E: Engine large idler oil feed

[fogrider]

Doing some engine work on son's Comet, the new, one piece, idler boss is drilled on its' shank for lubrication of the bush, but was not drilled right through from the rear where the gravity feed reservoir is. Good job he spotted that, I would have fitted it. Question is, how many have been made not drilled through and have been fitted ?
Where did it come from ?, (don't wish to say...... ) Any remarks on this will be very interesting !
Regards all

 

[greg brillus]

The timing chest gears act like one big oil pump so I wouldn't stress too much about it.......Not that any of that flung oil gets to the followers and lobes where it is needed more than any other engine part.

 

[davidd]

Where did it come from ?, (don't wish to say...... )

The design was changed to a cast one-piece design for the Series D. Those were preferred to the ET51 idler shaft being pushed into an aluminum base. I hope your Comet did not receive the defective ET51 shaft, mostly because there are two of the shafts used in the Comet: one in the large idler base and a plain shaft forward of the large idler. This would be the small idler. It also receives oil through the hole in the inside end.

Maughan uses the ET51 shaft for the small idler and the large idler and so far, they appear to have through holes. I assume that Maughan uses an interference fit in the base of the large idler. I have never had one come apart.

David

 

[fogrider]

Good point - must check the small idler is drilled too !

This one piece D type idler seemed very soft, drilled easy but not like cast iron drills. Dimensions and surface perfect though so seems OK to fit it.

Still have to wonder how many other idler shafts not drilled though....

Regards all, Terry.

 

[fogrider]

Must point out that was definately NOT from Maughans ! It would have been correct.

 

[davidd]

Here are several large idler mounts:

Left, the old aluminum mount with a spun spindle.
Middle, a Series D mount that is one piece.
Right, a Maughan mount that is two pieces.

Same order.

In situ on a Comet, looking down from the top of the timing chest:

A Maughn large idler mount and a small idler in place. The FT173 spacer sitting against the rib. I use 1/4 x 20 Allen screws because they are easy to lock wire.

The decompression block is cut away for a large cam.

The oil feed hole for the oil pump scroll is enlarged.

David

 

[fogrider]

Excellent and interesting photo's, the large idler in sons' Comet is a one piece but not the same base shape as any of those. It does now seem it's a one-off from a known local source. I think I will advise him to junk it and buy a Maughans 2 piece.
Good post, thanks David.

 

[Peter Holmes]

Andy Davenport sells the one piece ET51/1, Andy prides himself on selling top quality components, so I would assume it would be correct in every way, but I would also assume the Maughan two piece item is equally good.

 

[fogrider]

Just found an old/original ET 51 shaft, tried it with an automatic centre punch, no pock mark. Tried the one piece idler assembly and the punch easily indented it.
Spark test confirms it's mild steel.
It's going in the bin.....

 

[LoneStar]

Any reason you can't share the supplier of this part? It's perfectly fair to report accurately on quality issues, and not much use for us to know that someone, somewhere is making substandard components.