Finally got around to checking the timing chain last nite. I can move the
crank about 8 degrees before the distributor starts to move. This is within
the ten degrees which I think I saw posted here so I don't plan to do
anything with it now but what I don't know is how these things wear. Does a
new chain have zero slop that then slowly gets looser or do they begin life
with quite a bit of slop then suddenly get much looser. What happens on the
455 when the chain gets near failure? On other engines people tell me you
can here it banging the case before it fails. Are there warning signs on
the 455 or does it just die? Lastly; Is there possibility of serious
damage or does it just stop gracefully?
Per an earlier thread I decided to change the gasket between the oil filter
bracket and the oil cooler bracket. I removed the three bolts where the
bracket attaches to the engine. Big mistake! I needed to remove the
exhaust manifold to get it back in. The proper procedure is to just remove
the oil filter then there's a 1 1/8 nut inside there. Remove that nut and
the oil line bracket will drop off exposing the gasket inside. I used the
gasket off a new oil filter to replace it. The old gasket in there was old
and brittle but I don't think it was about to fail soon but it's easy
enough to change that it's good cheap insurance.
Now while the manifold is off anyway The gasket in there is pretty
seriously burned and it's only been a few thousand miles since having the
manifold milled and put in new gaskets. I'm using Mr gasket gaskets as
recommended by a local racing machine shop. They're the ones with a greyish
rubbery look to them. The plugs are still gapped at .080 but I plan to
change them to '045 when it goes back together.
The plugs are running a dark brown color. I've had it started several times
to move it around the ward so am not sure how they would look after an on
the road trip. Normal driving doesn't show any signs of the mixture being
too lean and mpg can be about 10 if on continuous Interstate. There's been
comments on making the mixture richer to cool the manifolds but no comments
on what that does to gas milage nor on what the actual mixture being
achieved may be. Ideally I would think the mixture should be just a little
on the rich side of best effeciency but I don't what is being done. It may
well be that I just need to change the mixture to get longer life from the
manifolds and gaskets without hurting milage but I don't yet know enough
yet to even have an opinion.
I need some education on this one.
On this same line. Do the coated headers keep things cool enough that all
the heat problems go away or do the problems just take a different form?
Are the headers a direct drop in for the stock manifolds or does the
exhaust pipe need to be adjusted at the same time? I think (hope) I've
still got some life left in the present system so don't want to do major
surgery at this point. If it takes a major loss in effeciency to get the
manifolds to survive the headers may pay for themselves with better milage.
(Somehow I don't think I'll get the wife convinced on that point!)
I've got a buddy who has an exhaust gas analyzer. If I ever get far enough
ahead of the game to get out of the emergency mode maybe I can persuade him
to make some measurements. Meanwhile I'm listening so educate me!
Thanks
Dick
crank about 8 degrees before the distributor starts to move. This is within
the ten degrees which I think I saw posted here so I don't plan to do
anything with it now but what I don't know is how these things wear. Does a
new chain have zero slop that then slowly gets looser or do they begin life
with quite a bit of slop then suddenly get much looser. What happens on the
455 when the chain gets near failure? On other engines people tell me you
can here it banging the case before it fails. Are there warning signs on
the 455 or does it just die? Lastly; Is there possibility of serious
damage or does it just stop gracefully?
Per an earlier thread I decided to change the gasket between the oil filter
bracket and the oil cooler bracket. I removed the three bolts where the
bracket attaches to the engine. Big mistake! I needed to remove the
exhaust manifold to get it back in. The proper procedure is to just remove
the oil filter then there's a 1 1/8 nut inside there. Remove that nut and
the oil line bracket will drop off exposing the gasket inside. I used the
gasket off a new oil filter to replace it. The old gasket in there was old
and brittle but I don't think it was about to fail soon but it's easy
enough to change that it's good cheap insurance.
Now while the manifold is off anyway The gasket in there is pretty
seriously burned and it's only been a few thousand miles since having the
manifold milled and put in new gaskets. I'm using Mr gasket gaskets as
recommended by a local racing machine shop. They're the ones with a greyish
rubbery look to them. The plugs are still gapped at .080 but I plan to
change them to '045 when it goes back together.
The plugs are running a dark brown color. I've had it started several times
to move it around the ward so am not sure how they would look after an on
the road trip. Normal driving doesn't show any signs of the mixture being
too lean and mpg can be about 10 if on continuous Interstate. There's been
comments on making the mixture richer to cool the manifolds but no comments
on what that does to gas milage nor on what the actual mixture being
achieved may be. Ideally I would think the mixture should be just a little
on the rich side of best effeciency but I don't what is being done. It may
well be that I just need to change the mixture to get longer life from the
manifolds and gaskets without hurting milage but I don't yet know enough
yet to even have an opinion.
I need some education on this one.
On this same line. Do the coated headers keep things cool enough that all
the heat problems go away or do the problems just take a different form?
Are the headers a direct drop in for the stock manifolds or does the
exhaust pipe need to be adjusted at the same time? I think (hope) I've
still got some life left in the present system so don't want to do major
surgery at this point. If it takes a major loss in effeciency to get the
manifolds to survive the headers may pay for themselves with better milage.
(Somehow I don't think I'll get the wife convinced on that point!)
I've got a buddy who has an exhaust gas analyzer. If I ever get far enough
ahead of the game to get out of the emergency mode maybe I can persuade him
to make some measurements. Meanwhile I'm listening so educate me!
Thanks
Dick
