On the way to the 2026 rally, my oil pressure dropped and I could not get the pump to work. The sequence is as follows: During the winter engine re-build, I made a new T key to connect the crank shaft to the oil pump. After fitting the timing cover and oil pump assembly to the engine, all was well for about 100 miles. However the key I made was too tight a fit, and was applying axial pressure to the pump gears wearing the brass away on the pump casing. See photo. I now have one gear sitting 0.22mm deeper into the casing than the idle gear. I have read elsewhere that the fit of these gears needs to be near 0.05mm not 0.22mm. The bright colour brass on the r/h chamber is where it has been worn away
So what to do? I can skim the pump by 2.2mm, then I can either thin down the idle pump gear 0.22mm or machine the counterbore chamber by 2.2mm. Neither an attractive option. Maybe a visit to spares will solve my problem.
Oil pump failure and why
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Dhbangham
- Posts: 99
- Joined: Sat Sep 21, 2013 7:47 am
- Your interest in the forum: Jowett long four owner. Jowett club member. (Former Armstrong Siddeley 20hp 1932 owner and ASOC member and former Lancia Belna 1935 saloon) Lanica owners club member. Interested in driving my cars especially in europe and making and repairing parts for the cars. I consider myself an oily rag owner.
- Given Name: Daniel
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Oil pump failure and why
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