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Feb 12, 2017 12:58 pm
Feb 12, 2017 12:58 pm
Subject: Re: Meadows Engine Help
Barry,
The previous owner had my LG6 (Meadows) engine rebuilt by vintage engine "engineers", who (correctly) used modern TWR Volvo pistons. However they assembled the engine using modern Volvo tolerances.
Result: the engine seized after 500 miles. Reason: although maximum RPM is relatively low, the piston speed is quite high. Oil thrown up from the crank doesn't just lubricate the piston, it cools it. That oil has to travel much higher than it would in a modern short stroke engine.
So: less lubrication, less cooling (and remember that with the lower compression ratios used, engines run hotter) and higher piston speed mean that Meadows engine pistons run much hotter than the same piston in modern engines. More heat means more expansion, hence the need to use wider tolerances than the Volvo piston manufacturers state, for Meadows application.
As an aside, the "engineers" correctly diagnosed the problem with my engine, and rebored the engine...this time going too far...so my engine lacks compression and blows out oil, despite being a fully "professionally" rebuilt engine.
Laurence
Barry,
The previous owner had my LG6 (Meadows) engine rebuilt by vintage engine "engineers", who (correctly) used modern TWR Volvo pistons. However they assembled the engine using modern Volvo tolerances.
Result: the engine seized after 500 miles. Reason: although maximum RPM is relatively low, the piston speed is quite high. Oil thrown up from the crank doesn't just lubricate the piston, it cools it. That oil has to travel much higher than it would in a modern short stroke engine.
So: less lubrication, less cooling (and remember that with the lower compression ratios used, engines run hotter) and higher piston speed mean that Meadows engine pistons run much hotter than the same piston in modern engines. More heat means more expansion, hence the need to use wider tolerances than the Volvo piston manufacturers state, for Meadows application.
As an aside, the "engineers" correctly diagnosed the problem with my engine, and rebored the engine...this time going too far...so my engine lacks compression and blows out oil, despite being a fully "professionally" rebuilt engine.
Laurence