rebuild time. 3.6 or 4.0.....?

[T40ORA]

Might seem a silly question, and I think I already know what I'll opt for, but what would you do? Stay 3.6 or go 4.0?

Any downside to the 4.0, wich doesn't actualy offer much more power (on paper)?

Ta.

[S5TVR]

What about rebuilding the 3.6 to red rose spec ?.

[icraigmy]

Hi Lee,

I have now done 9,500 since my 4.0L upgrade/rebuild. The most noticable thing about the 4.0L is that it has more torque than the 3.6L. I don't know if it is faster because I have'nt really exercised the engine yet. I think a rolling road session is in order soon when I have racked a few more miles up.

..... Again it depends on where you get your rebuild/upgrade done. Read my article in March's 2008 Sprint.

[Tangoed]

What about the Wilder option! or Power are doing a 4.3 upgrade, due out next month. Not sure of the costs

[T40ORA]

I'm going to go for the 4.0l Red Rose spec; Wilder too expensive (can't remember the BHP of Wilder engine?). Similarly, the 4.3 is probably to expensive. There has to be an upper limit on what I can spend.

RG have done a hell of a lot of research into improving the longevity of the engine and I'm very impressed. So 'll stick with them, even if the 4.3 is within my budget.

Drove a Tusc S yesterday,and the engine felt as tractable as the 3.6 so there doesn't seem to be any downside. Didn't feel much quicker than mine, but it did feel torquier, so maybe easier to drive when not just hooning. I think that is what you said Ian.

Ian, yeah saw your article in SPRINT (can't find my bloody mMarch issue at the mo as I want to read it again). RG similar price, but a lot of bespoke improvements. Mind, I hope they don't prove necessary and yours lasts as long as mine will!

I'm looking at balancing and gas flowed head. Interestingly, RG don't want to take any more money from me for blueprintingas they don't think it will make much difference. Their engines are virtually blueprinted anyway so they suggest I save myself a few hundred quid.

[hollowpockets]

I have the 4ltr rr and the 3.7 diff, i still think the car could do with 100bhp more, that aint gonna happen overnight, if it needs rebuilt again i'd like to try some form of V8 or a charged s6 if someone has developed one by the time that day comes.

For now removing of some furniture to reduce the weight will have to do.

[hab1966]

Tangoed said:

What about the Wilder option! or Power are doing a 4.3 upgrade, due out next month. Not sure of the costs

TVR Power ad in this months Sprint, states 4.3 Speed 6 upgrades £7999 with 3 years unlimited mileage warranty.

[Tangoed]

8k

Now thats some wedge!

[fairclp]

Tangoed said:

8k

Now thats some wedge!

How's the engine m8 after the Power rebuild? Smooth as silk when I heard it last.

[T40ORA]

hab1966 said:

Tangoed said:

What about the Wilder option! or Power are doing a 4.3 upgrade, due out next month. Not sure of the costs

TVR Power ad in this months Sprint, states 4.3 Speed 6 upgrades £7999 with 3 years unlimited mileage warranty.

Interesting. Is there detail on the power output?

[hollowpockets]

T40ORA said:

hab1966 said:

Tangoed said:

What about the Wilder option! or Power are doing a 4.3 upgrade, due out next month. Not sure of the costs

TVR Power ad in this months Sprint, states 4.3 Speed 6 upgrades £7999 with 3 years unlimited mileage warranty.

Interesting. Is there detail on the power output?

When i was last in power i did ask this, they couldn't give me a 'figure' as such as they hadn't had it on the rollers yet (this was the 4.3 with nitrous i was asking about). I would hazard a guess at probably a good 400bhp with 350lb torque plus whatever the nitrous gives(not really important to most people). Remembering the larger the capacity the less likely the speed six is to rev, and its high revs that make the power in them. I doubt it would have as much as 430 bhp as people have mentioned, willing to be prooved wrong...

[Ebo100]

Hijacking the thread slightly, I have been looking for a new car and have a T350 on my shortlist.
I have noticed that some of the adverts mention some sort of engine rebuilding on cars I would consider reasonably low mileage. Is this need for a rebuild a common occurance, or is it on a track day and/or abused cars and is it a costly affair?

