Lotus Elan

Adjustable Cam Sprockets

PostPost by: types26/36 » Tue Nov 07, 2023 3:59 pm

What is the consensus on the use of an alloy or a steel centre boss on adjustable cam sprockets?
Both are available from the usual suppliers, is there an advantage/disadvantage to the use of either?
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PostPost by: Hawksfield » Tue Nov 07, 2023 5:29 pm

Hi
Colin would have picked the alloy

John :P
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PostPost by: types26/36 » Tue Nov 07, 2023 5:38 pm

Hawksfield wrote:Hi
Colin would have picked the alloy john :P


You could be right there :roll:
Last edited by types26/36 on Tue Nov 07, 2023 6:21 pm, edited 1 time in total.
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PostPost by: Donels » Tue Nov 07, 2023 6:01 pm

Alloy will use less rotational energy, important if you're after every gram of weight saving for racing. Steel would be stronger. For road use you won't know the difference.
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PostPost by: Fred Talmadge » Tue Nov 07, 2023 10:28 pm

If you are dialing in your camshaft then your choices are to machine offset keys or use an adjustable sprocket. If you are just going to "line up the dots" then it's an extra expense for nothing.
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PostPost by: englishmaninwales » Tue Nov 07, 2023 11:24 pm

Fred Talmadge wrote:If you are dialing in your camshaft then your choices are to machine offset keys or use an adjustable sprocket. If you are just going to "line up the dots" then it's an extra expense for nothing.


Fred, I think the OP is asking about the merit of aluminium v steel construction of the adjustable timing sprockets rather than their value over other methods of setting the valve timing.
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PostPost by: types26/36 » Wed Nov 08, 2023 9:17 am

Fred Talmadge wrote:If you are dialing in your camshaft then your choices are to machine offset keys or use an adjustable sprocket. If you are just going to "line up the dots" then it's an extra expense for nothing.


Fred, Malcolm is correct, I’m fully aware of the off-set dowels and have used them many times, I was inquiring about the pro’s & cons of using one type of adjustable sprocket versus the other.
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