Replacement/rebuilt engines -eg Powers Taraka and V8D 5l
Discussion
Just a comment on deBaron’s post. The 4.0 and 4.6 are, I believe, the same block. It’s the different internals and crank that gives it the extra capacity. Top hatting costs about a grand, and you definitely want it cross bolting and internally balancing.
You have to decide whether you want more torque or more bhp. More torque across the rev range makes it pull like a train in any gear, so great for road use and track dayers like me. More bhp is what race drivers go for, keeping the car at high revs all the time. So choose your cam according to your intended use. I had a V8D stealth cam in my 5 litre, and it was over 300 lbs ft between 2000 and 5000 rpm, so very torquey.
You have to decide whether you want more torque or more bhp. More torque across the rev range makes it pull like a train in any gear, so great for road use and track dayers like me. More bhp is what race drivers go for, keeping the car at high revs all the time. So choose your cam according to your intended use. I had a V8D stealth cam in my 5 litre, and it was over 300 lbs ft between 2000 and 5000 rpm, so very torquey.
And another thing.
My 5 litre was 315 bhp, restricted by having only stage 3 heads. It would have made about 340-345 bhp with stage 4 heads, as that is what Daz’s makes.
Phazed’s 5.5 makes 400 bhp and 450 lbs ft. Wow.
But on the road it was only marginally quicker than anyone else (we have driven around the Surrey Hills in convoy, so I speak from experience). On the track at Hethel, which is a load of twisty corners with a couple of decent long straights, with us both really on it, he was gaining about 10 yards a lap on me.
Since the turbocharging, he now gains 5 yards a lap on me.
The 5.5 involves a complete new set of forged internals (won’t be cheap), an H404 cam (£300?), Yella Terra rocker rollers, a 5.5 crank, which is £400 for the blank and a grand (and six months) to have machined, a top hat linered block at £1000, stage 4 heads at £3000, and to get from 380 to 400 bhp he added equal length exhaust manifolds at £1200. Plus an Emerald or similar ECU (£2500 fitted and mapped), plus assembly and installation of everything.
If you do all the mechanical stuff yourself then there’s a saving, but my basic 4.6 build cost £1800 in labour and sundry bits, plus another grand getting it all into the car and running properly.
And then, when you have done all that, you have a car that, like an Aston, returns 15 mpg. But is an awesome, free revving, piece of kit. And is a long way from just occasionally checking the oil and giving it a wash - it needs regular attention.
My 5 litre was 315 bhp, restricted by having only stage 3 heads. It would have made about 340-345 bhp with stage 4 heads, as that is what Daz’s makes.
Phazed’s 5.5 makes 400 bhp and 450 lbs ft. Wow.
But on the road it was only marginally quicker than anyone else (we have driven around the Surrey Hills in convoy, so I speak from experience). On the track at Hethel, which is a load of twisty corners with a couple of decent long straights, with us both really on it, he was gaining about 10 yards a lap on me.
Since the turbocharging, he now gains 5 yards a lap on me.
The 5.5 involves a complete new set of forged internals (won’t be cheap), an H404 cam (£300?), Yella Terra rocker rollers, a 5.5 crank, which is £400 for the blank and a grand (and six months) to have machined, a top hat linered block at £1000, stage 4 heads at £3000, and to get from 380 to 400 bhp he added equal length exhaust manifolds at £1200. Plus an Emerald or similar ECU (£2500 fitted and mapped), plus assembly and installation of everything.
If you do all the mechanical stuff yourself then there’s a saving, but my basic 4.6 build cost £1800 in labour and sundry bits, plus another grand getting it all into the car and running properly.
And then, when you have done all that, you have a car that, like an Aston, returns 15 mpg. But is an awesome, free revving, piece of kit. And is a long way from just occasionally checking the oil and giving it a wash - it needs regular attention.
As Qbee said, the turbo lag talked of on here was from the 80's. A V8 driving a turbo done properly will give very little lag. I'm a fan of both n/a and FI, they're V8's for crissakes what's not to like?
PS: Anthoney, my 4.7 Aston V8 (420hp) returned 22mpg recently
soon to have equal length performance manifolds and 200 cell sports cats fitted, can't help myself. 
