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Author Topic: 8v advance/retard cam timing  (Read 4077 times)

Offline Craigwilson

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8v advance/retard cam timing
« on: 29 March 2014, 15:32 »
 okay as you may know I have a 270 cam in my 8v and baisically I had it set up about 15deg retarded and it ran perfect and it pulls like a train between 3k and 6k rpm but after a while it decided it wouldn't want to run well any more and it would take ages to start, so I put the timing back to tdc and perfect again just gives less top end.

also it started to misfire at just above 5k under load like an early rev limiter and as I moved the cam back to tdc it moved this misfire to about 5500 rpm,

could anyone shed some light on how to set the cam up properly
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Offline gazareth

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Re: 8v advance/retard cam timing
« Reply #1 on: 29 March 2014, 16:46 »
why do you think its the cam that's the problem? did you not have an issue with fuel getting into your oil? and did you sort this?
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Offline Craigwilson

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Re: 8v advance/retard cam timing
« Reply #2 on: 29 March 2014, 19:39 »
I don't think it's sorted my oil still has a smell of petrol but it's not as strong and the oils still clean, I was told it could also be related to the cam/ignition timing can't remember how he explained it tho
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Offline gazareth

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Re: 8v advance/retard cam timing
« Reply #3 on: 30 March 2014, 18:41 »
is the woodruff key in the end of the camshaft okay? if it is okay then I would check the flywheel/cam/distributor marks all line up as they should. is there a chance your timing belt could have jumped again?
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Offline Craigwilson

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Re: 8v advance/retard cam timing
« Reply #4 on: 31 March 2014, 01:11 »
I've had a look and all my marks are still lining up, I'm more just curios why the car decided it didn't like the timing set up after running fine for so long
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Offline Sgt_Lemon

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Re: 8v advance/retard cam timing
« Reply #5 on: 31 March 2014, 13:31 »
Should different cams be set to different timing?
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Offline Craigwilson

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Re: 8v advance/retard cam timing
« Reply #6 on: 02 April 2014, 10:53 »
well that's the purpose of a vernier pulley, when the cam is at different timing you get power at different rev bands
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Offline gazareth

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Re: 8v advance/retard cam timing
« Reply #7 on: 02 April 2014, 22:02 »
have you checked the camshaft woodruff key? the marks would still line up even if the key had sheared.
« Last Edit: 02 April 2014, 22:04 by gazareth »
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Offline Craigwilson

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Re: 8v advance/retard cam timing
« Reply #8 on: 02 April 2014, 22:41 »
had a look at it tonight, the timing is still lined up and the woodruff key is still in place
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Offline gazareth

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Re: 8v advance/retard cam timing
« Reply #9 on: 03 April 2014, 00:38 »
are you checking the marks line up via the flywheel through the plastic cap on gearbox? if you are and they all line up ok then I would be looking elsewhere. I would check the main fuel pump flow rate as if your getting a misfire higher in the revs maybe the pump is getting weak. failing that check the in tank pump flow rate aswell. have you got a decent ignition coil?
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