Development 92 to 03
Discussion
Hi all,
I have a question for you - How much did the Chimaera change from 92 to 03? I have heard there were significant improvements in build quality throughout the production run - is this the case? What was changed? I have read about the facelift, headlights and so on, but I am more interested in the mechanical changes.
Does serp/pre-serp make a significant difference in reliability? Did they change any of the other internal components and in what year?
Cheers all!
I have a question for you - How much did the Chimaera change from 92 to 03? I have heard there were significant improvements in build quality throughout the production run - is this the case? What was changed? I have read about the facelift, headlights and so on, but I am more interested in the mechanical changes.
Does serp/pre-serp make a significant difference in reliability? Did they change any of the other internal components and in what year?
Cheers all!
Hmmm quite a difficult question to sum up in a post.
You should do your research online to find out in proper detail, there are many resources. Here's one
http://www.chimaerapages.com/resources_buyers.php
Serp (94 on?) features slightly different oil pump and the T5 gearbox. Some non-serpentine engines with T5 box (mine is like this, a '94 car) exist. I think the cooling system was updated too, different expansion tank fitted? I 'm not sure, someone will know.. No difference in reliability if they are both in good shape but the later gearbox is supposed to be a lot better to use as well as stronger etc etc.
Also the chances of the older engine being in good shape is probably less likely but not impossible as my perfect '94 example has proven. By contrast I drove two later cars, one with new cam that didn't even come close.
IIRC the very latest cars all had the same brakes as opposed to the earlier 400's having smaller brakes and solid rears.
Minor changes to the dash layout too.
I think if you're talking about the very earliest cars you will find many suffering from rusted chassis outriggers and possibly camshaft wear. To me, these are the two potential I've bought a ''lemon'' areas of Chimaeras although there are many many more things to check/look out for. A lot of buying guides exist on line and also in the Steve Heath book, know as the bible.
You should do your research online to find out in proper detail, there are many resources. Here's one
http://www.chimaerapages.com/resources_buyers.php
Serp (94 on?) features slightly different oil pump and the T5 gearbox. Some non-serpentine engines with T5 box (mine is like this, a '94 car) exist. I think the cooling system was updated too, different expansion tank fitted? I 'm not sure, someone will know.. No difference in reliability if they are both in good shape but the later gearbox is supposed to be a lot better to use as well as stronger etc etc.
Also the chances of the older engine being in good shape is probably less likely but not impossible as my perfect '94 example has proven. By contrast I drove two later cars, one with new cam that didn't even come close.
IIRC the very latest cars all had the same brakes as opposed to the earlier 400's having smaller brakes and solid rears.
Minor changes to the dash layout too.
I think if you're talking about the very earliest cars you will find many suffering from rusted chassis outriggers and possibly camshaft wear. To me, these are the two potential I've bought a ''lemon'' areas of Chimaeras although there are many many more things to check/look out for. A lot of buying guides exist on line and also in the Steve Heath book, know as the bible.
I was hoping to avoid dodgy outriggers by buying a car that had them treated already! This problem seems to be very well known...
Also, would cam wear not be linked to higher mileage or irregular servicing rather than age? This would support getting a lower mileage car (rather than a later MY car)?
Thanks for the replies - v helpful!
Also, would cam wear not be linked to higher mileage or irregular servicing rather than age? This would support getting a lower mileage car (rather than a later MY car)?
Thanks for the replies - v helpful!
The later oil pump is crank driven and avoids the problems with driving off the cam nose. Water pump has little benefit, removal of integral bypass could be classed as a backward step.
None of these things are anything to worry about, and there are a lot of early chassis in much better condition than later ones. Looking at production numbers and when the factory was stressed by demand is better indicator of quality than the development timeline IMHO.
None of these things are anything to worry about, and there are a lot of early chassis in much better condition than later ones. Looking at production numbers and when the factory was stressed by demand is better indicator of quality than the development timeline IMHO.
alephnull said:
Also, would cam wear not be linked to higher mileage or irregular servicing rather than age?
Up to a point, yes. But perhaps the most important factor is how sympathetically it's been driven.If the previous owner(s) have habitually revved it hard before the oil is warm, then it doesn't matter how regularly it's been serviced. The cam lobes could still be worn even after modest mileage with that sort of abuse, and I'm sure there are lots of car owners out there who don't understand that all engines should be treated gently until warmed up.
The exception, of course, is rental cars. You can rev the b
ks off them from cold and it doesn't matter. 
These cars do seem to be able to eat their cams at really low mileage. I have been surprised by some things I've read regarding cam wear.
I think maybe some owners just think because it's a TVR it can/has to be thrashed to death but also cam wear seems just to be an issue with this engine.