[T40ORA]

Ebo100 said:

Hijacking the thread slightly, I have been looking for a new car and have a T350 on my shortlist.
I have noticed that some of the adverts mention some sort of engine rebuilding on cars I would consider reasonably low mileage. Is this need for a rebuild a common occurance, or is it on a track day and/or abused cars and is it a costly affair?

Tee hee. Oooo. Can of worms.

Seriously, lots of threads on here about this. But when you buy an SP6 engined car you are getting an amazing bit of kit. Jason Clegg likened it to Lambourghini in that respect. So you cannot expect Nissan reliability.

However, there are engines about with lots of miles on without a rebuild and even mine at 42k I'm not too surprised at. But later models tend to be better, or older ones with a rebuild. But what rebuild and by whom is probably significant too.

As for costly....I'm paying more than the £7999 mentioned above, so yes.

BTW this is a several beers answer.

[T40ORA]

hollowpockets said:

T40ORA said:

hab1966 said:

Tangoed said:

What about the Wilder option! or Power are doing a 4.3 upgrade, due out next month. Not sure of the costs

TVR Power ad in this months Sprint, states 4.3 Speed 6 upgrades £7999 with 3 years unlimited mileage warranty.

Interesting. Is there detail on the power output?

When i was last in power i did ask this, they couldn't give me a 'figure' as such as they hadn't had it on the rollers yet (this was the 4.3 with nitrous i was asking about). I would hazard a guess at probably a good 400bhp with 350lb torque plus whatever the nitrous gives(not really important to most people). Remembering the larger the capacity the less likely the speed six is to rev, and its high revs that make the power in them. I doubt it would have as much as 430 bhp as people have mentioned, willing to be prooved wrong...

I admit to being totally ignorant of all things mechanical, but wouldn't a well sorted blueprinted and balanced 4.0s spec engine give similar to those figures?

[hollowpockets]

T40ORA said:

hollowpockets said:

T40ORA said:

hab1966 said:

Tangoed said:

What about the Wilder option! or Power are doing a 4.3 upgrade, due out next month. Not sure of the costs

TVR Power ad in this months Sprint, states 4.3 Speed 6 upgrades £7999 with 3 years unlimited mileage warranty.

Interesting. Is there detail on the power output?

When i was last in power i did ask this, they couldn't give me a 'figure' as such as they hadn't had it on the rollers yet (this was the 4.3 with nitrous i was asking about). I would hazard a guess at probably a good 400bhp with 350lb torque plus whatever the nitrous gives(not really important to most people). Remembering the larger the capacity the less likely the speed six is to rev, and its high revs that make the power in them. I doubt it would have as much as 430 bhp as people have mentioned, willing to be prooved wrong...

I admit to being totally ignorant of all things mechanical, but wouldn't a well sorted blueprinted and balanced 4.0s spec engine give similar to those figures?

Sorry but i think thats optimistic, the engine builders may tell you these figures but theres very few cars producing the goods following a rebuild, expect more like 385bhp/320lbft for a good 4ltr. I dont think my car even with the 'red rose' spec 4ltr, the carbon airbox with trumpets, de-cats and a new chip/ecu is making 400 but i'll let you know once its been on the rollers (soon).

[tail slide]

hollowpockets said:

T40ORA said:

hollowpockets said:

T40ORA said:

hab1966 said:

Tangoed said:

What about the Wilder option! or Power are doing a 4.3 upgrade, due out next month. Not sure of the costs

TVR Power ad in this months Sprint, states 4.3 Speed 6 upgrades £7999 with 3 years unlimited mileage warranty.

Interesting. Is there detail on the power output?

When i was last in power i did ask this, they couldn't give me a 'figure' as such as they hadn't had it on the rollers yet (this was the 4.3 with nitrous i was asking about). I would hazard a guess at probably a good 400bhp with 350lb torque plus whatever the nitrous gives(not really important to most people). Remembering the larger the capacity the less likely the speed six is to rev, and its high revs that make the power in them. I doubt it would have as much as 430 bhp as people have mentioned, willing to be prooved wrong...

