History of 4.0HC engines
Discussion
After taking many jibes about the 'HC' engine in the V8S I've done a bit more digging.
In the past SH has correctly said that my car maybe a little too early to have what is accepted as a normal Chim 4.0HC engine.
So after just having the service done and knowing it's been getting a bit tappety I had the compresions done, whilst not bad they are down
.
Two plus two = cam, it may need doing in the near future .
I've assumed until now that the HC had the same cam as the early 500's, the 435, so I had a brief conversation with TVR Power this afternoon.
It turns out as suspected I think by SH, it was a developement engine that went before the 4.0HC and is a "speed 8 GT spec" according to Power. Unfortunately it wasn't ported as I'd secretly wished it does, albeit slightly rounded off now 
, have a developement cam that was subsequently tamed and called the kent 214 cam and stronger valve springs fitted
. This may go some way to explaining the low rev performance of the car.
What is the earliest 4.0HC car out there you know of, mine is a march 94, when did the HC really come into being/standard (yes I know standard is not a term we should be using in the TVR context)
Some more questions, I will get this cam and associated bits done, probably towards the end of summer, but is it worth getting Power to provide/fit the same cam in keeping with the car, or go for the HC 435 one, or go for a better mannered 218
.
Another Q, the standard ECU is labeled as HC (well the permanent marker says so, to be more accurate), I read somewhere that even the standard TVR ECU EPROMS have been updated over the years, has anyone done this, rather than go down the tornado route, just updated the standard EPROM. Its £75 for new EPROM against £350 plus ? for the tornado,can't be much harm in it or is it a waste of time .
Harry
In the past SH has correctly said that my car maybe a little too early to have what is accepted as a normal Chim 4.0HC engine.
So after just having the service done and knowing it's been getting a bit tappety I had the compresions done, whilst not bad they are down
. Two plus two = cam, it may need doing in the near future . I've assumed until now that the HC had the same cam as the early 500's, the 435, so I had a brief conversation with TVR Power this afternoon.
It turns out as suspected I think by SH, it was a developement engine that went before the 4.0HC and is a "speed 8 GT spec" according to Power. Unfortunately it wasn't ported as I'd secretly wished
it does, albeit slightly rounded off now , have a developement cam that was subsequently tamed and called the kent 214 cam and stronger valve springs fitted. This may go some way to explaining the low rev performance of the car. What is the earliest 4.0HC car out there you know of, mine is a march 94, when did the HC really come into being/standard (yes I know standard is not a term we should be using in the TVR context
) Some more questions, I will get this cam and associated bits done, probably towards the end of summer, but is it worth getting Power to provide/fit the same cam in keeping with the car, or go for the HC 435 one, or go for a better mannered 218
. Another Q, the standard ECU is labeled as HC (well the permanent marker says so, to be more accurate
), I read somewhere that even the standard TVR ECU EPROMS have been updated over the years, has anyone done this, rather than go down the tornado route, just updated the standard EPROM. Its £75 for new EPROM against £350 plus ? for the tornado,can't be much harm in it or is it a waste of time . Harry
Mines definately a 4.0HC - says so on the order sheet (still have a copy of the original and delivery note!!! - mind you that doesnt mean much these days). The car is a 94 model Chimaera and does definately have more power than a 4.0.
However, on the question of ECUs - be careful. Get it checked out. My ECU went last year and I had an awful job getting one sorted out. The 'normal' 4.0HC actually runs a non-standard chip in it from the 4.0 - small changes to the mapping I am lead to believe. It is supposed to be the same as the 4.0 as the HC is supposed to indicate the porting of the head and a couple of other internal changes - not a chip change...
So can you have the chip changed or a Tornado fitted - probably but could be risky. Chances are you have a non-standard chip present and therefore you need to have that program adjusted rather than a standard / modified 4.0 chip added. My recommendation would be get the car to Mark Adams and let him do his magic. Complete rolling road and re-tune of the chip will sort that out for you - better than a Tornado one anyway. Looking at around the £800 mark I think - its expensive because Mark needs the rolling road session to sort out the program - they arent cheap...
Cheers,
Paul
However, on the question of ECUs - be careful. Get it checked out. My ECU went last year and I had an awful job getting one sorted out. The 'normal' 4.0HC actually runs a non-standard chip in it from the 4.0 - small changes to the mapping I am lead to believe. It is supposed to be the same as the 4.0 as the HC is supposed to indicate the porting of the head and a couple of other internal changes - not a chip change...
