"Ray Block" <BPracing@wowway.com> wrote:
>> -----Original Message-----
>> From: jon@dakota-truck.net
>>
>> Assuming that I have understood correctly so far, rather than
>> imbalance each engine the same, why the heck didn't they just build
>> the 360 internally balanced in the first place? Seems like this would
>> save a lot of money since all harmonic balancers, flexplates and
>> torque converters could them be shared between the 318 and 360 with no
>> interchange worries or the resulting confusion?
> I gather it was cheaper to Externally balance the engines. I don't think
> the factory worried much about interchangeability. Then again, its been my
> experience that some engineers make changes just to justify their jobs. ;)
Yep, you're probably right about the interchanability, though I
would have expected the bean counters to be worried about it. So,
this begs another question - if it was cheaper to externally balance
the engines, why did they go with internal balance on practically
everything else?
>> Were the 360 rods and
>> pistons simply too heavy to add enough weight to the crankshaft with
>> the block clearance involved?
> No. The rods are the same for all small block mopars. The 360 pistons s/b
> lighter than the 340's since the bore is smaller. They are slightly larger
> than 318 pistons. The 360, for some reason, has larger mains. Don't know
> why unless it was perceived durability for the proposed applications and
> because of the 360's longer stroke. Remember, the original 360 was offered
> only in two-barrel form in 1971 and became the standard engine instead of
> big blocks in heavy cars from '71 up. Torque was the apparent goal. They
> first became available as performance engines in the '74 model year
> utilizing the 340 cams when the short stroke 340's were
> discontinued...perhaps due to emissions. I've read that large bores and
> short strokes are not emissions friendly. ??
Weird. So it sounds like there was no engineering reason (that
anyone has come up with yet, anyway) to go with external balance on
the 360 rather than an internal balance. Since the 360 was based off
the 318 and 340, it would seem to make sense to stay with the same
balancing system - what the heck caused them to change? Is this just
one of those "Chrysler" things that makes no sense and yet is? :-)
Possibly it was one of those things where, like you said, an
external balance was thought to be better for some reason, but wasn't
actually, however they stayed with that system just because there
wasn't a good enough reason to switch to internal? Kinda like left
hand threaded wheel studs on the left side of the car? They
eventually stopped doing that though. :-)
--
-Jon-
.- Jon Steiger -- jon@dakota-truck.net or jon@jonsteiger.com -.
| '96 Kolb Firefly, '96 Suzuki Intruder, Miscellaneous Mopars |
`-------------------------------- http://www.jonsteiger.com --'
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