[ROVERNET - UK] RE: rovernet Digest, Vol 45, Issue 51

[James Radcliffe]

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>Message: 3
>Date: Sun, 20 Aug 2006 22:17:09 +0000
>From: "Steven Dibdin" <sdibdin at hotmail.com>
>Subject: [ROVERNET - UK] I need the wisdom of RoverNet!
>To: rovernet at lyris.ccdata.com
>Message-ID: <BAY124-F1334B4429D2E4C82A6A79AB0400 at phx.gbl>
>Content-Type: text/plain; format=flowed
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>Interesting problem on my 2000TC.
>
>We had a trip two monthes ago and on the trip back the I noticed a loss of
>power on the highway. It had started idling pretty roughly in traffic and
>the accelaration was rather flat across the range.
>
>I found the king lead from the coil to the dizzie was arcing at the coil
>right onto the mouting. I wasn't sure how old the all the HT leads were so
>replaced them all with a new set. To my surprise the arcing was still 
>there.
>It was then I noticed the hairline crack in the coil's bakerlite nose. I
>have a new one on the way and have put some insulating grease around the
>nose as a stop gap until the new one arrives.
>
>I decided to check the ignition timing while I was at it and set that to 
>the
>correct mark. (I use a lead substitute so I haven't noticed any
>pinking/pinging). I checked the spark plugs only to find that the previous
>owner's mechanic had fitted N9Y sparks instead of N6Y. I regapped them to
>0.025" (they were 0.040") and the with timing I now have idle down at the
>specified 800 RPM. The torque and responsiveness has returned somewhat but
>feel like it had more 'umph' before. Any ideas?
>
>By the way I had fitted new-old-stock carbs' and the car was running very
>well before. I did a compression test on all cylinders and got
>165-160-155-155, I know that the factory manual says that I should get a
>minium of 170psi but I feel that if the compressions had dropped more on 
>one
>or two cylinders I would be thinking head gasket or damaged valve seat.
>
>
>I look forward to any pointers.
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>Thanks,
>
>Steven Dibdin
>
Has the motor been rebuilt previously, or the motor replaced at some stage 
in it life with one from Europe? Some of the TC's such as the ones sent to 
Australia were 9: 1 compression ratio. Also if the pistons have been 
replaced at some stage then they may have been changed to 9:1 compression 
ratio. My book says 160psi for 9:1 so your compression numbers could be  
very good. The compression ratio can be determined by examining the pistons. 
If you know an aviation mechanic, the may be able to lend you a borescope to 
look down the spark plug hole and have a look at the pistons.These tools are 
more common in aviation workshops than automotive workshops.  You can buy 
borescopes from Sears for $180. I have never used one though so I do not now 
how practical the would be for this.

James Radcliffe.