durability of JH block internals and going turbo

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

As far as I know the JH and 3A rods are the same length at 144mm center
to center. The extra stroke is accomodated by moving the piston pin a
little higher in the piston.
The JH really is a good starting point cause it's rugged and it has a
low compression ratio. The 3A is good because of the greater
displacement (which probably won't make a huge difference in ulitmate
power, but will be alot more driveable off boost), I think it has piston
oil squirters (although I can't find the 3A in ETKA to save my ass) but
it's really big drawback for a turbo application is the 10:1 CR. So,
special pistons or the ghetto fix of stacking head gaskets.
Joe Doty's post on this subject is on the money and highlites the
critical issue here. I just assumed fuel and ignition would be correct
in stating the JH could handle 200 Hp. No engine will make even
moderately large power if the fuel and ignition are hosed.
Hopefully, in the next few months I'll be putting a T3/T04E on a JH
fueled with a Haltech E6K. I want to see how much I can make before I go
back to a 2.0 and add the turbo to that.
Dan


Jeff Toomasson wrote:
> 
> Thanks, Dan - definitely a good starting point.
> 
> One more question (actually, two, I guess...): can one use JH rods with 3A
> crank and pistons in a 3A block to lower compression?  Would the added
> displacement make as much difference in a forced induction setup as it does
> N/A? I guess that opens up reference point issues, but just humor me...  :)
> 
> Thanks again - JT
> ----- Original Message -----
> From: "Dan Bubb" <jdbubb@ix.netcom.com>
> To: "Jeff Toomasson" <jtoomasson@yahoo.com>
> Cc: <scirocco-l@scirocco.org>
> Sent: Monday, October 28, 2002 1:11 PM
> Subject: Re: durability of JH block internals and going turbo
> 
> > I think the general consensus on the VW Hardcore forum is that the stock
> > JH internals are good for at least 200 hp. You might want to go there at
> > www.vwsport.com and look for the Hardcore forum. The top thread is about
> > the easy way to get 200 hp.
> > As far as new pistons; new as in slightly oversize? of something special
> > like forged?
> > I think the stock pistons can handle it, but if they're worn or there is
> > a lot of blowby, that might cause some problems.
> > Dan
> >
> > > Jeff Toomasson wrote:
> > >
> > > I was curious what the general consensus is on the durability of stock
> > > JH internals (i.e., crank, rods, pistons, etc.)
> > >
> > > The reason I ask is that I have really no idea what rigors a JH block
> > > could withstand.
> > >
> > > Given a rebuild, knifing the crank and balancing the internals - could
> > > the stock components RELIABLY handle ~200 whp and the ~15psi of boost
> > > required to get there?
> > >
> > > I repeatedly see people going with new pistons, rods, etc., but I
> > > don't ever see anyone talk of the benefits (other than increasing
> > > bore) that those pistons are supposed to achieve...
> > >
> > > TIA, JT