M
mikep996
Guest
On a discussion a few days ago we talked about the use of various sealers for exhaust systems. We all agreed that Silkolene is clearly the one to use for hi-temp stuff. However, I found an interesting item as I was re-assembling the exhaust system on one of my 8V71Tis. In cleaning the turbo flanges and the showerheads, I found that permatex hi temp - the copper stuff - had been used between the showerhead and turbo flange. The part that was interesting was that it looked perfectly normal - just like it would look on any other gasket surface that was not exposed to high heat.
I am not suggesting that it can handle as hi a temp as silkolene - per specs on both, it cannot. In fact, silkolene can handle approximately double the temp - 1470F vs 750F. But since the permatex has been in place since the engines were overhauled in 1998, it obviously worked fine in this application. So apparently, in the 8V71ti the exhaust temps are not particularly high at this joint. I have never measured them with the temp gun at this spot but I will later today on the other engine. Since the water-jacketed shower head is attached directly to the turbo flange, it clearly has the heat-carrying capacity to reduce the temps at the joint to relatively low levels.
Only after I shoot the temps on both turbo flanges of the operating engine to confirm that the temps are well below the limits of the permatex would I consider using it instead of the silkolene. But if it is appropriate temp-wise, permatex is only a few bucks a tube.
Why does this matter? Because I can't find my tube of silkolene - I don''t remember when I used it last or what the heck I did with it - but I do have the permatex in my kit!
I am not suggesting that it can handle as hi a temp as silkolene - per specs on both, it cannot. In fact, silkolene can handle approximately double the temp - 1470F vs 750F. But since the permatex has been in place since the engines were overhauled in 1998, it obviously worked fine in this application. So apparently, in the 8V71ti the exhaust temps are not particularly high at this joint. I have never measured them with the temp gun at this spot but I will later today on the other engine. Since the water-jacketed shower head is attached directly to the turbo flange, it clearly has the heat-carrying capacity to reduce the temps at the joint to relatively low levels.
Only after I shoot the temps on both turbo flanges of the operating engine to confirm that the temps are well below the limits of the permatex would I consider using it instead of the silkolene. But if it is appropriate temp-wise, permatex is only a few bucks a tube.
Why does this matter? Because I can't find my tube of silkolene - I don''t remember when I used it last or what the heck I did with it - but I do have the permatex in my kit!
