This is not argument. This is a discussion and what forums are for. To gain Information. I don't claim to know everything and I am still learning. But I learn fast . Bet most of the people on here never even heard of or understood the purpose of cam analyzer before I posted this. What I do know is the old BC 272 has basically the same lift as DSM HKS 272/delta 272. But on your cam test at 31psi degreed in BC 272 made 514whp and delta 272 made 536whp at the same boost. Then at 33psi BC 272 only made 529whp and BC may even a be little bigger on the "claimed duration". But you say they are now going smaller? I know the cam design does have an effect on performance but not more than duration and I also know more lift and shorter duration favors stokers more than it would on a plain 2.0L. Look at that cam test and see cams with more way more lift make less power than cams with less lift and that have slightly more "real" duration. I'm just saying a company can claim anything. put it in the cam analyzer and it will tell all to a tee. No guessing. I just don't understand why they wasn't in the test. You can over night the cams. But as I stated I'm not saying the cams wont make power. I truly do believe they will be bad ass. I know what BC on. I can see right thru it . I also feel people's mouths are going to drop when they see how well they perform..

You are still getting duration and lift mixed up. lift is the height of the lobe or how far the cam lifts the valve at peak opening 10.8mm lift 11.2mm lift ect. Duration is how long the valve stay open at a certain time at peak dwell in degree of crank rotation before starting to close. I didn't say bc is making their cams smaller by no means in fact they are making them bigger (higher lift) with less degrees in crank rotation (shorter duration). this way you have a cam that spools a the turbo quicker (because of less over lap) and sustain hp in the upper rpm range. That is why in my cam test I maneuvered the cam gears to decrease overlap and was able to still make lots of hp up top. case in point the bc 272 vs hks 264 both had the same identical power curve down low but the bc 272 made more hp up top I maneuvered the bc 272 cam settings to have the same overlap as the hks 264 and having more degreses of opening per crank rotation they were able to keep the valve open longer than the hks264 up top which led to 14more hp up top. this type of maneuvering is what allowed me to break the cyclone record and to put down over 500lbs of torque at only 4800 rpm I know how to manipulate cams setting I spent a lot of time trying to master it!

 

[spoolin ddub]

You are still getting duration and lift mixed up. lift is the height of the lobe or how far the cam lifts the valve at peak opening 10.8mm lift 11.2mm lift ect. Duration is how long the valve stay open at a certain time at peak dwell in degree of crank rotation before starting to close. I didn't say bc is making their cams smaller by no means in fact they are making them bigger (higher lift) with less degrees in crank rotation (shorter duration). this way you have a cam that spools a the turbo quicker (because of less over lap) and sustain hp in the upper rpm range. That is why in my cam test I maneuvered the cam gears to decrease overlap and was able to still make lots of hp up top. case in point the bc 272 vs hks 264 both had the same identical power curve down low but the bc 272 made more hp up top I maneuvered the bc 272 cam settings to have the same overlap as the hks 264 and having more degreses of opening per crank rotation they were able to keep the valve open longer than the hks264 up top which led to 14more hp up top. this type of maneuvering is what allowed me to break the cyclone record and to put down over 500lbs of torque at only 4800 rpm I know how to manipulate cams setting I spent a lot of time trying to master it!

I'm not getting it mixed up. Shorter duration for the most part is what makes a cam smaller. BC 280 has a shorter duration then Kelford 272. So how is BC going smaller on the advertised duration when the new BC 276 cam aka kelford 272 clone has longer duration than the old BC 280?

 

[keltalon]

I'm not getting it mixed up. Shorter duration for the most part is what makes a cam smaller.?

See I told you , you don't understand how it all work.

 

[spoolin ddub]

See I told you , you don't understand how it all work.

you didn't answer my question . how is the duration of the kelford 272/BC 276 smaller than the shorter duration BC 280? Evo BC 272 has more lift but shorter duration than Evo Jun 272 cam. Which one is the bigger cam?

