Rebuilt engine
Discussion
I have finally got my Chimaera back with a rebuilt engine. For many reasons, some of them my fault, some not (and would probably make a good Sprint article one day), the whole exercise took almost 3 years!
It’s a 4.6 that has been steadily modified over the years, it’s best days were 305bhp before the rings decided to eat themselves. Two cylinders dead, two more dying, eating oil and never going to get through an MoT, time to sort it. About the only bits never touched by my mods were the heads and I always said that if any engine work was needed then they would be improved so here was my opportunity.
I chose Rob at V8D for the job (though I did briefly flirt with another builder but that didn’t work out too well). It’s a 4.6 and although slightly tempted by easy power from a capacity change where would it all end… 5.7L twin turbo etc.etc. so I stuck with the original. I chose their ‘Warrior’ spec with top hat liners, stage 4 heads and one of Rob’s Stealth cams as I wanted torque and driveability over top end power. I already had the larger plenum, ported intakes and a custom exhaust by Janspeed.
Rob did an immaculate job of the engine rebuild and change and delivered the car to Joolz at Kits and Classics where the old KMS ECU was to be changed to an Emerald. Joolz did the original KMS fit and mapping in 2006 and has developed his ECU fit further over the years. This now includes removing all the old Lucas engine loom and replacing it with his own bespoke loom with relays and fuses. It sprang into life first turn and went on to produce 323.6 bhp (yes, the 0.6 is important!) on the dyno and 345ft-lbs of torque. Even at 1700 rpm there is about 310ft-lbs, which is nice. Hopefully I have managed to attach a copy of the plot.
The torque is awesome and Joolz has worked his magic to make it smooth at low rpm and small throttle openings. And its magic to be out in a TVR again!
So top marks from me for Rob at V8D but especially to Joolz at Kits and Classics as he was there for advice when things were looking a bit dodgy and it was great to know there was someone calm and knowledgable to bounce ideas off.
lwt said:
I have finally got my Chimaera back with a rebuilt engine. For many reasons, some of them my fault, some not (and would probably make a good Sprint article one day), the whole exercise took almost 3 years!
It’s a 4.6 that has been steadily modified over the years, it’s best days were 305bhp before the rings decided to eat themselves. Two cylinders dead, two more dying, eating oil and never going to get through an MoT, time to sort it. About the only bits never touched by my mods were the heads and I always said that if any engine work was needed then they would be improved so here was my opportunity.
I chose Rob at V8D for the job (though I did briefly flirt with another builder but that didn’t work out too well). It’s a 4.6 and although slightly tempted by easy power from a capacity change where would it all end… 5.7L twin turbo etc.etc. so I stuck with the original. I chose their ‘Warrior’ spec with top hat liners, stage 4 heads and one of Rob’s Stealth cams as I wanted torque and driveability over top end power. I already had the larger plenum, ported intakes and a custom exhaust by Janspeed.
Rob did an immaculate job of the engine rebuild and change and delivered the car to Joolz at Kits and Classics where the old KMS ECU was to be changed to an Emerald. Joolz did the original KMS fit and mapping in 2006 and has developed his ECU fit further over the years. This now includes removing all the old Lucas engine loom and replacing it with his own bespoke loom with relays and fuses. It sprang into life first turn and went on to produce 323.6 bhp (yes, the 0.6 is important!) on the dyno and 345ft-lbs of torque. Even at 1700 rpm there is about 310ft-lbs, which is nice. Hopefully I have managed to attach a copy of the plot.
The torque is awesome and Joolz has worked his magic to make it smooth at low rpm and small throttle openings. And its magic to be out in a TVR again!
So top marks from me for Rob at V8D but especially to Joolz at Kits and Classics as he was there for advice when things were looking a bit dodgy and it was great to know there was someone calm and knowledgable to bounce ideas off.
It’s just these graphs often have what is a very smooth and linear torque curve.
Nice numbers
lwt said:
I didnt ask about the small dip in torque, probably just so pleased to be driving it again! Somehow I dont think I will notice it…
true PS I have a rebuilt 4.6 engine running after market ecu all done by Doms boys and collectively the two aspects really improve torque and smoothness and general drivability. You could say it transforms the car.
Mines was mapped Catted so about 300 hp which I think could be about 315 de catt and even Catted about 340-345 ft of torque so very similar power but looking you have more torque earlier in the Rev range which I think could be your extra head/ induction work. Nice that
Mine managed 12.6 for the 1/4 mile so you could knock a few tenths off that which if you look at the recorded drag times for TVR is indeed very fast so you have a very quick car there. Top job by the look of it
Pictures are usually the norm here though sir,,,,,,
ETA Arrr Ive just realised when I did 12.6 it was using Clive's Y piece so indeed de catt that day. Best I ever did Catted was a 13.1
It’s not to brag at all it’s to show what it means in real terms and 1/2 a second at these extremes could be 20 yards ahead after only 1/4 mile so a big difference in overall usual power. Nice job indeed.
Edited by Classic Chim on Saturday 23 July 09:33
Hoofa; so many questions!
That is some serious power and torque, so how do you get it to the road? Even on a moderately aggressive standing start I can get wheelspin in 2nd on a dry road so what on earth do you get? (I cant bring myself to really abuse a car I own, now if it was a hire car…).
What gearbox? What diff?
That is some serious power and torque, so how do you get it to the road? Even on a moderately aggressive standing start I can get wheelspin in 2nd on a dry road so what on earth do you get? (I cant bring myself to really abuse a car I own, now if it was a hire car…).
What gearbox? What diff?
lwt said:
Lovely engine bay - what exhaust mainifold/downpipe is that?I also have a stage 3 4.6 with stealth cam and emerald (standard manifolds and catted Y-piece) - its not as strong as yours (312bhp/320lbft) but it still bloody shifts!!
Exhaust; its a one-off special hand built by Janspeed of Salisbury, so no jigs. The brief was long primaries for lots of torque and a pair of free flow cats. The result is automotive art/porn I think. I agreed a fixed price for the manifolds & fitting and when I picked it up they had rebuilt the intake manifold, added copious stainless heat shields and also made a new intermediate pipe from the Y piece back to the join to the (empty) silencer box complete with lambda probe boss. All for the fixed price.
One of the cats disintegrated quite spectacularly, probably because the leaking rings were putting oil and unburnt fuel through it. A firm called Alunox in Wrexham cut and welded new cats and did a brilliant job, you would be hard pressed to see the join is not original.
One of the cats disintegrated quite spectacularly, probably because the leaking rings were putting oil and unburnt fuel through it. A firm called Alunox in Wrexham cut and welded new cats and did a brilliant job, you would be hard pressed to see the join is not original.
Wow that is a fantastic result, very impressive headline figure and a nice flat torque line. I bet she is lovely to drive. Those are very healthy 500 figures let alone 4.6 so you must be very pleased.
The .6 is important, you can technically round that up - haha.
I am sure it is worth the wait. Nothing is ever simple when completing big jobs on TVR.
The .6 is important, you can technically round that up - haha.
I am sure it is worth the wait. Nothing is ever simple when completing big jobs on TVR.
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