1.8T pistons in a 16v motor

[jdbubb at ix.netcom.com (Dan Bubb)]

----- Original Message -----
From: "Dave Ewing" <MK1Scirocco16v@comcast.net>
To: <scirocco-l@scirocco.org>
Sent: Monday, September 22, 2003 1:45 PM
Subject: Re: 1.8T pistons in a 16v motor


> > First off, I wouldn't assume the 1.8T pistons are forged. Forged pistons
> are
> > rare in production cars and some of the 1.8T's even have cast cranks.
Just
> > because the engine is turbo doesn't mean the piston is forged. It may be
> > stronger since it's designed for boost, but not necessarily forged.
> > Second, that will be one effed up combustion chamber. The cylinder head
is
> > the top of the chamber and the piston is the bottom and they are
designed
> to
> > provide a total volume that burns quickly with high resistance to
> > detonation. When you mix and match you will most likely end up with a
poor
> > combustion chamber more likely to detonate.
> > Third, have you thought about valve clearance? The 16V has a pretty
large
> > valve clearance notch that is missing in the 1.8T piston.
>
> I believe lower compression (along with the possibility that the pistons
> were forged) was the goal so the 1.8T pistons are more than likely dished
> enough to clearance the valves.  I am not sure but it seems that way.

Take a look at this: http://home.comcast.net/~xr4tic/audi_eng_top_lo.jpg
Recall how the 16V intake valves are right at the edge of the bore?
I think the valves will hit.

>
> > I've been keeping an eye on your posts ever since you started talking
> about
> > Megasquirt 6 months ago.
> > I've got one piece of advice. Learn to walk before you try to run!
> > just my .02
> > Dan
>
> The reason why we are here is to help others (and get some help once in a
> while) through the experiences of our own not to tell someone what they
lack
> personally.  I think this message would of been perfect if it weren't for
> the slam on Derrick's level of VW knowledge.  We all started somewhere and
I
> find myself learning faster when I get in over my head a little!

You know I spend alot of time trying to help people on this list.
I'd like to delude myself into thinking it's a contribution.
In this case I think it's appropriate and helpful to tell Derrick to slow
down and take things one step at a time. He posts to this list, on the
Megasquirt list and on Vortex. He has really big plans and that's fine. Most
young guys his age that are really into cars want to do what he wants to do.
But, you have to have the knowledge base to do it! You don't jump from a
stock 16V to a 350 hp turbo 16V in one step.
I hope Derrick doesn't take my comment as a slam, but unfortuneately I do
believe he needs to realign his short term goals more closely with his
knowledge base. I think it's helpful to point it out even though it's bound
to be ill received.
OTOH, Dave, it is a little hard to swallow your input on being considerate
of others in light of the crap and alligations you spew when you're in
attack mode! I have a hard time viewing you as fairminded list moderator!
Dan