Take it apart and have a look!!
Discussion
After reading much of the discussions on the S6 engine regarding reliability and design changes etc., I'm compelled to ask the question:
Has someone/organisation ever actually taken an old engine and compared it to a newer supposedly sorted engine and published their findings on PH?
An engine is after all a fairly simple machine be it a TVR engine or otherwise. Component design/material changes should be easy to spot by a trained eye.
It would put an end to the hearsay and rumor a lot of the threads are based on and actually shed some light on what appears to be a needlessly murky topic.
Has someone/organisation ever actually taken an old engine and compared it to a newer supposedly sorted engine and published their findings on PH?
An engine is after all a fairly simple machine be it a TVR engine or otherwise. Component design/material changes should be easy to spot by a trained eye.
It would put an end to the hearsay and rumor a lot of the threads are based on and actually shed some light on what appears to be a needlessly murky topic.
I have to admit I'm really surprised that Sprint, who used to be really cautious with respect to the factory, have run this article, and the Speed Six Engine tech one...
Not to sure about the policy of 'advertorials, adverts are one thing, but this seems like an endorsement.
Edited to add , liked you article, you're never old enough to have 21 year old surely...
B
>> Edited by bjwoods on Saturday 6th August 16:04
Not to sure about the policy of 'advertorials, adverts are one thing, but this seems like an endorsement.
Edited to add , liked you article, you're never old enough to have 21 year old surely...
B
>> Edited by bjwoods on Saturday 6th August 16:04
I’d like to read the article but I’m gonna have to wait till I’m back in Blighty....is there a Baghdad branch of the TVRCC? ;-)
Have you read the article? Is it factual and to the point? Does it actually detail what the S6 engine problems are and how to get them fixed or does it have a whiff of endorsement to it as bjwoods suggested?
Have you read the article? Is it factual and to the point? Does it actually detail what the S6 engine problems are and how to get them fixed or does it have a whiff of endorsement to it as bjwoods suggested?
dvs_dave said:
I’d like to read the article but I’m gonna have to wait till I’m back in Blighty....is there a Baghdad branch of the TVRCC? ;-)
Have you read the article? Is it factual and to the point? Does it actually detail what the S6 engine problems are and how to get them fixed or does it have a whiff of endorsement to it as bjwoods suggested?
If you would like to email me an address through my profile I would be more than happy to photocopy the article and send it to you.
Di
bjwoods said:
I have to admit I'm really surprised that Sprint, who used to be really cautious with respect to the factory, have run this article, and the Speed Six Engine tech one...
Not to sure about the policy of 'advertorials, adverts are one thing, but this seems like an endorsement.
Edited to add , liked you article, you're never old enough to have 21 year old surely...
B
>> Edited by bjwoods on Saturday 6th August 16:04
Yep,
daughter just finished UNI, its owning a Tuscan that keeps me young. There you go Barry, another reason for getting one.
Di
dvs_dave said:
Has someone/organisation ever actually taken an old engine and compared it to a newer supposedly sorted engine and published their findings on PH?
That's a great idea. I guess that TVRCraft have done it but are keeping there findings until the talk/for their customers.
I get the impression that there's not a lot of difference from the first to the newest apart from some improved materials - hopefully. Some improvements like throttle bodies have been mentioned on PH but nothing ground breaking.
Forget the sprint article - there's nothing new and many mistakes. Great reading for the casual obserber and some nice 'photos but nothing that wasn't on here long ago.
JR said:
I get the impression that there's not a lot of difference from the first to the newest apart from some improved materials - hopefully. Some improvements like throttle bodies have been mentioned on PH but nothing ground breaking.
Forget the sprint article - there's nothing new and many mistakes. Great reading for the casual obserber and some nice 'photos but nothing that wasn't on here long ago.
This was very much my impression. Could be described as an infomercial, something you might find on late night sky telly. Nothing new here.
On my factory tour in April I asked this question. Normally they don't show people round the engine workshop anymore, probably due to the sensitivity, but we pushed a little and they took us inside.
The guys working there were engine builders as opposed to mechanics. they didn't no too many details of the spec of the engine, they just assemble it. For example we asked them questions like bore, stroke, weight of flywheel, throttle bodies, and they didn't know. they did weight the flywheel for us and it was only 5Kgs though. They probably wouldn't be aware if the grade of a component had changed unless it looked totally different.
We asked them whether the design of the engine had evolved in any way, and they showed us a new housing for where the oil pump bolts on to the block. The previous housing had a 90 degree bend, whereas the new version was straight through for improved oil flow. They were just starting to fit these in April.
So from this we can ascertain that at least 1 thing has changed. And that being the case it's quite possible that more have change because having spoken to them, I doubt the guys would notice unless the component looked obviously different.