PS: Anthoney, my 4.7 Aston V8 (420hp) returned 22mpg recently
soon to have equal length performance manifolds and 200 cell sports cats fitted, can't help myself. Edited by macdeb on Wednesday 20th June 09:32
macdeb said:
As Qbee said, the turbo lag talked of on here was from the 80's. A V8 driving a turbo done properly will give very little lag. I'm a fan of both n/a and FI, they're V8's for crissakes what's not to like?
PS: Anthoney, my 4.7 Aston V8 (420hp) returned 22mpg recently soon to have equal length performance manifolds and 200 cell sports cats fitted, can't help myself.
Nice one Mac.........still the same geezer we all know and love! PS: Anthoney, my 4.7 Aston V8 (420hp) returned 22mpg recently
soon to have equal length performance manifolds and 200 cell sports cats fitted, can't help myself. Edited by macdeb on Wednesday 20th June 09:32
900T-R said:
Capacity increase does nothing but determine at what rpm you're hitting max airflow - the heads (and induction) determine how much air the engine will flow.
^^^^^this 
So turbo just makes it easy to attain huge air flow
This does change how the engine feels as forcing it rather than sucking changes the sound and you hear the woosh of air rather than the roar of it being drawn in. I for some reason just like that roar even if it is less powerful. I often go upto 2800 just to hear that roar forming, its ace and lots of fun without even going fast.
It’s the sense of occasion rather than its outright speed that I like about them.
Saying that the quietness turbos create is going to be really nice on longer runs but again most of us don’t use them enough for long enough to truelly deafen ourselves
It’s just fun really but big power can have lots of unknown consequences so choose based on what your prepared to spend basically. Power ain’t cheap to get or then maintain in any form.
Bloody eck MAC, 22mpg from a brand new engine,,, maybe it’s still tight
Let’s go drag racing,, I fancy my chances,,,,,,,,,
Maybe next year or the year after,,,,
macdeb said:
My 4.7 Aston V8 (420hp) returned 22mpg recently ]
That's almost 90bhp per litre compared with the low 70 horsepower numbers even the most tuned RV8s are achieving, which just goes to show how much more efficient a modern engine is, 22mpg is fantastic fuel consumption too especially given the Aston engine is pushing a 1,630kg car along.]Of course 420hp moving 1,630kg is still only 258bhp per ton, so roughly the same power to weight ratio as a 1060kg Chimaera making 274hp at the crank which is really just a bog standard 5.0 litre TVR.
Weight has a big influence on fuel economy too which is why most Chimaeras of any engine size will still deliver 27mpg on a run and average around 22mpg if you drive it sensibly. So while the old Rover V8 is a world away from the Aston V8 in terms of efficiency, stick the ancient engine in a 1060kg car and the package claws its way back to deliver very similar performance and economy to the far more modern and sophisticated AM.
Colin Chapman certainly knew what he was talking about when he spoke about..... "Adding Lightness".
ChimpOnGas said:
macdeb said:
My 4.7 Aston V8 (420hp) returned 22mpg recently ]
That's almost 90bhp per litre compared with the low 70 horsepower numbers even the most tuned RV8s are achieving, which just goes to show how much more efficient a modern engine is, 22mpg is fantastic fuel consumption too especially given the Aston engine is pushing a 1,630kg car along.]Of course 420hp moving 1,630kg is still only 258bhp per ton, so roughly the same power to weight ratio as a 1060kg Chimaera making 274hp at the crank which is really just a bog standard 5.0 litre TVR.
Weight has a big influence on fuel economy too which is why most Chimaeras of any engine size will still deliver 27mpg on a run and average around 22mpg if you drive it sensibly. So while the old Rover V8 is a world away from the Aston V8 in terms of efficiency, stick the ancient engine in a 1060kg car and the package claws its way back to deliver very similar performance and economy to the far more modern and sophisticated AM.
Colin Chapman certainly knew what he was talking about when he spoke about..... "Adding Lightness".
