I have a z6 head with valve job and milled of course. I'm going to put this on my z6 build for now. I have a spare a6 head laying around. Would it make sense to build the a6 then slap that on? Will i get the same flow/power from an a6 head with PnP, cam, springs, valve job. As I would from a z6 head with the same?

 

a6 heads outflow z6 heads. You just won't have the MaD TyTe VeEtAcK!

 

You need to bump the A6 valves up .5mm in size, the same as Z6, before that flow is realised.

Be careful with a high lift cam in the A6 head, with the Z6 piston flycuts. There's typically *acres* of piston-valve clearance on SOHC, but if you play with cam gear settings or get the timing belt one tooth off you might end up in the danger zone.

 

great info. Thanks .

 

if your putting it on the Z6 you will need to have the head or block machined for a oil jet. since it is in the block on the A6 and in the head on a Z6.

 

It's in the head on a Z6? You sure about that?

I always threw the oil restrictors away, never saw a difference in performance. They were #1 reason for cam failure in the old D15A's, it was common practice to ditch them, and there were no bad side effects.

 

I thought all VTEC's had them in the head? I always install them, I'm afraid of loosing pressure to the main bearings.

The old D15's (I knew them as EV/EW series, i never had an 87) clogged the port to the dizzy end cam journal didn't they? I know they had a problem snapping cams, but i was told it was a port, not the restrictor. Whoever told me could have been wrong though.

 

It was an oilling problem, or a broken timing belt, that broke the cam. The EV or EW1 or EW3/D15A had hollow camshafts, very fragile. Removing the restrictor was SOP. I believe there was a TSB about drilling them a little larger, but the old skool dealer techs told me they just ditch them.

And I was asking about the resitrictor, not calling you out... I own two Z6 heads, but I can't say I've looked closely at either of them. I just figured I would have noticed if they had a restrictor in them

 

It's cool. I don't have a Z6 head, only a Y8 head. My only basis was every Mini-Me swap guide i found said all of them had it.

That's neat info on the old engines. I'll keep that in mind, I've always wanted to get another 1st gen for a project car and that could be usefull knowledge. My first cars were both 1G CRX's, and they both rusted out.