We did get to see the blocks, cranks, pistons, cams, heads, valves etc. My own impression of the engine (and I have rebuilt my own in the past) are that it has been designed as a very strong unit. The block is heavily braced for extra rigidity. It's design is more akin to a motorcycle engine than a car. Please take into account that this was a 20 min visit so I'm only giving you my impressions. But going by what I saw I would have to say that the intention did seem to be of a very strong hi-tech race bred engine. The components were of good quality (you can tell BTW). My guess is that these failures have been related to one or two components in particular that have proven to be substandard or of poor quality, perhaps coupled with a minor design flaw, such as the main oil feed.
The fact that something has changed though would indicate that they are working on the problem. They wouldn't change the design on the housing just for fun if something else was badly wrong. Would they?
The guys working there were engine builders as opposed to mechanics. they didn't no too many details of the spec of the engine, they just assemble it. For example we asked them questions like bore, stroke, weight of flywheel, throttle bodies, and they didn't know. they did weight the flywheel for us and it was only 5Kgs though. They probably wouldn't be aware if the grade of a component had changed unless it looked totally different.
We asked them whether the design of the engine had evolved in any way, and they showed us a new housing for where the oil pump bolts on to the block. The previous housing had a 90 degree bend, whereas the new version was straight through for improved oil flow. They were just starting to fit these in April.
So from this we can ascertain that at least 1 thing has changed. And that being the case it's quite possible that more have change because having spoken to them, I doubt the guys would notice unless the component looked obviously different.
We did get to see the blocks, cranks, pistons, cams, heads, valves etc. My own impression of the engine (and I have rebuilt my own in the past) are that it has been designed as a very strong unit. The block is heavily braced for extra rigidity. It's design is more akin to a motorcycle engine than a car. Please take into account that this was a 20 min visit so I'm only giving you my impressions. But going by what I saw I would have to say that the intention did seem to be of a very strong hi-tech race bred engine. The components were of good quality (you can tell BTW). My guess is that these failures have been related to one or two components in particular that have proven to be substandard or of poor quality, perhaps coupled with a minor design flaw, such as the main oil feed.
The fact that something has changed though would indicate that they are working on the problem. They wouldn't change the design on the housing just for fun if something else was badly wrong. Would they?
I went to a talk at Speed 6 Engine Tech(Henley Heritage) a month or two ago where they have
a senior engine builder from the TVR factory now working for them doing re-builds, you might see them advertised in Sprint.
From what I learnt that night, basically if you have an engine from 2004 onwards or a 2004 + rebuild it should be fine. Biggest problem at the factory is lack of time and care in the re-build department.
Also you will get your own engine block back but may get a different head, so it could be a head that is new or been re-built 4 times.
The chap at HH did a lot of work on the race engines so when he re-builds them he can put a handful of little extra mods in that the factory don't bother with at re-builds due to time constraints.
Main engine changes on 2004+ engines are:
Solid camshafts (rather than hollow with oilways)
Teflon coated valves
Rock solid finger followers
Harder head bolt washers to stop head gasket failures
Plus a few others I cannot remember.
He said the finger follower problem was due to it being a 2 piece design and of crap quality. Now is it a one piece high quality component.
The engine chap reckoned a good engine will last 35,000 miles which is still crap, but he said it really is a race car engine design.
Since then I have learnt of 3 2005 factory engines that have failed....
One thing he said was the rear 2 cylinders get very hot due to lack of water cooling so is is just as important to let it cool down as well as warm it up. ie at a track day don't thrash it then switch the engine straight off, let it run for a bit to cool down. Race engines have a special mod in the block to help this.
cheers
Whitey
a senior engine builder from the TVR factory now working for them doing re-builds, you might see them advertised in Sprint.
From what I learnt that night, basically if you have an engine from 2004 onwards or a 2004 + rebuild it should be fine. Biggest problem at the factory is lack of time and care in the re-build department.
Also you will get your own engine block back but may get a different head, so it could be a head that is new or been re-built 4 times.
The chap at HH did a lot of work on the race engines so when he re-builds them he can put a handful of little extra mods in that the factory don't bother with at re-builds due to time constraints.
Main engine changes on 2004+ engines are:
Solid camshafts (rather than hollow with oilways)
Teflon coated valves
Rock solid finger followers
Harder head bolt washers to stop head gasket failures
Plus a few others I cannot remember.
He said the finger follower problem was due to it being a 2 piece design and of crap quality. Now is it a one piece high quality component.
The engine chap reckoned a good engine will last 35,000 miles which is still crap, but he said it really is a race car engine design.
Since then I have learnt of 3 2005 factory engines that have failed....
