Honda Twins banner

1 - 20 of 35 Posts

·
Premium Member
Joined
·
607 Posts
Discussion Starter #1
Hi, new here, about to embark on a cb500t project. Can anyone tell me what the differences are between this engine and the cb450 engine?
 

·
Sensei
Joined
·
27,164 Posts
The 500T has a longer stroke and less compression ratio.... Otherwise, pretty much the same engine... The exact gearing may be a tad different as well....
 

·
Sensei
Joined
·
27,164 Posts
Don't forget finned rocker covers and slightly different carbs (air-cut).... :lol: LMAO!
They are basicly variants of the same engine design, slightly adapted for/to different purposes...
Some of the internals won't swap due to these differences, but the engines as a unit will for the most part.....
Specifically what do you need to know?......
 

·
Premium Member
Joined
·
607 Posts
Discussion Starter #5
Thanks for the info.
I'm just wanting to know what my options are-- Gasket kits etc seem to be more common for the 450, I'll be scratching up parts soon. Rings, seals, gaskets, clutch plates, hopefully not much else. I have 2 motors to take parts from so hopefully not much else will be needed. Both will start and run, one sounds good the other has a few 'noises'.
 

·
Premium Member
Joined
·
489 Posts
Sorry for the resurrect.

Was wondering whether or not its possible to take the complete engine of a 500t and build it onto the crankcase of a 450 and vice versa?

Saves having to buy extra parts, is the crankcase of a 500t the same as 450 and are the parts interchangeable, I'm aware that the barrel, head and gearing are different on a 500t, but I was under the impression that the cranks are the same?
 

·
Sensei
Joined
·
27,164 Posts
The 500T has a STROKED crank...It won't "just fit" in 450 cases...It uses different bearings.....
 

·
Premium Member
Joined
·
489 Posts
66Sprint said:
The 500T has a STROKED crank...It won't "just fit" in 450 cases...It uses different bearings.....
Any way to make it fit? Can you not just fit the 500T bottom end into a 450?
 

·
Sensei
Joined
·
27,164 Posts
Use the 500 lower cases or do some machining work....
Anything CAN be done (given enough time expertise and money), but sometimes it's wasted effort.......
Yes, the 500T engine will fit in a 450 frame complete or as a 450/500 hybrid
 

·
Premium Member
Joined
·
489 Posts
Any idea what would need to be machined to make it happen?

Surely if the head and barrel are from a 500T and everything is else is from a 500T the engine will effectively be stroked??
 

·
Registered
Joined
·
8,867 Posts
The cranks will be very similar, however there are differences as the stroke is longer, I believe (although I do stand to be corrected here) that the main bearings are different on the 500T

Steve has great typing speed as well :lol: :lol: :lol:
 

·
Sensei
Joined
·
27,164 Posts
Yes, but WHY?... The 500T bottom cases, jugs, and crank can accept the 450 top end, Tranny gears can be swapped on the shafts if desired...... Finding some suitable pistons (different deck height on the two bikes) is the problem..... The 450 and 500T have the same bore.....displacement difference is all in the stroke.....Compression ratio difference is all about piston dome shape and deck heights....
 

·
Registered
Joined
·
7,061 Posts
I looked into this last summer when my CB450 got really cranky (pun intended :lol: :lol: ) and the K0 bomber, K1 to K7 and 500T has different cranks (bearings). Somewhere at the K1 or K2 there was a bearing upgrade (if I remember correctly slightly ticker rollers and slimmer bearing races) but I think all K1 to K7 cranks with bearings are interchangeable.


EDIT:
And Nige, I'm obviously the slowest of us. :D
 

·
Registered
Joined
·
8,867 Posts
Also, as far as I am aware, 500T pistons are as rare as rocking horse s**t :(
Wheras, you can get 450 pistons :D :idea:
 

·
Premium Member
Joined
·
489 Posts
For re-registering purposes in the EU, I will not be able to change the engine number and hence will have to keep the 450 crank, but I would prefer to run a 500T engine so it means either having seperate complete 450 and 500t engines which is a hassle as I don't have the space or doing an upgrade on the 450 crank and retaining the 450 engine number which I would prefer.
 

·
Premium Member
Joined
·
489 Posts
Koolio
Can I ask you to add your location to your profile please. Where are you based in the EU?
Not too sure why its important but here goes. At the moment I'm mainly in Poland and sometimes in the US, and registration of bikes is notoriously difficult here, 99% of everything has to be correct.

I intend to bring a 450 over register it in Poland, if I ever intend to move in the EU for example to Germany I will need the engine and chassis numbers to match the papers, any changes such as a 500t engine in a 450 chassis will blow up in my face when I try and re-register its happened to me before.
 

·
Sensei
Joined
·
27,164 Posts
That I understand.....BUT, why would you want the lower performing engine (500T) over the 450 engine?..... As I said, the gearing changes are easy, and displacement isn't always performance.....
 

·
Registered
Joined
·
8,867 Posts
Koolio we ask people to add their location as a courtesy and of course, you might find that there are people living close that can help.
I live within the EU, but here in the UK the chasis is considered more important than the engine (which of course can be replaced if it has blown up beyond repair).
I have no understanding of the title law in Poland, and therefor would not comment on them.
 
1 - 20 of 35 Posts
Top