ChimpOnGas said:
macdeb said:
My 4.7 Aston V8 (420hp) returned 22mpg recently ]
That's almost 90bhp per litre compared with the low 70 horsepower numbers even the most tuned RV8s are achieving, which just goes to show how much more efficient a modern engine is, 22mpg is fantastic fuel consumption too especially given the Aston engine is pushing a 1,630kg car along.]Of course 420hp moving 1,630kg is still only 258bhp per ton, so roughly the same power to weight ratio as a 1060kg Chimaera making 274hp at the crank which is really just a bog standard 5.0 litre TVR.
Weight has a big influence on fuel economy too which is why most Chimaeras of any engine size will still deliver 27mpg on a run and average around 22mpg if you drive it sensibly. So while the old Rover V8 is a world away from the Aston V8 in terms of efficiency, stick the ancient engine in a 1060kg car and the package claws its way back to deliver very similar performance and economy to the far more modern and sophisticated AM.
Colin Chapman certainly knew what he was talking about when he spoke about..... "Adding Lightness".
Peter can certainly relate to this comment 
macdeb said:
^^^^ couldn't agree more Dave. How is ole' gas bag mate?
Against all the odds 'Ol Gasbag' seems unstoppable Mac 
Recently my Prins LPG reducer shaat itself though
, so I took the opportunity to upgraded to a new design which as it turned out delivered even better throttle response 
When are you coming back to Plastic Fantastic land mate, you know you want to
Sardonicus said:
Except Macs ears dont ring after a long drive its not like a sauna in hot weather and its composed going quickly down an undulated fast B road Peter can certainly relate to this comment
Ha ha, good point Simon Peter can certainly relate to this comment But I do worry if I switched to an Aston Martin I'd miss all the dodgy wiring, cable ties, and polyurethane sealant that are so much part of the TVR experience
, I believe Aston uses crazy new technology like nuts and bolts, TVR would never use such sophisticated fasteners where a cable tie or adhesive would do.ChimpOnGas said:
macdeb said:
^^^^ couldn't agree more Dave. How is ole' gas bag mate?
Against all the odds 'Ol Gasbag' seems unstoppable Mac Recently my Prins LPG reducer shaat itself though
, so I took the opportunity to upgraded to a new design which as it turned out delivered even better throttle response When are you coming back to Plastic Fantastic land mate, you know you want to
Sardonicus said:
Except Macs ears dont ring after a long drive its not like a sauna in hot weather and its composed going quickly down an undulated fast B road Peter can certainly relate to this comment
Ha ha, good point Simon Peter can certainly relate to this comment But I do worry if I switched to an Aston Martin I'd miss all the dodgy wiring, cable ties, and polyurethane sealant that are so much part of the TVR experience
, I believe Aston uses crazy new technology like nuts and bolts, TVR would never use such sophisticated fasteners where a cable tie or adhesive would do. A different experience for sure but somehow similar with the positive comments it gets (apart from neighbours, lol). It's just so right. Drove to Southampton to see some mates and I could've easily driven straight back again. Apologies OP, budget and needs/use dictates your question.Edited by macdeb on Wednesday 20th June 16:16
macdeb said:
A different experience for sure but somehow similar with the positive comments it gets (apart from neighbours, lol). It's just so right. Drove to Southampton to see some mates and I could've easily driven straight back again. Apologies OP, budget and needs/use dictates your question.Edited by N7GTX on Wednesday 20th June 18:11
i think it has been mentioned but big power brings all sorts of unforseen problems if you are going to actually use the power, nicks blown chim i built isnt the most powerfull engine around but we cooked clutches, broke drive shafts, screwed the prop shaft and stuffed the gearbox so it now has mcleod 10.5 in clutch with servo to make the pedal acceptable, bespoke prop shaft with large joints and a flexible rubber damper to soften the load to the new btr diff, uprated drive shafts (thanks mac) and now a tremec tko gearbox and water injection to keep things nice and cool. dont want to count the pennies but supstantial but at least now it wont break.
john
john
Last point is a fair point re: additional power and impact on the driveline etc.
With this in mind probably would not want to stray too far from parameters of a 500 (which the current T5 box should be ok with I would hope).
Someone mentioned Topcats - when I looked on their site LS conversions were mega bucks (ie of the order of 25-30K).
I suspect it will be a week before I hear back on the diagnosis - which will guide the next steps beyond that,and whether a rebuild is needed.
