Replacement/rebuilt engines -eg Powers Taraka and V8D 5l
Discussion
Squirrelofwoe said:
spitfire4v8 said:
Most sports car like feel would be a nicely tuned 4 litre revver .. 300hp should be very achievable if you can live with a bit of cam related drivability issues low down, 270hp.
You have just described my exact goal!
What would you say is the best bang-for-buck way to go about achieving a reasonably rev-happy 270bhp in an N/A 4.0?
For reference it's a 4.0hc with pocketed pistons and has just had a Taraka 855 cam fitted to replace the worn original.
Next step over the winter is to get the Canems system installed (principally for drivability / usability / reliability / ilityility reasons).
I presume after that I'd be looking at upgrading the plenum / trumpets etc? Could I get close to 270 on the standard heads?
Having replaced my original 3.9 (4 Litre) with a 4.6 from a Range Rover then gone down the road of:
Bigger Heads,
Bigger Intake,
Bigger Cam, then even bigger cam then finally roller cam...
Bigger Plenum,
Roller Rockers,
Chrome Moly Adjustable pushrods
MegaSquirt
I wish I'd just gone FI from the start. Now building a 4.8L with forged pistons for exactly that!
OP - do it right - get a blower.A decent rebuilt 4.6 from a Range Rover won't be that much especially if you can do some bits yourself.
Then it's fairly bolt on stuff from SC Power or similar.
The 4L is a wheezy underpowered thing and always will be no matter what you throw at it short of FI
Schoolboy error - you can put all the big stuff on a low compression Rover engine and it still won't bring the goods. 
No excuse to make it a turdo motor (if that's your thing, why not buy a Skyline in the first place?) 
(My 4.3 made 300 horses on standard sized valves at 10-10.5ish:1 c.r.)
Boggo 4 litre still on a par with a 4.3 litre Aston (which is a hugely stiffer platform with some tech to keep it on the straight and narrow, too) - frankly enough to keep the standard chassis and suspension entertained.
No excuse to make it a turdo motor (if that's your thing, why not buy a Skyline in the first place?) (My 4.3 made 300 horses on standard sized valves at 10-10.5ish:1 c.r.)
Boggo 4 litre still on a par with a 4.3 litre Aston (which is a hugely stiffer platform with some tech to keep it on the straight and narrow, too) - frankly enough to keep the standard chassis and suspension entertained.
debaron said:
Having replaced my original 3.9 (4 Litre) with a 4.6 from a Range Rover then gone down the road of:
Bigger Heads,
Bigger Intake,
Bigger Cam, then even bigger cam then finally roller cam...
Bigger Plenum,
Roller Rockers,
Chrome Moly Adjustable pushrods
MegaSquirt
I wish I'd just gone FI from the start. Now building a 4.8L with forged pistons for exactly that!
OP - do it right - get a blower.
A decent rebuilt 4.6 from a Range Rover won't be that much especially if you can do some bits yourself.
Then it's fairly bolt on stuff from SC Power or similar.
The 4L is a wheezy underpowered thing and always will be no matter what you throw at it short of FI
Couldn't agree more with this. Spend loads of money as said here to achieve what exactly? So you end up with a N/A engine wheezing along with a max of 300 bhp. Oh wait. Didn't TVR say the 5 litre put out 340? But it didn't just like all the factory claimed specs for all the cars. Bigger Heads,
Bigger Intake,
Bigger Cam, then even bigger cam then finally roller cam...
Bigger Plenum,
Roller Rockers,
Chrome Moly Adjustable pushrods
MegaSquirt
I wish I'd just gone FI from the start. Now building a 4.8L with forged pistons for exactly that!
OP - do it right - get a blower.A decent rebuilt 4.6 from a Range Rover won't be that much especially if you can do some bits yourself.
Then it's fairly bolt on stuff from SC Power or similar.
The 4L is a wheezy underpowered thing and always will be no matter what you throw at it short of FI
If you want to get to the next level forced induction is the way. Wonder why so many manufacturers fit turbos these days? Oh yes, cleaner emissions, more bang per buck at a relatively cheap cost.
