TVR 430 engine differences
Discussion
USChimaera said:
Does anyone know what makes the 430 make so produce power? It seems to me 300ccs isn't enough engine increase for 280 HP. I want to go to a larger engine but are the heads, valves, cam or something else different in the 430 and worth keeping?
Tvr were famous for exaggerated power figures!The 430 is highly regarded by those that have driven them but it would be difficult to overlook a 4.6 build if you were doing something from scratch.
The 430 engine basically is a Land Rover 4.2 crankshaft combined with 3.9 pistons of which the crowns have been machined down so they don't stick out of the block at TDC, making for a rather higher compression ratio than the 9.35:1 of the standard 4.0 engines (no matter what TVR literature says, they're in fact standard Land Rover 3.9 engines with a different cam and exhaust), even allowing for the thicker copper head gaskets originally used on the 4.3.
The heads are very nicely ported and have O- rings around the chambers to 'bite' into the head gasket. The cam is normally a Kent 214 which is fairly lively for a road going RV8 and double valve springs are installed. A 4.3 *should* have a Duplex timing chain with vernier timing gear, too.
A good 4.3 tends to make power into the mid-250s hp range, which is about where an average 5 litre is, for a 4 litre, assume a true 210-215 hp for a 400 (although there are some known anomalies of ones that make close to their advertised power - which might be HC versions not ordered/advertised as such) It doesn't seem to make any difference whether the 4.3 in question is a BV or not. If you'd build one now, you'd rather use the 'intermediate' large valves than the even larger TVR big valves.
The 430 is probably the nicest all round factory TVR Rover V8 engine by quite some margin. However, the previous poster is right that if you'd build an engine 'from scratch' it would be hard to overlook using the later 4.6 engine as a base and apply similar principles to it (using 4.0 - not 3.9 - pistons in a std. 4.6 engine would raise the compression ratio to a more sensible starting point and doesn't require any modifications...).
The heads are very nicely ported and have O- rings around the chambers to 'bite' into the head gasket. The cam is normally a Kent 214 which is fairly lively for a road going RV8 and double valve springs are installed. A 4.3 *should* have a Duplex timing chain with vernier timing gear, too.
A good 4.3 tends to make power into the mid-250s hp range, which is about where an average 5 litre is, for a 4 litre, assume a true 210-215 hp for a 400 (although there are some known anomalies of ones that make close to their advertised power - which might be HC versions not ordered/advertised as such) It doesn't seem to make any difference whether the 4.3 in question is a BV or not. If you'd build one now, you'd rather use the 'intermediate' large valves than the even larger TVR big valves.
The 430 is probably the nicest all round factory TVR Rover V8 engine by quite some margin. However, the previous poster is right that if you'd build an engine 'from scratch' it would be hard to overlook using the later 4.6 engine as a base and apply similar principles to it (using 4.0 - not 3.9 - pistons in a std. 4.6 engine would raise the compression ratio to a more sensible starting point and doesn't require any modifications...).
Also I'd say if you have a 430 I'd keep the capacity and focus on induction, exhaust manifolds, engine management etc. instead. There will not be a lot of difference to a 4.6 litre and much above that, you'll be basically trading revability for torque, which has always struck me as the wrong way around for a lightweight sports car.
Before the latest round of improvements, I got a round 300 hp out of a 4.3 on the standard valve size with an ACT twin throttle plenum on a 45 mm ported manifold with big carbon trumpets, ACT performance exhaust manifolds with decats, big Bosch AFM and mapped iginition. Current target is 320-340 bhp which is enough for the car, really (further performance improvements will come from 'lightweighting' the car...)
Before the latest round of improvements, I got a round 300 hp out of a 4.3 on the standard valve size with an ACT twin throttle plenum on a 45 mm ported manifold with big carbon trumpets, ACT performance exhaust manifolds with decats, big Bosch AFM and mapped iginition. Current target is 320-340 bhp which is enough for the car, really (further performance improvements will come from 'lightweighting' the car...)
900T-R said:
Also I'd say if you have a 430 I'd keep the capacity and focus on induction, exhaust manifolds, engine management etc. instead. There will not be a lot of difference to a 4.6 litre and much above that, you'll be basically trading revability for torque, which has always struck me as the wrong way around for a lightweight sports car.
Before the latest round of improvements, I got a round 300 hp out of a 4.3 on the standard valve size with an ACT twin throttle plenum on a 45 mm ported manifold with big carbon trumpets, ACT performance exhaust manifolds with decats, big Bosch AFM and mapped iginition. Current target is 320-340 bhp which is enough for the car, really (further performance improvements will come from 'lightweighting' the car...)
Which further confirms how well and nicely ported even the stock valve sized heads are they really do make the BV 500 heads with their no more than a tickle look like bin fodder in comparison except the valve sizing Before the latest round of improvements, I got a round 300 hp out of a 4.3 on the standard valve size with an ACT twin throttle plenum on a 45 mm ported manifold with big carbon trumpets, ACT performance exhaust manifolds with decats, big Bosch AFM and mapped iginition. Current target is 320-340 bhp which is enough for the car, really (further performance improvements will come from 'lightweighting' the car...)
, agree with the inflated HP but the 4.3 seldom fails to deliver good numbers as 900T proves even with those mods 
once you rise above 4.6 you also start showing up the heads short falls , keep in mind that on the 5.0 and what the yanks were using on their factory hot-rodded motors inlet valves alone fall short by at least 7mm over the TVR BV heads for starters 
never mind the head flow numbers themselves Edited by Zener on Wednesday 28th April 09:54
Has anyone got pictures of factory fit BV430 heads we can all lust over.
Wasn’t the LR 4.6 influenced by what John Eales in particular but also what Tvr were doing with these engines and a sort of half way house between the two as LR engines would still need good torque figures etc.
Going by my standard 38 mm inducted 4.6 engine on original pistons but new rings, cam and timing gear all built by Powers then Dyno’d about 8 years and 25,000 miles later when they installed the MBE system it produced 256bhp which now I’ve finally worked out most dyno are adding Upto 20% for road train loss comes to 307 bhp. Taking into account the rebuild and MBE ability to eek out a bit more it’s about bang on really and around what a 430 produces so I’d stick with a 430bv if I had one.
Weirdly enough speed itself doesn’t interest me much anymore but a feeling of instant deep power does so I love the 4.6 for its torque. It’s in-fact what I wanted out the rebuild and Mentioned I wanted a torquey engine over a revver,,, must be my age.
I think enough is known and the tools are there to make all the Tvr engines go a bit hey Simon
Wasn’t the LR 4.6 influenced by what John Eales in particular but also what Tvr were doing with these engines and a sort of half way house between the two as LR engines would still need good torque figures etc.
Going by my standard 38 mm inducted 4.6 engine on original pistons but new rings, cam and timing gear all built by Powers then Dyno’d about 8 years and 25,000 miles later when they installed the MBE system it produced 256bhp which now I’ve finally worked out most dyno are adding Upto 20% for road train loss comes to 307 bhp. Taking into account the rebuild and MBE ability to eek out a bit more it’s about bang on really and around what a 430 produces so I’d stick with a 430bv if I had one.
Weirdly enough speed itself doesn’t interest me much anymore but a feeling of instant deep power does so I love the 4.6 for its torque. It’s in-fact what I wanted out the rebuild and Mentioned I wanted a torquey engine over a revver,,, must be my age.
I think enough is known and the tools are there to make all the Tvr engines go a bit hey Simon
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