I admit to being totally ignorant of all things mechanical, but wouldn't a well sorted blueprinted and balanced 4.0s spec engine give similar to those figures?

Sorry but i think thats optimistic, the engine builders may tell you these figures but theres very few cars producing the goods following a rebuild, expect more like 385bhp/320lbft for a good 4ltr. I dont think my car even with the 'red rose' spec 4ltr, the carbon airbox with trumpets, de-cats and a new chip/ecu is making 400 but i'll let you know once its been on the rollers (soon).

Agree that's what you'll get, my 4.0's to similar spec with forged internals for strength/lightness and though we're still making tweaks, was close to this after day at Austec, after just run in using Newman cams and Bosch higher-quality injectors. Austec and TVR Power (John R.) are only two who can do live mapping to suit your particular engine at every position on the fuel map, seeing the readout while changing the flow, fascinating to watch. Not cheap as it takes half a day but you know it's right, won't be lean risking the engine and won't be rich robbing torque/power.

Helpfully this set up also gave 28mpg at 80mph on a very low diff (so 3900rpm) over 150 miles, which helps offset the heavy drinking on track!

[JR]

hollowpockets said:

Sorry but i think thats optimistic, the engine builders may tell you these figures but theres very few cars producing the goods following a rebuild, expect more like 385bhp/320lbft for a good 4ltr.

Can you not get that from a 3.6?

Paxo1 said:

my s6 engined car puts out circa 110 bhp/litre ... my 'genuine' RR has a number of improvements e.g. ported and polished head along with the usual matched and balanced components.

[tail slide]

JR said:

hollowpockets said:

Sorry but i think thats optimistic, the engine builders may tell you these figures but theres very few cars producing the goods following a rebuild, expect more like 385bhp/320lbft for a good 4ltr.

Can you not get that from a 3.6?

Paxo1 said:

my s6 engined car puts out circa 110 bhp/litre ... my 'genuine' RR has a number of improvements e.g. ported and polished head along with the usual matched and balanced components.

Erm.... not quite but torque & hp around 7000rpm remarkably similar (as you may know?) when looking at a 3.6 & 4.0 run on same dyno.

If you can beef up the torque over the few thousand revs below that there's a fair difference through the gears 3.6 > 4.0. Mine gained over 60lbft torque above 3.6 run earlier at Austec @ 4000rpm and still 40lbft more @ 6500, but 3.6 was close for last few revs at peak.

Would ideally like the manic leap for red line of the 3.6 on top of the extra shove of the 4-litre...

But, these engines are already in a high state of tune, so either be happy with what you've got or start saving for lots of expensive tweaks, or REALLY expensive if you want to start again and build a 9k rpm engine or forced induction.

Edited by tail slide on Sunday 6th July 10:38

[T40ORA]

So back to my original question really; is it worth going to 4.0? It will all be ported and polished, balanced and gas flowed whatever I do. I know the figures 3.6 - 4.0 would be similar, but I'm wondering if I can save myself a few quid and spend it more usefully elsewhere? Like changing the diff and/or better manifolds.

It's a hefty wedge to spend and I'd like to ensure I don't have any regrets afterwards!

[tail slide]

T40ORA said:

So back to my original question really; is it worth going to 4.0? It will all be ported and polished, balanced and gas flowed whatever I do. I know the figures 3.6 - 4.0 would be similar, but I'm wondering if I can save myself a few quid and spend it more usefully elsewhere? Like changing the diff and/or better manifolds.

It's a hefty wedge to spend and I'd like to ensure I don't have any regrets afterwards!

Beyond extra durability (esp. mods to the oil supply, lighter weight con-rods/pistons available from Dulfords etc.) just depends how important slightly quicker acceleration is, and - more frequently noticeable in everyday driving - the extra mid-range shove below high revs.

A lower diff ratio can give you a little more acceleration as you say, but manifolds are already optimised, though de-cats can help.

Edited by tail slide on Sunday 6th July 11:42