As for comparisons with a GT car weighing half a ton more, ridiculous. A luxury car versus a kit car is meaningless. Oh dear.......
For a relatively small amount of money, you can achieve quite a lot.
The money to spend first is petrol money, driving around and visiting all us friendly Chimaera owners and getting rides in our cars. That way you can see what power level you will get for what expenditure, and work out will be right for you. You can try NA cars and FI cars, and you will be able to cut out all the other stages in between and save yourself a fortune in wasted expenditure.
Alternatively you will discover that all modified cars are a little bit quicker than your stock 4 litre, but only a little bit, and that they all use more fuel to achieve it, and the little extra acceleration is simply not worth the thousands spent to achieve it, especially in 70 mph GB.
I for one am happy to let you try my 395 bhp/ 525 lbs ft 4.6 turbo. I am sure there will be others similarly happy.
I would also add that my car has another setting on the ECU that will let you try it at 325bhp/395 lbs ft, which feels very similar to the way my old V8D 5 litre drove.
The money to spend first is petrol money, driving around and visiting all us friendly Chimaera owners and getting rides in our cars. That way you can see what power level you will get for what expenditure, and work out will be right for you. You can try NA cars and FI cars, and you will be able to cut out all the other stages in between and save yourself a fortune in wasted expenditure.
Alternatively you will discover that all modified cars are a little bit quicker than your stock 4 litre, but only a little bit, and that they all use more fuel to achieve it, and the little extra acceleration is simply not worth the thousands spent to achieve it, especially in 70 mph GB.
I for one am happy to let you try my 395 bhp/ 525 lbs ft 4.6 turbo. I am sure there will be others similarly happy.
I would also add that my car has another setting on the ECU that will let you try it at 325bhp/395 lbs ft, which feels very similar to the way my old V8D 5 litre drove.
Edited by QBee on Tuesday 19th June 16:17
A bog standard '06 Aston 4.3 (n/a) with circa 30k miles turned up recently and made 380hp which is bang on what the factory quote just for comparison to above quote and an example how time and technology moves on. I'm presuming the author meant power/weight thing. FI is my thing and some numbers can be achieved with it. I liked it, no I loved it. 
as QBee says how much d'ya want? Must admit, I do miss that 573hp hit at times but it all comes with cost. Cheap 'n cheerful would be 450, ported, flowed BV skimmed heads, induction to suit, piper 285 cam, MS management.
as QBee says how much d'ya want? Must admit, I do miss that 573hp hit at times but it all comes with cost. Cheap 'n cheerful would be 450, ported, flowed BV skimmed heads, induction to suit, piper 285 cam, MS management. Edited by macdeb on Tuesday 19th June 16:38
macdeb said:
A bog standard '06 Aston 4.3 (n/a) with circa 30k miles turned up recently and made 380hp which is bang on what the factory quote just for comparison to above quote and an example how time and technology moves on. I'm presuming the author meant power/weight thing.
Yes of course. We're talking nearly 1,600 kg versus 1,050 and 0-50 times around the 5 seconds mark. Only the Aston has far more technology and a massively stiffer platform to harness a broadly similar level of performance (bar top speed) which sort of puts the perceived need for vastly more power in a car that's arguably got more brawn than brains already into perspective. And personally, I don't see why you would spend significant amounts of money and time in converting a naturally aspirated performance car to forced induction in a world full of forced induction cars - wouldn't it make more sense to celebrate and build on the car's naturally aspirated response? It would be like ripping the innards of a vinyl record player to make an audio streamer from it IMO.
Similar comment - I did a track day on Sunday at a twisty Anglesey. Used my low boost 325 bhp map, as there were no long straights.
There was a Mercedes AMG GT 4 litre biturbo on track.
I wasn’t too much slower than him around the corners, but on the straights it was no contest, he just powered out of the corners and shot past me. Watching him, he was as fast/faster than a 911 GT 3 RS that was also on the track day.
