5 litre piston rattle - what cost to fix?
Discussion
The pistons supplied for my 5ltr rebuild by JE were 4.2 pistons, modified and supplied by Omega. So clearly I have the 4.2 offset. Not sure how that matches up with the TVR offset but the engine was quiet before the rebuild and quiet after.
Dougal.
Dougal.
Edited by Dougal9887 on Friday 7th February 11:42
Who knows? somebody does.
My 5L didn't rattle pre-rebuild. They didn't replace the pistons or little ends, everything else was replaced. Perhaps honing the bores created just enough clearance for a rattle. On a positive note the engine is really strong and produced the magic 300bhp without any other mods. As Mat Smith Said "it means you have a really loose engine that produces good power".
Urrr. Just need an engine builder that can guarantee it wont rattle. I'm not going smaller in capacity, the 5L torque and grunt is addictive. I suspect a 4.7 with turbo or supercharger is a superior option but at all that cost and complexity. Ummmm
My 5L didn't rattle pre-rebuild. They didn't replace the pistons or little ends, everything else was replaced. Perhaps honing the bores created just enough clearance for a rattle. On a positive note the engine is really strong and produced the magic 300bhp without any other mods. As Mat Smith Said "it means you have a really loose engine that produces good power".
Urrr. Just need an engine builder that can guarantee it wont rattle. I'm not going smaller in capacity, the 5L torque and grunt is addictive. I suspect a 4.7 with turbo or supercharger is a superior option but at all that cost and complexity. Ummmm
Boosted LS1 said:
^That's interesting. The 4.6 has a larger pin bore then the earlier rovers. I wonder what rods you have? I think you probably have a set of fast freddies own pistons but made to suit your bore diameter and rods.
Oops! 4.2.Edited by Boosted LS1 on Friday 7th February 10:33
I'll edit the post
Dougal.
What we all need to accept is the more TVR messed with stuff the more unreliability they built in, every TVR is like this! And in the case of the generally very reliable Rover V8, TVR's 5.0 litre variant was the one they messed about with most.
At the end of the day when the highly skilled engineers at Buick sat down in the late 1950's with a clean sheet of paper to design what we now call the Rover V8, they had a very clear design brief, just as any large well resourced car maker would. Right at the top of that brief was a capacity of 215ci, the bore and stroke being carefully calculated on paper before the first block was ever cast, which is clearly the only proper way to design an engine.
To be fair the Brits went on to eventually stretch this capacity from the original 3.5l to 4.6l and they did a pretty good job of it too given what they had to work with, but there's absolutely no escaping it every evolution of the Rover V8 was governed by that original Buick design brief and despite the benefit of expensive block casting changes by BL/Land Rover the legacy and challenges of that original 3.5l capacity and block architecture never ever went away.
What TVR should have done when they wanted to develop the Rover V8 was to recruit the services of a proper engineer, someone who already had a deep understanding of the engine, because the reality was while TVR were cooking up their Heath Robinson 5.0 recipe Ian Richardson had already solved all the issues by designing all the perfect solutions. If they'd recruited his help, got a good production engineer involved too and teamed up with a decent foundry things could have been very different. They then just needed one of the more modern and vastly superior engine management systems appearing in the late 1990's and they could have squeezed another 10 years out of the Rover V8 skipping the AJP 6 pain years entirely.
What they did of course was cook up their own rather odd ball ill conceived stroker kit and slapped it all together without balancing the rotating assembly properly, worse still while the serpentine blocks they were using at the time came with the bosses to cross bolt the mains they decided this element wasn't really necessary in on their poorly balanced bottom end so what you end up with is a long history of cracking crankshafts and rattles on the overrun due to poorly chosen pistons with the wrong gudgeon pin offset.
See.... the more TVR messed with stuff the more unreliability they built in.
At the end of the day when the highly skilled engineers at Buick sat down in the late 1950's with a clean sheet of paper to design what we now call the Rover V8, they had a very clear design brief, just as any large well resourced car maker would. Right at the top of that brief was a capacity of 215ci, the bore and stroke being carefully calculated on paper before the first block was ever cast, which is clearly the only proper way to design an engine.
To be fair the Brits went on to eventually stretch this capacity from the original 3.5l to 4.6l and they did a pretty good job of it too given what they had to work with, but there's absolutely no escaping it every evolution of the Rover V8 was governed by that original Buick design brief and despite the benefit of expensive block casting changes by BL/Land Rover the legacy and challenges of that original 3.5l capacity and block architecture never ever went away.
What TVR should have done when they wanted to develop the Rover V8 was to recruit the services of a proper engineer, someone who already had a deep understanding of the engine, because the reality was while TVR were cooking up their Heath Robinson 5.0 recipe Ian Richardson had already solved all the issues by designing all the perfect solutions. If they'd recruited his help, got a good production engineer involved too and teamed up with a decent foundry things could have been very different. They then just needed one of the more modern and vastly superior engine management systems appearing in the late 1990's and they could have squeezed another 10 years out of the Rover V8 skipping the AJP 6 pain years entirely.
What they did of course was cook up their own rather odd ball ill conceived stroker kit and slapped it all together without balancing the rotating assembly properly, worse still while the serpentine blocks they were using at the time came with the bosses to cross bolt the mains they decided this element wasn't really necessary in on their poorly balanced bottom end so what you end up with is a long history of cracking crankshafts and rattles on the overrun due to poorly chosen pistons with the wrong gudgeon pin offset.
See.... the more TVR messed with stuff the more unreliability they built in.
Boosted LS1 said:
Daz, is it pinking? Sounds to me as if it had knock/detonation under load in which case it needs setting up on the rollers.
