Cam wear

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greenfyregirl
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Location: cheltenham

Cam wear

Post by greenfyregirl » 15th September 2017 - 12:01pm

Hello

I have got a 4 rivet late cam, how can i tell if i need a new one? I have bought new lifters, cuz they are dished. Are there measurements or wear to look for?
Can I change the oil pump to an early one if i need to change the cam?

Thanks Clare
Clare - living in Cheltenham

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purplepeter
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Re: Cam wear

Post by purplepeter » 15th September 2017 - 7:19pm

The easiest answer is show it to Rich & Barry... You're looking for worn/chamfered areas on the edges of the lobes & Also look for abnormalities in the bearing faces

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greenfyregirl
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Re: Cam wear

Post by greenfyregirl » 15th September 2017 - 11:37pm

theyve seen the engine coming apart and didnt tell me that dished lifters need replacing, so id rather get as much all round different help as possible :)
Clare - living in Cheltenham

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purplepeter
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Re: Cam wear

Post by purplepeter » 16th September 2017 - 12:49pm

Look at it under a bright light & look for areas as described.
You know You'll need to run in your new lifters with a cam burn don't You?... Also, when You install them, line up the oil hole with the oil gallery to ensure they get oil straight away (stick a teeny blob of grease under the head of the lifter to "glue" them into the case)

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broady_6
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Re: Cam wear

Post by broady_6 » 16th September 2017 - 2:14pm

show us some pictures. if the lobes are squared or flattened off its badly worn. You can normally tell from the change of colour where it has worn through the surface hardening.
The sultan of swing

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greenfyregirl
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Re: Cam wear

Post by greenfyregirl » 19th September 2017 - 1:37pm

Thank you both :) i think that i do need a new cam- one lobe is def a bit flat and all are different heights- if they are suposed to be the same. Baz measured them- pete!!!

sooo... can i/ is it a good idead to change to an early 3 rivet pump and cam??
Clare - living in Cheltenham

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packers1712
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Location: Bedfordshire (nr Luton)

Re: Cam wear

Post by packers1712 » 2nd October 2017 - 9:01am

Sorry for hijacking your thread, but I have had my car on a dyno/rolling road to confirm that as a result of running much more ignition timing than the manual says I am not running to lean at the high end of the rev range and also not pinking, which luckily I'm not. However when I quizzed the guy at the guy at the dyno for his opinion why I might need to run so far advanced he replied with either the cam timing could be out or/and the cam could be beginning to wear, so how do I check both with the engine still in the car?
I have done some very basic checks with small screwdriver down the bore to find TDC versus valves on the rock/closed and that proved good but when I mentioned this to the dyno man he said needed to be a lot more accurate than that to determine weather or nit the timing was out - angle gauge on the crank pulley and DTI on the rockers/push rods to measure lift versus crank angle. I was hoping there might be an easier method!

Thanks Doug.

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broady_6
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Re: Cam wear

Post by broady_6 » 2nd October 2017 - 2:15pm

A forlorn hope unfortunately. it doesnt take many degrees of cam timing to cause issues. So it will need to be measured accurately as the man has suggested. or youll have to take the engine to bits and check.
The sultan of swing

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packers1712
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Re: Cam wear

Post by packers1712 » 4th October 2017 - 1:43pm

I thought as much, seems that there are 50 teeth on the cam gear so that means if its only 1 tooth out it is 7.2° wrong, just need to figure out if I can actually do the checks with the engine in the car!

Doug.

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broady_6
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Re: Cam wear

Post by broady_6 » 4th October 2017 - 7:23pm

I cant see how you would be able too, the point where the cam gear meshes with the crank gear is roughly where i have high lighted. You need to be able to see there to work out if theyre lined up

Image

Unless you can calculate the precise potion of the rockers vs the TDC
The sultan of swing

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packers1712
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Re: Cam wear

Post by packers1712 » 4th October 2017 - 8:47pm

Yes that's exactly what I'm going to do , I need to get a pertractor on the crank pulley and a DTI on a push rod so that I can measure valve lift versus crank angle.Push rod displacement will tell me if the cam is worn and crank angle will show if the timing is out.😗

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broady_6
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Re: Cam wear

Post by broady_6 » 5th October 2017 - 9:52am

keep us psoted, lots of photos please, i do enjoy some real technical work :D
The sultan of swing

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