My car is around 300 bhp per tonne. The Merc is 456 bhp in 1615 kg of car, so a tad under 300 bhp per tonne. But the modern machine puts the power down so much better. And he was on Michelin Pilot Cup Sport 2’s, the Porsche track day tyre of choice.
There was a Mercedes AMG GT 4 litre biturbo on track.
I wasn’t too much slower than him around the corners, but on the straights it was no contest, he just powered out of the corners and shot past me. Watching him, he was as fast/faster than a 911 GT 3 RS that was also on the track day.
My car is around 300 bhp per tonne. The Merc is 456 bhp in 1615 kg of car, so a tad under 300 bhp per tonne. But the modern machine puts the power down so much better. And he was on Michelin Pilot Cup Sport 2’s, the Porsche track day tyre of choice.
Wow.. what a response, and food for thought.
Thanks for the offers of passenger rides to get a feel for some of the options.. Would love to take you up, I suspect time constraint realities of work/family etc may preclude this ...at least for a while..
A few people questioned what the budget is, or could be. My starting point is that I am expecting an engine out rebuild will be needed (I may be proved wrong...but unlikely I fear).
At this point, it's turns into a what do I get it rebuilt into.
If I was not needing to rebuild..FI would I feel be the clear winner (or sell it and buy a 500). However that is likely not to be the case..
Anyway, developments since my Sunday post.
Took it out on Monday, and at idle the car has developed a new 'sound'..(or at least it is louder/more noticeable than it was). Described by the nearest local mechanic at the time as 'sounds a bit bottom endy... ..though it might be just a slipped liner.."
Car has is now left at the nearest TVR specialist garage to avoid further damage for investigation, so will wait to hear back..
In the meantime, I'm hearing:
-turbo for big power
-supercharger for power w/out lag
-NA tuning/capacity increase to retain original character
- straight rebuild, plus possible update 14cux to something more modern/less fragile.. (though to be fair, my 4l, once I had the cam done was very drivable .... albeit it had a few electrical gremlins )
Thanks for the offers of passenger rides to get a feel for some of the options.. Would love to take you up, I suspect time constraint realities of work/family etc may preclude this ...at least for a while..
A few people questioned what the budget is, or could be. My starting point is that I am expecting an engine out rebuild will be needed (I may be proved wrong...but unlikely I fear).
At this point, it's turns into a what do I get it rebuilt into.
If I was not needing to rebuild..FI would I feel be the clear winner (or sell it and buy a 500). However that is likely not to be the case..
Anyway, developments since my Sunday post.
Took it out on Monday, and at idle the car has developed a new 'sound'..(or at least it is louder/more noticeable than it was). Described by the nearest local mechanic at the time as 'sounds a bit bottom endy... ..though it might be just a slipped liner.."
Car has is now left at the nearest TVR specialist garage to avoid further damage for investigation, so will wait to hear back..
In the meantime, I'm hearing:
-turbo for big power
-supercharger for power w/out lag
-NA tuning/capacity increase to retain original character
- straight rebuild, plus possible update 14cux to something more modern/less fragile.. (though to be fair, my 4l, once I had the cam done was very drivable .... albeit it had a few electrical gremlins )
Edited by HiAsAKite on Tuesday 19th June 22:30
There’s no turbo lag at the sort of boost psi we run. Boost is for 1980s rally Audis, running anything up to 30 psi. Most you need on our cars is 15 psi, mine runs at 2.5 psi (325 bhp) or 7.5 psi (395 bhp). Engine is a bog standard 4.6 with Range Rover cam and heads.
Edited by QBee on Wednesday 20th June 06:58
All I can add is I have a Powers rebuilt 450 that’s essentially standard other than adding a better Ecu. It’s done 25,000 miles since rebuild and still feels like new and full of grunt/ power.
With ported heads it’s likely to be around 325 hp and over 360 ft lb torque and I think about as fast as it would need to be. This option is by far the cheapest and most likely the most reliable.