 

[keltalon]

Increasing lift has exactly the same effect as increasing the cam's
duration, except that you are not actually altering the opening and closing
points of the cam lobes. Increasing duration allows more air in & out, and
so does increasing your maximum lift (the former increases the size of the
valve opening while the latter simply increases the amount of time that
opening is open). A lot more goes into determining a cam's maximum lift
(or rate of valve opening) than does its lobe timing, though. Maximum
lift's main enemies are mechanical in nature, and have to do with a) coil
bind and B) valve-to-piston interference. therefore a shorter duration higher lift cam achieve the same a as longer duration lower lift cam.
That is why bc can achieve what they have by going higher lift short duration and still make more power.

 

[spoolin ddub]

Increasing lift has exactly the same effect as increasing the cam's
duration, except that you are not actually altering the opening and closing
points of the cam lobes. Increasing duration allows more air in & out, and
so does increasing your maximum lift (the former increases the size of the
valve opening while the latter simply increases the amount of time that
opening is open). A lot more goes into determining a cam's maximum lift
(or rate of valve opening) than does its lobe timing, though. Maximum
lift's main enemies are mechanical in nature, and have to do with a) coil
bind and B) valve-to-piston interference. therefore a shorter duration higher lift cam achieve the same a as longer duration lower lift cam.
That is why bc can achieve what they have by going higher lift short duration and still make more power.

We all know you can play with cam gears to make slight changes etc. You still didn't answer my question . Does the BC 276 have more lift or the same lift as kelford 272?

 

[keltalon]

We all know you can play with cam gears to make slight changes etc. You still didn't answer my question . Does the BC 276 have more lift or the same lift as kelford 272?

The 276 are not in production for our application yet. once we test them and before they go on the market specs will be released. they know what they are doing and I know you want me to say they are the same lift so you can say how is that possible I am not at liberties to say anything yet and not so stupid to get caught up in some trick question

 

[keltalon]

you didn't answer my question . how is the duration of the kelford 272/BC 276 smaller than the shorter duration BC 280? Evo BC 272 has more lift but shorter duration than Evo Jun 272 cam. Which one is the bigger cam?

Here is a good read so you can understand cam basics this is not mine but a good Quoted article on lift and duration

