SOHC.co.uk Forums > CB350/400
CB400/4 ENGINE STRIP, ASSESSMENT AND REBUILD BY JULIE - NOW COMPLETE
Seabeowner:
Very interesting to see the 400 in so much detail. Thanks for posting. And interesting it's completely different to the 500/550, where not only are the restrictors at the base, but oil is fed to under the camshaft surfaces only and the cam faces are dipped in a bath. Honda either had teams working in pretty much isolation or they were doing a lot of experimentation and we were the guinea pigs.
hairygit:
My feeling is that the 400/4 was a later idea/development than the 750/500/550 fours, and experience from the earlier motors led the the cam spraying idea. Done from the design stage they probably hoped it would reduce problems and warranty claims and improve reliability. It would have been prohibitively expensive and disruptive to modify the heads of the earlier models in this way. Just my take on it.
Johnwebley:
--- Quote from: hairygit on October 14, 2017, 10:24:58 AM ---My feeling is that the 400/4 was a later idea/development than the 750/500/550 fours, and experience from the earlier motors led the the cam spraying idea. Done from the design stage they probably hoped it would reduce problems and warranty claims and improve reliability. It would have been prohibitively expensive and disruptive to modify the heads of the earlier models in this way. Just my take on it.
--- End quote ---
I like the 500 cam lubrication,with pressure feed to the journels and oil dip/bath for the lobes and followers ,how does the spray
work better ?
BUT. very interesting ,love these threads
hairygit:
The 500/550 oil bath works okay, but when the cam is turning at 4000+ rpm at high engine speeds, centrifugal force will obviously decrease the amount of oil that can cling to the cam lobes compared to a constant spray like the 400 gets, as I said, just my take on Honda's thinking at the time. After all, the 400 system would increase production costs per unit, so they obviously thought it was worth the cost.
Sent from my X6pro using Tapatalk
Laverda Dave:
John,
There is an oil bath of sorts in the 400 head directly below the camshaft. From memory I think only the cam lobes themselves dip into the oil in the bath as the cam spins.
As the oil sprays out of the drillings from the spray bar over the cam it collects in the oil bath to a certain level. When the level is reached the oil runs back down into the engine. Maybe Julie has a photo of the top of the cylinder head to demonstrate the theory?
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version