You just have to ask yourself the questions. Where will I use the power and when, if you like cruising and really most of us don’t spend our lives foot to the floor.
So then it’s about the character.
I don’t care it’s a bit slower than this or that, it’s sounds glorious, feels glorious, country roads it’s blindingly fast, and gets over 28 mpg on a regular basis.
To me these cars are about dreams more than reality and so a 1/2 or even a full second slower than say a really fast one and not until your over 100 mph means absolutely nothing.
If you want big power then Turbo a good base engine but incl Ecu change it’s huge bucks and possibly loose you some all important character and sound. Probably cost as much as the cars worth.
By going old school with lovely BV and ported and matched heads/ inlet you make the best of what it is without risk of breaking it quite so easily. It retains its charm and still simple to work on.
Those heads and that work will never leave or break, still makes the car do 0-60 sub 4.0 seconds and lasts the lifetime of the engine.
I’ve just been reading up on porting a Yamaha RD 350LC engine and how simple smoothing and slight opening of various areas release lots of power,,,, it’s like uber cool to me, rare as rocking horse teeth these days as it takes hundreds of hours to complete but to have an old school tuned engine using these now old techniques might not provide turbo power but it will be very fast.
Sardonicus 4.0 with such brilliance applied is absolutely as fast as my 4.6 as we both did 13.1 1/4 mile. I only went faster on another occasion because I had better tyres and de Catted the car for the day
Mine is very standard and effectively has 4.0 heads and inlet so even a 450 really needs decent heads as a starting point. It will give a longer power curve if you go FI at a later stage too.
My point is the better the state of tune and especially the heads which is cool as you like and gives you the best power whatever you do. I’d try and get a good short block 4.6 then get some proper heads on it which opens up the power potential for any and all additions later.
A second hand 4.6 with decent crank and bores, with new piston rings and decent cam will be spot on. Might need honing or crank grind and some oil pump gears but you should be good for years. Spend the money on the heads and it will be really quick.
I’ve got a pair of heads I’ve been slowly porting and if I’d had these 6 years ago when rebuilding my engine I’d likely have had closer to 330hp than the 300 i have.
72mm Plenum and bigger injectors being other parts you’ll need to spend money on so none of it is exactly cheap.
Food for thought
With ported heads it’s likely to be around 325 hp and over 360 ft lb torque and I think about as fast as it would need to be. This option is by far the cheapest and most likely the most reliable.
You just have to ask yourself the questions. Where will I use the power and when, if you like cruising and really most of us don’t spend our lives foot to the floor.
So then it’s about the character.
I don’t care it’s a bit slower than this or that, it’s sounds glorious, feels glorious, country roads it’s blindingly fast, and gets over 28 mpg on a regular basis.
To me these cars are about dreams more than reality and so a 1/2 or even a full second slower than say a really fast one and not until your over 100 mph means absolutely nothing.
If you want big power then Turbo a good base engine but incl Ecu change it’s huge bucks and possibly loose you some all important character and sound. Probably cost as much as the cars worth.
By going old school with lovely BV and ported and matched heads/ inlet you make the best of what it is without risk of breaking it quite so easily. It retains its charm and still simple to work on.
Those heads and that work will never leave or break, still makes the car do 0-60 sub 4.0 seconds and lasts the lifetime of the engine.
I’ve just been reading up on porting a Yamaha RD 350LC engine and how simple smoothing and slight opening of various areas release lots of power,,,, it’s like uber cool to me, rare as rocking horse teeth these days as it takes hundreds of hours to complete but to have an old school tuned engine using these now old techniques might not provide turbo power but it will be very fast.
Sardonicus 4.0 with such brilliance applied is absolutely as fast as my 4.6 as we both did 13.1 1/4 mile. I only went faster on another occasion because I had better tyres and de Catted the car for the day
Mine is very standard and effectively has 4.0 heads and inlet so even a 450 really needs decent heads as a starting point. It will give a longer power curve if you go FI at a later stage too.