Camshaft Lift and Duration Theory
QUESTION:
Could someone please explain what the advantage to having short duration like my 270 over say 320
would be? or the advantage a 320 would have over a 270?
ANSWER / EXPLANATION:
One would think that the ideal camshaft would have 180 degrees of duration
and zero degrees of overlap. That is, the intake would open precisely at
TDC, close at TDC, and cycle through the compression and power strokes
until you were at BDC again, where the exhaust valve would open for another
180 degrees until you reached TDC at the beginning of the intake stroke.
Some have even commented that the ideal valvetrain would open the intake
valves instantaneously at TDC, leave them open for 180 degrees, and then
slam them closed instantaneously at BDC (likewise for the exhaust valves).
This would work fine on an engine up to about 2000 RPM, after which power
would be seriously compromised.
The main problem is that air has momentum. Because of this, the intake
valve must open before TDC in order to make sure that the valve is open far
enough to allow the incoming air/fuel charge in with the least amount of
restriction once the piston begins to move downward. Likewise, exhausted
gases that leave the combustion chamber create a vacuum behind them that is
used to assist the flow of the intake charge into the combustion chamber,
hence the need for a certain amount of overlap (ie: when both the intake
and exhaust valves are open between the end of the exhaust stroke and the
beginning of the intake stroke). This technique is called "scavenging" and
is present it properly designed exhaust manifolds as well (which time each
exhaust pulse so that each one helps draw the next ordered pulse out of the
engine). The opposite is also true... long overlap allows the intake
charge to help push the exhaust charge out of the cylinder if it is moving
fast enough.
Finally, there is funny physics going on between the crankshaft's circular
motion and the piston's linear up & down motion. Around TDC and BDC, the
crankshaft can rotate almost 20 degrees in either direction while moving
the piston downward very, very little. The piston does not move at a
fixed, linear velocity inside the cylinder. Rather, it follows the path of
a sin wave (eg: accelerating from TDC to a point exactly halfway down,
where it decelerates to a stop at BDC).
It all has to do with a factor called "volumetric efficiency", or "VE". VE
is a measurement of how efficient an engine is at drawing in air into the
cylinders. A cylinder has a fixed volume while the piston is at BDC, and
an engine with a VE of 100% should be able to cram in exactly the same
volume of air as the calculated volume of the cylinder. Because of
restrictions in the intake, however (primarily the venturis on carburetored
engines), most stock engines have a maximum VE of around 80%, while most
race engines hover around 95-100%. With the proper cam and/or ram air
induction, it is possible to achieve a VE greater than 100%. Forced
induction engines (ie: those that use turbos or superchargers) develop VE
ratings in excess of 100% the moment they develop boost, with each 14.7 PSI
equaling an additional 100%. Simply put, the higher the VE, the more air
you can cram into the cylinders, and the more power the engine can make.
A camshaft with a large duration (300+) can allow a normally aspirated
engine to get very close to a VE of 100% at high RPMs because the exhausted
gases leaving the cylinder help to draw in a larger intake charge. By
assisting the incoming air to enter the cylinder you cram more air into the
engine, and therefore increase the engine's VE. Port velocities are
critical, and velocities increase as engine RPMs increase. A long duration
camshaft usually has a power band way up the RPM range (6,000+), and a race
motor that sees frequent sustained high RPMs can really make a lot of power
with that high VE.
There is a tradeoff, however. A camshaft with a long duration doesn't run
well at all at idle or low RPMs. At low RPMs the port velocities aren't
nearly as high, and scavenging simply doesn't take place. In fact, since
there is a slight vacuum in the intake manifold and a slight pressure in
the exhaust manifold at all times, opening the intake valve too soon
creates a path of lesser resistance for the exhaust gases. Instead of
going out the open exhaust valve, the burned air/fuel charge tries to enter
the intake manifold instead (commonly called "reversion" because the air in
the manifold near the valve actually reverses direction). What results is
normally called "polluting of the fresh intake charge". Burnt exhaust
gases mix with the incoming unburned air/fuel charge and dilute it,
effectively reducing the amount of fuel and free oxygen entering the
cylinder (which means a lowered VE). Any drop in VE means an equal drop in
power. With long duration cams running at idle, the result is the typical
rough idle that you hear on many hopped up V8s. Some of them won't even
idle at all without raising the idle RPMs above what is considered normal
(in order to introduce more air/fuel, which increases port velocities,
which raises VE).
Intake manifold design (dual plane, single plane, high rise, velocity
stacks, etc.) can all contribute to engine tuning as much as header design
does. The choice of camshaft defines both. An engine's displacement and
camshaft define the style of intake and exhaust manifold used on an engine.
Get everything right and you get free power. Get one or two things wrong
and you lose power.
Remember way back when I mentioned the theory of instantaneous valve
openings and closings? Many people thought that this was an ideal (albeit
highly impractical) method of allowing the maximum amount of air in and
out. After all, how could a design that allowed the valves to slowly open
and close provide any real flow during those periods of low initial lift?
Actually, it has been determined that the slow openings and closings are
*necessary* for proper engine operation. When the piston begins its
downward travel from TDC during the intake stroke, the first few degrees of
crankshaft rotation create hardly any downward movement in the piston.
