[6pack] New Engine AUTOpsy

[Sally or Dick Taylor]

Kendall---In another post to you, I recommended a machine shop not too far from you.

I would agree with others who suggested that if the oil supply was good, the engine was probably misassembled. Either too tight, or with a backward cap. Caps are identified by matching numbers stamped on the block, or rod. The numbers should always be on the same side. This will align the "anti spin" feature, which normally would prevent a bearing from spinning when under duress.

The lack of oil to the rocker could be from a partially blocked passage in the cam bearing. 

Dick 


-----Original Message-----
From: Kendall Larsen
Sent: Monday, September 8, 2008 2:46 AM
To: 6pack List
Subject: [6pack] New Engine AUTOpsy

List,

I've been putting off this email for awhile now. It was actually way back at new years eve '08 that my new engine started making very bad sounds. It didn't really start rattling until I had been on the freeway for 40 miles or so, the longest trip that I had taken the new engine on yet.  The problem likely existed much earlier but when oil pressure was up I didn't hear any knocking. After towing the car back to my apt I didn't open the engine for awhile because I didn't have the time or money (or motivation) to get into it. I've since secured a garage to work in and now need to finish the job before the TR6 wears out its welcome!

Here are some pathology pics of the damage. Cylinder 1 rod bearing spun.
http://picasaweb.google.com/kendalll/TR6Engine08#

So we now know what what the loud noise was, but the question is why, and what do I do to keep it from happening again?

The rust on the rocker arm is curious. But the car sat for quite awhile after the tow home, and I had to start it up and run the engine for a few seconds to occasionally move the car. Seem like there was no oil on the rocker arm to keep the rust off it.

What are the possible causes for a rod bearing to spin? This engine probably had less than 5 hours on it.

I had the machine shop put the bottom end together, because I didn't want to screw up a ring or something. I did the rest of the engine assembly, cam timing etc. How likely is it that this is the result of a mistake on their end?

Interested to hear what you guys have to say. This is late night email for me so hopefully it's coherent!

Kendall
San Clemente, CA
6pack at autox.team.net
http://autox.team.net/mailman/listinfo/6pack

http://www.team.net/archive

You are subscribed as tr6taylor at webtv.net