SBC manual/auto cranks?

Technical aspects of automobiles, et. al., post #17,793
Author:
Date:
Subject:
 ray
 2008-04-17 21:09:53
 SBC manual/auto cranks?
My 1990 1/2 ton made a new noise today, sounded like valvetrain
problems... then it went away. But that's somewhat irrelevant for right
now - but it got me thinking if I had to replace the motor in it - it's
a stickshift. If I was to borrow the smallblock from my race car (GM
crate engine) will it bolt up to the trans? Is there such a thing as a
manual trans crank? Some googling showed that for some engines you need
to drill the crank to install the pilot bushing - am I likely going to
need to do this on my truck?

And if anyone can tell me what's so special about my truck motor? GM's
base crate engine is rated at 260HP and yet can't be used in a vehicle
with a GVWR over 7000lbs. My truck motor was only rated at 200hp and
apart from center bolt valve covers (and one piece rear seal etc...)
it's basically the same old small block. Do the truck motors have
anything but cast pistons and a cast crank?

Ray
Author:
Date:
Subject:
 sdlomi2
 2008-04-20 02:34:49
 Re: SBC manual/auto cranks?
"ray" <[email protected]> wrote in message
news:B0PNj.67126$Cj7.10353@pd7urf2no...
> My 1990 1/2 ton made a new noise today, sounded like valvetrain
> problems... then it went away. But that's somewhat irrelevant for right
> now - but it got me thinking if I had to replace the motor in it - it's a
> stickshift. If I was to borrow the smallblock from my race car (GM crate
> engine) will it bolt up to the trans? Is there such a thing as a manual
> trans crank? Some googling showed that for some engines you need to drill
> the crank to install the pilot bushing - am I likely going to need to do
> this on my truck?
>
> And if anyone can tell me what's so special about my truck motor? GM's
> base crate engine is rated at 260HP and yet can't be used in a vehicle
> with a GVWR over 7000lbs. My truck motor was only rated at 200hp and
> apart from center bolt valve covers (and one piece rear seal etc...) it's
> basically the same old small block. Do the truck motors have anything but
> cast pistons and a cast crank?
>
> Ray

Can't answer your question knowledgeably, Ray, but I'd bet 3 things:
first, the truck motors (barring hi-po) would have only cast pistons and
crank as you suggested; second, GM would make the base-engine cranks
universal if for no reason other than to reduce *their* inventory and yet
supply the gamut. My 3rd guess is that the 7000lbs max GVWR may be due more
to camshaft design and torque ranges than to HP. Again note I cannot
document: these are just speculations and based on a likely GM goal to
control cost, esp. with the first 2 guesses. s