Changing Cams

[rickprice]

My 2000 4.5 has now done 52,000 miles and has a tapping not dissimilar to tappets in another car. Ben at Offord Motors seems to think its the cam.

So my question is, what are the pros and cons of the various cams out there?

I use the car on the road, generally in the dry. I would like a car that drives well, especially at lower revs, and is good in normal day-today use.

Any suggestions/advice?



Rich

[TVRJAS]

Thought mine was the cam... Turned out to be Manifold gasket.. same tappets noise.

Is it this kind of noise.. https://www.youtube.com/watch?v=RstjSrv9Iko

Edited by TVRJAS on Thursday 14th August 15:37

[rickprice]

Thats very useful.

Mine sounds higher pitched, and more like a tapping but will get manifold gaskets changed anyway - presumably much cheaper?

Rich

[TVRJAS]

rickprice said:

Thats very useful.

Mine sounds higher pitched, and more like a tapping but will get manifold gaskets changed anyway - presumably much cheaper?

Rich

Unfortunately my gasket replacement ended up not being cheap. One bolt would not budge and resulted in the engine having to be lifted out so they could drill and tap the bolt out.

Cost of Labor just over £1,000 + parts. But if you have no problems with the bolts yes cheaper. Fingers crossed for you.

If you enter into the search box "Manifold tappy noise" you can see many topics such as yours.. Here is one under that search http://www.pistonheads.com/gassing/topic.asp?t=955...

[ianwayne]

I wasn't 100% sure my tapping noise was the exhaust gaskets but it was. I got a tip off here, tape a feather to a pencil and lower it close to the exhaust ports on the engine. Even at idle, any gases leaking will buffet the feather around. It confirmed it for me. Cost £300 ish but like said above, none of my bolts seized thankfully.

[zed4]

If you do decide to change the cam, I went for the V8D MC1. My car is very easy to drive, so smooth and ours out good power. 240hp at the fly for a standard 400.

[shake n bake]

As it's been diagnosed by a mechanic as a suspect cam I'd like to think he'd know the difference between a manifold and a cam noise.
Has it had an oil change recently? That can make a fair bit of difference on engine sounds.

[zed4]

We'll I'd get a second opinion. Or at least use the feather test.

[SILICONEKID345HP]

Why not dyno it .

[Bluebottle]

SILICONEKID345HP said:

Why not dyno it .

Hows does ragging the nuts off of it on a RR help exactly with diagnosing manifold leak of worn cam Daz?

[SILICONEKID345HP]

Bluebottle said:

Hows does ragging the nuts off of it on a RR help exactly with diagnosing manifold leak of worn cam Daz?

Power will be down with a worn cam ..If it has not lost any power and you do not have an exhaust leak turn the stereo up .

[domV8]

...on the assumption you knew what the power was beforehand, you used the same rolling road, and tested it on the same day...

[SILICONEKID345HP]

domV8 said:

...on the assumption you knew what the power was beforehand, you used the same rolling road, and tested it on the same day...

Everyone knows what power the whole range makes in standard form .

[EGB]

TVRJAS said:

Unfortunately my gasket replacement ended up not being cheap. One bolt would not budge and resulted in the engine having to be lifted out so they could drill and tap the bolt out.

Cost of Labor just over £1,000 + parts. But if you have no problems with the bolts yes cheaper. Fingers crossed for you.

If you enter into the search box "Manifold tappy noise" you can see many topics such as yours.. Here is one under that search http://www.pistonheads.com/gassing/topic.asp?t=955...

Soak bolts overnight with plus gas or WD 40. Or a mix of acetone ATF. Worked for me.

[TVRJAS]

EGB said:

Soak bolts overnight with plus gas or WD 40. Or a mix of acetone ATF. Worked for me.

They tried that,48hrs later I get the phone call that it simply will not come out and told me the next procedure and do I want to come over and look. It was being carried out by one of the major specialists.

No doubt that what you say will work on some,but mine was a no no.

[EGB]

TVRJAS said:

EGB said:

Soak bolts overnight with plus gas or WD 40. Or a mix of acetone ATF. Worked for me.

They tried that,48hrs later I get the phone call that it simply will not come out and told me the next procedure and do I want to come over and look. It was being carried out by one of the major specialists.

No doubt that what you say will work on some,but mine was a no no.

Yes understood. Perhaps a slight engine warm up may help if all fails. Aluminium of the head may/should expand differentially away from the steel bolt and could then be slackened with the 9/16 or a 14mm spanner.

[QBee]

I had six bolts stuck on mine.....couldn't be shifted by an expert who, once he had sheared the first one off, actually took the heads off the car complete with manifolds to attack the rest on the bench when he couldn't shift them. Still couldn't shift them, ended up sawing through them and removing the remains. It can happen to the best of us.....

[rickprice]

Couple of years ago it made 274 bhp (4.5L). Could re-do this I suppose and might make an interesting comparison before-vs-after.

But, back on topic, how do I choose a new Cam?

Rich

[QBee]

Feather test first......

Cam choice? Tell the garage, or Rob at V8Developments, (01775 750000) what you want to do with the car and get an expert to specify it. Fit the wrong cam and you can end up destroying the engine if the pistons hit the valves. Or spoiling your driving experience.

[Milky400]

Offords? I'd get a second opinion...