[Top] [All Lists]

RE: Carbs, cats(!),etc. was:Re: Clearance troubles...

To: <>, <mgs@Autox.Team.Net>
Subject: RE: Carbs, cats(!),etc. was:Re: Clearance troubles...
From: "Chris Delling" <>
Date: Fri, 11 Sep 1998 15:21:29 -0400

The 100 H.P. (95 actually) advertised was incorrect using "modern"
mathmatical expressions for H.P.  Using the standards that were adopted in
the mid-70's, the original, pre-emission B motor made around 84 H.P. in
"modern" terms.  The rubber bumper cars were capable of 62 H.P. when new.

Loss of H.P. between the two motors was caused by multiple modifications,
including the carburation and intake/exhaust manifold, the cat converter, a
10% reduction in compression ratio, and a very mild cam tuned for mid-range.
My understanding is that the single biggest contributor to the H.P. loss was
the cam, which is also very prone to premature failure.  Many blame the loss
on the airpump, which is not really accurate.  It was heavy, prone to
failure, and did put some drag on the motor, but really didn't cost a lot in
the H.P. department when working properly.


Chris Delling

> -----Original Message-----
> From: []On
> Behalf Of
> Sent: Friday, September 11, 1998 1:28 PM
> To:
> Subject: Carbs, cats(!),etc. was:Re: Clearance troubles...
> "Speaking of dual carb conversions, etc, what, in listers
> experience, is the
> primary cause for the loss of horsepower on later B's? I know there is a
> change in carburetion, addition of an air pump, and a cat converter. Is
> there anything else? What is responsible for the lion's share of lost
> horsepower? I assume it is "breathing" related because very little torque
> is lost, but hp peaks at a lower rpm (and the peak is less)."
> The main loss in power is the horrible design of the
> intake/exhaust manifold.
> The exhaust gases are forced together in very little space and
> shoved through
> a U turn, then a catalytic converter...It was a temporary solution to a
> permanant problem.
> That and a bunch of little things that all combined to reduce the
> horsepower
> from about 100 to about 55.
> Steve Sanchez
> "Still holding on in a *new and improved* '77 'B!"

<Prev in Thread] Current Thread [Next in Thread>