Opening the valve instantaneously at this point would cause port velocities
to plummet, causing turbulence in the intake system and cause fuel to drop
out of suspension.
Now getting back to your question:
A low duration camshaft works best at lower RPMs. Even though the stock
cam has a duration of about 250 degrees, a mild aftermarket cam like the
Engle 100 (duration 270 degrees) will still move the point of maximum
torque/horsepower further up the RPM range. A cam such as the Engle 100
will idle smoothly and possess good port velocities at low-to-mid RPMs,
increasing the engine's VE within that range (a good guess-timate would be a
VE of about 85%). Eventually the low overlap of the 100 will hurt the
engine at high RPMs because the low overlap does not allow much scavenging
to take place. The valves are also open for less time over all, which
limits the engine's maximum VE (unless you resort to forced air induction
using ducts, turbos, or superchargers).
A super-high duration camshaft like the "320" you mentioned (the closest
Engle equivalent being an FK-87) is pretty much an all-out race cam. It
works best at very high RPMs where the scavenging effect could conceivably
push the VE up beyond 100%. 100% is greater than the 85% of the Engle 100,
and potential maximum torque and horsepower are much greater with the FK-87
as a result. The down side is that the FK-87 would idle like a poorly
tuned Harley (due to reversion) and have very poor off idle performance
(due to low port velocities at low-to-mid RPMs).
Lift is another matter entirely (are you getting tired of reading yet?).
Increasing lift has exactly the same effect as increasing the cam's
duration, except that you are not actually altering the opening and closing
points of the cam lobes. Increasing duration allows more air in & out, and
so does increasing your maximum lift (the former increases the size of the
valve opening while the latter simply increases the amount of time that
opening is open). A lot more goes into determining a cam's maximum lift
(or rate of valve opening) than does its lobe timing, though. Maximum
lift's main enemies are mechanical in nature, and have to do with a) coil
bind and B) valve-to-piston interference.
Coil bind is what you get when you attempt to open a valve so far that the
spring that normally holds the valve closed can't compress any further (the
coils end up coming in contact with each other until it is nothing else
than a solid column of spring steel). Valve-to-piston interference is a
no-brainer, since a valve that opens too far stands a good chance of coming
in contact with the top of the piston at TDC (the common solution being to
machine valve pockets in the piston dome to provide clearance).
That's the easy part. A cam's maximum lift doesn't just determine how far
the valves lift off their seats, however. It also determines how *fast*
the valve moves off the seat to the point of maximum lift and back down
onto the seat again (commonly referred to as "ramp speed"). A high lift,
high duration cam lobe is gentler on the valve train than a high lift, low
duration cam because the ramp speed isn't as quick. High ramp speeds
coupled with weak valve springs can result in a) "ski jumping" just after
maximum lift is achieved and B) valve float.
"Ski jumping" occurs when the lifter is accelerated off the tip of the lobe
so fast that the lifter actually leaves the surface of the lobe and becomes
"airborne". This will affect valve timing-- specifically altering the
moment that the valve closes. It also means that the valve will come down
on the valve seat harder than normal. "Ski jumping" often occurs at high
RPMs without sufficient valve spring tension and when matching high ratio
rockers on camshafts designed only for use with the stock 1.1:1 ratio.
Valve float happens when the valve isn't placed back on its seat gently
enough, causing it to bounce once or twice before the valve spring tension
holds it down firmly. This is "A Very Bad Thing"™, as it will pound out
seats, break the heads off of valves, and be generally rough on the rest of
the valve train components. Maximum lift isn't the sole contributor to ramp
speeds, however. The overall silhouette of the lobe is the key.
The camshaft is the heart of an engine, and it influences all the other
factors of your engine design. When building a motor, cams are almost
always chosen first (sometimes second when you are dealing with an engine
who's displacement is easily changed-- like the Type 1 ACVW).
PS: Not all identical model camshafts should be considered equal. It used
to be a common practice to "regrind" camshafts. The existing lobes were
shrunk in size to compensate for any areas on the original lobe which
experienced extensive wear (IOW, modified the original shape of the lobe).
Cam lobes contain an area called the "base circle" which is the part of the
lobe that the lifter rests against when the valve is fully closed (think of
it as the coast side of the lobe). The top of the lobe is what provides
the valve train with its maximum lift. Maximum lift is essentially the
difference between this point and the lobe's base circle. If you think
about it, it is easy to see that you can reshape the existing lobe and
create a cam with the same characteristics as it had before, by simply
"shrinking" the lobe. As long as the difference between the high point and
the base circle is the same as before, total maximum lift has not changed.
And as long as the rise and fall ramps of the lobe start in the same degree
positions as before, duration hasn't changed either. However, the lifters
will sit further out of their bores and you'll have to turn in your valve
adjusting screws another turn or so to make up the difference. Likewise,
it is conceivable that a camshaft manufacturer created a cam with lobes
larger than what your valve train can handle. Stories regarding lifters
that bottom out in their bores prior to the cam achieving maximum lift are
nothing new. My point? Don't assume that your new camshaft will simply
drop in. Measure everything at least three times and if you are ever in
doubt, ask someone else.

