Joined: Aug 2017 Posts: 620 Threads: 7
Reputation:
7
Location: queensland
Lovely article Terry, thanks for sharing. I have bored out 1/4 bsp fittings to 5/16 ID and will look at adapters for the larger hose.
We have a 3 bearing crankcase which has the plain centre camshaft bush, The original oil feed has been lost with the removal of the centre bearing so we propose to feed it from a tapping at the rear jet plug and a capillary tube going around the back of the block and in through the bush locater bolt. The gallery will have pressure if we will leave out the internal gallery blanking plug at the front .
In view of the quantity of oil flying about do you think that feeding the bush is necessary?
I have printed your article for my reference file , always worth reading. Regards Russell
Joined: Aug 2017 Posts: 739 Threads: 13
Reputation:
5
Hi,
Dumping the excess oil back down the filler neck might not be the best idea.
My engine is coil ignition so any overpressure oil going into the filler neck will meet the crankshaft as it spins around. I can not comment on Mag engines which have the filler neck in a different postion.
I have tapped the front right of the crankcase so that the oil squirts front to back along the right hand side of the crankcase below the arc of the crankshaft.
I use a 1/4 BSP banjo fitting which just fits between the front of the chassis and engine.
My in build engine project will use an adjustable valve in the original position and an oilpump which is a bolt in new one using the original oil galley as feed to the crankshaft as per the Speedy Pressure fed engine.
If you do not plug the front of the oil gallery oil will flow back to the oil jets unless they have been blanked off.
Joined: Aug 2017 Posts: 620 Threads: 7
Reputation:
7
Location: queensland
your right dickie, dumping oil down the filler hole is not a great idea, I was just trying to minimise the ugly rubber pipe run. Perhaps squrting the oil onto the camshaft gear through the inspection plate is better?
The front oil gallery is plugged to minimise the delay in filling at startup.
Do you advise giving extra side clearance to number 4 big end and if so what dimension?
Joined: Aug 2017 Posts: 327 Threads: 1
Reputation:
19
Location: Bristol
Russel side clearance of 10-12 thou on pressure fed 12-14 on splash rods, if you have your oil pressure relief valve set at 65psi oil warm there is no need for any extra clearance. your nose feed bolt should have a 1/4"/6.5mm cross feed hole and at least the same size bore some were smaller restricking the feed. Terry.
Joined: Aug 2017 Posts: 620 Threads: 7
Reputation:
7
Location: queensland
Thanks SO much guys for your very pertinent advice which we will follow . It's all coming together, very exiting.
