Quad4 modifications

[Mark Romans]

D. T. Kelly wrote:
> 
> Mark,
>      Thanks for the reply. Here's a brief run-down on what I have: A 1990
> HO Quad4 with the HO intake and exhaust manifold, HO cams, and 10:1
> compression (stock). When I rebuilt the engine, I had to bore it .010 over
> and deck the heads .010. I have searched high and low for the Olds
> performance catalog, to no avail. The GM catalog has a few things, but they
> are geared toward carburetion (thanks to racing rules).
>      As far as changing lobe centers and adding a header is concerned, I
> have found NO parts for this engine...no different cams, no header, etc.
> >From what I've gathered, the stock HO exhaust manifold is supposedly the
> best, and a header would offer no improvement.
>      Any help from anyone would be greatly appreciated.
> 
> Thanks,
> Tim
> 
> > Hi Tim; what year quad 4 do you have? There were two different types,
> > The HO and later quad 4's had a different intake manifold with short
> > runners. Different cams and compression. Oldsmobile did have a catalog
> > that listed a bunch of parts for the quad4. The HO stock made 190-200
> > horsepower. If you got the ho stuff, changed the lobe center on the
> > cams, shaved the heads .020 and put a header on it. The quad 4 will make
> > 230+ horse easy.   Mark.

Hi Tim, The Catalog is called "Oldsmobile Rocket Parts, Catalog and
technical manual" 1993. I got mine from Dennis Weglarz, He's the
motorsports guru at Oldsmobile. It features Dave Jolly, the Olds
showroom stock champion (1992 SCCA world challeng class C drivers
champion in an Acheiva SCX). The article doesn't go into a lot of detail
but it does say that .020 max may be removed from the head before the
hydraulic chain tensioners are adversly affected. It also says to
"Advance the intake camshaft 2 deg and retard the exaust camshaft 2
degrees." "This camshaft timing will produce the best torque and
horsepower output."  "The cam timing may be changed by installing
specially drilled rocket parts sprockets (#22551543 and #22551503)."
Headers would have to be custom built. Olds rocket parts header flange
pn 22551516 would help. Valve springs pn 22551519m nhra approved and pn
22551704 stock replacement. Quad 4 motorsports ecm pn 22551577, who
knows if any of these parts are still serviced. Jim Fueling in Ventura
CA has done a ton of stuff with the quad4 too. Have fun.  Mark.