The V8 Owners Forum -

This is my first message on this forum and hopefully someone may be able to shed some more light on the engine specs of my V8.
Since last year I own a Ginetta G33 and I enjoy my car very much. I try to find out the specs of my engine and while surfing on the internet I found many different specs for one type of engine.
The engine number reads the following: CR 9 35.1 TVR 240 G2 47A00990A.
The first part presumably indicates the compression ratio, and the last part refers to an engine type used for a Morgan Plus 8.
I contacted a former employee of Ginetta who informed me that this engine was sourced by Ginetta from TVR Power. My plenum cover shows the text: '400 SE'. It may thus be well possible that my Ginetta has the same engine as a TVR 400 SE.
I have seen specs for a 400 SE engine with displacements varying from 3.943 cc up to 3.998 cc and power outputs varying from 268 to 278.8 hp. I had my car dyno-tested and (after new exhausts and changes to Air/Fuel Ratio) output showed 236.7 hp @ 5275 rpm and torque 365 Nm @ 3887 rpm.
What did TVR power modify on this engine compared to a standard 3.9 Rover V8 to increase the power output, without changing bore and stroke?

Looking forward to your comments!

Regards,
Miel[/b]

What did TVR power modify on this engine compared to a standard 3.9 Rover V8 to increase the power output, without changing bore and stroke?

welcome to the forum,

main mods are head work and cam changes,
hopefully some of our TVR owners on the forum can give you more info,

BUT never believe genuine TVR quoted figures, not sure on TVR Powers figures though

My 4.3 from a Griff had about 270 on the rollers so not a million miles from the 280 quoted by TVR, just wish it was the BV version

Miel,

Power output is what I would expect from a 3.9 engine with fast road cam and stage 3 big valve heads and possibly a rechip on the ECU.

And yes TVR were notorius at overstating power outputs on the Rover engines.

Although it states the compression ratio as 9.35/1 on the block the head mods may have increased the CR to around 10/1

As a rule of thumb an old pushrod V8 will produce in fast road tune approx 60 BHP per litre or 1 BHP per cubic inch whichever you prefer so 3.95 x 60 = 237BHP so your figure is very close.

Kevin.

Ask TVR Power they will know exactly what they built.

CastleMGBV8 wrote:Miel,

Power output is what I would expect from a 3.9 engine with fast road cam and stage 3 big valve heads and possibly a rechip on the ECU.

And yes TVR were notorius at overstating power outputs on the Rover engines.

Although it states the compression ratio as 9.35/1 on the block the head mods may have increased the CR to around 10/1

As a rule of thumb an old pushrod V8 will produce in fast road tune approx 60 BHP per litre or 1 BHP per cubic inch whichever you prefer so 3.95 x 60 = 237BHP so your figure is very close.

Kevin.

Hi Kevin,

Thanks for your reply, and your explanations. They are very welcome!
Being a newbie and not mechanically educated ( I am a civil engineer) I am more and more surprised to notice the existence of so many interpretations and variations in types and specs for a single type V8 engine produced by one fabricator for a single model car.
The engine was produced in the beginning of the '90's, a period in which to my opinion quality assurance, databases and engineering/production documents were common sense and well accepted, however, apparently not yet by TVR Power. Besides that it is unclear to me what people mean by power output; i.e. bhp, hp, DIN-hp, SAE-hp, and how and where measured. (When I bought this car it was stated to have approx. 300 hp!) By the way: good to hear my figure seems quite close.
Furthermore, it is difficult for me to judge the specs from an engine just from the outside. If I would really want to know the specs, there is probably only one solution: Open up the engine. Only then I may be able to know my engine has another cam, big valves, a different CR and a Stage 3 head!? I am very reluctant to do that: if it is not broke, do not repair it!
Re-chipping the ECU might be one of the first solutions in order to let this machine perform as intended. Just to let you know, I am only interested to have a smooth running fast road engine: I am not using my car for races and/or hill climbs.
Thanks again, this forum is a good opportunity to enhance my knowledge, which increases more and more on this subject!

spend wrote:Ask TVR Power they will know exactly what they built.

Hi Dave,

I have sent an email through the website of TVR (http://www.tvr.co.uk/). This site shows 'website launches soon' and when you click that item one is able to send an email to sales@tvr.co.uk. Unfortunately that mail has to date not yet been answered.
I visited the local importer of TVR in the Netherlands and, although very friendly, they could also not help me. I also got the impression that they accept the present situation not hearing much from the fabricator regarding future developments of any new models from TVR. And thus not having contact with them frequently.

