Donut case vs non-donut case

Posted: Tue Aug 04, 2015 5:01 pm

Please, with pics, show the difference between a donut case and non-donut case (and for the smart asses, I am not talking about posting a pic of the actual donut Razz

). From what I understand, under the cylinder mating surface, there is supposedly extra ribbing / reinforcement, but can someone show pics of this difference, and any other difference noted?

Posted: Tue Aug 04, 2015 5:19 pm

I just happen to have been looking at that very thing this past weekend. Still have the donut and non-donut cases sitting out, I will try to remember to take some photos tonight.

Posted: Tue Aug 04, 2015 5:27 pm

djhurayt wrote:

I just happen to have been looking at that very thing this past weekend. Still have the donut and non-donut cases sitting out, I will try to remember to take some photos tonight.

Thanks, appreciate it ...

Posted: Tue Aug 04, 2015 5:33 pm

There was a good thread on this two or three months ago with pictures....

Posted: Tue Aug 04, 2015 5:34 pm

Wayne750F wrote:

There was a good thread on this two or three months ago with pictures....

I'm pretty good with searches .... but gave up after a few minutes.

Posted: Tue Aug 04, 2015 6:27 pm

When I get home on the 9th Darren I can take pictures for you or there's some on my JES BUILT Motorcycles Facebook page. Scroll through the pictures and you'll see them.

Posted: Tue Aug 04, 2015 6:46 pm

http://www.cb1100f.net/modules.php?name=Forums&file=viewtopic&t=78587&start=0&postdays=0&postorder=asc&highlight=case+differences

Posted: Tue Aug 04, 2015 6:48 pm

Wayne750F wrote:

http://www.cb1100f.net/modules.php?name=Forums&file=viewtopic&t=78587&start=0&postdays=0&postorder=asc&highlight=case+differences

I saw that, and it doesn't answer my question ... I want to see, specifically, the differences in the internal reinforcement under the cylinder mating surface between a donut and non-donut case.

Posted: Tue Aug 04, 2015 7:22 pm

Ahhhh I saw the internal sections somewhere too as I was looking for that too....it didn't specifically use the word donut in the thread...I'll try and remember a key word from it...problem is the rememberer doesn't work as good as it used too...

Posted: Tue Aug 04, 2015 8:19 pm

Didn't the captain post the pics? I remember seeing them and thats who I remember posting them. But I'm in the same boat as Wayne. .....What were we talking about?

Posted: Tue Aug 04, 2015 11:41 pm

like this ? pics 1 and 4 are donut cases 2 and 3 are not.

Don.

Posted: Wed Aug 05, 2015 12:28 am

Yea!!!! That's it!!!

Posted: Wed Aug 05, 2015 1:07 am

Not seeing it? I must not know what to look for?

Posted: Wed Aug 05, 2015 1:31 am

Perfect, thanks!

CB1100F Joined: Feb 17, 2009 Posts: 2105 Location: Oz

Hondo57 wrote:

Not seeing it? I must not know what to look for?

Posted: Wed Aug 05, 2015 3:42 am

Now that there is an understanding of exactly what "Donut" cases are and as can be seen in the pictures posted in this thread I can add a little more.

To date the general consensus and advice from others has maintained that the 750 "Donut" cases are the cases of choice, but there is a little more to this that could / should be considered when building a serious bigger capacity "Bullet"
Donut 750 cases are fine as is any other donut of any year, however IMO the best of all are the 1100F/R as in addition to what has been stated before and having the longer spiral wound cylinder studs, larger case opening for the cylinder sleeves, there are a couple of other small differences which put them in front of the rest.

1, The 3 case bolts directly behind the clutch and which clamp the cases between the bearings for the gear box input and output shafts and primary shaft are the larger 7mm verses 6mm
2, The breather pipe fitted to the cases situated in the same area is full size and slash cut where as all other models are restricted.

These are small things but they are positive improvements towards a stronger build.

Captain

Posted: Wed Aug 05, 2015 11:58 am

ya, what cnut posted, thanks, was gonna post this morning, but . . . , thanks

Posted: Wed Aug 05, 2015 4:05 pm

Ok, another question .... has anyone ever seen (aside from factory works racing pieces) cases that have the ribbing but no donut? Trying to figure something out for a friend ....

