What difference does 'HC' make to engines?
Discussion
I have followed many threads on this topic and am still none the wiser.
There are some threads in the Griff forum too if you want to look.
The real answer appears to be that nobaody knows, not even the factory! So many conflicting answers.
The one I like the best is the one in my handbook ('96 500HC Griff) which says 500HC = 340BHP.
I know its not true but I still says it in the book so for the meantime, Im happy
There are some threads in the Griff forum too if you want to look.
The real answer appears to be that nobaody knows, not even the factory! So many conflicting answers.
The one I like the best is the one in my handbook ('96 500HC Griff) which says 500HC = 340BHP.
I know its not true but I still says it in the book so for the meantime, Im happy
test drove all sorts of chims before I bought mine. The only variant I didnt try was a 4.3 - and that wasnt for want of trying eh trackdemon 
Personally I couldnt notice any difference with the HC engine against the standard. certainly not the quoted 30bhp or whatever its supposed to be. Maybe a drag race you may notice a slight difference but I certainly didnt. Having said that, IMO no 2 TVRs drive the same anyway. Some of the 4 litres I drove seemed quicker than others. Same was said about my last TVR, an S3, which was said by many to be very quick for a V6S....
Personally I couldnt notice any difference with the HC engine against the standard. certainly not the quoted 30bhp or whatever its supposed to be. Maybe a drag race you may notice a slight difference but I certainly didnt. Having said that, IMO no 2 TVRs drive the same anyway. Some of the 4 litres I drove seemed quicker than others. Same was said about my last TVR, an S3, which was said by many to be very quick for a V6S....
There is a "slight" difference in power between a non-HC 400 and a 400HC. However, I would stress that its only "slight". There is a little more torque too, but it varies soo much between engines that its not worth bothering about. There is not a huge about of difference mechanically too - though other than the cam, the chip in the ECU is different. The standard 400 has a normal LR chip, while the HC has a TVR specific one..... as I know from bitter experience...
"hooks Crumpet" but they all do that sir. The 4.0L HC is meant to have a different cam polished inlet porting, and pocketed pistons, it's true that some standard cars made more power but this is because TVR Power probably used the occasional high spec cam standard engines it's a case of what was available that day, on the whole the HC produces a bit more grunt.
for the 500 they are all "HC" bar a few high torque engines.
Tim
>> Edited by 2 sheds on Wednesday 19th May 16:10
pbrettle said:
There is a "slight" difference in power between a non-HC 400 and a 400HC. However, I would stress that its only "slight". There is a little more torque too, but it varies soo much between engines that its not worth bothering about. There is not a huge about of difference mechanically too - though other than the cam, the chip in the ECU is different. The standard 400 has a normal LR chip, while the HC has a TVR specific one..... as I know from bitter experience...
I'll go along with this. I can testify that on the open..... erm... track
(!!) the 4.0HC has the same performance as the 4.0 for all practical purposes. On paper the HC has more power and torque due to having a higher lift cam (hence HC, not High Compression) a different ECU, and IIRC, some very slight head fettling?? (open to being corrected here....), but in my experience it makes no difference..... my HC seems to have the same performance as non HC 4.0 Chims. PS:
Paul.... had a good trip back then, I trust?The HC engine has a high lift cam, pocketed pistons and a better speck engine. It also has a TVR ECU, and some porting done to the head.
All this is what is supposed to happen but these are TVRs!!
As for bhp figures, I was told that TVR power built a pre-production model of each engine and bench tested it. This is where the BHP figures come from.
All this is what is supposed to happen but these are TVRs!!
As for bhp figures, I was told that TVR power built a pre-production model of each engine and bench tested it. This is where the BHP figures come from.
TheHobbit said:
PS:
Oh yes - managed Warrington to Wiltshire in a pretty amazing time. Then again it was 1:00AM! Roof off of course - did get some strange looks from a few drivers though, but to be expected I suppose.
Hope you had a good drive back too... everyone made it back OK I trust?
jonnyb said:
..
As for bhp figures, I was told that TVR power built a pre-production model of each engine and bench tested it. This is where the BHP figures come from.
I am lead to believe in my previous discussions with TVR power that mine was a'bench mule' for the 4ltr HC (TVR214 cam)engine.
When the engine the stripped last year for a complete rebuild the heads were standard, however the cam had changed to TVR435
, the pistons were pocketed though. The best bit was that it was, quiet rare for a TVR engine, fully dymanically balanced . AS for power, I don't think it had any where near the calimed standard 4ltr power let alone the HC one 
. If you wnat to aproach the calimed HC power, effectively what a good 5ltr actually produces, then it will cost many thousnads, trust me
. Harry
Thats right. TVR upped the standard 4 litre to a 4.0HC for absolutely no reason what so ever. They also stopped producing the standard 4 litre in preference to the 4.0HC some time ago because there was so little difference between them. A 98 4.OL is in fact a 4.0HC, its just that TVR were only producing the HC engine by then and so stopped differentiating.
'But you can't tell the difference'. Wrong. In the short time you get to take a car for a test drive, I'll give, you you can't tell the difference. However drive a 4.0HC for a few weeks then drive a 4.0L you'll know. I wander how many people posting on this topic have 4.0L engines ?
'But you can't tell the difference'. Wrong. In the short time you get to take a car for a test drive, I'll give, you you can't tell the difference. However drive a 4.0HC for a few weeks then drive a 4.0L you'll know. I wander how many people posting on this topic have 4.0L engines ?
roobarb said:
Thats right. TVR upped the standard 4 litre to a 4.0HC for absolutely no reason what so ever. They also stopped producing the standard 4 litre in preference to the 4.0HC some time ago because there was so little difference between them. A 98 4.OL is in fact a 4.0HC, its just that TVR were only producing the HC engine by then and so stopped differentiating.
'But you can't tell the difference'. Wrong. In the short time you get to take a car for a test drive, I'll give, you you can't tell the difference. However drive a 4.0HC for a few weeks then drive a 4.0L you'll know. I wander how many people posting on this topic have 4.0L engines ?
well i have but my opinion is based on a number of drives in different chims and having been on countless TVR runs with HC engined cars. I take that as meaning you are suggesting that its because we dont want to admit to having a slower car or that we havent driven an HC for long enough to know? shirley the same applies to HC owners that havent driven a standard 4 litre long enough to know?
I didnt notice a difference in the test drives. But as you rightly point out thats not really a long enough time to notice a subtle change (although long enough to notice a 5 litre
) . On the various TVR days out I cant say I have noticed an HC as being faster. But then every driver is different and I remain of the view every TVR is different. ON a drag strip the HC may be victorious, but I would also go so far as suggest on the rollers some 4 litres are putting out equivilent or more power than HCs. Every TVR engine appears to be completely different. The first chim I drove was an unloved HC (so many leaves under the bonnet you could barely find the engine) and it felt no quicker than my V6 S3. Gassing Station | Chimaera | Top of Page | What's New | My Stuff