Valve Train noise

[John Hess]

This is what I mean by an instant expert.  First of all, the very fact 
that GM spent those millions dictated that they were obligated to 
cover their costs.  The original TPI was designed for the 305 engine 
and is woefully inadequate for even a mildly built 350.  The air 
foils, ported plenums, opened up MAF do, in fact, increase horsepower 
easily measurable on a dyno, 0-60 time, quarter mile, or even the seat 
of ones pants.  I agree that the GM MAF system is the way to go for 
someone building a street engine.  There are numerous tradeoffs 
between maximum horsepower, maximum torque, and drivability.  One 
thing we must understand in all this is that GM is forced to build an 
engine that meet CAFE (Corporate Average Fuel Economy), emission 
controls, smooth idle, low to mid-range torque, and easy cruising at 
(in '86) 55 mph.  If the end users concerns lean toward one or more of 
these criteria, there are aftermarket products that will satisfy their 
needs.  To state that these parts are fraudulent or that the people 
who sell them are liars is irresponsible and/or stupid..

While it is true that the requirements of a particular engine may 
vary, there are some parts that will increase horsepower and torque, 
but were not placed on the original engine purely due to 
economics...Headers, dual exhaust (with dual catalytic converters), 
high flow air filters, high flow Mass Air Flow sensors, roller 
lifters, and throttle body air foils are notable among these.  Even 
the calpak can be remapped for improved performances if done so to 
accomodate a particular engine and driving conditions.  These engines 
(from the factory) are made for mass production.  Plainly and simply, 
they are designed so that the lowest common denominator is met.


----------
From:  George M. Dailey[SMTP:gmd at tecinfo.com]
Sent:  Friday, January 17, 1997 12:52 PM
To:  diy_efi at coulomb.eng.ohio-state.edu
Subject:  Re: Valve Train noise

You may not like what I'm about to say. In my opinion you should junk 
the
Electromotive ECM. Buy an GM MAF type ECM ($100.00) and prom ($50.00) 
build
or buy an engine harness. You will then have a system that is well 
proven
(over 1,000,000 units)and supported. Unless you are using after market 
ram
tubes, plenum, and base, your best performance will come with the 
stock
components. All of the stock TPI components are designed to work 
together.
When you buy into the "bigger ram tubes - more flow" thinking, 
remember that
if 50 extra horses could be added by only using a larger what ever, GM 
would
have done it. The cost to cast a bigger throttle bodie, ram tubes, or 
what
ever is probably pennies. GM spent millions developing TPI and it 
works. The
MAF will, of course, help you if you have a warm cam.

Don't feel bad. After market parts can confuse even the most seasoned 
hot
rodder. Some of the venders are liscened and bonded LIERS. Oh, it's 
not a
total loss though, I've heard that the Electromotive ECMs make 
excellent and
attractive door stops or paper weights:}

Good luck
GMD


At 03:34 PM 1/16/97 -0500, you wrote:
>Greetings:
>
>     I am the most recient victom/customer of Electromotive.  I
>purchased a TPI
...cut out the long face and sad songs...
>I can and keep the fuel/air balanced at idel.  However, each time 
the
>engine
>experiences load conditions I hear valve noise.  The kind of noise I
>most
>commonly would associate with poor fuel.  110 octane and valve
>adjustment
>has helped but, not as much as narrowing squt.   Still I have valve
>train noise.
>
>Any Ideas on how to solve this prolem short of canning the system 
and
>bolting on a one barrel, magneto, and adding a timing stick to the
>steering colum?
>
>Ray.
>
>
>
>