N.A. cams?
#1
#2
From everything I have read, there is a pretty substantial gain from them, especially when you add other performance mods to go with it. I'll let you know - I'm in the process of installing a set in my car right now.
if you go to some of the more performance-oriented forums like swedespeed and turbobricks, you'll find most of the guys who are running super high HP cars are all running n.a. cams.
if you go to some of the more performance-oriented forums like swedespeed and turbobricks, you'll find most of the guys who are running super high HP cars are all running n.a. cams.
#3
The info I have found on the cams suggests there COULD be gains to be had. I have not yet looked at them in a "scientific" way yet, but plan to do that soon as I am building a new motor.
There is considerably more lift and slightly longer duration on the N/A cams. This might appear to be on it's face a performance improvement.
BUT:
I have seen NO actual Dyno tests (unless someone knows of one) that show the cams alone are an improvement.
Longer duration could actually HINDER performance if the increased overlap allows charge air into the exhaust tract and vice versa.
Valve train, cam timing, profiles etc are a pretty complicated mess. There are no "hard and fast" rules to apply.
I would think that used in conjunction with other mods such as larger exhaust, more boost, ECU tune etc. they can't HURT but the jury is still out on how much they help.
Remember, if you think of your engine as an "air pump" you can see that more air in = more power, BUT if during say the compression stroke one or more valves are open you lose dynamic compression and some air/fuel mixture right out the tail pipe or back into the intake tract causing other issues with the cylinders that are on intake.
I suspect that the "gains" being seen are most likely from the more agressive profile meaning the partial lift duration being longer and ramping up and down faster than from the actual lift of the cams. If you could figure out how to make a cam and valves work with "square off" lobes you could make a LOT of power. LOL
There is considerably more lift and slightly longer duration on the N/A cams. This might appear to be on it's face a performance improvement.
BUT:
I have seen NO actual Dyno tests (unless someone knows of one) that show the cams alone are an improvement.
Longer duration could actually HINDER performance if the increased overlap allows charge air into the exhaust tract and vice versa.
Valve train, cam timing, profiles etc are a pretty complicated mess. There are no "hard and fast" rules to apply.
I would think that used in conjunction with other mods such as larger exhaust, more boost, ECU tune etc. they can't HURT but the jury is still out on how much they help.
Remember, if you think of your engine as an "air pump" you can see that more air in = more power, BUT if during say the compression stroke one or more valves are open you lose dynamic compression and some air/fuel mixture right out the tail pipe or back into the intake tract causing other issues with the cylinders that are on intake.
I suspect that the "gains" being seen are most likely from the more agressive profile meaning the partial lift duration being longer and ramping up and down faster than from the actual lift of the cams. If you could figure out how to make a cam and valves work with "square off" lobes you could make a LOT of power. LOL
#4
#6
From everything I have read, there is a pretty substantial gain from them, especially when you add other performance mods to go with it. I'll let you know - I'm in the process of installing a set in my car right now.
if you go to some of the more performance-oriented forums like swedespeed and turbobricks, you'll find most of the guys who are running super high HP cars are all running n.a. cams.
if you go to some of the more performance-oriented forums like swedespeed and turbobricks, you'll find most of the guys who are running super high HP cars are all running n.a. cams.
#7
#9
oh Lord.... Not again...
#10
obviously the difference isn't going to be noticeable with the naked eye. If you had to get new pistons and needed over sized ones, just because they don't look any different than factory ones to the naked, are you not going to get them? Just because the difference isn't obvious glancing at them doesn't mean it's not there. Water and Vodka look the same to the naked eye.
#11
regime, I realize that this is a topic that gets brought up often, BUT, I have been all over the net and I cannot find anyone who has actually dynoed a car before and after only a cam change. That was my reason for chiming in, I was hoping someone had actual DYNO sheets showing the improvement.
Most (if not all) the posts I see on the whiteblock engines seem to have subjective "butt dyno" claims as to performance gains from a myriad of mods. I was figuring since I am in the process of rebuilding a motor out of a 98 C70 to go in my 94' 850 I would try to gather all the shreds of info and do a writeup that can cite actual data.
For a "safe" answer to the question of whether or not to go with N/A cams, I would say that mechanically there is no danger of the valves contact pistons with stock block height, rods and pistons (assuming proper cam alignment) AND they DO have increased lift and duration along making a more agressive lobe so I would say go ahead and do it.
As long as the cams are in good shape, cheap and it is not your only reason for taking the head apart.
#12
I don't get why people are debating whether or not to put them in and if you get any power gains out of them. Look on VS, built cars there are to stock cars on here. Here's some threads with information regarding them. I know there are no dyno sheets, but the majority of those with built cars and years of experience are running them and say they had gains from them, if that isn't enough to sway you to run them I don't know what is. It's not some new thing either that is just now being explored, it seems like it just hit this forum and is new here, but it's been well explored on other sites.
http://volvospeed.com/vs_forum/index...1#entry1820547
http://volvospeed.com/vs_forum/index...1#entry1728852
http://volvospeed.com/vs_forum/index...1#entry1706495
http://volvospeed.com/vs_forum/index...1#entry1686766
http://volvospeed.com/vs_forum/index...1#entry1820547
http://volvospeed.com/vs_forum/index...1#entry1728852
http://volvospeed.com/vs_forum/index...1#entry1706495
http://volvospeed.com/vs_forum/index...1#entry1686766
#14
regime, I realize that this is a topic that gets brought up often, BUT, I have been all over the net and I cannot find anyone who has actually dynoed a car before and after only a cam change. That was my reason for chiming in, I was hoping someone had actual DYNO sheets showing the improvement.
I didnt mean it personaly against you. Its just that this question NEVER leads to any real answer with any REAL evidence. (dyno sheets)
You get things like:
more duration + more lift = good
which i will agree with... and
its also been settled that this mod does more good on a car that is modified already rather then on a stock car... (obviously)
So... go ahead... lets try to find some dyno sheets for this mod...
Good luck...
#15
#17
THANK YOU TECH!!
I would be happy with a before and after on ANY motor. I am concerned with the actual gains that are directly made by the cams. Not to beat a dead horse but dyno numbers don't lie and are not subjective like a "butt dyno".
I am even thinking that the most gain would be had on the exhaust side but to realize that gain I first need to get rid of my restrictive conical flange turbine housing. (all set I pick up a junkyard 19T on Friday)
Post em' up TECH!
I would be happy with a before and after on ANY motor. I am concerned with the actual gains that are directly made by the cams. Not to beat a dead horse but dyno numbers don't lie and are not subjective like a "butt dyno".
I am even thinking that the most gain would be had on the exhaust side but to realize that gain I first need to get rid of my restrictive conical flange turbine housing. (all set I pick up a junkyard 19T on Friday)
Post em' up TECH!
#18
#20
19Ts come on 2000 V70Rs. I'm running a 19T as well.