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Engine basics => Engine set up tips => Topic started by: Rick Campbell on November 26, 2022, 12:39:19 PM

Title: Double Star 54 Front Bearing
Post by: Rick Campbell on November 26, 2022, 12:39:19 PM
A friend was having a bit of trouble with his DS54 running consistently. Now that we've had a chance to poke at it, the tank had a leak, so that'll get fixed.

The front end of the engine was leaking air when tested submerged in fuel. Normal? Should we look to replacing the front bearing with a sealed unit? Boca bearing does not list this engine. Anyone know what bearing fits? Thanks.
Title: Re: Double Star 54 Front Bearing
Post by: Brian Stas on November 26, 2022, 02:33:46 PM
Rick, If you've got it out, measure it, it'll be metric of course.  At the Boca Bearing site you can look it up by size and they have what you need.  I just rebuilt 8 engines with bearings from them.  You can choose the type of seal as well.  They ship fast.
Brian
Title: Re: Double Star 54 Front Bearing
Post by: Air Ministry . on December 01, 2022, 07:16:09 PM
Generally , if its got fuel leaking from the prop drive , its looseing fuel , and the consuptions higher , flights shorter . AND its messy . Which is whay a sealed bearings pretty much a standard fit these days . Pe Oil ! .

You dont want a dry seal in anything . Particularly water pumps - You drop anti freeze on the seal & spin . Try something similar - See its lubed - as theres less circulation up there with it atmospherically sealed .
Title: Re: Double Star 54 Front Bearing
Post by: Steve Helmick on December 02, 2022, 04:15:29 PM
Can you describe the way the engine was tested for the 'leak' out the front? 

A reasonable amount of leakage is to be expected and ensures that the front bearing is getting its ration of oil. If it's severe, then get a new sealed bearing and remove the inboard seal before installation. I've done it, but I don't know how long the seal would do your buddy any good. I did it on an early K&B .40 front intake for FF, the front bearing was bad, and I happened to have a sealed bearing that fit. It helped keep the dirt out more than the oil in. y1 Steve