Did I contact the wrong people?

Regards,
Miel

r2d2hp wrote:My 4.3 from a Griff had about 270 on the rollers so not a million miles from the 280 quoted by TVR, just wish it was the BV version

Can you please explain to me what BV version is?

Thanks!
Regards,
Miel

Hi
BV is Big Valve engine, ie stage 3 heads (well ish if the rest of the flow work has been done) If they are a semi production engine as this one probably is they will be stage 2 1/2 in that the big valves will have been fitted and a basic opening out of the area behind the valves done but probably not hand finnished.
Best regards
Mike

Miel,

I think you said it, if it isn't broke don't try and fix it.

The power output you have will provide ample performance for road use, more power is always seductive but may not provide the driving experience you expect, In my opinion, overall drivabilty is more important with a smooth spead of power across the rev range.

You can further increase the power of a 3.9 but for more power at the top you you will have to sacrifice quite a bit at the bottom.

Drive it as it is and see how you like it, if you feel you need more, look out for a good 4.6 bottom end and fit a decent cam and new lifters and transfer the other parts from your existing engine, check the heads when they are off to see if they would benefit from more work to release a bit more power from the 4.6 (4552cc.) engine.

A good road cam would be a Crower 50232 which has peak power at 5500RPM and in an 4.6 with decent heads would make 280 + BHP but you might have to swap the ECU to a programmable one such as Megasquirt or similar this gets rid of the airflow meter which also restricts flow and consequently ultimate power.

The 4.6 is a long (82mm.) stroke engine so makes lots of torque so you can get away with a hotter cam like the Crower 50232 which I have in my 4.35 engine, especially in a fairly light car, no point fitting anything much hotter as the 4.6 does not like to rev much over 5500RPM.

Let us know how you get on and if you need any help or advice on where to source parts, you know where to come.

Kevin.

kiwicar wrote:Hi
BV is Big Valve engine, ie stage 3 heads (well ish if the rest of the flow work has been done) If they are a semi production engine as this one probably is they will be stage 2 1/2 in that the big valves will have been fitted and a basic opening out of the area behind the valves done but probably not hand finnished.
Best regards
Mike

Thank you Mike for your explanation.
Next challenge is: How to find out? Engine numbers are hard to distinguish and opening engine is not what I prefer, besides that my budget is very tight this year.
Regards,
Miel

Miel wrote:

spend wrote:Ask TVR Power they will know exactly what they built.

Hi Dave,

I have sent an email through the website of TVR (http://www.tvr.co.uk/). This site shows 'website launches soon' and when you click that item one is able to send an email to sales@tvr.co.uk. Unfortunately that mail has to date not yet been answered.
I visited the local importer of TVR in the Netherlands and, although very friendly, they could also not help me. I also got the impression that they accept the present situation not hearing much from the fabricator regarding future developments of any new models from TVR. And thus not having contact with them frequently.

Did I contact the wrong people?

Regards,
Miel

Miel TVR and TVR power are 2 seperate entities, you need to send your email to Dom at http://www.tvrpower.co.uk/

You won't get a reply from TVR as they no longer, in any real sense, exist.

Baracus wrote:

Miel wrote:

spend wrote:Ask TVR Power they will know exactly what they built.

Hi Dave,

I have sent an email through the website of TVR (http://www.tvr.co.uk/). This site shows 'website launches soon' and when you click that item one is able to send an email to sales@tvr.co.uk. Unfortunately that mail has to date not yet been answered.
I visited the local importer of TVR in the Netherlands and, although very friendly, they could also not help me. I also got the impression that they accept the present situation not hearing much from the fabricator regarding future developments of any new models from TVR. And thus not having contact with them frequently.

Did I contact the wrong people?

Regards,
Miel

Miel TVR and TVR power are 2 seperate entities, you need to send your email to Dom at http://www.tvrpower.co.uk/

You won't get a reply from TVR as they no longer, in any real sense, exist.

Great!
Thanks, I shall send them an email!
Regards,
Miel

Yes its dom at tvrpower you need to email, he has been there long enough to know the history

TVR BV heads are extensively ported with 1.69"/1.5" valves and will happily support 350bhp+ NA. Not sure stage 3 is what you called them, but I don't really care for that scaling anyway. I've only ever heard of one instance of them being installed on one road going 4 litre car BTW and that wasn't by the factory.

Most TVR400SE will produce 230-250BHP on the rollers. (so within 10% of quoted TVR figures)
Main mods was Ported heads, Better Cam, Higher compression, with flat pistons.