Speed Six engines - myths and misconeptions

Speed Six engines - myths and misconeptions


TUS 373

Original Poster:

4,060 posts

264 months

Thursday 6th May 2004
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There has been a great deal of questions and debate about Speed Six engines on here - most of us are pretty sick and tired of it and hearing about how our engines are going to go bang and how the Tuscan's value is plummeting as a used buy. Unfortunately, one of the dangers of the internet is that anyone can post anything so fiction is difficult to divorce from fact.

Yesterday I visited the factory to openly ask them the questions I have always wanted to about this engine. I managed to speak to a nice gentlemen who certainly knows his stuff although I would prefer not to name names as the conversation was between him and me. Some interesting but truthful observations were made which I hope will go to dispel some of the myths on here once and for all.

Engine failures
The principal failure has been the finger followers (as we all know). The supplier of these components did not harden them all to spec so there has been variability from batch to batch - but there was no way of knowing which, and into what engine they went.

Current failures
Some cars receive more use than others but where finger followers have worn - cars have done between 6,000-12,000 miles. There are cars out there still failing because they have only just reached that kind of mileage. The occasional Sunday Tuscan driver does not necessarily rack up the miles.

Fixing it
The factory acknowledges the finger follower issue and continues to look upon customers with this resdiual problem sympathetically. However, it is a pre-requisite that the car has had the necessary services and at the correct intervals.

Mechanical sympathy
Not all drivers are the same. Some cherish their cars, others will have the engine bouncing off the rev limiter as soon as the ignition is on. It is essential that owners follow the sequence of allowing the OIL (not water) to reach temperature BEFORE exploring the higher reaches of the rev range.

Interestingly, TVR are capable of interrogating the ECU and seeing how the car has been driven. Those drivers who abuse the engine can be identified - and won't necessarily encourage goodwill from the factory.

2002, 2003 and 2004 spec engines
Complete myth. All Speed Six engines continue to follow the same design and use the same parts (OK, the finger followers are hardened to correct spec now). Anyone who has had a 2000-2001 engine rebuilt - has it rebuilt to the original spec - identical to the current engines. There have been no changes to oil ways etc etc. The heads from a 2000 and 2004 engine can be swapped over. They are identical OK! Therefore, anyone buying a 2000/2001 car is getting the same components they would today (except capacity difference between 3.6 and 4.0). If the engine has had its rebuild, there should be no fear of it giving up the ghost again.

Other problems
As with all engines, other bits can fail still as with any manufacturer. There are people out there who have had more than one rebuild or had a major catastrophe. These problems are less common and normally unrelated to the finger followers.

There are cars out there with 60,000-80,000 miles on the clock and have never had a rebuild at all. They have been looked after properly with respect to warming up and servicing, but nevertheless driven hard using the full rev range.

Differences between engines e.g. 4.0, 4.0 RR, 4.0 S
I didn't ask about the 3.6 unit but wanted to know the difference between the 4.0 litre variants. There will be differences to the ECU mapping, but their are mechanical difference between the engines with respect to components such as high lift cams - therefore it is not a programmed difference.

I know this will not answer everyone's questions and I have not included everything I learned here. However, people are welcome to email me offline with any specifics they have. I hope that this provides an objective viewpoint and dispels many of the myths that have been born.

I would like to thank everyone at TVR for their time and openess and giving me a little peak into what the supercharged S6 will be capable of in the Tyhpon. I think I would quite like one of those now!

Bryan / TUS 373

Mrs Fish

30,018 posts

241 months

Thursday 6th May 2004
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Well said Brian


34,334 posts

286 months

Thursday 6th May 2004
quotequote all
Useful info. I think we'll leave it at that as rather than let it get lost in a sea of opinion