An off list friend with a lot of TR3 engine rebuilding experience suggested that
the flywheel might not be seated properly/fully; or pressure plate or clutch
imbalance; pistons and connecting rod not of same weight, even pistons installed
backwards and facing the wrong direction; the transmission not mated properly to
the engine was a good thought also!
From: email@example.com [mailto:firstname.lastname@example.org]
On Behalf Of email@example.com
Sent: Wednesday, April 08, 2009 9:07 PM
Subject: [TR] Vibration in TR 3 Engine
Okay, I finally got the engine rebuild from hell in the car and, yes another
First the background. New AE pistons and liners (87 mm), all new bearings (10
over), cam checked out as okay and lifters reground, All new valves and guides,
new timing chain. All internal moving parts including the flywheel were balanced
by a local race engine builder, the main bearing journals were line bored. The
distributor was totally rebuilt as were the carbs.
Started the engine up and ran it per instructions of the cam company to seat the
lifters. Engine ran smooth and idles beautifully.
On driving the car the engine is again very smooth and has plenty of power.
The problem is that as it approaches 2800 RPM a vibration starts, peaking at
about 3000 RPM and fades out at 3500 RPM. The vibration is bad enough to cause
the body panels to all start ringing. At first I thought it was the drive shaft
but you can get the vibration even if the car is not moving although it is not
After having the carbs and distributor rebuilt I installed them in my other car
and tuned the carbs so has to have then at least close on start up of the new
engine and there was no vibration it that engine.
I'm not looking forward to tearing the engine down especially since I have no
idea where to even start looking for the problem.
Any suggestions as where to start looking for the cause of the vibration?
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