Posted: Wed Aug 05, 2015 5:33 pm

Those can now be called "T-bone" cases, from the looks of the extra webbing.

Posted: Wed Aug 05, 2015 9:32 pm

jtmillan wrote:

Those can now be called "T-bone" cases, from the looks of the extra webbing.

The "dougnut" that marks that extra strength is on the outside, so you dont have to pull one apart to know what it is.

Posted: Wed Aug 05, 2015 10:09 pm

That was a joke that kinda fell flat

CB1100F Joined: Feb 17, 2009 Posts: 2105 Location: Oz

Link

Posted: Wed Aug 05, 2015 11:28 pm

petrat wrote:

Ok, another question .... has anyone ever seen (aside from factory works racing pieces) cases that have the ribbing but no donut? Trying to figure something out for a friend ....

No, I don't remember because they are not an option, but if you ask Brian O'Shea (AKA Mr Superbike) he might be able to throw some light on this. If you don't have his contact details I'll sort it for you.

Captain

Posted: Wed Aug 05, 2015 11:38 pm

Captain wrote:

petrat wrote:

Ok, another question .... has anyone ever seen (aside from factory works racing pieces) cases that have the ribbing but no donut? Trying to figure something out for a friend ....

No, I don't remember because they are not an option, but if you ask Brian O'Shea (AKA Mr Superbike) he might be able to throw some light on this. If you don't have his contact details I'll sort it for you.

Captain

I do, and will forward him a message ....

One of your SPA companions has some factory works cases that have the internal reinforcements but no externally identifiable donut, and so the questions arises if Honda made these special run of cases for the teams .... I believe he has 3 without the donut, and 1 with ....

Posted: Wed Aug 05, 2015 11:42 pm

If he has some without the "Donut" then I'm fairly sure that they are RSC parts. I believe that they might even be heat treated as this was mentioned occasionally. But Brian will know more than me so it will be interesting what he has to say.

Captain

Posted: Thu Aug 06, 2015 3:48 pm

interesting info - thanks - i'll go looking next time I take my engine apart
notes of diffrence I recall with respect to what I presume are RSC cases - but may not be - the obvious diffrence I recall is Studs versus bolts for the main journals - copper washers and dome nuts on the bottom

Posted: Thu Aug 06, 2015 4:04 pm

That film clip was absolutely hilarious. Where in the hell did you find that?

Maybe I should use that now.

"....let's all meet at T-bone's for a beer after the ride..."

Kinda has a nice ring.

Of course, most of my buddies are regular smart-asses. I could see it rapidly degenerating into "bonehead".

Probably better left for the likes of George, on second thought.

Jim in Houston

Posted: Fri Aug 07, 2015 1:12 am

Captain wrote:

Now that there is an understanding of exactly what "Donut" cases are and as can be seen in the pictures posted in this thread I can add a little more.

To date the general consensus and advice from others has maintained that the 750 "Donut" cases are the cases of choice, but there is a little more to this that could / should be considered when building a serious bigger capacity "Bullet"
Donut 750 cases are fine as is any other donut of any year, however IMO the best of all are the 1100F/R as in addition to what has been stated before and having the longer spiral wound cylinder studs, larger case opening for the cylinder sleeves, there are a couple of other small differences which put them in front of the rest.

1, The 3 case bolts directly behind the clutch and which clamp the cases between the bearings for the gear box input and output shafts and primary shaft are the larger 7mm verses 6mm
2, The breather pipe fitted to the cases situated in the same area is full size and slash cut where as all other models are restricted.

These are small things but they are positive improvements towards a stronger build.

Captain

Also the 750 and CB1100R doughnuts case do not have the rubber engine mount provisions of the CB1100F cases.

CB1100F Joined: Feb 17, 2009 Posts: 2105 Location: Oz

stoutblock wrote:

Also the 750 and CB1100R doughnuts case do not have the rubber engine mount provisions of the CB1100F cases.

Nor does the Australian 900s prior to the FC.