can someone tell me the difference between the 204 & 185 hp sr20ve & cam spec as i, think mine is a 1997-2000 ve & i need 220-240 hp also at what revs the cams change as i will be running injection throttle bodies & a adjusttable computer

check the sr20ve board, theyll help you out

thanks dan ,but i am after more detailed cam spec ie duration & lift intake & ex opening etc

Intake Cam
SR16VE Low lobe 7.1mm lift @ 200 duration High 11.1 lift @ 280
SR20VE Low lobe 8.4mm lift @ 220 duration High 10.7 lift @ 264
Exhaust Cam
SR16VE Low 7.95 mm @ 244 High 11.1 @ 280
SR20VE Low 6.6 mm @ 244 High 10.34 @ 268

Hello,

I haven't seen the specs for the roller S3 on the forums and since it caught my eye ... I'm giving it here.

JWT roller rocker S3
262 duration and 11.43 mm lift for intake and exhaust

They have more lift than the 20VE high cams and only 2 degrees less duration. All other pecs on the cams are supposed to be just like stock. Roller S3s are pretty wild.. aren't they?

http://www.gonzonx.com/veseries/thesr20vetcams.html

Check here for the overlap and lift specs for some cams

Thanks for the info ,this is my first forum i have been involved with
and I'v found it verry halpful I'v sold my toyota 4ag [215hp] & about to start spending $$$ on the ve i use a engeen dyno again
The mods so far will be 4 throttle body injection, hawk management, headers, this is just the starting spec i'm hoping for
at lest 210-220 hp if not achieved i will look at the cams sr16ve cams are NZ $700 each I will let the forum now how I get on hopfuly by mid Nov:)

Originally posted by 1FastP11
Hello,

I haven't seen the specs for the roller S3 on the forums and since it caught my eye ... I'm giving it here.

JWT roller rocker S3
262 duration and 11.43 mm lift for intake and exhaust

They have more lift than the 20VE high cams and only 2 degrees less duration. All other pecs on the cams are supposed to be just like stock. Roller S3s are pretty wild.. aren't they? Ah that old trap,

You cannot compare durations on different cams unless you know that they were measured at the same amount of lift. Some measured at .050" lift, some at .020 or .010 etc. Advertised duration is often a 0 lift.

It's misleading unless you have that information.

Originally posted by T4 Primera
Ah that old trap,

You cannot compare durations on different cams unless you know that they were measured at the same amount of lift. Some measured at .050" lift, some at .020 or .010 etc. Advertised duration is often a 0 lift.

It's misleading unless you have that information.

Oops

It seems I asumed too much then, care to explain a liltle more? I just gave the numbers on the packaging and assume all other numbers were the same... since they drop right in with no modifications, shims or anything.

Claudio
shhh!!! monkey learning

Often, cam duration is measured at some reference point of lift.

A dial test indicator or similar is set to zero on the base circle of the cam lobe, then the cam is rotated until the instrument begins to show some lift.

Because it is difficult to tell the exact position that lift begins, often a reference point is chosen at a certain amount of lift. It may be .003, .010, .020, .050 etc.

The degrees of rotation are then measured from that point until the point where the lift decays back to the original .003 or whatever.

Because of this, the same cam will show different durations depending on what reference lift was chosen. So a quoted duration on a cam means nothing unless the reference lift is specified like this XXXdeg duration @ 0.0X0 lift.

This makes for an easy way for marketing types to make a mild cam look wild without strictly telling lies. It also makes comparisons difficult without knowing the reference lifts for both cams.

You will notice, by following the link in this thread http://www.sr20deforum.com/showthread.php?s=&threadid=24011, that SCC specified the lift at which the cam durations were measured for the JWT S3 (0.003"). If you know the reference lift for the high speed VE lobes was also .003" - then you would be able to compare durations with some certainty.

Hope you find that helpful and not too confusing. :)

Digging up old threads is fun! :D

Also, remember that roller engines can use wilder profiles with less trouble because they are rollerized. The ramp shape itself is very different because a roller can be accelerated much more quickly than a friction contact.

the roller actually limits agressive cams because it is eating up 1mm lobe height. the roller ads a completely different geometry. it has less friction and frees hp.