429 bhp @ 6500 rpm

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Transmitter Man

Original Poster:

4,253 posts

223 months

Sunday 8th February 2015
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For those that don't already subscribe: http://www.v8forum.co.uk/forum/viewtopic.php?t=123...

80+ bhp from a naturally aspirated RV8 ain't half bad.

I think it is only a matter of time until one of the racers with these heads hit's the 100 bhp per litre mark.

Phil

2 sMoKiN bArReLs

30,230 posts

234 months

Sunday 8th February 2015
quotequote all
Transmitter Man said:
80+ bhp from a naturally aspirated RV8 ain't half bad.
I think that's a tad disappointing hehe

Transmitter Man

Original Poster:

4,253 posts

223 months

Sunday 8th February 2015
quotequote all
2 sMoKiN bArReLs said:
I think that's a tad disappointing hehe
I should of added 'per litre' biggrin

Phil

glenrobbo

35,066 posts

149 months

Sunday 8th February 2015
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2 sMoKiN bArReLs said:
Transmitter Man said:
80+ bhp from a naturally aspirated RV8 ain't half bad.
I think that's a tad disappointing hehe
I agree. I would expect at least four times that figure. wink

rev-erend

21,404 posts

283 months

Sunday 8th February 2015
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Very good result from a 5 litre car.

Those heads must be very good.

SILICONEKID345HP

14,997 posts

230 months

Sunday 8th February 2015
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Whats the damage are are they a straight swop ?

Transmitter Man

Original Poster:

4,253 posts

223 months

Monday 9th February 2015
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ChimpOnGas

9,637 posts

178 months

Monday 9th February 2015
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SILICONEKID345HP said:
Whats the damage are are they a straight swop ?
Quotes about the TA heads directly from v8bloke himself in the Major Mods section....

v8bloke said:
Including tax they were £3.5k so not exactly cheap. Cheers Mark
v8bloke said:
The price included the very nice quality shaft mounted roller rockers.
But I would guess you can't just slap a Rover V8 inlet manifold on with these heads, and lets face it you probably wouldn't want to even if you could. It's almost certainly the same story with the exhaust manifolds so you'd need to see Mark's quoted £3.5k as a starting point.

After spending £3.5k on the heads & valve gear you'll still be looking at adapting the TVR exhaust manifolds with TA flanges and cooking up an inlet manifold, at which point costly throttle bodies would be the logical path to follow.

I very much doubt you'll get much change out of £5k all in to properly convert your existing engine to these heads, it certainly isn't the straightforward bolt of performance mod it first seems.

As I understand it Mark's engine is now 5.0 litres, so 429hp / 5 = 85.8hp per litre for probably around the £5k mark as a complete turn key bolt on performance mod on a more or less standard Chimaera.

Or you could just leave your heads, manifolds and plenum exactly as they are and spend the same money on buying and installing an SC-Power Rotrex supercharger kit, which will easily give you over 90hp per litre.

Not only will you make more power than the TA heads, I wouldn't mind betting with the Rotrex blower correctly installed and mapped you'll end up with the more refined & drivable car too.

To me, as good as the TA heads are all this kind of makes them a bit of a non-starter.

Surely if you're going to spend in the region of £5k for a big power hike on your TVR Chimaera the SC-Power Rotrex supercharger kit (or turbo) has to be the better option?

Well that's the way I see it, but perhaps I'm missing something?

rev-erend

21,404 posts

283 months

Monday 9th February 2015
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As a quick turn key solution the supercharger route makes a lot of sense but the way a big throttled engine such as one with TA or Wildcat heads is impressive.

Kokkolanpoika

161 posts

150 months

Tuesday 10th February 2015
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What is so impressive?

+200cc bigger engine and more radical cam is worth at least 30hp
You can calculate that head´s are worth approx 30hp.. With good ported original head´s difference is not that big.. 43mm inlet valve will flow enought air for +440hp

My target is +420hp in the next summer with my 5.2l and home ported head´s.. I will not use my welded head´s in this summer.. Bodywork take to mutch time..

But 429hp result´s are good for rover, but not worth of that money.. He has got 35hp more than my engine, and i use milder cam and STD home modded head´s.. frown

Chuffmeister

3,597 posts

136 months

Tuesday 10th February 2015
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Kokkolanpoika said:
What is so impressive?

+200cc bigger engine and more radical cam is worth at least 30hp
You can calculate that head´s are worth approx 30hp.. With good ported original head´s difference is not that big.. 43mm inlet valve will flow enought air for +440hp

My target is +420hp in the next summer with my 5.2l and home ported head´s.. I will not use my welded head´s in this summer.. Bodywork take to mutch time..

