Honda CB 450 T

[Mr Merde]

I putn the word around that I was after an engine for a bike that I could build into a straight liner, a 1/4 mile special.

I have the possibility of getting an old CB450 T that is still running but in tatty condition cosmetically.

What I want to know is if anyone out there has any experience with tuning these engines. Can they be made to scream? I know they reved out to about 10,000 rpm and stock they put out 45-50 hp.

Has any one here ever pushed it higher.

The bike comes complete so I will have the frame to play around with.

This is a longish term project, but I would like to be able to give it a run when the next season of drag racing starts.

So you people in the know, please be forthcomming.

Advice please.


Mr :shit:

[jonbuoy]

http://www.motorcycle.com/mo/mctext/h_hon.html Not sure if this is the same era as the motor you have

[Paul in NZ]

Thats odd - I've 'obtained' a dead (ish) CB450 me self... for a project... I assume you mean the old DOHC CB450 and not the later SOHC 400?

Research thus far tells me that the CB450's were / are used in the USA as pretty fair classic road racers BUT that a hell of a lot of frame modification is required to get them to handle (which would fit with my memory of my flatmates one when they were new). Engines are expensive to fix if shagged and a lack of oil filter means they are often shagged. The recommendation I have thus far is to strip the engine and see if the crank is OK and if it is - procede.

Cheers

[Mr Merde]

Thats odd - I've 'obtained' a dead (ish) CB450 me self... for a project... I assume you mean the old DOHC CB450 and not the later SOHC 400?

Research thus far tells me that the CB450's were / are used in the USA as pretty fair classic road racers BUT that a hell of a lot of frame modification is required to get them to handle (which would fit with my memory of my flatmates one when they were new). Engines are expensive to fix if shagged and a lack of oil filter means they are often shagged. The recommendation I have thus far is to strip the engine and see if the crank is OK and if it is - procede.

Cheers

Thats correct as far as I know so far. The bike is really rough but is running. I'm not really looking for handling as I only plan in travelling for 1/4 mile in a straight line. Possibly turning around at the end of it and then travelling down the pit lane to get ready to do it again.

Was pointed to a site in the previous post where they worked on one of these machines. Changed the heads for one from a 500T. How rare are these beasts in NZ

The whole page looks good.

Gives me ideas of where to go.

My aim was for an engine that pumped out a lot of torque. A single would have done this but probably may have lacked at the later part of the 1/4 mile. A 4 cylinder would have the back end power but loose out somewhat at the start.

Compromise. A 2 cylinder.

The class I'm hoping to compete in is from 0-499cc. So I think this engine fits the bill quite nicely. even a little freeway to overbore if needed.

[Big Dave]

Advice please.


Mr :shit:

Madness.
What was the objective? - find the most unsuitable engine you can?
Pushing Merde up hill with a pointy stick. ;-P

[Paul in NZ]

Madness.
What was the objective? - find the most unsuitable engine you can?
Pushing Merde up hill with a pointy stick. ;-P

Why unsuitable? (no really - I need to know before I get the spanners out myself) The CB450 is old and heavy but people have got pretty respectable power out of them in the classic racing world?

[Mr Merde]

Madness.
What was the objective? - find the most unsuitable engine you can?
Pushing Merde up hill with a pointy stick. ;-P

Find any engine I can play with. I know what class I want to enter now to find an engine that fits into this class. If you can suggest a better alternative I would be most appreciative.

Lots of torque at start with enough power to be still pulling at the end of the 1/4 mile.

From what I have seen the national record for this class is something like 11.3 seconds. That must be able to be bettered.

Budget dictates what can be used.

This bike and engine were free and this works fine by me.

I like the "pushing" line.

[Paul in NZ]

Find any engine I can play with. I know what class I want to enter now to find an engine that fits into this class. If you can suggest a better alternative I would be most appreciative.

Lots of torque at start with enough power to be still pulling at the end of the 1/4 mile.

From what I have seen the national record for this class is something like 11.3 seconds. That must be able to be bettered.

Budget dictates what can be used.

This bike and engine were free and this works fine by me.

I like the "pushing" line.

Big 500 class two stroke MX bike should do the trick I'd have thought?

[Logan5]

It's no good for telling you how to make them scream, but I have in my posession one Clymer Publications Honda Service Repair Manual All 450 Models 1965-1973. Free to a good home. Interested?

[Paul in NZ]

Shit yes....

[SPman]

Have a mate in Waitara who knows a bit about 450 twins - he's restored a K4 & a Black Bomber and has mates who race these things. (he's currently trying to collect/restore, one of every model Honda made in the 60's...:eek:) I'll dig his Email addy out when I get home, if ya like

[Paul in NZ]

Have a mate in Waitara who knows a bit about 450 twins - he's restored a K4 & a Black Bomber and has mates who race these things. (he's currently trying to collect/restore, one of every model Honda made in the 60's...:eek:) I'll dig his Email addy out when I get home, if ya like

That would be great.. Thanks

[Mr Merde]

Have a mate in Waitara who knows a bit about 450 twins - he's restored a K4 & a Black Bomber and has mates who race these things. (he's currently trying to collect/restore, one of every model Honda made in the 60's...:eek:) I'll dig his Email addy out when I get home, if ya like


I would appreciatew it also. Thanks


:shit:

[Big Dave]

'The CB450 is old and heavy'

My first road going motorcycle.
I remember how it went very well. Madness.

Power to weight.
And there was something else that they did - don't remember - but most of them died the same death - conrods?? or a valve - nah, gone.

I had a SR500 after that was a whole lot more fun.

