Do these cams look okay?

[wca]

I am replacing the inlet manifold and was told I should look at the cam lobes while it was open. I have looked and it is very interesting. What am i meant to look for? Do the photos below look okay, if you can tell from phone photos. Also some pictures of the holes in the engine banks in case you want to comment on them.












All comments wlecome, some ignored ;-)

Advice on removing gasket sealant on the inlet manifold thread welcome too

[Wedg1e]

The cam lobes should be pretty well all the same shape (at any rate, all the exhaust lobes should be the same as each other, as should all the inlets), no flat spots or trenches in them. You can turn the engine over with a big socket on the crank pulley bolt (easier with the spark plugs out) to see the lobes that are facing the wrong way. Visualise a boiled eg: if you smashed the 'pointy' end of the egg with a spoon that's how a knackered lobe would look!
From the photo they look OK to me; generally if they start to disintegrate it's a very quick process once the case-hardening has been fractured. Slight wear would be taken up by the hydraulic lifters so it'd be pointless trying to measure it.

[wca]

Thanks. They looked okay to me. No obvious scratches, grooves or discolouration but I have never been this far into an engine before. Prior to the TVR i have had Hondas and Mercedes so the nearest you get to the engine is topping up the oil.

I hope my frequent questions aren't too stupid / irritating

[adam quantrill]

They don't have to look like a smashed egg, I have seen them wear down smoothly to a near circle.

What I would advise is that you take off the two rocker covers and observe the rockers going up and down.

Either do this on the starter for a quick visual, or do it slowly (my favourite method is jack upa rear wheel, stick it in 4th and rotate the wheel) while measuring each one with a dial gauge. You will soon find out if any rockers aren't moving as much as the others.

Fianlly before reassembly make sure there aren't any obstructions building up in the top faces of the valley where oil drips down and onto the cam lobes.

[Wedg1e]

adam quantrill said:

They don't have to look like a smashed egg, I have seen them wear down smoothly to a near circle.

OK so I egg-zaggerated I was just making the point that if it's not a smooth egg shape it needs looking at.

[wombat172a]

I think they look okay, but if you're concerned you could pop the rockers off and have a look at the base of the hydraulic lifters while you're there.

I think that would be more telling than eye-balling the cam, but I'll let someone else confirm.

[Wedg1e]

wca said:

Thanks. They looked okay to me. No obvious scratches, grooves or discolouration but I have never been this far into an engine before. Prior to the TVR i have had Hondas and Mercedes so the nearest you get to the engine is topping up the oil.

I hope my frequent questions aren't too stupid / irritating

Supposedly, there are no stupid questions, only stupid answers. Well, you're in the right place

Many people, often bright people with highly-technical jobs in their own right, shy away from mechanical stuff because they think there's some kind of black magic going on. By the time you've had your engine back together and on the road for 6 weeks you'll wonder what all the fuss was about
When I did my C&G in motor vehicles, one of the lecturers was a 'proper' motor engineer of the old school. You'd sit down for a brief rundown on, say, camshafts, and four hours later the guy still hadn't run out of things to teach you about camshafts. From a mechanic's point of view it was information overload: as long as you know what a good one looks like you can spot a duff one. The intricacies of opening and closing ramps, timing and valve overlap, base circle and so on can wait till later.

[Campbell]

You can use a sharp stanly blade to get off the old sealent but i would be bothered with the old crapy carbon oil baked to the gally.
Your cam dosnt look to to bad considering the colour of the gallery.

Cambelt

[Wedg1e]

Campbell said:

Your cam dosnt look to to bad considering the colour of the gallery.

Cambelt

True, this was mine BEFORE I stripped it:

[wca]

Rocker covers coming off this morning and I will have another look (probably post pictures up too).

Is it worth spraying some carb cleaner into the gallery to try and get that cleaner? I am planning an oil and filter change before starting the engine so a little cleaner dripping into the engine shouldn't be the end of the world - should it?

I could always pack the gap above the cam with some paper towels before starting the clean to catch the curd before it falls in the hole.

[vampire222]

wca said:

Rocker covers coming off this morning and I will have another look (probably post pictures up too).

Is it worth spraying some carb cleaner into the gallery to try and get that cleaner? I am planning an oil and filter change before starting the engine so a little cleaner dripping into the engine shouldn't be the end of the world - should it?

I could always pack the gap above the cam with some paper towels before starting the clean to catch the curd before it falls in the hole.

Dude carb cleaner / brake cleaner is like some kind of ethyl. It'll just burn or evaporate. So no problem spraying it in anything aslong as you wipe it clean after ofcourse, and give it time to evaporate!

Only dont use it on anything plastic and stuff it'll ruin it!

[Campbell]

Wedg1e said:

True, this was mine BEFORE I stripped it:

Thats more like it...nice and clean

Nick...got any pics taken under the rocker covers yet...
As Vampire said you can use carb cleaner, brake cleaner to help remover the old carboned oil but since you have your ramp to help i would recomend you remove the sump after draining the oil and give it a good clean, you should be able to take it off with out too much hassle, i can get mine off with out moving the engine.
I would use a narrow paint scrapper to get most of the crap off then a stiff brush to get the rest, remember to wash off what may land on the crank and cam.

Cambelt