Replacement engine for Mercedes D3a

franzkait · 8 October 2006, 12:42 PM

tell me one engine , using the hole in the conrod to lub the cam ? the gipsy queen has a hole each side in the conrod , so for what is the second one ?

jumpinjan · 8 October 2006, 04:19 PM

Quote:

Originally Posted by franzkait

tell me one engine , using the hole in the conrod to lub the cam?

An old Sunbeam.
I just assembled one this past week & the weep holes face the camshaft side.
I recall seeing them on "old" GM Inline & V8 engines, but their holes (very small diameter) are out of the side of the rod's big end, not on top of the big end.
On your two hole Gypsy engine rod, look were the oil pressure passage in the crankpin align with the each weep hole in it's rod. That angle should maybe indicate where it's deliberately spraying oil: One to the piston, the other to the camshaft, perhaps? I would be interested to know...
Two holes make sense, being its aircooled, any aircooled engine lives on air & oil.
Jan
(Afternote) - Franzkait, I check the Sunbeam and it sprays a stream a few degrees BTDC, directly on the cylinder wall. The cam lobes probably get something too (not the main stream) because the cam is very near the cylinder. So to speak correctly about this, the holes are NOT there just to lube the cam lobes only. The intent is to get oil on the cylinder wall, but the cam gets some too (As I mentioned earlier). Okay? Do you agree?

aerobuilder · 10 October 2006, 05:56 AM

franzkait,

You mentioned that you have to make the prop hubs; what material are you using. Are you using a mild steel or some form of alloyed steel such as 4140 or 4140 prehard? just curious.

Thanks!

franzkait · 24 October 2006, 05:12 PM

aerobuilder, for an engine like the Gipsy Queen 4140 not hard, 1918 engine 4130.
Jumpingjan, for sure this holes are to lub the cylinder walls, and maybe the cam gets a little to.

franzkait · 26 October 2006, 04:07 PM

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drrivah · 27 October 2006, 04:38 PM

Franzkait: How much time and expense for inverting a Gypsy Queen?-drrivah

R Pope · 27 October 2006, 06:16 PM

Regarding the cam getting oil from the squirt holes in the rods, GM had no problem with cam failures in small block engines until they decided to do away with the grooved caps, that did the same thing. This was apparently done to reduce oil consumption with less ring tension in smog engines. Now they are noted cam eaters.