[Mr Merde]

'The CB450 is old and heavy'

My first road going motorcycle.
I remember how it went very well. Madness.

Power to weight.
And there was something else that they did - don't remember - but most of them died the same death - conrods?? or a valve - nah, gone.

I had a SR500 after that was a whole lot more fun.

Know of any going for sale anywhere then?

I am getting what I wanted from this thread,


information and ideas.

[Eurodave]

Heres some pix of what I did to my CB450 a wee while ago :)

[Mr Merde]

Very nice job


Mr :shit:

[Eurodave]

Why, thankyou sir :), FYI I made the fibreglass tank & seat, designed the pipe patterns then got them mandrel bent & made the alloy 'beauty plates' .The swingarm is now 3" longer, I added another front disc , got the wheels rechromed/respoked, polished a lot of the alloy bits at home & resprayed it too

[Mr Merde]

Why, thankyou sir :), FYI I made the fibreglass tank & seat, designed the pipe patterns then got them mandrel bent & made the alloy 'beauty plates' .The swingarm is now 3" longer, I added another front disc , got the wheels rechromed/respoked & sprayed it too

Reminds me so much of the US dirt trackers of the late 70's. Is this what you intended? If so IMHO you have suceeded.


Mr :shit:

[Eurodave]

Yep, that was the idea, I originally wanted to do this to an XS650 Yamaha, but the CB came up 1st at a very good price

[jimbo]

Know of any going for sale anywhere then?

I am getting what I wanted from this thread,


information and ideas.

Mate of mine may be flicking a rough SR soon.Will pm you if it happens:yes:

[Motu]

Even got the K70's,they were a favorite flattrack tyre in the '70's.

[Paul in NZ]

Heres some pix of what I did to my CB450 a wee while ago :)

Niiiccceee Dave..

Mines more complete but buggered anyway. Have you had the engine apart?

Paul N (ps the LM2 seats holding up OK btw - managed the long SI trip and Vicki is still talking to me)

[xwhatsit]

Heres some pix of what I did to my CB450 a wee while ago :)

Faaaark that's nice. Love your work. Is that road legal?

[moko]

450/500 motor has an unusual torsion spring set-up rather than the usual springs.All the parts of the valve set-up are individually matched and if you mix them up you'll get in all kinds of trouble.Motor should rev to 12,000 in standard trim for short bursts without exploding but the 500s were pretty notorious for being badly thrown together and they dont seem to last anything like as well as the 450,including the motor.General opinion of the bike press here was that stretching it to 500 was too much,whenever a bike mag runs a "worst ever bike" feature the old 500T is always in there along with the XS250 Yam and the other "usual suspects".
Think for what you're looking at doing I'd be considering something like a GPZ500 motor,you're already 10 bhp up on the Honda without touching it in bog standard form and the whole project will be a lot simpler,more info available,easier parts availability e.t.c.You could spend a lot of time and effort just getting your old Honda up to stock Kawa performance.If you were just looking at a bit of fun then what the hell,you'd have fun whatever you ran and however quickly you got it to go but if you're serious about that record then you dont really want to start with something so out-dated.The original Balck Bomber was an amazing bike in it's day but that day has gone and bikes have moved on tremendously.As a historic racer or to renovate yes but I'd want something a whole lot more modern if speed and reliability is essential.

[pete376403]

How about a Triumph Daytona - they are nothing special as motors go but there is a shitload of hot up bits and information to make them go. They would prolly be a lot more expensive than the Honda.

OR if you were to consider a 500 single - current speedway motors are powerful. lightweight and physically pretty strong

[Paul in NZ]

How about a Triumph Daytona - they are nothing special as motors go but there is a shitload of hot up bits and information to make them go. They would prolly be a lot more expensive than the Honda.

OR if you were to consider a 500 single - current speedway motors are powerful. lightweight and physically pretty strong

True - but Honda 450's can be found for nothing and Daytonas cost a fortune. Besides, the 450's a cool looking engine and it's not about going really fast, it's about looking like it may have gone fast... once...

[Eurodave]

Have you had the engine apart?

Not yet, still need to rewire everything, so havnt fired it up yet, has got good compressions though

[Eurodave]

Faaaark that's nice. Love your work. Is that road legal?

Not quite legal yet, still a little bit of finishing work to do, but soon.......

[nudemetalz]

I've got those "Cycle World Road Tests" books which in the Hinda one has about 3 road tests on the then new 450's.
The very first ones that came out were 360 degree cranks but were very quickly changed to 180 degree cranks (ala GPz500).

I'm happy to photocopy/lend these articles as they describe the 450 motor in great detail.
Nice looking machine if you got one and restored to mint.

[Paul in NZ]

I've got those "Cycle World Road Tests" books which in the Hinda one has about 3 road tests on the then new 450's.
The very first ones that came out were 360 degree cranks but were very quickly changed to 180 degree cranks (ala GPz500).

I'm happy to photocopy/lend these articles as they describe the 450 motor in great detail.
Nice looking machine if you got one and restored to mint.

Erm - beauty in in the eye of the beholder.... Early 450's were nice looking but the later ones? Not quite my cuppa char....

[nudemetalz]

Erm - beauty in in the eye of the beholder.... Early 450's were nice looking but the later ones? Not quite my cuppa char....

No.. the very first ones (the Black Bombers) are the ones I'm referring to.
(like this one)

The CB500T's...errr......nope....

[moko]

Found a site in the U.K. about a drag-raced CB500T,good little site actually with lots of useful info if you follow the links,last up-dated last year but maybe worth e-mailing the guys if you've any queries
http://www.thefang.co.uk/bikespecs.htm