 

[spoolin ddub]

The 276 are not in production for our application yet. once we test them and before they go on the market specs will be released. they know what they are doing and I know you want me to say they are the same lift so you can say how is that possible I am not at liberties to say anything yet and not so stupid to get caught up in some trick question

im not asking to know. I want to make a point. All more lift does is allow you to play with the cam gears more to alter the powerband...to a certain degree. Because this is what I know. On an evo or a dsm with cams in similar situation. If it has the same mods there is no way a BC 272 will ever make more power then with a jun 272. Adjust all you want. It won't come even close. So if the BC 276 has similar "real" duration to kelford 272 but with alot more lift. Yes it could possibly make more.

 

[keltalon]

im not asking to know. I want to make a point. All more lift does is allow you to play with the cam gears more to alter the powerband...to a certain degree. Because this is what I know. On an evo or a dsm with cams in similar situation. If it has the same mods there is no way a BC 272 will ever make more power then with a jun 272. Adjust all you want. It won't come even close. So if the BC 276 has similar "real" duration to kelford 272 but with alot more lift. Yes it could possibly make more.

Come on dub this not true more lift does the same exact thing as longer duration keep the valve open longer plain and simple read the article up top. the problem with most on the forum is that they refuse to read other post you are a prime example , you like others are so dead set on proving me wrong you can't see logic. My conversation here is done!

 

[spoolin ddub]

Come on dub this not true more lift does the same exact thing as longer duration keep the valve open longer plain and simple read the article up top. the problem with most on the forum is that they refuse to read other post you are a prime example , you like others are so dead set on proving me wrong you can't see logic. My conversation here is done!

No. I don't ever just respond to respond. I'm not trying to prove you wrong. I've seen and know people who do what you are stating. It depends on the setup also. It can be done...to a degree. But for the most part on a 2L duration is where the power comes from.


I got some info also. From someone Who has had his hands on some of the current most whp, quickest and fastest Evo's and dsm's still in the game.

Duration first. Lift is subjective only to if the port wants to keep flowing more cfm as the valve gets opened farther. AKA, on a flow bench, you could have a port that lets say flowed 200 cfm at .400 and then 190 at .450, then 185 at .500. Opening it more at that point can be diminishing returns.

But!!! You are under boost pressure. So more lift can help as it gets the valve out of the way as airflow comes in. Duration will still give more power, apples to apples tho. The longer you can leave the valve open under boost, the more air packed into the cylinder.

Hope it helps. I would go with more duration first. You have to remember that with these mitus heads, we are lift limited with respect to coil bind. Not a lot of spring installed height, or spring pressure to work with.

 

[Seamus]

Oh Really. I am not the only one that thinks so read this article and enlighten yourself okay. thanks.

Cam tuning - Turbo and N/A *Sticky please?*

I'm ok. I'm sure if it is well written and based on facts it has the same info as any other cam write up or dyno comparison.

Just think about what you are saying.

 

[spoolin ddub]

The 276 are not in production for our application yet. once we test them and before they go on the market specs will be released. they know what they are doing and I know you want me to say they are the same lift so you can say how is that possible I am not at liberties to say anything yet and not so stupid to get caught up in some trick question

BC read this post and contacted me because of my perspective on this threads topic. They also gave me the advertised specs of the soon to be released BC 276 cam. I have a lot of respect for BC because of the way they represent themselves.

