- Jul 10, 2013
- Reaction score
u think i havent already tried that ? i already lapped my 7th plunger and housing just now and it failed again. like i said i have information from the probalby most reliable guy and he uses o rings on all his engines since the early 1990s and they never failed he said. i just dont know if he made the o ring on the plunger or inside the liner. and pls as a reminder. i would like to stay with brass and steel as a plunger . and i d like to stay on same dimensions , so pls no other suggestions. the main goal is now to achieve 100% tight pump. not another pump with cast iron...no longer plunger....it must be 18mm plunger ( same bore depth ) +- 1mm bore depth . i found that when i drill 1.9mm and then ream 2mm H7 it is a hole about 2.02mm because my plungers fit as soon i reach under 2.023mm at 2.019 they are alreadx to loose and at 2.020 they start to work good , but only for short time once the brass is a bit peeled or ground by the plunger they get leaky... i hope my o ring set arrives soon. i ordered them from ebay. 12-Size Waterproof Rubber Watch Crown O-Ring Gasket Assortment 1000Pcs 1.4-2.8mm | eBay
with those o rings i should be able to fit one or two in a row on the 2mm plunger .when i make a samll groove in it ...well lubricated they last forever i have been told!
You used cylinder made of brass instead cast iron. The problem with brass: the gringing particle by lapping paste will be embedded in brass where is very difficult to clean up free from lapping paste. Hence you got leakage in short time.