But 429hp result´s are good for rover, but not worth of that money.. He has got 35hp more than my engine, and i use milder cam and STD home modded head´s.. frown
Out of interest. Can you do a full write-up on your welded heads?

Transmitter Man

Original Poster:

4,253 posts

223 months

Tuesday 10th February 2015
quotequote all
Kokkolanpoika said:
What is so impressive?

+200cc bigger engine and more radical cam is worth at least 30hp
You can calculate that head´s are worth approx 30hp.. With good ported original head´s difference is not that big.. 43mm inlet valve will flow enought air for +440hp

My target is +420hp in the next summer with my 5.2l and home ported head´s.. I will not use my welded head´s in this summer.. Bodywork take to mutch time..

But 429hp result´s are good for rover, but not worth of that money.. He has got 35hp more than my engine, and i use milder cam and STD home modded head´s.. frown
440 bhp in theory so why few, if any cars even come close to this figure, even with latest race heads and cam?

Phil

Transmitter Man

Original Poster:

4,253 posts

223 months

Tuesday 10th February 2015
quotequote all
+ V8 blokes heads have had no serious porting work - there's still work to be done to stretch out that 35 bhp.

I firmly believe someone will break the 100 hp per litre naturally aspirated and possibly with TA heads.

Phil

v8bloke

255 posts

210 months

Thursday 12th February 2015
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Standard exhaust manifolds fit the TA heads and I would imagine that inlets fit too with a bit of port matching.
Also using 4.6 Elring head gaskets.
The TA heads have larger chambers and of course the valves are closer to the centre line, so cutouts in pistons in a different place.
My Engine is using 45mm Jenvey throttle bodies which may be restricting flow at the top end as well as the exhaust system which is 2.5 inch diameter.
I now have an issue with one of the new Asnu injectors so haven't got it back yet.
Hoping it will go rather well!
Cheers
mark

Brummmie

5,284 posts

220 months

Thursday 12th February 2015
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v8bloke said:
Standard exhaust manifolds fit the TA heads and I would imagine that inlets fit too with a bit of port matching.
Also using 4.6 Elring head gaskets.
The TA heads have larger chambers and of course the valves are closer to the centre line, so cutouts in pistons in a different place.
My Engine is using 45mm Jenvey throttle bodies which may be restricting flow at the top end as well as the exhaust system which is 2.5 inch diameter.
I now have an issue with one of the new Asnu injectors so haven't got it back yet.
Hoping it will go rather well!
Cheers
mark
I have a twin 2.5" exhaust, but 8x55mm chokes on my LS and that flows 565bhp with 620lbs/ft torque.
According to DART (who make my heads) you want the inlet valve to be slightly smaller than the choke, with a gentle taper so gas speeds up along the tract, sounds plausible?

rev-erend

21,404 posts

283 months

Thursday 12th February 2015
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What size (mm) are the inlet valves in the TA heads ?

v8bloke

255 posts

210 months

Thursday 12th February 2015
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If I remember rightly they are 1.9 inches 48.26mm so 50mm throttle bodies would be spot on!

v8bloke

255 posts

210 months

Thursday 12th February 2015
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would love a set of these. http://www.triumphroverspares.com.au/page.asp?pare...
Quite pricey though.

rev-erend

21,404 posts

283 months

Thursday 12th February 2015
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My inlet valves are just 47mm and the tb's are 48mm.

wildcat600

49 posts

115 months

Thursday 19th February 2015
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Hi Mark

I read with interest your thread here and on the V8 forum.
Very impressive. Hats off to you bow

From what I read, you have invested a lot of time and money in developing your various Rover V8 engines.
I'm in awe of your openness to share your experience and results which I have found informative.
I hope the negativity of some of the posts does not deter you or cause any doubt.
Some of the power figures being quoted for Rover V8 engine using standard casting are in the realms of a place far far away.
Anyone who has worked with the standard casting knows the limits of these, therefore the limits of the horsepower they are going to produce. Yes they can be welded, seats and ports moved, but this is expensive and not always reliable over time as the finished heads end up unstable. I've seen the reworked heads needing the valve seat recutting on a regular basis (at least once a year) and then having new seats fitted and the process continues.
Yes, one can build an engine to make an impressively high horse power figure, but how long would it last on supermarket fuel?
As your engine is destined for your Track day car, which you drive to and from the track, and not an out and out race engine you have done very well. Your engine builds using the Merlin, then the TA heads, are what I call 'usable reliable low maintenance performance engines'.

Keep up the good work and enjoy every mile driven driving

wildcat600