 

[keltalon]

BC read this post and contacted me because of my perspective on this threads topic. They also gave me the advertised specs of the soon to be released BC 276 cam. I have a lot of respect for BC because of the way they represent themselves.

This is an email from bc e today

Brian crower-"Also what we did with the BC #profiles for the DSM is we shortened the advertised duration and raised the#[email protected]” and lift.

This changes the ramp speed and acceleration numbers which gave great results."

 

[bastarddsm]

I've said it before and I'll say it again. This is dumb. There is not one person on this board that can look at a set of cam specs and tell wether or not it is better than another. Unless you have years of CFD experience the only way to do it is by dyno testing on your specific combo. That AMS article in turbo is barely scratching the surface of what actually happens. You will never ever get any real information out of a magazine. It took me a long time to realize that.

You need to understand that lift and duration are a minimal portion of the picture. You need to know what the ramp looks like, and you need to know what your head actually flows like. Not on a flow bench but on laboratory equipment used to measure and create coefficient of discharge maps. Then things like intake tuning and exhaust tuning. It's dumb to compare cams on lift and duration. Lol dwight you and your magical "tech" posts that have no actual tech.

I'm still waiting for someone to send me some cams that will make more power than my HKS272's on my car. I want cams and dyno time paid for. If they make 25whp more, I'll buy the cams and pay for the dyno time.

Also, still waiting for dwight to show up at the track....

 

[spoolin ddub]

I've said it before and I'll say it again. This is dumb. There is not one person on this board that can look at a set of cam specs and tell wether or not it is better than another. Unless you have years of CFD experience the only way to do it is by dyno testing on your specific combo. That AMS article in turbo is barely scratching the surface of what actually happens. You will never ever get any real information out of a magazine. It took me a long time to realize that.

You need to understand that lift and duration are a minimal portion of the picture. You need to know what the ramp looks like, and you need to know what your head actually flows like. Not on a flow bench but on laboratory equipment used to measure and create coefficient of discharge maps. Then things like intake tuning and exhaust tuning. It's dumb to compare cams on lift and duration. Lol dwight you and your magical "tech" posts that have no actual tech.

I'm still waiting for someone to send me some cams that will make more power than my HKS272's on my car. I want cams and dyno time paid for. If they make 25whp more, I'll buy the cams and pay for the dyno time.

Also, still waiting for dwight to show up at the track....

As I stated Knowing the actual duration makes it more even across the board. You'd be surprised how many cams claim to have more advertised duration over a similar cam and actually have less real duration. BC contacted and told me for comparing cams I was correct!!!

As for you and me racing that has nothing to do with my thread. Pm me. We can make it happen .

 

[keltalon]

I've said it before and I'll say it again. This is dumb. There is not one person on this board that can look at a set of cam specs and tell wether or not it is better than another. Unless you have years of CFD experience the only way to do it is by dyno testing on your specific combo. That AMS article in turbo is barely scratching the surface of what actually happens. You will never ever get any real information out of a magazine. It took me a long time to realize that.

You need to understand that lift and duration are a minimal portion of the picture. You need to know what the ramp looks like, and you need to know what your head actually flows like. Not on a flow bench but on laboratory equipment used to measure and create coefficient of discharge maps. Then things like intake tuning and exhaust tuning. It's dumb to compare cams on lift and duration. Lol dwight you and your magical "tech" posts that have no actual tech.

I'm still waiting for someone to send me some cams that will make more power than my HKS272's on my car. I want cams and dyno time paid for. If they make 25whp more, I'll buy the cams and pay for the dyno time.

Also, still waiting for dwight to show up at the track....

Bastard I must say you speak with exceptional knowledge and I always listen when you post! I agree with you 100%. On this one! As far as Dwight taking his car to the track don't hold breath. Good to have you back!!