Mind you, my old 440ci (7.2L) 425bhp Mopar big block that I used to have in my old '67 Dodge managed to eat it's cam too and as I recall it wasn't that unheard of even in the American muscle scene for cams to go. We're talking pretty much identical engines apart from of course the Detroit 'iron' is, well, iron!
Again, I use my vehicle as an example. I've done 10k since last August including trip to Europe. Bought with 39k now just onto 50k with not a single hint of loss of power due to cam wear so I see no reason why it will suddenly go now. The car was by far the quickest one I tested before buying and as I say none of that has gone in 10k so if I didn't know about the issue I'd be blissfully unaware that cam wear happens with the RV8. Sorry for any less fortunate owners who have had problems at lower mileages.
Sadly there seems to be no explanation of why some have suffered prematurely so all I can say is do as I did. Drive plenty and as well as condition of chassis etc, look out for the one that feels quickest and then service it with fully synthetic oil frequently! Of course several cars that you see may have incorrect timing or a host of other things which might make one faster than the other, even bloody throttle cable adjustment, so you'll need to use your experience and instinct to help you choose the sweetest one
And BTW, I only got to drive mine up and down an old runway when I went to see it and I don't think I went past 40mph but you could just feel it was sooo eager and 'ready to go' it felt really perky - exactly what it should feel like if cam is good.
By contrast I also drove a ste one at a dealership (never intended to buy was just getting feel for them) with 'only' 60k and it felt like it was underpowered and full of treacle. Luckily even before I knew what a good one was like I managed to guess that this particular example was shafted
I think maybe some owners just think because it's a TVR it can/has to be thrashed to death but also cam wear seems just to be an issue with this engine.
Mind you, my old 440ci (7.2L) 425bhp Mopar big block that I used to have in my old '67 Dodge managed to eat it's cam too and as I recall it wasn't that unheard of even in the American muscle scene for cams to go. We're talking pretty much identical engines apart from of course the Detroit 'iron' is, well, iron!
Again, I use my vehicle as an example. I've done 10k since last August including trip to Europe. Bought with 39k now just onto 50k with not a single hint of loss of power due to cam wear so I see no reason why it will suddenly go now. The car was by far the quickest one I tested before buying and as I say none of that has gone in 10k so if I didn't know about the issue I'd be blissfully unaware that cam wear happens with the RV8. Sorry for any less fortunate owners who have had problems at lower mileages.
Sadly there seems to be no explanation of why some have suffered prematurely so all I can say is do as I did. Drive plenty and as well as condition of chassis etc, look out for the one that feels quickest and then service it with fully synthetic oil frequently! Of course several cars that you see may have incorrect timing or a host of other things which might make one faster than the other, even bloody throttle cable adjustment, so you'll need to use your experience and instinct to help you choose the sweetest one
And BTW, I only got to drive mine up and down an old runway when I went to see it and I don't think I went past 40mph but you could just feel it was sooo eager and 'ready to go' it felt really perky - exactly what it should feel like if cam is good.
By contrast I also drove a s
te one at a dealership (never intended to buy was just getting feel for them) with 'only' 60k and it felt like it was underpowered and full of treacle. Luckily even before I knew what a good one was like I managed to guess that this particular example was shaftedEdited by dog man on Monday 28th March 09:57
dog man said:
...Sadly there seems to be no explanation of why some have suffered prematurely so all I can say is do as I did...
That's rather misleading TBH...ZDDP, suitability of oil, how radical particular cam is, state of followers & valve train, rev limits are all just as important as usage and well documented information wise.
I fail to see what temp of oil has to do with it, warming engine components for tolerances and having good flow of oil to moving parts yes, but oil temp v cam wear???? In a hot engine oil is likely the most important coolant since water passages don't go anywhere near the important parts so it's arguable that very cool oil is a big positive once warmed up. Constant revs are more likely to wear the cam ie leaving at tickover to warm up, frequent acceleration over the lobes without excessive high revs (upto 4000 rpm) is ideal AIUI.
Cooling isn't very important to the bottom end of the engine. The important thing is whether the oil can flow quickly enough to replenish the film covering the cam lobes as they rotate over the followers. Cold oil may not flow quite fast enough to prevent metal-to-metal contact at high revs.
StupidT055ER talking gobshire said:
Cooling isn't very important to the bottom end of the engine. The important thing is whether the oil can flow quickly enough to replenish the film covering the cam lobes as they rotate over the followers. Cold oil may not flow quite fast enough to prevent metal-to-metal contact at high revs.
So where does the oil comes from to lubricate the follower - cam lobe surfaces in your view? And why would temperature make a difference?Edited by spend on Wednesday 13th April 12:59
I believe it's lubricated by splash, isn't it?
