chimaera camshaft
Discussion
I am looking at joining the club and getting my first Chim at some point. Most models are now at about 30,000+ miles. From what I have established, by 40,000 miles the cams usually need replacing? Is this a rule of thumb or can the cams last a lot longer.
I don't mind spending money on a good one but don't fancy replacing the cams until I've had a bit of fun out of it first. Are all the engine sizes the same for cam wear or are some better than others. If the cams do need replacing, how difficult a job is it and what are the best cams to use.
I don't mind spending money on a good one but don't fancy replacing the cams until I've had a bit of fun out of it first. Are all the engine sizes the same for cam wear or are some better than others. If the cams do need replacing, how difficult a job is it and what are the best cams to use.
There's only one camshaft for starters. Some engines will do 100k miles on a cam, others seem to go very much earlier. I guess it's a question of different wear due to different oil, driving habits and maintenance.
IMHO if the cam's alright when you buy a car (ascertained with a compression test I guess, because inspection requires significant disassembly) it should continue to be alright if you use the right oil, treat the engine sympathetically, and maintain it properly.
Cam change is quite involved and includes more new bits than just the camshaft. You also need to set the lifter preloads which by all accounts is a faff.
IMHO if the cam's alright when you buy a car (ascertained with a compression test I guess, because inspection requires significant disassembly) it should continue to be alright if you use the right oil, treat the engine sympathetically, and maintain it properly.
Cam change is quite involved and includes more new bits than just the camshaft. You also need to set the lifter preloads which by all accounts is a faff.
It is true that the cam is a weak spot of the RV8 although 60,000 is normally the watershed.
Regular oil changes, at least annually regardless of mileage, with decent quality oil is a way of putting replacement off. Also, as pointed out, is regular running, as is keeping the revs down when the engine is cold.
100+k is not that unusual on the original cam, although this is often with engines that are used regularly. But then, if they are not used regularly there's less chance of them having 100k on the clock I suppose. Given the cost of replacement it's not what you might call a major deterrent to ownership.
The only other known weak spot is the bores. This is not a problem with 3.5 engines but once it was bored out to 3.9, the liners became 'borderline' and pourosity is an issue. The larger engines sizes are via extended throws of the crank. I've read that the 5.0 and above can give rise to piston slap but most people I've talked to say this is rubbish.
Replacement engines are cheap. Certainly under £3000 for a standard one is easy enough to find.
What is true about the RV8 is that if you are sensible there is no reason to expect problems. It is a very reliable engine. Mind you, I'd avoid any engine you can hear ticking at a distance. Buy on condition.
But, of course, anyone can be unlucky. I've got 57000 on my 4.0 at the moment so I'll let you know.
Regular oil changes, at least annually regardless of mileage, with decent quality oil is a way of putting replacement off. Also, as pointed out, is regular running, as is keeping the revs down when the engine is cold.
100+k is not that unusual on the original cam, although this is often with engines that are used regularly. But then, if they are not used regularly there's less chance of them having 100k on the clock I suppose. Given the cost of replacement it's not what you might call a major deterrent to ownership.
The only other known weak spot is the bores. This is not a problem with 3.5 engines but once it was bored out to 3.9, the liners became 'borderline' and pourosity is an issue. The larger engines sizes are via extended throws of the crank. I've read that the 5.0 and above can give rise to piston slap but most people I've talked to say this is rubbish.
Replacement engines are cheap. Certainly under £3000 for a standard one is easy enough to find.
What is true about the RV8 is that if you are sensible there is no reason to expect problems. It is a very reliable engine. Mind you, I'd avoid any engine you can hear ticking at a distance. Buy on condition.
But, of course, anyone can be unlucky. I've got 57000 on my 4.0 at the moment so I'll let you know.
WokingWedger said:
97K pulls like a train !
any advance ?
Yes,122k on original,although very slight pitting and signs of slight wear on three lobes(checked with recent sump removal)and still spins up to 6k no problem(HC cammed) any advance ?
i have been all round this engine and its had no work and with all the receipts i have i have no evidence to prove otherwise(one of the reasons i purchased the car was the fact it had not been frigged about with)well unless by me 
and dont let them idle when cold try to keep the revs over 2k,what i am really saying is start the car and drive off dont let it warm up on idle unless you like losing cam lobes 
Edited by That Daddy on Tuesday 26th August 21:34
That Daddy said:
WokingWedger said:
97K pulls like a train !
any advance ?
dont let them idle when cold try to keep the revs over 2k,what i am really saying is start the car and drive off dont let it warm up on idle unless you like losing cam lobes any advance ?
Edited by That Daddy on Tuesday 26th August 21:34
Changing the cam is not that big a job if you tackle it in the right frame of mind and it can be done with the engine still in the car. fiddley job but can be done and save your self a small fortune. just be sure to put in the correct cam as one of my friends found out and had to start again. he is now quit fast at changing chim cams
Edited by scotty_d on Thursday 28th August 12:25
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