88 Police 350 specs

[steve ravet]

Had this problem in my S-10 V8 conversion for a long time ('91 cop car
motor).  Was caused by a bad knock sensor -- smashed while installing
engine.  Unfortunately it was impossible to get at until I had the front
diff out for unrelated repairs!  I have since replaced the knock sensor
(in a more accessible location) and all is well.

The ECM runs a test when the engine is hot and TPS > 50%.  It advances
the ignition and expects to see knock.  If it doesn't it assumes ESC is
bad and sets a code.  On mine it would also use some kind of back up
timing, because after the check engine light came on the engine would
run very poorly, bad throttle response, temp gauge up 10-15 degrees,
etc.  Shutting off the engine would fix that, until the next time you
got in to the throttle.  The knock test is very painful to hear.  With
no knock sensor it lasts about a  second and sounds like the fan has
come loose.  Very audible knock.  In this conversion the knock sensor
was relocated to the (custom) motor mount.  Seems to work fine there.

--steve

Eric Deslauriers wrote:
> 
> Hi all,
> 
> Some time ago, I swapped a (carbureted) center bolt head police 350 into
> my TBI Blazer with the problem that a knocking code would get thrown
> after warmed up and > 1/2 throttle.
> 
> I've been able to obtain what I believe to be the cam specs for that
> engine. This doesn't seem to be a huge cam.
> 
> How does that compare to a typical 88 truck 350? I know the timing on
> the police motor is set at 6 degrees, while the truck wants 0 degrees.
> The police engine won't run in my truck unless I move the timing to 6
> degrees (backfires through the TBI - ouch). Why would that be?  FWIW, I
> had to reuse the distributor from the police engine since the cam gear
> is backwards from the regular distributor. Would this be related?
> 
> <snip>
> police 87 and 88 are the same. they both had 8.2 to 1 compression, 4
> barrels, and duration 194*int.- 202*ext. (my guess is this duration is
> @.050). the lift is .384" int.- .404" ext.  112* lobe separation.
> replacement part number for crane cams is  104121
> <snip>
> 
> Thank you,
> Eric D
> 
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-- 
Steve Ravet
steve.ravet at arm.com
ARM,Inc.
www.arm.com
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