Hi
I am trying to get a really nice 47 DeSoto back on the road. I suspect the last owner bailed because of a problem I have discovered. The engine, which is a fairly recent rebuild, runs great until the choke begins to open. Then the vacuum sags to 15" and it runs LOUSY. I shot some WD-40 along the manifold gaskets, and it picked right up when the spray was near the center intake runner. I pulled off the manifolds, put a machinist's square on the flanges, they looked good. The gaskets looked pretty cooked; it was hard to see a definite leak path, although I am convinced there is one.
Rebuilt the heat damper, replaced the bolts mating intake to exhaust, and reinstalled assy. using all new studs and NOS nuts.
Used Fel-Pro gaskets, with a little Hylomar on the intakes and a little hi-temp RTV on the exhausts.
Same **** situation.Exactly.
Now I'm ready to do it right (and spend enough to ENSURE it's right).
Suggestions?
I have had many Mopar flatheads over the last 35 years, and I've never seen this bad behavior before.
H E L P