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Camshafts

As the JTS engine apparently is hard on its camshafts as it ages , and Alfas prices are horrendous,do people still reprofile camshafts or is that a thing of the past?
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I think most people would just replace the cams and the tappets. The trouble is metal from the worn cams tends to find its way elsewhere through the engine.

In my opinion the extra wear that tends to happen on JTS cams is caused by the fact Alfa specify a thick oil (10w-60) in an attempt to cut oil consumption.
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Quote:
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I think most people would just replace the cams and the tappets. The trouble is metal from the worn cams tends to find its way elsewhere through the engine.

In my opinion the extra wear that tends to happen on JTS cams is caused by the fact Alfa specify a thick oil (10w-60) in an attempt to cut oil consumption.
The trouble is that JTS cams are 350 a piece , let alone tappets. I can't follow you reasoning on oil viscosity , how does "thick" oil give less protection than " thin" ? Surely the deciding factor on wear is the thickness of the oil film on a component?
My JTS engine has covered 123000 miles and uses no oil worth talking about , however sometimes the oil pressure light is slow to go out after cold start and one tappet takes forever to charge,other than those problems its a cracking engine,far nicer than my younger
TS.
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Because with the thicker oil there is less circulation, and the oil takes longer to get to the top of the engine.

Film strength of an oil isn't nessesarily better with a thicker oil either.
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Quote:
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Because with the thicker oil there is less circulation, and the oil takes longer to get to the top of the engine.

Film strength of an oil isn't nessesarily better with a thicker oil either.
But this is the point of multigrade , cold oil = thin,quicker circulation , hot oil = thick,better protection when it is needed.
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The thing is it is thicker when hot. An oil of 60 hot rating will probably never get to its optimum operating temperature on a road car used in the UK climate.

Alfa had massive problems with TS engines running out of oil in between services as people coming from Other Marques didn't think they needed to open the bonnet and check the oil.

They then switched to 10w-60 for later TS engines and the JTS as thicker oil tends to burn less readily.
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I think you have defeated your own argument:

You maintain thick oil is causing the damage , yet you recon that 60 grade will never get hot enough to reach its maximum viscosity so remains thiner than designed.
So if say 10-40 is used , it will never reach a viscosity of much more that parrafin!!!
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Quote:
Originally Posted by m0bzy View Post
I think you have defeated your own argument:

You maintain thick oil is causing the damage , yet you recon that 60 grade will never get hot enough to reach its maximum viscosity so remains thiner than designed.
So if say 10-40 is used , it will never reach a viscosity of much more that parrafin!!!
No it will not get thin enough to work properly.

All oils get thinner as they warm up, even though by looking at the viscosity rating it would appear otherwise.

A 10w-60 is thicker at a given temperature than a 10w-40

This is quite a good article as are most others on the opie website.

http://www.opieoils.co.uk/pdfs/tech-...10w-60-oil.pdf
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Multi-grades

I feel we are going round in circles. Try this link.Motor Oil Viscosity Grades Explained in Layman's Terms
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Yes we are going around in cicles, that link basically says the same as the one I posted.

Say for arguments sake you car ran at 100C operating temperature, which is probably close to what it really does run at if the thermostat is ok.

A 10w-60 oil will be thicker at this temperature than a 10w-40, hence it would not flow around the engine as easily. (The hot rating on oils is measured at 100C)


They may be the same viscosity at 0C (the temperature than the "W" rating is measured at), but at anything above this the 10w-60 will be thicker.

A 10w-60 oil has an optimum operating temperature for about 130C, so if you car is running at less than this the oil will not be within its ideal operating range. This will make more drag, heat and wear.

Giulietta 2.0JTDm (170), BMW 120d M sport
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So all the research to help cold cranking,and yet ensure the oil still does its job @ running temps is for nothing,as all oil thins as it warms!! So 10sae must be less than water.


Last post on this subject.BORED.
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Plenty of info on the net on multigrades and how the viscosity is measured.
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I think there are people who can re-profile cams... though another option is to find a younger, second-hand engine and have the cams out of that. You would have to run them in though, even though they're used parts.


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alfa gt jts

My jts had a new cam shaft "and" cylinder head last yr, december in fact. It was running like a dream for a week then i noticed it sounding like a taxi almost. well it ticks loudly when the engine temp reaches about 80. I took it back to the garage, he said something about topping some things up with oil and thats all he could do.( to technical for me).Anyway its still no different. Any ideas as to what it could be as it doesnt sound like an Alfa shoud?????
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I would agree with symon. I had to replace the inlet cam and tappets on my car, if you had seen the cam you would of thought it came form another car. I posted a topic a short while ago regarding oil and i think an alfa mechanic replied, he said he had seen many jts cams worn and need replacing from using 10w60 oil. I questioned him on what the hand book states and he wouldn't commit but he gave the impression to use 10w40 and Bonellos who did the work on my car said the same.
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Here is a JTS exhaust cam, its normally the exhaust cam that wears down quickest:

http://cgi.ebay.co.uk/Alfa-Romeo-JTS...item4cf47d8653

We also have inlet cams in stock.
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