How to check for performance cams... have I been ebayed?

rabidh

Hi everyone. I'm new here, so sorry if this info is somewhere and i didn't manage to find it...

A while ago I saw a gas flowed Z22SE cylinder head on ebay, complete with performance cams. It seemed too much of a good deal to pass up on at £200, so I got it.

I decided swapping heads was a bit risky on my everyday car, so looked into just swapping cams over. When I got the rocker cover off my car I noticed the part numbers on the cams were almost the same (apart from an L-xx number), and with some tracing paper I found the profiles were pretty similar. I measured the width/depth of the lobes and found they were the same too (so its unlikely its been reprofiled).

I asked the guy what the cams were - he said he didn't know, but they were german. I'd expected a noticably more agressive profile on them - I fitted a fast road cam to an old Pinto engine and it was really obviously different.

Do you think i've been ripped off? The head was off an Astra, and I've got a VX220. Do the Astra/VX220 use different cams? - could his idea of a performance cam have been to use the VX220 one?

I guess the other question then is whether the head was infact gas flowed. It looks pretty smooth inside the inlets - I can't imagine it being much better for airflow, but what does the stock head's inlet look like?

thanks for the help,

coopa

Another VX220.org'er :wink:

I suppose if the part numbers on the cams are the same then to be 'performance' they would have to be reground. To get extra duration on the cam I think therefore means decreasing the diameter of the cam base circle, so if you can measure them accurately and they are the same then maybe they haven't 🙁

As for the gas flowing, I've not seen inside mine yet but from what I understand modern heads flow pretty well. The only worthwhile gains in flow (for road use) are made by removing any obvious machining marks inside the valve pocket where the port drilling ends. The ports don't need to be widened necessarily unless going for BIG bhp as wider ports means less charge velocity on a road engine, which can be a bad thing.

Not much help, but I've seen you post this on a couple of forums so may as well give my 2p notsure.gif

Mark_Dj

I am not sure but I am sure someone will be able to help you out on here 🙂. Welcome to the forum from me 🙂.

vocky

just measure the height, they do indeed remove some of the lower lobe to increase valve lift

rabidh

Thanks. This forum seems like a good place - I can't believe I never found it when i was looking for Z22SE info before!

The lobe height is identical - Looks like i've been had. The strange thing is the springs look like they've been replaced (They're green + have paint on the bottoms of them). Maybe the head didn't get the price he was after so he took the cams out and sold them separately what..

Vocky - I seem to recall you said it looked like a courtenay head when we were discussing it on the vx220.org.uk forums - can you remember what made you think that?

Still, £200 isn't bad for another head I guess. I might as well have a play with it - any ideas for head things that'll get me a bit more power without bankrupting me?

cams - do piper still regrind them for £200? (have they sorted out the whole rocker-wrecking thing Thorney came across?)
Head skimming - it'd be good to get the compression up a bit - but is that likely to mess with the cam timing noticeably? Can you get thin gaskets that would do the same thing?

vocky

the reason I suspect it's a courtenay head is the shape of the ports, I've seen another of their ported head's and it looked the same

piper have changed the profile of the cams, they were 260 degree, mine are 266 degree and I've not had any problems as of yet 🙂
still £235 inc vat 😃

fit some performance valves to the head, you don't need to change the size of the head, but they have wasted swirled stems, this increases flow a fair amount over standard

cheaper from the states :wink:

solorider

even if the cam lobes are the same height it doesnt mean they are not performance cams,it only takes a very small change on the lobe to make a difference as the 2.2 has roller rockers and is more sensative to small changes to the cam lobe,you dont need more lift to give power increase unless going for a race tune,cam duration is more important for the road

solorider

looking at epc it seems the vectra b uses aq different inlet camshaft to the astra g/vx220/vectra c so that may explain why there are different "part" nos on your cam shafts

rabidh

solorider said:
looking at epc it seems the vectra b uses aq different inlet camshaft to the astra g/vx220/vectra c so that may explain why there are different "part" nos on your cam shafts

Thanks! I guess that could be it. Maybe this guy's idea of a high performance cam was to use the one off of the VX220/Astra :roll: A shame, but at least it'll allow me to send some cams off for Piper to regrind.

coopa

Please keep us informed!

Interesting that Piper changed the profile of the cams, I wonder if they realised that they had a problem at high RPM with the standard springs?

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