What is an engine refresh
 

I was on the Mercury racing site and that had a chart showing how often an engine refresh should be completed. It was as low as every 25 hours for some and up to 200 hours on others.
What is an engine refresh and what does it cost. How many times can an engine be refreshed. How does it differ from a rebuild.

a rebuild....... you can rebuild the top end or bottom end or both. take the warn parts out and put new. coast all depends on the motor and work need. how many time all depends on wear.

what would need to be redone after 25 hours

Top ends. The classic supercat engines are very hard on valve-trains.

A naturally aspirated racing engine with an extremely high lift duration agressive camshaft running solid lifters need to be checked every 15 hours on some models.

Everybody includes different things on a refresh so the question is actually dependent on that particular shops definition- and it varies dramatically.

A classic Mercury Black engine rule of thumb runs the most hours many 1000 or more but they are tame

Merc Blue engines run "rule of thumb" 200/250 hour top end and 500 hours bottom end



UD