Author Topic: Adjustment Valves  (Read 1817 times)

Offline renos-a10

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Adjustment Valves
« on: 05.02. 2012 13:44 »
Hi to all,
 If you change the camshaft from 356 to 357 what happen with valves?
The bike is a10 swing arm 1960 and the engine 1961.
Also i replace the camshaft with 357.I bought from SRM . I adjust Inlet 0.10 and exhust 0.10 but make noise.
If i make the inlet 0.08 stop noise?
Advice?

Thanks
Renos
1954 BSA A10 Plunger
Cyprus

Online muskrat

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Re: Adjustment Valves
« Reply #1 on: 06.02. 2012 09:23 »
 G'day Renos,
                  I don't think they ever put 357 cams in iron head motors. 8 on the inlet should be fine and 10 or 12 on the exhaust. You will know if its too tight the first time you get it really hot, she will run like poo.
 Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline renos-a10

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Re: Adjustment Valves
« Reply #2 on: 06.02. 2012 11:52 »
hi muskrat ,

 Thanks for your reply. I don't know if they put 357 cams in iron head but i bought my A10 from England and when i release the engine has camshaft 357.So i order from SRM the same.
  Thanks for your help again and i will come back to inform you.
Renos
1954 BSA A10 Plunger
Cyprus

Offline TT John

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Re: Adjustment Valves
« Reply #3 on: 06.02. 2012 14:59 »
Renos.
Why are you adjusting the tappets to 10 & 10? the correct setting is for your bike is 10 & 16 , closing the tappet settings does not make it quieter, you only get more problems. I know that in the books it is quite confusing sometimes with the different settings for different years.
Kind regards TTJohn *smile*

Offline emilios

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Re: Adjustment Valves
« Reply #4 on: 06.02. 2012 15:14 »
Hi TTjohn
I dont think that 67-357 cam need 16thou exsaust clearance..
I think only the 67-334 cam need 10 inlet and 16 exsaust clearance between 55-59 years both A7 and A10
But i would like to know if a 357cam on iron head A10 could cause any problem..
By the way, Renos is my big brother...we are 2 of 5 person in Cyprus that we have A10..
1956 BSA A10 Plunger
1954 BSA B31 Goldstar Replica
1970 Honda cb750K0 project
Cyprus

Offline Topdad

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Re: Adjustment Valves
« Reply #5 on: 06.02. 2012 16:23 »
Hi Emilios and everyone, if the 357 cam is the " sports cam" then I can say that they work with an iron head ,whenrebuilding my engine I used SRM to do most of the engineering work, iwanted an alloy head but wouldn't wait so they fitted super rocket valves and supplied a superrocket cam, they insisted that I change the followers but that was all ,so far nearly 10 yrs on no probs at all and still runs sweet and clear ,tremendous low down grunt ( for me ) I'm sure i used standard settings when doing the tappets. regards BobH
" rules are made for the guidance of wise men and the blind obediance of fools"
United Kingdom

Offline TT John

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Re: Adjustment Valves
« Reply #6 on: 06.02. 2012 16:56 »
Emilos. I really don't think that the difference between a 356 & a 357 cam makes when setting the tappet clearance. I have a 357 cam on my plunger & I use the original settings with no problem or noise.
BTW I was stationed in Cyprus in 1964-65 on Nicosia airport with the U.N. I think its most likely changed a bit since then.

Kind regards TTJohn

Online Brian

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Re: Adjustment Valves
« Reply #7 on: 06.02. 2012 23:34 »
My 61' has a iron head with 357 cam and I run .008" inlet and .010" exhaust with no problems.

Offline renos-a10

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Re: Adjustment Valves
« Reply #8 on: 07.02. 2012 06:34 »
Hi to all ,
 Thanks all for reply. Another question. If i will use .006 & .008 for exhaust may be have any problem?

Renos
1954 BSA A10 Plunger
Cyprus

Offline TT John

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Re: Adjustment Valves
« Reply #9 on: 07.02. 2012 10:40 »
Renos.
Yes, indeed you could have problems, you could damage the push rods, with the heat expansion rate, in my opinion its just not worth it, the factory put these tappet settings down for a reason and the reason usually is for the best running conditions without damaging anything elae in the engine.

Regards TTJohn

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Re: Adjustment Valves
« Reply #10 on: 07.02. 2012 12:18 »
 I agree, no less than 10 thou on the exhaust. That's why racing clearances are greater, to compensate for the motor running hotter. As the motor gets hotter the clearance gets less, and if not enough when cold the valve will be propped open a tad when hot.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline renos-a10

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Re: Adjustment Valves
« Reply #11 on: 07.02. 2012 13:53 »
Hi again ,
 
  Thanks everyone for advices.I will check the clearance beacuse i think it's not ok .
I will back again .
Thank
Renos
1954 BSA A10 Plunger
Cyprus

Offline renos-a10

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Re: Adjustment Valves
« Reply #12 on: 12.02. 2012 16:32 »
Hi again to all,

 I adjusted the valve ( the space is to big .023 inlet and 0.22 exhust ) I make inlet .008 and exhust .010.
Now its ok.

Thanks all for your advice.
1954 BSA A10 Plunger
Cyprus