Originally Posted by LostSoul Evo

gotta love it when people act like as*es over someone asking a simple question. GSUJEFF55 does have a good point about the search option. i tried doin search on cams as well as other things. most of the time u end up wit no info at all, except for what people have installed in there cars. hopefully the mods will clean up the forums soon.

ya really act like its that hard to answer someones question without giving an attitude. if u get mad over a repeated question then dont reply to it. it may be repeated to you but not to the person asking it.

this has been a rant, now we return u back to your topic.

by the way thats for the info on the cam lift and duration too. even though i still dont understand.

Originally Posted by LostSoul Evo

my bad 2k4evo. when i made my reply i didnt even see your your last post showing the difference between the different cams and their makers. after reading ur post now, i starting to understand cam duration and lift more. so thank u for that. my comment wasnt directed at u. so i hope u didnt take offence to it. so my bad for bein an a*s in general to everyone who just posted.

i just understand how difficult it is to use "search". sometimes its just easier to just re-ask the question.

Originally Posted by slt

2k4EvoVIII,

What determines the need for upgraded valve springs? I though it was related to lift but that doesn't seem true with the specs you posted. Thanks for posting some usefull info.

Originally Posted by 2k4EvoVIII

It is related to lift. The stock valve springs have a tensil strength of 60 which is not the strongest. I decided to go with the Buschur Springs and Titanium retainers that have a tensil strength of 120. I have seen evidence of even the HKS cams needing valvesprings even though they say they dont. Basically if the springs are to weak you will get valve float and run into all kinds of problems with playing the drums on your pistons. I would recommend getting valvetrain nomatter what cams you go with but HKS does not see a need for it and they are the professionals so who am i to doubt them? I just think it is weird that JUN uses very similar lift and they require them....hmmmm..

Chris

Originally Posted by 2k4EvoVIII

OK SMART A$$ how is this for backing it up?

Duration = Duration refers to how long a valve is opened in relation to crankshaft rotation. This open valve time period is expressed in degrees of crankshaft rotation. So, a cam specification of 220 degrees duration simply means the cam holds the valve open for 22 0 degrees of crankshaft rotation.

Lift = While duration refers to how long the valve is opened, cam lift is used to determine how wide the valve is opened.

If the valves are not opened wide enough, they will cause a restriction for the air trying to enter or exit the cylinder. However, opening the valve past a certain point will not increase the flow to (or from) the cylinder.

Seperation = Separation refers to the spacing between the intake lobe and exhaust lobe on the cam shaft. This spacing (or separation) is expressed in degrees on the cam, not on the crankshaft. So, a 108 lobe separation means the intake and exhaust lobes are 108 degrees apart from each other on the cam shaft.

This spec by itself really doesn't mean anything. If you hear someone else is using a cam with 108 separation, don't think that you should use cams that only have 108 separation!

Separation, just like centerline, is another way to tie the duration to the crankshaft rotation and end up with valve events. This spec is a little more complicated though, because it is in cam shaft degrees and the crankshaft rotates two degrees for each one degree of cam rotation. Also, if the cam has been installed either advanced or retarded, the valve events will be different.

Centerline = The cam's centerline specification is used to tie the valve timing to the crankshaft's rotation. This spec is expressed as the number of degrees the crankshaft must rotate from top dead center until the cam has rotated to the peak (or centerline) of the lobe.

The centerline spec and the duration spec can be used to calculate when the valves open and close in relation to the crankshaft's rotation. When the valves open (or close) relative to the crankshaft's rotation is known as valve events or valve timing. Some cam manufacturers will provide valve event information and others only provide duration and centerline information


MAYBE YOU WANTED SPECS ON THE CAMS??

HKS 264:
Duration of 264 deg
Duration of 206 deg @ 1mm
Lift of 10.8mm intake / 10.2mm exhaust
Stock valve springs OK

HKS 272:
Duration of 272 deg
Duration of 214 deg @ 1mm
Lift of 10.8mm intake / 10.2mm exhaust
Stock valve springs OK

JUN 264:
Duration of 264 deg
Duration of ___ deg @ 1mm
Lift of 10.5mm
Upgraded valve springs required

JUN 272:
Duration of 272 deg
Duration of 235 deg @ 1mm
Lift of 10.8mm
Upgraded valve springs required

Tomei Poncam:
Duration of 260 deg
Duration of ___ deg @ 1mm
Lift of 10.7mm intake / 10.2mm exhaust
Stock valve springs OK

Tomei Procam:
Duration of 260 deg
Duration of ___ deg @ 1mm
Lift of 11.5mm
Upgraded valve springs required

Piper Ultimate Road cams:
Duration of 265 deg
Duration of 217 deg intake / 211 deg exhaust @ 1mm
Lift of 11.5mm intake / 10.8mm exhaust
Upgraded valve springs required

Piper Rally cams:
Duration of 265 deg
Duration of 217 deg @ 1mm
Lift of 11.5mm
Upgraded valve springs required

Piper Race cams:
Duration of 272 deg
Duration of 224 deg @ 1mm
Lift of 12.0mm
Upgraded valve springs required

PEOPLE LIKE YOU **** ME OFF!!!!

Chris

Originally Posted by BLiu

Dayum, I think someone got b***h-slapped by Chris....

Thank you Chris for the extra info...The one redeeming thing is that he actually provoked you into dispensing more info...hmmm...perhaps that was a ploy to aviod doing a search....Very helpful!

Brent

Originally Posted by smack_evo

i think that it's not just lift, but how fast it gets to that lift value. if one cam take 50 degs. of rotation to get to let say 10mm of lift but another one gets there in only 15degs. the ramp up is alot faster. this makes the valve travel faster and try to stop at the top of peak faster. thats where the heavier springs come into effect. they help keep the valve pressed against the lifter instead of letting it "float" off of the lifter with the extra momentum cause by the increased lift speed.

i hope that made some sense

good luck
sean

something i thought i should add even though it's probably obvious...
the valve speed also increases as the rpm's increase so even with the stock cams
you can get float if you spin the motor high enough(you would have to reflash ecu
raise the rev limiter though)

Originally Posted by gsujeff55

thanks to the view people with answers, i appreciate it. to you other jackasses who would rather pretend like they know the answer, and say search, than to actually give it to me......you all suck.

have you ever tried to do a search on here? if i type in cams, the first 100 threads that come up are where people are listing their mods and talking about getting cams and all that ****. NONE OF THAT ANSWERED MY QUESTION.

and id be willing to bet i know more about modding an engine than any of you assclowns that called me a noob or told me to search. can't have good informative discussions on this forum because dip****s like yourselves wanna throw your useless .02 in.

again, thank you to the intellegent people who answered my question.