Compression for 440 Sportfire

Mailman · Post by **Mailman** » Sat Sep 24, 2005 1:40 pm

I checked the compression this AM on the 440 engine on the 81 Sportfire and got 140# on one cly. and 145# on the other just wondering if that's good enough? Havenen't got my manual yet so cant tell. Thanks. Mailman

harleysportster · Post by **harleysportster** » Sat Sep 24, 2005 4:35 pm

That sounds like it is in the ball park. The 5 pound difference is ok to, usually up to 10 pounds is exceptable.

JoeRainville · Post by **JoeRainville** » Mon Sep 26, 2005 6:55 pm

Hi Guys,

140/145 PSI is with in spec for a new motor much as less one 22+ years old. You are looking very good as far as compression is concerned. I always suggest new crank seals on any of these old sled, as that seems to be about the main reason they smoke pistons.

Good luck,
-Joe Rainville
"Tech-Ed"

Mailman · Post by **Mailman** » Mon Sep 26, 2005 10:55 pm

Can you replace the engine seals without breaking the engine apart? I've replaced them on the 295 but that was when I O/H the engine and had it apart any ways.

Mailman

Mailman · Post by **Mailman** » Sat Oct 01, 2005 7:29 am

Any thought's on replacing the engine seals without breaking the engine apart? I,ve checked the tech manual but haven't found anything except where you break it apart, just wondering if any of you have any short cuts that still will work?

:unsure:

harleysportster · Post by **harleysportster** » Sat Oct 01, 2005 8:53 am

Mailman,
You have to split the crankcase apart because the seals have a raised sealing-ring around the outside that fits into a groove in the crankcase.