455 Engine Specs

[waldo love]

Hi All,

Does anyone have vacuum specs for the 455? I'm pulling a ragged 15-16"
at idle on the intake manifold. If I recall, 20-21" is more
appropriate.

Researching old Chilton's, I found some interesting specs on older Olds
Toronado 455's. For example:

'70 8- 455 400 HP @ 3200 500fp @3200 12 btdc 10.25:1 comp

'71 8-455 350 HP @ 4400 465fp @2800 10 btdc 8.50:1
comp

'70 intake valve opens 24b, '71 opens 22b.

The '71 seems to have all the desirable characteristics for the GMC MH
if retrofitted with electronic ignition.

Anybody have more detailed specs on these engines? The '70 doesn't seem
practical unless you want to burn "super" gasoline with 10.25:1, but the
'71 seems a very good candidate.

Thoughts, anyone?

Waldo
76 PB

 

[wayne newland]

Waldo

I just went thru the vac thing and found the vac line coming off of the
lower "T" behind the carb was roasted and fell apart in my hands. This is
the line that feeds the vac tank that feeds the heater/ac controls (it's
very small, except at the ends). TYo repair it, I bought a foot of 1/4 inch
vac hose, cut about 2 inches off, put one end on the T and sprayed some
WD-40 into the other end and forced the stub of the small vac line into it
and it pulls 20 at the vac tank and about 19 out of the tank.I would like to
think that the coach will run better, but I can't really tell much
difference.

Wayne Newland F9300 75 Palm Beach

> Hi All,
>
> Does anyone have vacuum specs for the 455? I'm pulling a ragged 15-16"
> at idle on the intake manifold. If I recall, 20-21" is more
> appropriate.
>
> Researching old Chilton's, I found some interesting specs on older Olds
> Toronado 455's. For example:
>
> '70 8- 455 400 HP @ 3200 500fp @3200 12 btdc 10.25:1 comp
>
> '71 8-455 350 HP @ 4400 465fp @2800 10 btdc 8.50:1
> comp
>
> '70 intake valve opens 24b, '71 opens 22b.
>
> The '71 seems to have all the desirable characteristics for the GMC MH
> if retrofitted with electronic ignition.
>
> Anybody have more detailed specs on these engines? The '70 doesn't seem
> practical unless you want to burn "super" gasoline with 10.25:1, but the
> '71 seems a very good candidate.
>
> Thoughts, anyone?
>
> Waldo
> 76 PB