A: Oil Pipework Oil feed pipe diameter

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chark_mandler

Active Forum User
VOC Member
The spares co sell oil feed hose that is 7/16" ID. I really don't want to pay for an A66 feed pipe and would rather use a banjo at the crankcase end with hose all the way to the UFM. There are suppliers that sell 1/4" banjos with a 3/8" pipe outlet but none that I can find that sell with a 7/16" pipe outlet so thought I would make one. Measuring up I've noticed that the UFM side of A44 has an ID of only .270" and this is similar for the smallest part of T32. So I'm not sure as to why the ID of the hose is so big - is this to accommodate fluctuations in pumping?

I can make a banjo for 7/16" hose but easier to buy one for 3/8" hose which is still bigger than the ID of A44 / T32. Is 3/8" too small?
 
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chankly bore

Well Known and Active Forum User
Non-VOC Member
The oil pump feed hose was originally 3/8" i.d. The pump feed pipe, A66AS/ A66/2AS was originally 7/16" o.d. Some bright bugger in the U.K. has been making this in 12mm. o.d. which is obviously wrong; it also throws out the curvature and fit on to the banjo bolt. Hopefully the Spares Co. has fixed this by now.The eagle-eyed among you will note that the picture of the Comet engine/ gearbox unit in "Richardson" figure 43 is fitted with a strange pump feed pipe. The oil pump works at 1/15th. engine speed with a stroke of only 1/4", so fluctuations in pumping should not be caused by the pipe or hose diameter. Limiting factors are more likely to be cleanliness of the stop valve assembly and viscosity of the oil, I would think.
 
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robin

Well Known and Active Forum User
VOC Member
Please note that11mm pipe is within 0.004 of 7/16 pipe. 11mm pipe is widely available in stainless steel (A2) in UK.
Robin.
 
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