What Does Your 3.9 / 4.0 litre Wedge Make?

What Does Your 3.9 / 4.0 litre Wedge Make?

Author
Discussion

pwd95

8,382 posts

237 months

Tuesday 13th September 2011
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Alexdaredevilz said:
Could you honesty comment how bad that cam was low down please, as I'm thinking about fitting a mech cam with about 300 duration my self soon
It's lumpy as hell down low to be honest. My old 'Flapper' injection system probably needs a tweak here & there too but once it reaches 4k rpm it just takes off, all the way to 6500. Very addictive. yes

Alexdaredevilz

5,697 posts

178 months

Tuesday 13th September 2011
quotequote all
pwd95 said:
It's lumpy as hell down low to be honest. My old 'Flapper' injection system probably needs a tweak here & there too but once it reaches 4k rpm it just takes off, all the way to 6500. Very addictive. yes
Usable lumpy? or did you have to travel 100 miles to avoid a traffic jam?

Mine will be temporarily using the hotwire with a MA chip, then changing for mappable system in the near future

350Matt

3,733 posts

278 months

Tuesday 13th September 2011
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Chimpafrolic said:
"My old 1275GT Mini made 320hp when I replaced the SU carbs with a twin choke Webber"

Myths and stories are no good Wedgies nono


The mythical 270hp 4.0 litre Rover V8 still eludes us (in all TVR camps).

A 255hp Wedge remains the best confirmed result so far.

However I know of a certain Chimp that's about to surprise us all.

Who can it be scratchchin
Its no myth, it was on Emeralds rolling road about 7 years ago now

So it can be done

pwd95

8,382 posts

237 months

Tuesday 13th September 2011
quotequote all
Alexdaredevilz said:
Usable lumpy? or did you have to travel 100 miles to avoid a traffic jam?

Mine will be temporarily using the hotwire with a MA chip, then changing for mappable system in the near future
Useable for me no problem. Would be a bit tiresome on a daily basis but a proper fuel & spark system would probably tame it quite well.

Alexdaredevilz

5,697 posts

178 months

Tuesday 13th September 2011
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Thanks, good to know large cams aren't as bad as some people think

JMF894

5,478 posts

154 months

Tuesday 13th September 2011
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pwd95 said:
It's lumpy as hell down low to be honest. My old 'Flapper' injection system probably needs a tweak here & there too but once it reaches 4k rpm it just takes off, all the way to 6500. Very addictive. yes
My 450 feels exactly like this. Is there any way of working out the cam profile/duration with physically taking it out as i'm curious as to what it's running?

Jimbo

Alexdaredevilz

5,697 posts

178 months

Tuesday 13th September 2011
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Only way to tell is to take it out, then you might aswell change it

wooly350i

2,248 posts

207 months

Tuesday 13th September 2011
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The lads at v8dev did a good job with mine,give em a call and see what's on offer.

voltage_maxx

368 posts

208 months

Tuesday 13th September 2011
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Alexdaredevilz said:
Only way to tell is to take it out, then you might aswell change it
That's surely not true? With the rockers off, it should be possible to measure the valve lift and time the duration using a degree wheel?
Providing the cam profile isn't worn, I'm sure it should then be able to reference the figures back against known cam data.

KelWedge

1,278 posts

184 months

Tuesday 13th September 2011
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350Matt said:
Chimpafrolic said:
"My old 1275GT Mini made 320hp when I replaced the SU carbs with a twin choke Webber"

Myths and stories are no good Wedgies nono


The mythical 270hp 4.0 litre Rover V8 still eludes us (in all TVR camps).

A 255hp Wedge remains the best confirmed result so far.

However I know of a certain Chimp that's about to surprise us all.

Who can it be scratchchin
Its no myth, it was on Emeralds rolling road about 7 years ago now

So it can be done
Yes and that was with the Prototype Emerald box on it, which is still on the car now, I had to give Emerald the disk Matt gave me to give to Emerald as they could not remap the Emerald unit when I had it remaped! after the change to 4.6, So yes 270bhp has been done on a 4.0Ltr.
The only reason I changed from the 4.0 ltr is because I broke it frown
I went 4.6 to get a slightly better all round drive, and I knew I was going to have to go up a bit and still go quick smile
A few other bits were changed and some of the bits on the old unit kept.
It also drinks a bit less now,

Donks

21 posts

151 months

Wednesday 14th September 2011
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Shame this is more than a 3.9/4.0 litre.
But i bet it RATTLES a few CAGES !!!
Picture taken at NEC A few years ago.

Chimpafrolic

Original Poster:

9,637 posts

178 months

Wednesday 14th September 2011
quotequote all
OK, I think we have exhausted this one, I hope you all enjoyed the banter?

Ultimately it was just a frivolous bit of nonsense from me, & you should all know by now I am rather gifted at frivolous nonsense silly

Now we are coming to a close it may be worth summarising what we've learnt?

