Jays100
Veteran Member
Well, how would you like us to refer to ourselves?
...being in the asylum, that is....
I see a survey in the not too distant future!
...being in the asylum, that is....
I see a survey in the not too distant future!
Well, since the "inmates" nickname is already taken by one of the biggest forums ever bought to be destroyed by VS and the replacement forum members seem to be using the same nickname to some extent, we should be creative and come up with something more appropriate for our nickname.
Perhaps "addicts"
No siree, not an addict.
With this said, it is worth pointing out that in your case Troy, there was an update issued back in the day for the stock pump on the K0 CB450. It involved removing some material from the underside of the pump where the sump screen is. If you are going to use the stock pump from the K0 you would want to verify that update was done. Also as Tom mentioned you can fit a K1-K7 pump to your bike relatively easy I believe.
Of course the best option might be to buy this new pump from Jay if he has one available for sale and it fits the budget parameters for your project.
Budget!!! Oh my! That was over before it started. I've tried to to not think in terms of overall budget but rather how much I have to spend at any given time and then know that the project will just be done when it's done. As we all know with something like this once you start, it's pretty nearly impossible to stop. Yes I'm trying to stretch my dollars but I don't want to save money today that I will regret later.
Thanks to all for the good information. I will ponder this for a few days before making a final decision. I have found the original Honda service bulletin and it looks like there are some options:
1) The original pump is easily modified to improve oil flow somewhat.
2) Find a pump from a later model.
3) Install Jay's pump.
Jay your pump looks like the gold standard and although it may seem a little expensive at a first glance I think it represents good value considering the time and effort you have clearly put into it. I'm sure you aren't making a dime on these and it's really just a labor of love. Something tells me this is the route I will decide upon because I want my grandkids to ride this bike one day.
It would be great to leave your bikes to your grandkids and have them enjoy them. I wish I could say I'll have grandkids that would ride some of my bikes but I'm afraid that isn't in the cards for me.
As to your 3 options, I wouldn't bother with the first one. Good used K1 through K7 pumps are easy to find, I probably have one or two myself. As to the price comparison between Jay's pump and the other well-known option (Cappellini), there's no comparison at all - Jay's pump is a bolt-on option requiring only one simple mod to the clutch cover. The Cappellini kit (with an Eaton pump used in the Cappellini kit) requires the lower case to be removed and machined for a proper mounting surface and slightly modified for the remote pickup, plus the clutch basket gear has to be machined to clear the sprocket and chain that drives the Eaton pump, and you have to ditch the centrifugal oil filter as well and use the Cappellini paper filter... all for the price of well over $600 just for the parts, nevermind the machine work. And not that it should be an issue, but the Eaton pump puts out way more pressure than the stock engine requires with typical use, about 60 lbs, which could lead to some oil leaks you typically wouldn't encounter. All in all, Jay's pump makes the most sense by far for our purposes.
Love hanging out here though...
I'm new to the forum and thought I would mention that I just installed one of Jay's pumps in my '70 cl450 k3. Inadequate oiling by the original oil pump had resulted in significant damage to the cams and followers in my engine. This lead me to look for a better solution and eventually to Jay's pump. The gear pump is very nicely built and, since Jay has engineered it to fit into the place of the original piston pump, the installation is simple. It really is an elegant design and makes me wonder why something similar wasn't original equipment on the bike.
With the new pump in place, I pulled the head to begin rebuilding the top end. Oddly there are no torsion bars in place. It seems someone has replaced them with coil valve springs. I have a few questions for the group about this odd setup, but I'll start a new thread to do that. Thanks for adding me to the group. Once I get the engine back together I'll report back about the pump.

you need to take a look at this guy:
http://www.cappellinimoto.it
But have you ever installed a Cappellini pump in a DOHC 450? The bottom end has to be disassembled, machining on the lower case done to properly accommodate the pump mounting and machining done on the clutch basket gear to trim the width of the teeth to clear the drive for the oil pump which is just a commercially-available Eaton pump. Jay's pump requires none of that and only a 1/4" trimmed from the oil fence on the right crankcase cover, it can be installed in a couple hours with zero engine disassembly except the right crankcase cover. And it's also more than a little bit less expensive.
Edit: here's how simple it is to install - https://bit.ly/2UtmorW
I meant it more to look at the site for ideas. I know the pump setup is way out of the realm of most of us, but there are other things that improve oiling.
I didn't buy nor install a Jay's pump jet, but I did install a Cappellini oil filter setup on my CB450 K0 (but I certainly will do in the build of the three 450's coming next). As mentioned in a thread, the clutch basket touched the filter housing what resulted in aluminium particles in the oil. After sending a few emails without any response from them, I draw the conclusion that Cappelline stands for a lot of blabla, and in the end it's your problem (I didn't ask my money back, just wanted to report that a CB450 K0 clutch basket is just slightly bigger in diameter then the later versions, or that something else was not right). As an engineer I expected a good discussion, no ignoring behavior.
Personally, after learning more about paper filters and doing a little research into centrifugal filters, I would not fit a paper element filter instead of the original centrifugal filter which is just 'better' at filtering
As I recall (Jensen please correct) he did all of his evaluation with a stock oil pump. That pump is essentially intermittent flow by its extend/retract function.
It wouldn't be a massive problem to ream bore on a stock pump and make a new piston from something like 7075 which is a lot harder than 6061 and actually easier to get hold of than a chunk of cast aluminium of 'correct' (unknown) grade to match original under-size or worn piston.
Phosphor bearing bronze would also be a good alternative and 'same' as majority of British bikes from 1950's - 60's
I know aluminium on aluminium is a big no-no but either cast iron or phosphor bronze would be fine.
I was along the lines of thinking out loud with the earlier cast iron body oil pump.
If I remember right it can go 0.75mm oversize before walls get too thin to support piston and oil pressure because of the vibration possibility of cracking?
IIRC, max oil pressure is around 15-20psi?
I measured oil pressure at <1 psig for the OEM piston pump.
Pressure is needed to move the oil and it doesn't take much. With roller bearings the required pressure is quite low, while Babbitt bearings require higher pressure. With the design of the twin engines up to 1978 you had the roller crank bearings and Babbitt type cam bearings plus the cam/rocker interface. Lower pressure and high volume was a decent design.So, it is more about volume of flow rate than pressure. That's just a fart.
How does one acquire one of these oil pumps?