4.2 AJP Cranks

[Neil_M]

Just a quick question...

With the early 4.2 AJP's having cast cranks, which are reputed to be a little fragile... Any idea of the costs of having the later crank (assuming steel) installed?

Thanks,
Neil

Edited by Neil_M on Thursday 15th July 09:29

[450Nick]

I've got a steel one sitting in my garage for sale... Pm if you're interested...

[Gazzab]

I would imagine that you need to allow quite a few hours to remove, strip, build and reinstall the engine. Probably 30 hours of work I would guess?
Speak to APM as he will know EXACTLY what he would charge to do this, his rate is great, his speed is good and his AJP knowledge is the best.

[Neil_M]

Thanks for the replies folks.

I'm just concerned, as im looking at a very early 4.2. Where the crank is known to be weak AFAIK.

Should I be that concerned?

[Gazzab]

Its a 14 year old car that has the original engine and crank. The chances are it will be fine but of course you are buying a hihgly tuned, powerful supercar made in a shed years ago - so you should be prepared for some maintenance and repairs.

[Byker28i]

As GazzaB said, if it was weak do you think after 13/14 years it would have broken already?

[M3John]

Byker28i said:

As GazzaB said, if it was weak do you think after 13/14 years it would have broken already?

If only that was the case.

[Gazzab]

M3John said:

Byker28i said:

As GazzaB said, if it was weak do you think after 13/14 years it would have broken already?

If only that was the case.

There's always one ;-)
In fairness the crank probs still exist but are few and far between. I would say you are very unlikley to experience a crank failure.

[Steve_T]

How much longer a crank has left is a function of the time an engine is used and at what revs. Be wary of saying it would have gone by now, as there is no way of measuring how much useful life remains in a crank, you've no idea what how the car was driven by the previous owner.

[M3John]

Gazzab said:

M3John said:

Byker28i said:

As GazzaB said, if it was weak do you think after 13/14 years it would have broken already?

If only that was the case.

There's always one ;-)

Steve_T said:

How much longer a crank has left is a function of the time an engine is used and at what revs. Be wary of saying it would have gone by now, as there is no way of measuring how much useful life remains in a crank, you've no idea what how the car was driven by the previous owner.

Exactly that. Mine went at around 60mph in 3rd under very normal driving conditions.

[JensenA]

Neil_M said:

Thanks for the replies folks.

I'm just concerned, as im looking at a very early 4.2. Where the crank is known to be weak AFAIK.

Should I be that concerned?

Early 4.2 cranks aren't known to be weak, there is a just a possibility that it may be. Buying a Cerbera involves taking a risk - albeit a smaller risk than many people would have you think, I wouldn't let it influence you to walk away from what appears to be a good car.

[Adrenochrome]

I would certainly budget for replacing the crank,and if someone has one in their garage like above I would buy it and change it to be honest.

[Neil_M]

WOW thanks for the very informative replies folks .

I am doing as much research as much as possible. I am also looking to buy the best I can. Hence the reservations on the early car's crank and its possible build quality.

It's a decision I'm trying to make with my eyes open.

Maybe I should be done with it and get a 4.7 rebuild and get a billet crank with that ,

[450Nick]

Neil_M said:

WOW thanks for the very informative replies folks .

I am doing as much research as much as possible. I am also looking to buy the best I can. Hence the reservations on the early car's crank and its possible build quality.

It's a decision I'm trying to make with my eyes open.

Maybe I should be done with it and get a 4.7 rebuild and get a billet crank with that ,

...its not cheap!!!

[Steve_T]

Neil_M said:

WOW thanks for the very informative replies folks .

I am doing as much research as much as possible. I am also looking to buy the best I can. Hence the reservations on the early car's crank and its possible build quality.

It's a decision I'm trying to make with my eyes open.

Maybe I should be done with it and get a 4.7 rebuild and get a billet crank with that ,

There was a change to the 4.2 crank casting in 98 iirc.

HTH

[Tanguero]

M3John said:

Gazzab said:

M3John said:

Byker28i said:

As GazzaB said, if it was weak do you think after 13/14 years it would have broken already?

If only that was the case.

There's always one ;-)

Steve_T said:

How much longer a crank has left is a function of the time an engine is used and at what revs. Be wary of saying it would have gone by now, as there is no way of measuring how much useful life remains in a crank, you've no idea what how the car was driven by the previous owner.

Exactly that. Mine went at around 60mph in 3rd under very normal driving conditions.

I thought yours was the cam shaft not the crank shaft ???

[clive f]

does your sump have 2 drain plugs? if so then it might be one of the early ones with the weaker type of crank, they did change them for better ones before using the larger journal 4.5 cranks instead.

not so long ago, I saw new ones for sale, either at clevor trevors or racing green`s website, about £1300 I think.

[itiejim]

It's not even that simple I'm afraid.

There are two types of 4.5 (large journal) cranks, those with large counterweights and those with small ones. Apparently the small counterweighted cranks are prone to stress cracks which will, ultimately lead to failures, though at this stage there would appear to be few that are known of.

Keeps us all on our toes though eh?

[Neil_M]

Thanks again folks.

So potentially some 4.5s have issues on the same subject?

Flip its never easy... I don't think the ideal Cerb exists you know haha .

[JensenA]

Neil_M said:

Thanks again folks.

So potentially some 4.5s have issues on the same subject?

Flip its never easy... I don't think the ideal Cerb exists you know haha .

The ideal one has got a TVR badge on the front, and a Cerbera badge on the rear Just do your homework, and like the rest of us, be prepared to take a risk and just buy one. It's a lot smaller risk than you think.