strengthening the crankcase

classic Classic list List threaded Threaded
11 messages Options
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

strengthening the crankcase

John R-5
Has anyone done a big bore conversion to their Bullet more than 612cc?
 I know there is an upgrade "kit" for 650 or even 750 but the process
requires the crankcase to be strengthened.  I want to ask whether
anyone out there has done this process and if yes, what does it
entail, how are the cases strengthened?  The crankcases need
strengthening in order to hold a larger bearing (on timing side?).
Trying to search through the database brought nought.

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: strengthening the crankcase

hmrdimali
--- In [hidden email], "jsrhk" <jsrhk@...> wrote:
>
> Has anyone done a big bore conversion to their Bullet more than 612cc?
>  I know there is an upgrade "kit" for 650 or even 750 but the process
> requires the crankcase to be strengthened.  I want to ask whether
> anyone out there has done this process and if yes, what does it
> entail, how are the cases strengthened?  The crankcases need
> strengthening in order to hold a larger bearing (on timing side?).
> Trying to search through the database brought nought.
>

Perhaps you can try these guys
http://www.tollgateclassics.co.uk/500cctune.htm

HMR
Mumbai

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: strengthening the crankcase

shinerxl
> Perhaps you can try these guys
> http://www.tollgateclassics.co.uk/500cctune.htm
I have absolutely no connection with Tollgate and have not even used
them yet but those prices seem pretty good to me.
Shiner, Orkney.

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: strengthening the crankcase

malfisher500
In reply to this post by John R-5
I spoke to John from Tollgate on the phone before I made my mind up
which way to go 612 or 625, he is a nice feller and seems to know
whats what, but works in a totally different way to the off-the-shelf
kit from Hitchcock. Of course I asked about this mod and he told me
that what the mod entails is basically machining the timing side
casing to accept a bigger double row roller. I asked why, and he said
because "something moved" but this stops it. Fair enough, but he wasnt
specific so I cant be either.

I can only imagine that because he uses the standard flywheels bored
out to accept a bigger pin, but which are obviously still bolted
together, may be why this is deemed nessesary? Ive also asked Allan
Hitchcock about it when I was over there, and he was mystified as for
the need for the mod. I wondered would it be a good idea to get mine
done. But he was under the opinion it was unnessesary, and none of the
612's have had any problem in this area. I discussed this with him and
he has no reports concerning flex at the timing side.

There is quite a goodly difference in the price of the kits this is
true. But the difference between the relative crank/flywheels is night
and day in my opinion. Hitchcocks is a precision press-fit crank
(which you pay for granted) and looks like a jewell! Maybe the bolted
up flywheels even though strengthened by the addition of a wider pin,
still need this extra mod? Because perhaps it might be that however
tight you get the bolts, there may still be a possibility of flex?
Thats my theory anyway.

Malc.



--- In [hidden email], "jsrhk" <jsrhk@...> wrote:
>
> Has anyone done a big bore conversion to their Bullet more than 612cc?
>  I know there is an upgrade "kit" for 650 or even 750 but the process
> requires the crankcase to be strengthened.  I want to ask whether
> anyone out there has done this process and if yes, what does it
> entail, how are the cases strengthened?  The crankcases need
> strengthening in order to hold a larger bearing (on timing side?).
> Trying to search through the database brought nought.
>


Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: strengthening the crankcase

ric450classic
If you check out the exploded parts diagram on Hitchcocks site you will
can see that older british design originally came with a twin rollered
timing bearing ;)

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: strengthening the crankcase

malfisher500
--- In [hidden email], "Ric" <longstrokeclassic@...> wrote:
>
> If you check out the exploded parts diagram on Hitchcocks site you will
> can see that older british design originally came with a twin rollered
> timing bearing ;)
>


Yes, I know Ric, and Allan mentioned this also in our conversation,
but I cannot remember what he said concerning the old redditch
arrangement. But still said it simply wasnt needed in the case of the
612, and theres no history of problems to suggest he's wrong. So it's
a mystery to me.

Malc.

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: strengthening the crankcase

Royalenfield
In reply to this post by John R-5
Strengthening case is one thing, making new crank shafts end of a known
and superior grade of steel from the std item is another matter.
Bottom line is that the 1" shafs, cast iron flywheels, and high rpm,
are not conducesive to long life. And if you retain a big end based on
the std crank pin some serious heat treatment is needed to prevent
excesive flexiture.
A lot of engineering and a lot of reworking.


Tim
N.Z.

