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 Post subject: Camshafts
PostPosted: Sun Jan 15, 2017 4:49 pm 
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Joined: Tue May 06, 2014 6:59 pm
Posts: 14
I have at the moment NCR camshafts in my engine, would like to go back to original camshafts since the bike is used on the street only and I have no intends to race the bike.
Where can I get OEM camshafts from, looked all over the place but so far only bevelheaven seems to have the front camshaft, couldn't find the rear camshaft (might call them in the next days and see whether they can locate one). If someone has used ones please let me know, happy to take them of your hand!
What else would I need when replacing the NCR camshafts?
- Juergen


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 Post subject: Re: Camshafts
PostPosted: Mon Jan 16, 2017 10:14 am 
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Joined: Mon Oct 04, 2010 7:47 am
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Hi Juergen,

Not sure actually which motor/cylinder heads you have but you can use later stock Ducati two-valve cams in the older motors. For a good street motor I would suggest two 92-97 HORIZONTAL Ducati 900 SS cams from a carb SS bike. These cams will bolt in. You'll still want to check valve to valve and valve to piston since I don't know that you have now and you HAVE to degree the vertical cam as the keyway location is in the wrong location for the vertical head. For race motors a lot of us run the HORIZONTAL fuel injection 900 cams. Good luck.

Palmer


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 Post subject: Re: Camshafts
PostPosted: Mon Jan 16, 2017 11:25 am 
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Joined: Tue Mar 18, 2014 10:03 am
Posts: 360
Mr. Palmer...
When you say degree the vertical camshaft,(for the 900ss cams) does that mean adjustable cam pulleys?
Regards...
Flattop


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 Post subject: Re: Camshafts
PostPosted: Mon Jan 16, 2017 1:35 pm 
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Hi Palmer -
Thanks for the info, will try to find two horizontal 900 SS cams from a 92 - 97 (if someone here has some please let me know, happy to take them off your hands!). I have a the moment Ferraci forged pistons with the proper clearances. The heads were ported and flowed with 1mm larger valves installed. What do you mean with "HAVE to degree the vertical cam"?
- Juergen


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 Post subject: Re: Camshafts
PostPosted: Mon Jan 16, 2017 2:31 pm 
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Joined: Tue May 06, 2014 6:59 pm
Posts: 14
I also found the following at bevelheaven, would that work in case I can't find used 900SS cams?
Vertical/Rear: https://store.bevelheaven.com/Engine-Re ... -750-Paso/
Horizontal/Front: https://store.bevelheaven.com/Engine-Re ... ont-750F1/
- Juergen


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 Post subject: Re: Camshafts
PostPosted: Mon Jan 16, 2017 3:59 pm 
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Joined: Thu Oct 14, 2010 11:23 am
Posts: 1802
NO. The V (rear) Paso cam will not work on your F1 --- if that is what you have! That is the backwards head!

What engine do you have?


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 Post subject: Re: Camshafts
PostPosted: Mon Jan 16, 2017 6:33 pm 
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Joined: Mon Oct 04, 2010 7:47 am
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Flattop,

You can use adjustable pulleys or offset keys for the cam pulleys. My personal preference is offset keys and then once everything is degreed in using a drill bit to mark the pulley if I'm running the top rubber belt cover and a dot of paint or putting a drill mark in both the pulley and head where they line up and using a dot of paint. Make life easy when changing belts or pulling the head.

Palmer


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 Post subject: Re: Camshafts
PostPosted: Mon Jan 16, 2017 11:15 pm 
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618F1 wrote:
NO. The V (rear) Paso cam will not work on your F1 --- if that is what you have! That is the backwards head!

What engine do you have?


1986 F1 B with original engine. Based on my parts manual the cams are 0359.29.020 for the horizontal camshaft and 0675.29.010 for the vertical camshaft. The number at bevelheaven for the front camshaft is 0370.29.020 which is not what I have in my parts manual, therefore the confusion on what I need. I checked today a couple of sites but it looks like the 900 SS camshafts are nearly equally rare as the original 750 F1 camshafts.


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 Post subject: Re: Camshafts
PostPosted: Tue Jan 17, 2017 10:29 am 
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Posts: 360
Mr. Palmer....
So the slot is close enough to use offset keys. I was thinking the slot was was so far out as to be out of their range. Would you recommend a place to get "quality" keys? I don't think that the subject of the key slot, being out of position has ever been mentioned before, concerning the use of the 900SS cams. Good info.
Thank you...
Flattop


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 Post subject: Re: Camshafts
PostPosted: Tue Jan 17, 2017 12:58 pm 
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Joined: Thu Oct 14, 2010 11:23 am
Posts: 1802
Morning flattop. No, the cam cog for the V head (using any reverse-head H cam, like a 900) is about 160 degrees off after it is installed on the cam with a key. If the mark on that cam cog is used for belt installation that is a disaster waiting. 160 degrees is eight notches on the cog, so as a Start Point that mark must be moved forward, as the cog turns counter-clockwise. Either count eight including the existing mark, or count seven notches out from the original dot. Using that new mark, you should also see that the V intake valve is just a smidgen from full opening---one more notch turn and it will start to close, when the H cam is at TDC. You can eye-test that looking thru the plug hole, and by flipping the head over on the bench to see it. I also did a first installtion with no pistons installed. Look at this when belts are installed and the timing marks are aligned at the H head and on the clutch cover. Also good to find TDC for the V head, but that is harder to describe here: you can add a mark just below the front 6mm hole for the rubber belt cover. Once the V cam is that close then offset keys or adjustable cogs can be used; can anyone say ..... Carlo Leoncini? I like the new adjustable cogs because they are light, and pretty, and those dinky offset keys aren't cheap.

Anyway that method worked on F1 heads on the LS clone with 900ss cams set at 109 degees on center, and on a set of Pantah heads that Carlo put 35 & 41mm valves in.

Now others can correct me. One person said the that the H 900 cam is 180 degrees off, but that is not what I found. I have also read about the Ducati firing sequence, but that just twisted my eyeballs and my brain, so I used the redneck methods above. Whatever you do please be sure and confident about the opening and closing of the replacement V cam, and that when the belts are installed both cam/valve actions mimic the original sequence.

MikeV

PS: I should not use my I pad and a stylus to type this in the morning with only one cup of coffee. Forgive the typos, please.

Another PS: I think when Palmer says punching marks he means the dots that the racers and NCR put on the heads to replace those removed if the rubber plates are not installed. They show up in all kinds of photos of the vintage bikes --- and Palmer's engines --- I guess. I also use blue on the H head and red on the V head, and also mark the timing shaft cog the same. Plus I mark the V head TDC on the latter.

This was modified/embelished on Sept 20, 2023. MV


Last edited by 618F1 on Wed Sep 20, 2023 10:32 am, edited 7 times in total.

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