Camshaft Selection

[Gwyn Reedy]

Carl and others that commented earlier on my camshaft choice.

With 3.08 rear end (kinda high for towing) and 255/70x15 tires I think I'm
never getting over 3000 RPM at any towing speeds. Don't have a tach in the
truck - saving for the tach in the dash to match all the other gauges.

Here is what I decided to do - actually have done. The cam is already in the
engine, but not yet in the truck.

Stock cam, I believe is 193/203 duration and .409/.442 lift. Lobe separation
is listed as 104/116 (not sure if I understand why there are two
numbers....)

What I put in: 204/214 duration, .476/.502 lift and 107/117 separation. Also
put new 1.7 ratio rockers and Rhodes bleed-down lifters. Hope is that the
lifters will make the cam look just about the same as the stocker at 2200
RPM and less and then pump up and give the benefit of the increased lift
above 3-3500 RPM. Trying to get the best of both worlds. Will tell you all
how it runs in a month or so after it is back together.

For higher performance driving I'll eventually get my 69 El Camino with 396
back on the road. Being a used car I don't know what cam is in it, but it
sure idles rough <VBG>.

Gwyn Reedy
Brandon, Florida
mailto:mgr at mgrcorp.com
'72 Cheyenne half ton (driver)(actually a rebuilder also, at the moment)
'69 El Camino SS396 (rebuilder)



> -----Original Message-----
> From: owner-diy_efi at esl.eng.ohio-state.edu
> [mailto:owner-diy_efi at esl.eng.ohio-state.edu]On Behalf Of
> EFISYSTEMS at aol.com
> Sent: Wednesday, March 31, 1999 12:14 AM
> To: diy_efi at efi332.eng.ohio-state.edu
> Subject: Re: Camshaft Selection
>
>
> Hi Gwyn,
>      What RPM do you usually tow at??????
> -Carl Summers
>
> In a message dated 99-03-15 10:31:58 EST, you write:
>
> << Subj:	 Camshaft Selection
>  Date:	99-03-15 10:31:58 EST
>  From:	mgr at mgrcorp.com (Gwyn Reedy)
>  Sender:	owner-diy_efi at efi332.eng.ohio-state.edu
>  Reply-to:	diy_efi at efi332.eng.ohio-state.edu
>  To:	sixtiestrucks-l at chevytrucks.org (Sixties Truck List),
> diy_efi at efi332.eng.ohio-state.edu (DIY-EFI List), ckseries at f-body.org (CK
> Series List), chevelle at lists.best.com (Chevelle List)
>
>  I have the 402 BBC out of my 72 Cheyenne pickup torn down for a rebuild.
>  Dang oil pump inlet fell off and the bearings got fed a mixture
> of oil and
>  air...
>
>  The engine is not very badly damaged. Taking the crank in today
> to see what
>  it needs done to it, but it doesn't look very bad at all.
>
>  The cam shows a lot of wear. Looks like the original cam with
> 70k miles on
>  it. Some of the lifters are starting to get concave a bit too.
>
>  The truck is used for running errands around town, and from time to time
>  pulling a heavy trailer. The trailer is 6000 lbs empty and up to 14000
>  loaded. 3.08 posi rear end and THM-400.
>
>  Wondering what cam to put in it. This is an oval port (passenger car type
>  heads) with a low profile Quadrajet manifold, standard cast iron exhaust
>  manifolds. Need low end torque, not horsepower.
>
>  I'm wondering if any of these 'bottom-end torque for 4x4 off
> road use' cams
>  might be a good choice or should I just put a replacement
> factory cam back
>  in it?
>
>  Gwyn Reedy
>  Brandon, Florida
>  mailto:mgr at mgrcorp.com
>  '72 Cheyenne half ton (driver)
>  '69 El Camino SS396 (rebuilder)
>
>
>
>   >>
>