--- In [hidden email], "jsrhk" <jsrhk@...> wrote:
>
> Has anyone done a big bore conversion to their Bullet more than 612cc?
>  I know there is an upgrade "kit" for 650 or even 750 but the process
> requires the crankcase to be strengthened.  I want to ask whether
> anyone out there has done this process and if yes, what does it
> entail, how are the cases strengthened?  The crankcases need
> strengthening in order to hold a larger bearing (on timing side?).
> Trying to search through the database brought nought.
>


Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: strengthening the crankcase

John R-5
This flexiture terminology.....does that refer to the flexing of the
crankcase sides? Or is there something else flexing?  

I have seen the Tollgate Classics website but as I'm a bit of a numpty
when it comes to detailed mechanicalising it don't make much sense to
me.  My professional bike mechanic friend would be doing all the
serious bits on it.  I think they suggest an all new crank pin?  

I did actually phone them up but as I couldn't get too grips all that
well with what was being said at the other end of the phone I sort of
politely said "OK, I'll get back to you on that one".....ahem...

I still want to have a good look at this project though.  I know
Hitchcocks do their own big bore upgrade but just wanted to see what
ele lies beyond 612cc.  


--- In [hidden email], "Tim" <royalenfield@...> wrote:

>
> Strengthening case is one thing, making new crank shafts end of a known
> and superior grade of steel from the std item is another matter.
> Bottom line is that the 1" shafs, cast iron flywheels, and high rpm,
> are not conducesive to long life. And if you retain a big end based on
> the std crank pin some serious heat treatment is needed to prevent
> excesive flexiture.
> A lot of engineering and a lot of reworking.
>
>
> Tim
> N.Z.
>
> --- In [hidden email], "jsrhk" <jsrhk@> wrote:
> >
> > Has anyone done a big bore conversion to their Bullet more than 612cc?
> >  I know there is an upgrade "kit" for 650 or even 750 but the process
> > requires the crankcase to be strengthened.  I want to ask whether
> > anyone out there has done this process and if yes, what does it
> > entail, how are the cases strengthened?  The crankcases need
> > strengthening in order to hold a larger bearing (on timing side?).
> > Trying to search through the database brought nought.
> >
>


Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: strengthening the crankcase

Royalenfield
For a Hi Comp 500/612+cc engine the  std crank pin is too small a
diameter, and its length (depth) of fit into the flywheels is too
short, and it is too loose a fit.
With the std spec crank pin in any Hot-Rod Bullet motor the crank pin
frets in the flywheels and eventually snaps.
Tim
N.Z.


--- In [hidden email], "jsrhk" <jsrhk@...> wrote:
>
> This flexiture terminology.....does that refer to the flexing of the
> crankcase sides? Or is there something else flexing?  
>
> I have seen the Tollgate Classics website but as I'm a bit of a
numpty
> when it comes to detailed mechanicalising it don't make much sense
to
> me.  My professional bike mechanic friend would be doing all the
> serious bits on it.  I think they suggest an all new crank pin?  
>
> I did actually phone them up but as I couldn't get too grips all
that
> well with what was being said at the other end of the phone I sort
of

> politely said "OK, I'll get back to you on that one".....ahem...
>
> I still want to have a good look at this project though.  I know
> Hitchcocks do their own big bore upgrade but just wanted to see what
> ele lies beyond 612cc.  
>
>
> --- In [hidden email], "Tim" <royalenfield@> wrote:
> >
> > Strengthening case is one thing, making new crank shafts end of a
known
> > and superior grade of steel from the std item is another matter.
> > Bottom line is that the 1" shafs, cast iron flywheels, and high
rpm,
> > are not conducesive to long life. And if you retain a big end
based on
> > the std crank pin some serious heat treatment is needed to
prevent

> > excesive flexiture.
> > A lot of engineering and a lot of reworking.
> >
> >
> > Tim
> > N.Z.
> >
> > --- In [hidden email], "jsrhk" <jsrhk@> wrote:
> > >
> > > Has anyone done a big bore conversion to their Bullet more than
612cc?
> > >  I know there is an upgrade "kit" for 650 or even 750 but the
process
> > > requires the crankcase to be strengthened.  I want to ask
whether
> > > anyone out there has done this process and if yes, what does it
> > > entail, how are the cases strengthened?  The crankcases need
> > > strengthening in order to hold a larger bearing (on timing
side?).
> > > Trying to search through the database brought nought.
> > >
> >
>


Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: strengthening the crankcase

John R-5
OK, thanks Tim.  Now I'm clear on that.  Hopefully there'll be
something to report at the end of '09.
best rgds,
John

--- In [hidden email], "Tim" <royalenfield@...> wrote:

