Alternative Engines

[scott woodworth]

> will a 454 chev easily replace a 455 olds?

For several years I have been wondering about the possibility of
using a 500 Cadillac motor as a GMC power plant. The 454 Chevy would
require an adapter, but the Cadillac is a direct swap because it's bell
housing is the same pattern as the Oldsmobile.

A very good book on motor home and tow vehicle engine is Trailer
Life's Rx for Rv Performance and Mileage by Bill Geraghty. This
publication, which is out of print unfortunately, has good things to say
about the Cad 500.

This engine gets around 33% better mileage than the 454 according to
the people who have put them in their pickup trucks. It has been proven
to be extremely durable when subjected to heavy loads and will not
overheat. These 500's were designed with heavy vehicles in mind.

1970 Stock specs are: 400 hp at 4400 rpm and 525 lbs/ft at 3000 (gross)

This engine can be stroked by offset grinding the crankshaft for
even more cubic inches. (Read torque) 540 CID is easily obtainable
using the offset ground crank. Street Rodder magazine will be doing a
buildup story all year on this engine.

Scott Woodworth

 

[patrick flowers]

>
> the cad engine is interesting. The benifit of the 454 is can get
> new for the price of a quality rebuild on the olds or cad

Jim,

Having looked at this issue, any savings would be quickly consumed by
the costs of making everything fit. A conversion like this usually
requires fabrication of all sorts of brackets for accessories such as
a/c, power steering, alternator. Also, the 455 fan is tightly shrouded
and I doubt that the stock shroud would work - more custom work. Unless
you know a real cheap mechanic or place very little value on your time,
stick with the 455.

Also, most of these same issues will apply to the cad 500. The 455 can
make more horsepower than the rest of the drivetrain can effectively put
on the ground. A toasted transmission from driving at high output
levels for an extended period of time can be a real bummer. There was
an excellent article recently in GMCMM on this very subject.

IMO, money is better spent on moving the available power down into a
more appropriate speed range. An "RV" cam, headers(not for me, but some
owners love 'em), 3 in. exhaust, enriching the fuel mixture(good article
by Joe Mondello in Jan. 88 GMCMM) and final drive ratio change are good
investments.

Patrick
- --
Patrick Flowers
Mailtoatri63

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