So can you have the chip changed or a Tornado fitted - probably but could be risky. Chances are you have a non-standard chip present and therefore you need to have that program adjusted rather than a standard / modified 4.0 chip added. My recommendation would be get the car to Mark Adams and let him do his magic. Complete rolling road and re-tune of the chip will sort that out for you - better than a Tornado one anyway. Looking at around the £800 mark I think - its expensive because Mark needs the rolling road session to sort out the program - they arent cheap...
Cheers,
Paul
Paul
re the chip bit, I appreciate that the chip in my ECU is a HC chip not a standard 4.0 one, it was just that John Ravenscroft/TVR Power have updated the software on these chips over the years.
My specific question for the ECU was as mine is a very early HC chip would there be any mileage in getting a replacement one from TVR Power which would (assumption now) have an updated HC map, if you see where I'm going with this.
I do not dispute that Mark Adams can do more with a Tornado chip. I was thinking of the TVR chip as a cheap short term measure before a cam change, and whether anyone has had a new HC chip fitted recently, if so did it make any difference.
Harry
re the chip bit, I appreciate that the chip in my ECU is a HC chip not a standard 4.0 one, it was just that John Ravenscroft/TVR Power have updated the software on these chips over the years.
My specific question for the ECU was as mine is a very early HC chip would there be any mileage in getting a replacement one from TVR Power which would (assumption now
) have an updated HC map, if you see where I'm going with this. I do not dispute that Mark Adams can do more with a Tornado chip. I was thinking of the TVR chip as a cheap short term measure before a cam change, and whether anyone has had a new HC chip fitted recently, if so did it make any difference.
Harry
Harry
You would be better off getting the Mark Adams treatment than rely on getting an upgrade to match what ever new cam is fitted to your car. The engine is a real bitsa and the chances of one of the upgrades ECU chips being a good match is pretty slim. The real HC appeared around the August September time frame ish or about 4-500 engines on from yours!
The speed 8 designation also dates back to 1989! It was used on an internal development back then.
You would be better off getting the Mark Adams treatment than rely on getting an upgrade to match what ever new cam is fitted to your car. The engine is a real bitsa and the chances of one of the upgrades ECU chips being a good match is pretty slim. The real HC appeared around the August September time frame ish or about 4-500 engines on from yours!
The speed 8 designation also dates back to 1989! It was used on an internal development back then.
Chips are cheap (EPROMS) and easy to change them...the problem (and the money) goes to the drivers(engine managment) that leading it and who/how will programm it.
Best solution offcourse is a full re-mapable ECU, they are expensive, but you can do anything with the engine managment afterall.
ByronTVR
>> Edited by ByronTVR on Thursday 20th February 20:09
Best solution offcourse is a full re-mapable ECU, they are expensive, but you can do anything with the engine managment afterall.
ByronTVR
>> Edited by ByronTVR on Thursday 20th February 20:09
[trivia mode]
Another piece of trivia for those interested, found out today that the H214 is the standard cam for the 4.0HC, the kent 214 is apparently an approximation of the TVR one.
Some ('a handfull') of the 4.0HC's did have the 435 cam fitted, same cam as the early 500HC's, but this required bigger valves and pocketed piston crowns and gave limited improvement (possibily because of the standard 'restricted' breathing?) so wasn't done too often.
Again the 4.0HC, well 9 out of 10, have the vernier cam timing arrangement, but you'd have to take it apart to find out as it's not fully recorded, I'll let you know when mine comes apart later on what was there.
So are there mythical 4.0BV's out there as well as the 4.3's, :catpidgeoncat:.
[/trivia mode off]
Harry
Well I thought it was interesting anyway
Another piece of trivia for those interested, found out today that the H214 is the standard cam for the 4.0HC, the kent 214 is apparently an approximation of the TVR one.
Some ('a handfull') of the 4.0HC's did have the 435 cam fitted, same cam as the early 500HC's, but this required bigger valves and pocketed piston crowns and gave limited improvement (possibily because of the standard 'restricted' breathing?) so wasn't done too often.
Again the 4.0HC, well 9 out of 10, have the vernier cam timing arrangement, but you'd have to take it apart to find out as it's not fully recorded, I'll let you know when mine comes apart later on what was there.
So are there mythical 4.0BV's out there as well as the 4.3's
, :catpidgeoncat:. [/trivia mode off]
Harry
Well I thought it was interesting anyway
trefor said: So, has anyone had a Mark Adams session/Tornada chip on a 4.0HC and how much power/torque did it make pre/post tune up?
Yours interestedly.
I think maneks HC Chim, before he sold it, was making a true 240 once breathed on by MA.
Harry
Edited to add I think it may of actually been nearer 235bhp
>> Edited by HarryW on Monday 3rd March 21:53
Gassing Station | General TVR Stuff & Gossip | Top of Page | What's New | My Stuff