>
> For a Hi Comp 500/612+cc engine the  std crank pin is too small a
> diameter, and its length (depth) of fit into the flywheels is too
> short, and it is too loose a fit.
> With the std spec crank pin in any Hot-Rod Bullet motor the crank pin
> frets in the flywheels and eventually snaps.
> Tim
> N.Z.
>
>
> --- In [hidden email], "jsrhk" <jsrhk@> wrote:
> >
> > This flexiture terminology.....does that refer to the flexing of the
> > crankcase sides? Or is there something else flexing?  
> >
> > I have seen the Tollgate Classics website but as I'm a bit of a
> numpty
> > when it comes to detailed mechanicalising it don't make much sense
> to
> > me.  My professional bike mechanic friend would be doing all the
> > serious bits on it.  I think they suggest an all new crank pin?  
> >
> > I did actually phone them up but as I couldn't get too grips all
> that
> > well with what was being said at the other end of the phone I sort
> of
> > politely said "OK, I'll get back to you on that one".....ahem...
> >
> > I still want to have a good look at this project though.  I know
> > Hitchcocks do their own big bore upgrade but just wanted to see what
> > ele lies beyond 612cc.  
> >
> >
> > --- In [hidden email], "Tim" <royalenfield@> wrote:
> > >
> > > Strengthening case is one thing, making new crank shafts end of a
> known
> > > and superior grade of steel from the std item is another matter.
> > > Bottom line is that the 1" shafs, cast iron flywheels, and high
> rpm,
> > > are not conducesive to long life. And if you retain a big end
> based on
> > > the std crank pin some serious heat treatment is needed to
> prevent
> > > excesive flexiture.
> > > A lot of engineering and a lot of reworking.
> > >
> > >
> > > Tim
> > > N.Z.
> > >
> > > --- In [hidden email], "jsrhk" <jsrhk@> wrote:
> > > >
> > > > Has anyone done a big bore conversion to their Bullet more than
> 612cc?
> > > >  I know there is an upgrade "kit" for 650 or even 750 but the
> process
> > > > requires the crankcase to be strengthened.  I want to ask
> whether
> > > > anyone out there has done this process and if yes, what does it
> > > > entail, how are the cases strengthened?  The crankcases need
> > > > strengthening in order to hold a larger bearing (on timing
> side?).
> > > > Trying to search through the database brought nought.
> > > >
> > >
> >
>


Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: strengthening the crankcase

mercendarian
In reply to this post by hmrdimali
Dear "Mates" (--as in, Me-Matey, Arr, Arr...) Some dealership DID a 735cc Bullet, with little more than larger parts, and blue-printing of the same.  I haven't heard any more of this, so I suspect it "broke" spectacularly.  Why aren't STEEL flywheels used?  What's this about "cast iron" which is ancient technology!  I understand the design is Old, old, circa 1955, and those were the times when everyone and his British brother "fiddled"(and faddled), burning the ole whale oil to fix their ride for the work-shift on the morrow.  Occasionally, a wee bit of single-malt was downed in discrete quantities.   I HOPE to see the additive (3-D) printing industry, "print" OHC-Nortons or G-50 Matchless engines to slap under custom frames, done in stainless & Titanium substrates fused-together with lasers.   Actually, I can't see why the KSS Velocette of '38 isn't copied, also, because I personally believe most of the DNFs were due to lackidasicale metalurgy of the 30s.   Did you realize, an OHC Norton that never existed can be MADE, simply from blueprints accessible to the 3-D printer?   Need a larger shaft diameter to stave-off fly-wheel galling & failure?  draw it into the blueprints which are scanned into some CAD-program, and, bingo, new larger shaft, even though it might NEVER have been done that way before...  I think a RE Bullet should be a 750cc, have DOHC, with the engine alloy with a 6-spd Quaif behind the faceplate of the Burman.  certain parts should be constructed such that they are "set & nearly forget" for 100K miles or two.  The 750cc bullet doesn't have to rev highly, but it should get 50mpg, have 75-80hp, and an all-day, 80mph cruise.  And if you consider 3-D printing "not-doable", cut a Bullet engine down from a forged block of titanium, so you have a "billet-Bullet"
hmrdimali wrote
--- In royalenfield@yahoogroups.com, "jsrhk" <jsrhk@...> wrote:
>
> Has anyone done a big bore conversion to their Bullet more than 612cc?
>  I know there is an upgrade "kit" for 650 or even 750 but the process
> requires the crankcase to be strengthened.  I want to ask whether
> anyone out there has done this process and if yes, what does it
> entail, how are the cases strengthened?  The crankcases need
> strengthening in order to hold a larger bearing (on timing side?).
> Trying to search through the database brought nought.
>

Perhaps you can try these guys
http://www.tollgateclassics.co.uk/500cctune.htm

HMR
Mumbai
Loading...