One thing he said was the rear 2 cylinders get very hot due to lack of water cooling so is is just as important to let it cool down as well as warm it up. ie at a track day don't thrash it then switch the engine straight off, let it run for a bit to cool down. Race engines have a special mod in the block to help this.
cheers
Whitey
whitey said:
lots of informative stuff
***
I should qualify something - when I said I had rebuilt my own engines in the past I was not referring to the S6 LOL. I've rebuilt 3 engines. The most notable being a Kawasaki GPz1000A3 unit. These old jap bike engines are not a million miles from the like of the S6 in their basic design, except for being air cooled, wet sump, and wet multiplate clutch. The Zed had individual throttle bodies, and being a motorcycle there is no flywheel as such. But they are high revving, high compression, lightweight, all alloy, in-line engines with twin camshafts and 4 valves per barrel (at least I think it had 4 valves), hot cams and under bucket shims. They also have very beefy bottom ends. I'm not an expert but I can tell the difference between an engine that has been designed to be strong, and has been developed to operate under a high state of tune.
***
My guess is that the worst of the problems are now behind us. The TVRcraft solution will probably be more bombproof (just to be on the safe side).
I'm at 5000 miles now and the car is just feeling broken in. The exhaust note has become throatier and the engine feels free-er.
whitey said:
Biggest problem at the factory is lack of time and care in the re-build department.
a handful of little extra mods in that the factory don't bother with at re-builds due to time constraints.
Main engine changes on 2004+ engines are:
Solid camshafts (rather than hollow with oilways)
Teflon coated valves
Rock solid finger followers
Harder head bolt washers to stop head gasket failures
Plus a few others I cannot remember.
He said the finger follower problem was due to it being a 2 piece design and of crap quality. Now is it a one piece high quality component.
The engine chap reckoned a good engine will last 35,000 miles which is still crap, but he said it really is a race car engine design.
This is probably the most useful S6 thread ever.
Apart from the oil pump housing and general impressions it now appears to be confirmed that flawed details of both design and quality of the engine have been improved over time but that because of the basic design (is this the same point as it being basically a race engine?) and less than adequate quality of assembly of some cars then some engines are destined for a shorter than expected life.
The only change that surprises me is the loss of oilways in the cam shaft. This is only likely to add say 5% maximum to strength but (as well as adding a minimal amount of weight,) would surely cause cooling problems?
It will be interesting to see the approach that MCD favours over this apparent steady development.
Some very useful info has come to light in this thread.
It looks like the mods to the valve train have been made to make the system more rigid and reduce operating friction; A surefire way to control and minimise any undesirable/excess loads that can cause premature failures.
Regards the removal of the oil channel through the cam shaft...perhaps the camshaft was flexing a little too much in operation, potentially putting detrimental loads on the rest of the valve gear and causing the well known finger follower and valve guide modes of failure. It only takes a little of bit of flex for a high speed dynamically loaded shaft to start oscillating and flexing even more and compounding the problem.
The improved oil flow system probably compensates for the loss of the oil way through the camshaft.
It looks like the mods to the valve train have been made to make the system more rigid and reduce operating friction; A surefire way to control and minimise any undesirable/excess loads that can cause premature failures.
Regards the removal of the oil channel through the cam shaft...perhaps the camshaft was flexing a little too much in operation, potentially putting detrimental loads on the rest of the valve gear and causing the well known finger follower and valve guide modes of failure. It only takes a little of bit of flex for a high speed dynamically loaded shaft to start oscillating and flexing even more and compounding the problem.
The improved oil flow system probably compensates for the loss of the oil way through the camshaft.
dvs_dave said:
Regards the removal of the oil channel through the cam shaft...perhaps the camshaft was flexing a little too much in operation, potentially putting detrimental loads on the rest of the valve gear and causing the well known finger follower and valve guide modes of failure. It only takes a little of bit of flex for a high speed dynamically loaded shaft to start oscillating and flexing even more and compounding the problem.
The only thing is what dia. is the shaft and what dia is the oilway? eg a 13mm dia shaft and a 2mm dia oilway: remove the oilway and the strength increase is ( 2cubed x 100 / 13cubed ) or about less than half a percent.
>> Edited by JR on Monday 8th August 21:52
JR said:
The only thing is what dia. is the shaft and what dia is the oilway? eg a 13mm dia shaft and a 2mm dia oilway: remove the oilway and the strength increase is ( 2cubed x 100 / 13cubed ) or about less than half a percent.
It's a little more complicated than you make out. For example, it seems you have assumed that the shaft is of uniform cross section and that the oil way simply runs straight through the center of it. A camshaft does not have a uniform cross section and the oil way will have numerous outlets along its length considerably altering the stress concentrations in the shaft around these areas.
A detailed Finite Element analysis of the shaft (before and after the mods) in operation would display a lot more info about the shaft’s behavior than you might expect. A seemingly small yet well exceuted modification can produce significant behavior changes in components under complex dynamic stress patterns.
>> Edited by dvs_dave on Tuesday 9th August 08:15
whitey said:
The engine chap reckoned a good engine will last 35,000 miles which is still crap, but he said it really is a race car engine design.
35,000 miles? Why put a 'race engine' in a road car? There are plenty of engines putting out a reliable 350bhp that should sail past 100k.Gassing Station | Speed Six Engine | Top of Page | What's New | My Stuff