With this in mind probably would not want to stray too far from parameters of a 500 (which the current T5 box should be ok with I would hope).
Someone mentioned Topcats - when I looked on their site LS conversions were mega bucks (ie of the order of 25-30K).
I suspect it will be a week before I hear back on the diagnosis - which will guide the next steps beyond that,and whether a rebuild is needed.
I wanted to build a nice 4.6 with good heads and induction but got let down on the 4.6 bottom end. I decided to stay with the 3.9 and do the heads, cam, induction etc and it really does transform the car in the mid range.
Certainly makes it the car it should have been when it left the factory, more than you ever need on the public roads, and silly speeds can be reached very quickly!
Certainly makes it the car it should have been when it left the factory, more than you ever need on the public roads, and silly speeds can be reached very quickly!
QBee said:
T5 gearbox is used in all of the T cars - so good for north of 400 bhp.
At least, I hope it is!!
At least, I hope it is!!
When I asked Dom at Powers about the gearbox (T5) and diff (GKN), he said both were perfectly good for the turbo conversion. 3 years on and no issues at all. Just for peace of mind I put new joints in the propshaft and uprated CV joints on the driveshafts. But I do not do drag strips or track days.
If you are doing drag launches you will break almost anything when you repeatedly drop the clutch. So it all comes back to what you are going to be doing with the car?
I think QBee's offer is perfect so you can get an idea of what the car can do, will feel like and with different settings too.
ChimpOnGas said:
macdeb said:
My 4.7 Aston V8 (420hp) returned 22mpg recently ]
That's almost 90bhp per litre compared with the low 70 horsepower numbers even the most tuned RV8s are achieving, which just goes to show how much more efficient a modern engine is, 22mpg is fantastic fuel consumption too especially given the Aston engine is pushing a 1,630kg car along.]Of course 420hp moving 1,630kg is still only 258bhp per ton, so roughly the same power to weight ratio as a 1060kg Chimaera making 274hp at the crank which is really just a bog standard 5.0 litre TVR.
Weight has a big influence on fuel economy too which is why most Chimaeras of any engine size will still deliver 27mpg on a run and average around 22mpg if you drive it sensibly. So while the old Rover V8 is a world away from the Aston V8 in terms of efficiency, stick the ancient engine in a 1060kg car and the package claws its way back to deliver very similar performance and economy to the far more modern and sophisticated AM.
Colin Chapman certainly knew what he was talking about when he spoke about..... "Adding Lightness".
Weslake produced a single cyl test engine that produced over 100 Bhp per litre in the mid sixties. Dan Gerney got involved and they built a 3.0 for F1 that produced over 400 hp, it was reputed to produce around 137 Bhp per litre. All in the head design basically. I then realised the little 500cc Weslake engines I raced on grass bikes as a youth produced about 60 hp which again is extremely powerful with the power to weight of a grassbike but then it did use Methanol fuel.
Did I read somewhere that the Buick was first designed to be used as a boat engine,,,
Makes sense why we have low hp but big grunt built in.
The Weslake heads on this F1 3.0 engine had multiple valves if my memory is correct!
Talking to a chap on the Dan Gurney Facebook page he mentioned Gurney got the sponsorship and people together to build this engine but sadly the tooling was poor and they never overcame a few reliability problems.
Fascinating
Classic Chim said:
Did I read somewhere that the Buick was first designed to be used as a boat engine,,,
Makes sense why we have low hp but big grunt built in.
Nah, that's just the way Yank engines were laid out. The Buick/Olds 215 was specifically conceived for the 1961 Buick Special and Olds F-85 compacts and after three model years it was ditched by GM in favour of thinwall iron cast blocks. It was only after its short OEM career that it was used as a boat engine, and it was in a boat shed that the Rover man who was trying to sell Land Rover engines for marine applications in the USA, found it...Makes sense why we have low hp but big grunt built in.
When Rover took over the rights to the engine in 1965, GM sent one of the senior engineers who were responsible for developing the lump in the first place. Rover wanted to raise the rev limit (the original developed its peak power @ 4,600 rpm which was already on the high side by American standards) and the American was questioning why on Earth someone would want to do that. Allegedly, a short introduction to European driving habits by a Rover works test driver made him see the light...
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