1) It is possible to squeeze 270hp plus out of a 4.0 litre Rover V8

2) Doing so is likely to have a significant negative impact on driveability

3) Getting to 270hp plus will need a first rate set of ported & flowed heads, an aggressive cam and other induction mods

4) If the goal is over 250hp it's probably cheaper & more sensible to build a decent 4.6 lump than keep throwing money at a 4.0 litre

5) Even though it hurts me to admit it, the Wedgies do seem to have the most powerful 4.0 litre cars cry

6) A Wedge weighs 150kg more than a Chimp so this should even things up

EXAMPLE:
  • A Wedge with 270hp will have a PTWR of 222hp per ton.
  • A Chimp with 240hp will have a PTWR of 226hp per ton.
So all I really need is 240hp or more & not even a mighty 270hp Wedgie can beat me wink

My last rolling road session recorded a healthy 233hp at the crank.

But wait for it Wedgies, with my new twin port flugal horn (ACT De-cat Y Piece) going on next weekend I hope to see a genuine 240hp.

Wedge Spanker is hunting you down evil

Edited by Chimpafrolic on Wednesday 14th September 15:17

TVRleigh_BBWR

6,552 posts

212 months

Wednesday 14th September 2011
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Where are you getting your weight figures from, have you had both on a rolling road, I did not think a Chimp was that much lighter than a 400SE, my 4.0 FHC racer weighs just over 1000KG without driver. 45/55 rear/front

Chimpafrolic

Original Poster:

9,637 posts

178 months

Wednesday 14th September 2011
quotequote all
Ok, may have been a tiny bit out rolleyes

It seems there is some conflicting info in Wedge weights on the interweb.

Lets make it as fair as possible & look at the most favourable scenario for my Wedgie mates.
  • Wedgie at 270hp pulling along 1150kgs = 234.78hp per ton
  • Chimp at 240hp pulling along 1060kgs = 226.41hp per ton
So my Chimp would need 249hp to match the much fabled & elusive 270hp 4.0 litre Wedgie.

scratchchin, perhaps I need those stage 3 heads from Rob Robertson after all?

But hang on, looking at it another way any Wedge with less than 260hp is going to struggle against my Chimp with 240hp loser

idea Come on Wedgies who's brave enough for a bit of street drag with the Chimp?

driving


JR

12,722 posts

257 months

Wednesday 14th September 2011
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So after all these pages you've worked out that, all other things being equal, you won't out drag a well tuned 3.9/4.0 wedge or larger capacity wedge (which are all tuned) and you've found out that it's cheaper to drop in a lager capacity block than tune a 4.0. I think that TVR reached that conclusion about 25 years ago.

JR

12,722 posts

257 months

Wednesday 14th September 2011
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BTW I remember 350matt's car at the first BBWF. It had many impressive features in the engine bay but you might expect that from a Cosworth F1 engine developer with the remit to develop more power.

JR

12,722 posts

257 months

Wednesday 14th September 2011
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Chimpafrolic said:
You cheeky cheese you jester

Show me a real life Wedge with more than 260hp & I will gladly show you a winner.

But honestly where are they?

Wedge Spanker is ready for you biggrin
Hmmm, you've raised the bar again: 250, 255, 260...

From memeory there were about 2,500 wedges built. Of these about 400 were larger capacity cars (3.9 or above.) Of these 400 about 60ish will have had 250+ bhp from new and that includes the 4.2, 4.3 and 4.5 cars. Then we've got loss of power from wear and tear without being rebuilt and the fact that as you mention rather than an expensive 4.0 rebuild it's easier and cheaper to drop in a 4.6 or 5.0. I think that there are less than 1,000 wedges now and maybe 5 of those with your requirements so they will be rare beasts but they do exist.

Chimpafrolic

Original Poster:

9,637 posts

178 months

Wednesday 14th September 2011
quotequote all
JR said:
So after all these pages you've worked out that, all other things being equal, you won't out drag a well tuned 3.9/4.0 wedge or larger capacity wedge (which are all tuned) and you've found out that it's cheaper to drop in a lager capacity block than tune a 4.0. I think that TVR reached that conclusion about 25 years ago.
You cheeky cheese you jester

Show me a real life Wedge with more than 260hp & I will gladly show you a winner.

But honestly where are they?

One road, four cars:

1) KR (claiming 270hp but he admits it's a very old figure)

2) Wedg1e (with 256.6hp)

3) Jonny weggie (with 254.6hp)

4) Chimpafrolic (moving 100kg less with 240hp)

Wedge Spanker is ready for you biggrin

JR

12,722 posts

257 months

Wednesday 14th September 2011
quotequote all
Chimpafrolic said:
One road, four cars:

1) KR (claiming 270hp but he admits it's a very old figure)

2) Wedg1e (with 256.6hp)

3) Jonny weggie (with 254.6hp)

4) Chimpafrolic (moving 100kg less with 240hp)

Wedge Spanker is ready for you biggrin
Those four cars? I'd say it would come down to tyres and drivers. Would be interesting to watch.

KelWedge

1,278 posts

184 months

Wednesday 14th September 2011
quotequote all
JR said:
BTW I remember 350matt's car at the first BBWF. It had many impressive features in the engine bay but you might expect that from a Cosworth F1 engine developer with the remit to develop more power.
And it was the loudest at this years BBWF laugh