Author Topic: B44 motor rebuild, advice wanted  (Read 8489 times)

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Offline FourstrokeForever

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B44 motor rebuild, advice wanted
« on: October 25, 2013, 08:59:12 pm »
I'm in the process of rebuilding my B44 and am now working on the motor and was wondering if it will be worth the effort and $$ to put a B50MX cam in with the standard bore.
A couple of questions come to mind, seeing as I'm no expert with a bike that is nearly my age! I did a full rebuild on my B50 without any dramas so I know what I'm doing with the spanners but as for getting more out of the little 441, I'm clueless. And looking at the prices of the go fast suppliers, I want to stay within a meager budget.

Will I need different length pushrods if I put in the B50 cam? Is the cam wheel the same number of teeth? Is it worth putting B50 gear ratios in? What is the biggest piston that can be used in the standard liner?

I know there are 500cc options available but that's an expense that I don't particularly need at the moment.

Any help/advice will be much appreciated.

Cheers, Mark
Arrogance.....A way of life for the those that having nothing further to learn.

Offline matcho mick

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Re: B44 motor rebuild, advice wanted
« Reply #1 on: October 25, 2013, 10:09:19 pm »
my B44 motors on the bench in a gazillion pieces,replacing all bearings/seals etc,the usual stuff,be interested in what ifs too, :P
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Offline geoff

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Re: B44 motor rebuild, advice wanted
« Reply #2 on: October 25, 2013, 10:59:37 pm »


  Mark Cook in the UK does a suitable cam for the BSA B44 called a joy cam. It's supposed to give more mid range than the BSA B50 CAM.
      Also Terry Weedy again in the UK does a similar cam along with lots of other spares suitable for the BSA models. Both have web sites and both are good to deal with.

Offline bazza

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Re: B44 motor rebuild, advice wanted
« Reply #3 on: October 26, 2013, 07:51:21 am »
My b44 was given to me by an older guy who raced at the pointy end of the field and raced north / south meetings,it has b50 cam and its a nice power delivery.
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Maico - B44 -1976 CR250- 66 Mustang YZF450,RM250
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Offline FourstrokeForever

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Re: B44 motor rebuild, advice wanted
« Reply #4 on: October 26, 2013, 08:31:49 am »
my B44 motors on the bench in a gazillion pieces,replacing all bearings/seals etc,the usual stuff,be interested in what ifs too, :P

I've got the crank cases back together with the rebuilt crank in place. I'm rebuilding the oil pump today, which I recommend highly as mine was packed full of sludge! and then it's "what to do" time.  I suppose I could get the mower going and do my feral yard......

I did have a look at Mark Cooks cams but I have been told that the standard B50MX cam was the best to use in the B50 so I figure it should be good for the 441 as well  :-\

I got all my clutch bits for the b50 from Mark and ordered the same for the B44 while I was at it.  I just need to find what box I put it in..... And yes, he is great to deal with. The problem with looking at Mark's site is the possibilities and the money required...
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Offline big mac

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Re: B44 motor rebuild, advice wanted
« Reply #5 on: October 28, 2013, 11:46:32 am »
The b44 gp cam & the b50 mx cams have the same valve timing the only thing to stop it going in is the                                 size of the bearing at the back early b44's had a small bush b50 is larger.

Offline FourstrokeForever

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Re: B44 motor rebuild, advice wanted
« Reply #6 on: October 29, 2013, 09:44:04 am »
The b44 gp cam & the b50 mx cams have the same valve timing the only thing to stop it going in is the                                 size of the bearing at the back early b44's had a small bush b50 is larger.

Thanks for that big mac. I discovered that on sunday and as luck would have it I found a NOS GP cam in among all the boxes of parts I got years ago. Happy days  ;D

Is there any internal difference between the early b44 and the later b44 when it comes to webbing etc inside the cases?
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Offline grouty

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Re: B44 motor rebuild, advice wanted
« Reply #7 on: October 29, 2013, 11:02:23 am »
Mark, if you have not yet found it, have a look at www.b50.org Go to the forum and do a search. There is more information on there than you can wave a sludge trap at.
Yes, Mark Cook is great to deal with and a vast source of knowledge. I use his billet clutch and 3 speed box. Stunning ! (as well as his engines)
Over the years I have learnt that despite what I may think, the bugger is always right. So now I just keep quiet and take the advise.
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Offline FourstrokeForever

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Re: B44 motor rebuild, advice wanted
« Reply #8 on: October 30, 2013, 08:31:33 am »
Thanks Grouty. I have had a squiz at the b50 forum. Yep, heaps of info but that's part of the problem.....too much info for the space between my ears  ;D

Id love to have the 3 speed set up for both my B50 and the B44 but I have to do with what I have for now.. Too many bikes and not enough money to make them all exactly as I'd like them. I built an XL410 (pre78) and a MT/CR Elsinore hybrid earlier in the year so they took a fair chunk out of my fun tickets. I had a spare early B44 motor that has a new crank and bearings etc so I'm rebuilding it to get the bike running. Then I'll rebuild the original motor with all the fruit. Time to start saving for the bits I want for the pommy bikes....
Arrogance.....A way of life for the those that having nothing further to learn.

Offline cloggy

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Re: B44 motor rebuild, advice wanted
« Reply #9 on: November 02, 2013, 06:21:21 am »
  Yeh I met Mark and quizzed him about oil. Had to pin him down as he didn't like to badmouth companies but the only one he was confidant with was Morris. When I mentioned Amsoil he wondered if it had clutch slipping additives. I found that my clutch stopped slipping when I used it
 The joy cam will likely be one of Phil Joy's. He workmanship is first class

Offline grouty

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Re: B44 motor rebuild, advice wanted
« Reply #10 on: November 02, 2013, 10:21:25 am »
Ahh, the old oil debate !
I will only / have only used genuine Castrol R40 in the CCM. The KLX gets Castrol Actevo stuff. Only because I cannot locate some Shell Rotella T here in the UK.
Mark is an advocate of castor oils in the BSA/CCM motors because they run very hot. I do go with him on that.
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Offline FourstrokeForever

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Re: B44 motor rebuild, advice wanted
« Reply #11 on: November 04, 2013, 09:34:54 am »
"Oils aint oils Sol" .... I have also been told that the beezas like castor oils. Something about less foaming in the crank case when hot  ??? I've never seen any castor oil in Australia. Maybe I'm not looking hard enough. I was also told that if you switch from a normal to a castor based oil, everything needs to be thoroughly flushed or contamination will occur? Myself, I use Penrite MC mineral oil that has extra zinc in it. I stay well clear of any synthetic oils. Any engine will benefit from oil with zinc in it as the zinc helps in hardening. Be warned though, not ALL mineral oils have zinc in them these days. It pays to read the container before using it.
Arrogance.....A way of life for the those that having nothing further to learn.

Offline sprint76

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Re: B44 motor rebuild, advice wanted
« Reply #12 on: November 21, 2013, 06:33:22 pm »
I've been running shell M all year in my motor and clutch. But do use a mineral oil in the gear box which is a heavier grade. As for cams I have one by Tighe cams in Qld and it is a stump puller! Mark Cook has been invaluable and the clutch he sold me is just fantastic.  I highly recommend Mark not only for the parts he sells but also for his advice in decision making. Steve.