My point is the better the state of tune and especially the heads which is cool as you like and gives you the best power whatever you do. I’d try and get a good short block 4.6 then get some proper heads on it which opens up the power potential for any and all additions later.
A second hand 4.6 with decent crank and bores, with new piston rings and decent cam will be spot on. Might need honing or crank grind and some oil pump gears but you should be good for years. Spend the money on the heads and it will be really quick.
I’ve got a pair of heads I’ve been slowly porting and if I’d had these 6 years ago when rebuilding my engine I’d likely have had closer to 330hp than the 300 i have.
72mm Plenum and bigger injectors being other parts you’ll need to spend money on so none of it is exactly cheap.
Food for thought
HiAsAKite said:
though it might be just a slipped liner.."
"Just" a slipped liner?They are known for slipping liners and if you're unlucky enough to have one it really needs top hat liners fitting all round. Not really something you can carry on driving with.
I slipped one and it was at that point I switched to a 4.6 and got top hats done.
So if you *do* need liners then get them put in a bigger block and make that your base for a decent engine.
Something that nobody has mentioned so far - stroked crank.
Peter 'Phazed' has got a custom crank that puts his at 5.6L or somewhere close and around 400BHP Naturally Aspirated - Might be worth considering although I don't know what the costs are.
Boosted had some blank cranks available not too long ago....
Simply put - bigger displacement will give you easiest/cheapest power increase and can't help thinking Peter Phazed would have considered everything you've considered (cost/driveability) before he did his upgrade
Boosted/Phazed - can you weigh in?
Edited by debaron on Wednesday 20th June 00:05
HiAsAKite said:
QBee: Ok- I note in your profile you had a 5l V8D for a while - what led you to chop that in for the 4.6L turbo? Just hankering for more power o other reasons?
It broke. We thought it was just worn piston rings, as smoke was pouring out of the exhausts when hot, so sent it to V8D for strip down and replacement rings etc, but Rob noticed that it had suffered something like overheating at some point and the block had warped out of true.
That left the choices as a £3k rebuild, with another block, or do something different.
I thought about what I wanted, and that turned out to be a bit more power, as I do track days, but not massive amounts.
Toyed with an LS3 conversion, long enough to price it up and research selling a kidney, but in the end decided that, as the car needed chassis and bodywork refreshing as well, i just couldn’t spend that much - all the kit to do a proper LS3 conversion came to £19k, plus £3k to put it all together.
That left trying to get more power NA, or sticking on a turbo. Having had several frustrating years trying to do the former, and not wanting to break another NA lump, I decided to go the opposite route, and build a really basic and strong 4.6 Range Rover engine and let a turbo do the work, controlled by an Emerald ECU.
Nice little, and unexpected, side effect of adding the turbo - the car has gone from struggling with track day noise limits, to qualifying to run at 90 dB Thruxton........yes, from being around 105dB previously, it is currently 91 dB and I have bolt on silencers to give me certainty.
Have you considered an engine swap? Top Cats Racing in Aylesbury specialise in LS engine swaps for TVRs, they’ve done loads so you could call them for a price.
Stock LS1 will make 350 hp without any modifications and an LS2 400hp. Cam and intake on either will add about 75hp to either. It will also maintain the character of your car. I wouldn’t go centrifugal blower as they don’t really do much below 3k rpm and why go to the expense when you can get a second hand LS2 for such little money?
https://m.ebay.com/itm/2004-Pontiac-GTO-LS1-5-7L-c...
Stock LS1 will make 350 hp without any modifications and an LS2 400hp. Cam and intake on either will add about 75hp to either. It will also maintain the character of your car. I wouldn’t go centrifugal blower as they don’t really do much below 3k rpm and why go to the expense when you can get a second hand LS2 for such little money?
https://m.ebay.com/itm/2004-Pontiac-GTO-LS1-5-7L-c...
Edited by anonymous-user on Wednesday 20th June 07:24
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