Temperature is important because even a multigrade oil can't have exactly the same viscosity at lower temperatures as it does at full operating temperature. As the cam lobe moves over the follower, there shouldn't be metal-to-metal contact; it should be floating on a film of oil. Inevitably the film gets displaced by the lobe - but hopefully the oil film will spread back out again before the lobe comes back round again. Cold oil is less able to move quickly enough to do that if the cam shaft is turning rapidly.
Temperature is important because even a multigrade oil can't have exactly the same viscosity at lower temperatures as it does at full operating temperature. As the cam lobe moves over the follower, there shouldn't be metal-to-metal contact; it should be floating on a film of oil. Inevitably the film gets displaced by the lobe - but hopefully the oil film will spread back out again before the lobe comes back round again. Cold oil is less able to move quickly enough to do that if the cam shaft is turning rapidly.
spend said:
That's rather misleading TBH
I dont think it is. For a potential buyer it needs to be highlighted and he must approach any car he sees knowing that even low mileage cars might be suffering from this issue. However yes, I think a well looked after car will stand a better chance of being okay than an abused one but still, some nice cars have to have a replacement cam at very low mileage. I know for example, the BMW M30 6cyl will eat its cam but that's only if the banjo bolts come loose/are not tightened at every service so thats important to point out to potential buyers of any car using that motor. Whereas it seems a perfectly happy RV8 cam can just wear out all on it's own (not all of course, mine is fine and so are many many more) which I think is advise to point out to potential Chimaera owner. Certainly if a 17 yr old BMW with 50k sounds sweet under various driving conditions then it's pretty likely it's fine, with many miles left under it's belt but it seems in RV8 world 50k can be new cam time
Edited by dog man on Monday 28th March 12:03
Edited by dog man on Monday 28th March 12:06
Dr Mike Oxgreen said:
I believe it's lubricated by splash, isn't it?
Temperature is important because even a multigrade oil can't have exactly the same viscosity at lower temperatures as it does at full operating temperature. As the cam lobe moves over the follower, there shouldn't be metal-to-metal contact; it should be floating on a film of oil. Inevitably the film gets displaced by the lobe - but hopefully the oil film will spread back out again before the lobe comes back round again. Cold oil is less able to move quickly enough to do that if the cam shaft is turning rapidly.
Most of the oil on the follower / cam is going to come out of the pressure feed to the follower bore. There is a big sTemperature is important because even a multigrade oil can't have exactly the same viscosity at lower temperatures as it does at full operating temperature. As the cam lobe moves over the follower, there shouldn't be metal-to-metal contact; it should be floating on a film of oil. Inevitably the film gets displaced by the lobe - but hopefully the oil film will spread back out again before the lobe comes back round again. Cold oil is less able to move quickly enough to do that if the cam shaft is turning rapidly.
t off gallery along the lifter bores & what doesn't come down the bore (cold clearances will feed even more oil to the cam BTW!) spills out over the block recess for the lifter bores directly over the cam. Don't confuse oil drainback from the rocker covers with the pressure feed to the lifters.Lack of ZDDP in modern oils designed for roller cams is reputed to be the biggest problem with 'flat' tappets. The cunning angles on the cam and follower used to make the follower spin make your 'wringing out' and re-wetting analogy seem rather thin to me (pun intended :hehe). Hence I'd guess poor oil & followers (including worn bores) had a greater effect on lobe wear than activity with cold oil (which is still more 'clingy' when cold than hot). You are still going to see a wilder cam wear faster than the mild LR cams whatever... unless you convert to a roller cam you can't have your cake & eat it.
Dr Mike Oxgreen said:
Well, spend, if you're saying that you're happy to rev your engine from cold then that's fine - but that's very much a minority opinion. I'll just make a mental note not to buy your car from you! 
I'll have to defer to your expertise with cams & valvetrain then.... ..It would be very unlikely that I ever sold my car, and even then it would only be to someone who understood what was actually in it.
Whatever - returning to the question:
alephnull said:
I have heard there were significant improvements in build quality throughout the production run - is this the case?
It's not necessarily the case that build quality improved - it's probably truer to say that it "fluctuated". For example, if you talk to people in the know about the quality of the chassis and its powder coating, you'll often hear them talk about good years and bad years. Perhaps it was due to different materials used, or different storage conditions, or different techniques used.I think a lot of cam wear on TVRs can be due to lack of use. If a car is only used every 2 weeks say, then the cam may have all its oil drained away. If a car is use every day, then it may still have a thin coating to protect it at start up. My car reached almost 90K before it neede a cam change, but a previous owner used it as a daily driver.
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