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was tune-up routine? now Solid lifters



Is this the same guy that was the marketing dude at Drake that went on and on about how the 16V head was a pile of shit and couldn't make any more power than the 8V?
Sounds like him.
In any event the hydraulic valves are ~7mm shorter than the solid valves and they do use the same springs, spring seats and spring retainers. OTOH the guides for the hydraulic head are 6mm shorter than the guides for the solid head. So the bottom of the spring seat may be closer to the valve head, but the real question is does that effect the shape of the port. In any event it's doubtful the bottom of the guide is any closer to the valve head by more than a mm or so.
TT's website says nothing about having to clearance the cam follower tray to put in any of their hydraulic cams. Maybe this guy is talking "true high performance" in the sense of a 1970's SuperVee cam. It doesn't appear he's talking about any cam that you and I can buy with up to 11.5mm lift.
I'm not sure I have the energy to waste on checking out some ports and dimensions on some heads I have, but I'll just say I'm pretty skeptical about almost anything this guy has to say.
Dan

From: "Gordon Forbess" <gforbess@attglobal.net>
Sent: Friday, July 21, 2006 12:53 PM
Subject: Re: was tune-up routine? now Solid lifters


On Fri, 21 Jul 2006 11:40:02 -0400, "Mark F." <mk1mark@gmail.com>
wrote:

>Untrue...  Unless the base circle is different (shouldn't be), you
>will not have to change out the shims.  I've never had to change shims
>with any cam I've installed.  The gap is measured with the lobes
>pointing up...

This is some more Drake-think (1988 vintage) on the hydro head I just
re-read yesterday that seems to address the point:

"The 83-84 1.8L head is similarly simple, but since the valves are
specially made by Drake, the valve stem length is identical to stock,
and therefore the cam base circle can remain stock sized as well.

The hydraulic head is the real nightmare. In this head, MUCH has
changed. The valves are shorter. The cam base circle is smaller. The
distance between the cam bearing bore centers and cam follower holding
tray is much smaller, therefore requiring clearance grinding for
almost any (true) high performance cam. The valve guide protrudes much
farther into the ports. And the valve spring depth is deeper (though
the valve springs are the same size). All this is because of the
difference between hydraulic and mechanical lifters."


Gordon
75 Mk I/Drake 1.9
http://pws.prserv.net/gforbess/scirocco/scirocco.htm

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