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Found some history on my '77 / Piper 270 cam / Timing

To: mgs@autox.team.net
Subject: Found some history on my '77 / Piper 270 cam / Timing
From: mark.d.melvin@jpmchase.com
Date: Wed, 12 Nov 2003 16:47:59 -0500
I found my new '77 in one of the online registries, and its 20 year owner
who parted with it just 18 months ago. What a rough 18 months it was for
the car to go from a loving home to someone who managed to destroy the
trunk lid, bend the hood, bungle a bunch of things mechanical & electrical,
etc. But all that is being fixed now.

Anyway, I found out that the car has a Piper 270 cam, and was already bored
to +30. I ran out of time the other night to do a full static (plugs all
out) compression test, but got the running compression test (all but one
plug in, fully warm with automatic choke already opened, car idling)
reading 90 pounds in all four cylinders. Rock steady repeatability, took
four puffs to get there each time. Considering that usually running
compression is down close to 50% of static, I should be in decent shape but
not til I do full static with & without oil can I be sure the engine fully
survived the interim owner.

The colortune plug said bright neon blue right from the start. After all
the abuse and my simply replacing the bicycle brake cable twist-tied around
the throttle arm with a proper accelerator cable & new sleeve, removing the
K&N filter which had been patched with a few wads of epoxy and was missing
most of the cotton, and correcting the idle speed (but not mixture) screw.
Amazing. Gotta hate these DGV carbs ;-), they take the challenge out of
tuning

So to the topic of timing. What does the list say I should do for timing on
a '77 overbored 18V with the  Piper 270 Cam, a CEI electronic distributor
(proper for '80, but was retrofitted to this car), and the DGV carb?  Web
resource I found says the CEI distributor should be set to 10 BTDC at 1500,
as this distributor has a wide vac advance configuration.

What's a safe starting point for the timing? 10BTDC at 1500 seems awfully
retarded to me.

Does anyone know a source for information on the Piper camshafts? I can't
find anything but the homepages of various car owners ranging from Audis to
Triumphs who have installed them, and a few UK specialists who will build
engines with them, but no company or product data. Interim owner must have
hated books. He discarded everything the prior owner had given him. All I
found in the car is a receipt for some Bosch sparkplugs.




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