SuzukiSavage.com - Print Page

SuzukiSavage.com
/cgi-bin/YaBB.pl
General Category >> Rubber Side Down! >> Potential cure for oil leaks
/cgi-bin/YaBB.pl?num=1179938112

Message started by borne2fly on 05/23/07 at 09:35:12

Title: Potential cure for oil leaks
Post by borne2fly on 05/23/07 at 09:35:12

I'm in the middle of tearing an engine apart for oil leaks. The leaks I'm chasing have more to do with holes, cracks, and other casting defects, but I couldn't help seeing all the posts on this site about leaks through those seams that use only a sealer and no gasket.

Lycoming and Continental aircraft engines have been split down the middle forever, they go together without a gasket, and they are forbidden to leak oil (oil leaks lead to fires, which are not good in a fabric covered airplane way up in th sky). Granted, they have a lot more bolts around the perimeter than most other engines, but the big trick they use is a single silk thread carefully laid down on the mating surfaces before they go together. This thread runs all the way around the mating surface and crosses over itself when it gets back to where it started. The crossover is not a knot, just one end of the thread laid over the other at about a 30 degree angle with each end extending maybe 1/4" past the crossover.

Has anyone tried this with a Savage engine, either around the crankcase or the camshaft cover? I imagine a combination of this and the black sealer should make the thing properly oil tight.

Well .... almost. The rubber plug remains an issue. One day I'm going to thread that hole, fabricate a short bolt, and use a fiber washer between the bolt head and cylinder head.

Title: Re: Potential cure for oil leaks
Post by K1200LTryder on 05/23/07 at 09:50:46

Quit putting oil in it, eventually it will stop leaking.

;D

Title: Re: Potential cure for oil leaks
Post by justin_o_guy on 05/23/07 at 11:03:02

I cant see how that could hurt a thing. Where are these strings available? I have just done the cam chain & used the liquid gasket sealer. So far, no leaks.

Title: Re: Potential cure for oil leaks
Post by borne2fly on 05/23/07 at 11:10:54

I'm not sure exactly where to get the silk strings anymore, but I'd start by calling any place that services light planes and talk to one of their A&P mechanics.

Title: Re: Potential cure for oil leaks
Post by Kropatchek on 05/24/07 at 13:48:00

Coming from aviation maintenance myself I was surprised to see camshaft bearings in plain alluminium, where i was expecting a bronze bushing.
The sealing of crankcase halves or the like with liquid gasket is normal and will, if properly prepaired and applied will get the job done: Sealing.
On the RR engines we used to apply the blue stuff called Hylomar, worked very good.

Title: Re: Potential cure for oil leaks
Post by Greg_650 on 05/25/07 at 06:14:12

borne2fly wrote:

I'm not sure exactly where to get the silk strings anymore, but I'd start by calling any place that services light planes and talk to one of their A&P mechanics.

With the headcover, you have to remember the camshaft journals and the plain bearing surfaces. Changing the height of the headcover will change the clearance and affect oil pressure on the top end. It doesn't take much. Even .001" more gap will add to the bearing clearance.

(I forget the plasti-gage measure on the cam shaft, but it is around .003" or about the thickness of printer paper)

As for the silk thread...my wife makes jewelry and uses it all the time. You can get it a beading supply store or at some place like Michaels. Hope that helps.