Schrick cams on VX220

techieboy

Both TMS and Courtenay offer a Schrick cam kit for the Z22SE and both of them say it requires some head machining work. Any idea what this work involves? Is this to get the cams to physically fit or is this some kind of porting and polishing to make the most of the new cams?

vocky

it's to allow the valve spring to fit dunno..

not really sure exactly what they machine, probably the base area to allow a bigger spring seat to be fitted notsure.gif

techieboy

Thanks Vocky.

Hmmm. So they're wider springs that come in the Schrick kit? Is the profile of the Schrick that lary that these are needed as opposed to Piper's re-profiled cams. Does the same apply to the Cat cams versions?

Seems a bit of a missed opportunity, removing the head and having the seats machined without looking at the ports as well.

If I get the Schricks fitted and most of the valve train is being replaced, is it worth replacing the rockers as well?

Sorry about the Q's, all of this internal stuff is right at the edge of my understanding. Vaguely understand the concepts but the mechanics of it are where I get lost. :oops:

alanoo

vocky said:
it's to allow the valve spring to fit dunno..

not really sure exactly what they machine, probably the base area to allow a bigger spring seat to be fitted notsure.gif

Exactly
28mm diameter for the lower retainer in the head
Schrick springs and retainers are 28mm too so you have to shave some mm to get some clearance (for the springs not being retained by the walls).
It is easily done by hand, does not involve CNC machining...

What is a bit more complicated is that lower retainers need to be shaven 0.4mm, and this is a bit more technical

EDIT : oh and you have to change valve seals to bits working with high lift, it does not work using OE items

JohnnyN

I've got Schrick cams fitted in my Vectra by Courtenay. The double valve springs are to eliminate valve bounce at higher revs.

slindborg

the chap at Si Valves (the UsA) who was trying to sell me their entire product range said that upto 7Kish rpm the stock stuff works "ok" but they also supply single stiffer stprings that didnt need machining to fit.

would be worth finding out what springs cat cams offer though as their cams are nice and cheap 🙂

Tim_F

So is there any real benefit over Piper with power under 210bhp ?

Cheers, T

vocky

I don't think theres that much in it below 7k dunno..

my power curve never dipped at the rev limiter, so the piper cams must be holding back some more power notsure.gif

I like the piper cams, they're cheap and I've always used them in my tweaked engines 🙂

techieboy

How do the Shrick and Piper re-profiles compare on lift/duration etc? This is where it starts falling down for me as I'm not sure what effect those numbers really have in the real world. dunno..

Cat Cams list a few suitable options but some of them look pretty extreme to me. I'd rather not fit something thats going to cause a really lumpy idle or that needs an idle speed of 1500+rpm just to stop it stalling.

vocky

schrick are 256 degree and a higher lift

piper are 260 (mine are 266) degree and not so high a lift

to be honest, they are both good cams, the schrick are designed for over 7k rpm, the piper are designed for a standard rev limit.

the usa cams can be quite extreme :roll:

slindborg

all cam manufatcturers list the profiles differently.... V helpfull lol.

hence catcams giving two numbers of duration, one from no lift and another from 1mm of lift.
I think I settled on the 222Deg cams (there is only one set iirc) as they matched the GM performance cams in the build book. The yanks seemed to claim the GM perf cams idle fine.