weird. Nothing else changed?
All I can think of is that your cam timing might be off a bit and that the hi
lift rockers
exposed the problem a little more (i.e. if the exhaust valves open a little
too early
& open quickly then you'd get combustion still happening with valves open.
It's
just a guess though.
What are your cam specs? My engines were (at the time of changeover to 1.5
rockers)
, 286 duration and around 300 duration. Now they are at about 296 and 310. I
havn't
tried going back to standard rockers (why when I paid all that cash for high
lift cams
to get extra lift!!!)
Mike
----- Original Message -----
From "Larry Miller" <millerls at ado13.com>
To: "Mike and Kerry Gigante" <mikeg@vicnet.net.au>; <Daniel1312@aol.com>;
<spridgets@autox.team.net>
Sent: Saturday, November 18, 2000 10:20 AM
Subject: Re: Found a way to Quiet My Loud Exhaust
> Big time difference here. My wife even noticed, the first time she was in
> the car after the switch, she asked "What did you do to make it quieter?"
>
> Larry
>
> ----- Original Message -----
> From: "Mike and Kerry Gigante" <mikeg@vicnet.net.au>
> To: <Daniel1312@aol.com>; <millerls@ado13.com>; <spridgets@autox.team.net>
> Sent: Friday, November 17, 2000 3:13 PM
> Subject: Re: Found a way to Quiet My Loud Exhaust
>
>
> > There is something else going on here. I switched the other way on my
> > rally/race 1380
> > and in my race +0.020" motor and the noise levels were not noticebly
> > different.
> >
> > Mike
> >
> > ----- Original Message -----
> > From: <Daniel1312@aol.com>
> > To: <millerls@ado13.com>; <spridgets@autox.team.net>
> > Sent: Saturday, November 18, 2000 6:56 AM
> > Subject: Re: Found a way to Quiet My Loud Exhaust
> >
> >
> > > Did you measure how much less power it was making?
> > >
> > > In a message dated 17/11/00 18:56:09 GMT Standard Time,
> millerls@ado13.com
> > > writes:
> > >
> > > << Using a dB meter inside the car, pointing rearward, the exhaust noise
> was
> > > 125 dB at full tilt with the rollers. With the stock rockers it's 90 dB
> > > under same conditions.
> > >
> > > I had no idea that the rockers could make that much difference in the
> sound
> > > of the exhaust. This was the first time I had run this engine with
> stock
> > > rockers. >>
|