hiya all - I've just had a thought.... the few times I've put a cam into a motor, I've used a dial indicator and adjustable gears to get the cam timing where I want it, rather than just lining up the dots on the gears.... but I'm curious

my question is:

what are the symptoms of an incorrectly timed cam - specifically for a retarded cam - other than lower than expected power, might it overheat at high rpm in 4th gear (above 70kph)? what else?

as an aside, I think the cam in my current motor may be over advanced a little, as it is louder than normal, and has a distinct crackle and the exhaust comes out of the pipe faster (more pressure) than I'd expect - making me think that the combustion is still happening/expanding as the valve opens - not a big deal - my real question is above

In general terms slight cam advance gives more torque, slight retard gives more top end. With most cams.
But, going a whole tooth out is too far. That's 18* at crank.

I've been told some timing chain sets were made with about 10* retard, for emission purposes.
Another reason for checking cam timing during installation..... don't just line the dots up.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Where do you get the dial thingy ? what do they cost? are there different ones around and is one any better (ease of use etc) than another?

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David L


My greatest fear in life is that when I die my wife will sell my Mini and tools for the price I told her I paid for them!

Got mine here- http://www.hareandforbes.com.au/sample_2/home.php
Click on metal working catalog

Mag base is $38
Dial gauge 2" dia, 0-1" travel (.001" steps) is$38.

There is also a Metric one for the Imperially Challenged, but it does not have enough travel- only 10mm.


<edit>
Of course, you can spend more on Bling ones elsewhere- eg buy Starrett, Moore and Wright, Mitutoyo etc- but for most things on a car the cheapies are fine.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

No I meant the big clock face dial thingy with degrees marked on it that goes on the crank pully to line up the timing - I have a magnetic dial gauge.

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David L


My greatest fear in life is that when I die my wife will sell my Mini and tools for the price I told her I paid for them!

Try a speed shop.
That's where I got mine years ago, it's a Yankee one.

Kent Cams sell them too.

<edit> so do Crow Cams- http://www.crowcams.com.au/Products.shtml

There is a drawing of one on the web somewhere, Benjamin just printed that and made his own.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Thanks for the heads up - did a Google and found this

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David L


My greatest fear in life is that when I die my wife will sell my Mini and tools for the price I told her I paid for them!

Buy some spray glue from a craft shop ($??) and some 3mm MDF from Bunnings (about $3.00)

Spray glue on MDF, add printed wheel, cut with jigsaw ($14.99) and drill hole, beauty mate.

Daniel

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Videos - Turbocharged A-Series on Dyno & at Wakefield
Mafs waz not my strong subgeckt at skkol

I printed it on A4 then ran it through the A3 enlarger photocopier and got it 41% bigger

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David L


My greatest fear in life is that when I die my wife will sell my Mini and tools for the price I told her I paid for them!