Is the noise at cold the same noise you hear when hot and under load? A noise at cold could be anything, maybe a follower assuming your's are hydraulic.
It's all been setup ,it wasn't there one day and the next the noise came .
I would say after 2 minutes its completely gone .
Is the noise at cold the same noise you hear when hot and under load? A noise at cold could be anything, maybe a follower assuming your's are hydraulic.
It's all been setup ,it wasn't there one day and the next the noise came .
I would say after 2 minutes its completely gone .
Edited by Boosted LS1 on Friday 7th February 10:21
So, a light knock or a heavy knock? A tap or a rattle? I know it may seem daft but if you can identify the type of noise you may get clearer to the issue. Lifters can be irritating b
ds but usually after a blast they get pumped up and the knock goes. Assuming it's just the one. 16 rattling lifters would be just crazy!
ds but usually after a blast they get pumped up and the knock goes. Assuming it's just the one. 16 rattling lifters would be just crazy!
lancelin said:
Who knows? somebody does.
Urrr. Just need an engine builder that can guarantee it wont rattle. I'm not going smaller in capacity, the 5L torque and grunt is addictive. I suspect a 4.7 with turbo or supercharger is a superior option but at all that cost and complexity. Ummmm
Yeah that's where I am too so if you do find one I'd really appreciate an update. TVR Power in Coventry seem pretty well versed in this issue but I've not spoken with them yet. A bit of me is tempted to just leave it because it clearly doesn't seem to be something that causes any kind of catastrophic failure..it just bugs the hell out of me! Like you I still don't regret going for a 500. My father has a 450 and even he admits the difference in grunt is huge. I certainly don't need mine to go any faster!Urrr. Just need an engine builder that can guarantee it wont rattle. I'm not going smaller in capacity, the 5L torque and grunt is addictive. I suspect a 4.7 with turbo or supercharger is a superior option but at all that cost and complexity. Ummmm
Diagnose it properly and fix it once.
Assuming you need to do this or that gets very expensive, very quickly.
Internal and external callipers,, feeler gauge, a DTI gauge and a micrometer will be your friends assuming you have the turning gear to pull it all apart.
Don’t be like the last fella who had a full top-end job that wasn’t necessary - remember that ‘firing the parts cannon’ is the wrong approach.
Go and buy a crane before lunch, you’ll have the engine out before dinner.
Tomorrow is measire&check day, wait for Royal Mail and next weekend is rebuild&refit weekend.
Stop making excuses and do it.
Assuming you need to do this or that gets very expensive, very quickly.
Internal and external callipers,, feeler gauge, a DTI gauge and a micrometer will be your friends assuming you have the turning gear to pull it all apart.
Don’t be like the last fella who had a full top-end job that wasn’t necessary - remember that ‘firing the parts cannon’ is the wrong approach.
Go and buy a crane before lunch, you’ll have the engine out before dinner.
Tomorrow is measire&check day, wait for Royal Mail and next weekend is rebuild&refit weekend.
Stop making excuses and do it.
scoobywheeler said:
Not on my car. Only the clacking, tappetty rattle on overrun. Classic little end noise, but only there when warm.
As said above mine is the same, only the noise on overrun, as soon as revs drop and settle into idle the noise stops. The engine is normal, apart from the overrun noise, smooth until approaching 5k rpm when it changes with a harshness being felt - this is not an issue as the best performance is between 3750 and 4750 and pointless going beyond.Have had the overrun noise for 15 years and around 45k miles, without change - am not going to invest in changing to new pistons and perhaps new rods because of a irritating noise which only presents itself when blipping the throttle.
The car is approaching 95k miles, so perhaps in the near future cam, timing chain will need to be refreshed and will look at the bottom end as part of the project. The heads were refreshed 6 years ago when a cracked rocker pad mushroomed a valve stem, so had both heads rebuilt.
I believe that there is always a trade off - remember in my youth having a Cooper S with race engine - the pistons did not have a proper oil control ring and it was bored a little oversize, all to cut down on piston drag - it was very noisy due to the straight cut gear box and burnt a little oil on overrun - if I had wanted civility would have bought a Standard 850 Mini
Am sure that today far better configurations are available to build a 5L Rover engine, but back in 1994 probably with a development budget of £100.00 TVR made something that people wanted at very reasonable cost.
IMHO - Andy
This ^^^^^^^ 
I was talking about Silicone Kid noise which I think is from start up then disappears after a few minutes.
Sounds like oil starvation to big ends. ( I emphasise sounds like )
I’d at least get someone to check big ends shells for wear.
scoobywheeler said:
Not on my car. Only the clacking, tappetty rattle on overrun. Classic little end noise, but only there when warm.
Crossed lines I was talking about Silicone Kid noise which I think is from start up then disappears after a few minutes.
Sounds like oil starvation to big ends. ( I emphasise sounds like )
I’d at least get someone to check big ends shells for wear.
Classic Chim said:
This ^^^^^^^
I was talking about Silicone Kid noise which I think is from start up then disappears after a few minutes.
Sounds like oil starvation to big ends. ( I emphasise sounds like )
I’d at least get someone to check big ends shells for wear.
Is it possible a sandwich plate and oil cooler could starve oil ? Maybe I should remove it .scoobywheeler said:
Not on my car. Only the clacking, tappetty rattle on overrun. Classic little end noise, but only there when warm.
Crossed lines I was talking about Silicone Kid noise which I think is from start up then disappears after a few minutes.
Sounds like oil starvation to big ends. ( I emphasise sounds like )
I’d at least get someone to check big ends shells for wear.
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