Assembling camshaft

michipons

michipons

Hero member
Location
Palma de Mallorca
Hi!

I am mounting the 750 camshaft. After several tries, I reached the conclusion that the "correct" (may be) way to do it was to assembly all together outside, camshaft, bearings and flanges and then introduce them in the cylinder head and screw everything to the timing sprocket. I still don't have 100% clear, how should I position the key. Should I put it in one of the two halves like in the photo? The problem is then, that is difficult to do the same with the other flange, because the key slots get misalign when pressing the flange as it doesn't have a guide (key) to slide in. I have to tap all the parts quite hard as they don't slide easily to make things more complicated, making it impossible to realign the flange to match the key slot in the side that doesn't have it. The key is also very hard to slide, I don't know if it has to be that way or is because is a bit wear and should slide smooth... Anyway, I thing I would manage to assembly everything at the end, but if somebody could tell me if I am doing something wrong before I do something without return....?

I also wanted to change the nuts of the time sprocket, but they are 6mm for a 9mm wrench! The standard 6mm nut is for a 10mm wrench, which does not fit as is impossible to use a ring wrench to torque it properly.. any ideas there? I remember we talked in another topic about changing those nuts and washers, but now I don't see how, I think is not easy to find those non standard nuts...

Regards and thank you for your help as allways!
Miguel.

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The flange MUST be a very tight interference fit onto the cam. See the recent discussion regarding updates for longevity for an SF2, this is covered in detail. You can get new nuts, studs and the correct washers from among others OCT and it is worth doing this if yours are in poor condition (I can't tell from the picture) and use a good 9mm ring spanner.
https://www.laverdaforum.com/forum/index.php/topic,100654.0.html
The bearings (must be C3 bearings) and flanges are pressed onto the cam with the key in one side. Fit the studs (with nuts and washers on one side) on one side of the cam prior to installation. Warm the head enough that it you can still handle it with bare hands and the bearings will easily fit into place while you hold the sprocket in position. I have never had a problem gently tapping the keyway in and seating the two cam halves simply by holding one cam half and gently tapping the other with my plastic hammer, then bring it home with the studs. That same thread also points out that the surfaces on the flanges and sprocket are what holds the two cam halves in place, the keyway will shear very quickly if these surfaces are not properly mated. (in my 270 motor the key does not go through the sprocket at all). Heat the head the same for fitting your rocker arm spindles when you get to that point.
 
Much easier, if you cut the key in halves.
Advice by Piet, much appreciated.

Heat the head the same for fitting your rocker arm spindles when you get to that point.
Click to expand...
Works well with coolant spray into the spindle, too.

Ernesto
 
hi!

Thanks for all your advices, finally I didn't but the key, I didn't have spare keys, so I preferred not to take the risk.

I assembled both halves with the sprocket out of the engine, using the key to align the flanges with the shaft, thereafter disassembled both halves from the sprocket and then installed everything in the cylinder head. I put the head in the oven like 30/45 minutes at 90 degrees (wife looking at me like I became crazy) and the two halves in the freezer. It came all in just with the hand. I finally approached the flanges with the nuts that are a bit wear from the disassembling.

I am considering to change the nuts, but still not sure what sort of wrench to use to tighten them, I limed a ring wrench to make it thinner but still just holds the nuts form the corners so is not optimum for a good torque, I was thinking to use a hydraulic nut wrench and lime it as well...

Now that I finally understand the article from Laverdamania about the modifications to be able to adjust the cam timing, I will look for a spare cylinder head to try it. Wish me luck. ::)

Regards,
Miguel

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They are not normal spring washers, but are what I would call a serrated washer. They came original and I reckon are ok if they re in-tact and not misshapen, as often they are split or come off broken in pieces. Piet uses (and supplies) schnorr washers and I agree with him that they are ideal.
Good job getting the head assembled. I hope your flanges needed a hydraulic press to fit onto the cam.
 
Tippie said:
They are not normal spring washers, but are what I would call a serrated washer. They came original and I reckon are ok if they re in-tact and not misshapen, as often they are split or come off broken in pieces. Piet uses (and supplies) schnorr washers and I agree with him that they are ideal.
Good job getting the head assembled. I hope your flanges needed a hydraulic press to fit onto the cam.
Click to expand...

Hi Tippie

That would have been ideal... after this I thought about buying a small hidraulic press🤔...
I did the trick oven/freezer and a few taps with an adaptor and a heavy hammer in orden not to hit sensible parts, it came in but not without suffer and sweat😅.
Miguel
 
michipons said:
Hi Tippie

That would have been ideal... after this I thought about buying a small hidraulic press🤔...
I did the trick oven/freezer and a few taps with an adaptor and a heavy hammer in orden not to hit sensible parts, it came in but not without suffer and sweat😅.
Miguel
Click to expand...

That's one way of inventing a hydraulic press! Really should have been done with a workshop press, but if you're happy they went together without scoring the mating surface it is hopefully ok. I would definitely prefer to see Schnoor washers on the studs (but I have reused the serrated washers due to necessity and when they were pristine, as Tippie said) - two good quality 9mm open enders is all you need if the nuts are in good nick (ie not rounded at all).
 
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