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OleVix

Original Poster:

601 posts

33 months

[news] 
Wednesday 5th February quote quote all
So I went ahead and bought a tophatted 4.6 shortblock, fully rebuilt with 4.0 pistons and balanced. Stage3 BV heads are arriving in a month together with a ported intake. Plenum is std with carbon flared trumpets, cam is mc1. The 4.0 pistons should give me 10.7/1 compression.

Dazedpeterhaircut is selling me his old 4.6 fueling chip, he had a similar setup.

Just wondering if some of you have experience in similar builds... and if there are other mods I should be doing at the same time to make the most of it!

Chuffmeister

2,811 posts

22 months

[news] 
Wednesday 5th February quote quote all
A new ECU and bespoke map at the same time. It seems like a real shame to go to all that expense and then not spend a little more to get it running absolutely spot on and maximise the performance. I've had two cars mapped) not the Chim... yet) my E39 BMW and my Quattro (both oil burners). The difference it made was enormous.

db484bhpv8

6,605 posts

105 months

[news] 
Wednesday 5th February quote quote all
Similar spec to mine. It would be as it came from Peter a couple years ago.
4.6 tophatted, 4.0 pistons, ARP bolts and studs, 500 heads, ported inlet, blended trumpet base, typhoon cam,72mm plenum, full decat and running MS2. Drives lovely with good mpg and nearly 330 bhp.

debaron

666 posts

82 months

[news] 
Wednesday 5th February quote quote all
OleVix said:
So I went ahead and bought a tophatted 4.6 shortblock, fully rebuilt with 4.0 pistons and balanced. Stage3 BV heads are arriving in a month together with a ported intake. Plenum is std with carbon flared trumpets, cam is mc1. The 4.0 pistons should give me 10.7/1 compression.

Dazedpeterhaircut is selling me his old 4.6 fueling chip, he had a similar setup.

Just wondering if some of you have experience in similar builds... and if there are other mods I should be doing at the same time to make the most of it!
See mine here:

http://www.pistonheads.com/gassing/topic.asp?h=3&a...

Didn't finish the thread off fully but the main thing would be ARP studs for the heads!!! Are you using a vernier timing sprocket or something a bit more static?

900T-R

19,368 posts

142 months

[news] 
Wednesday 5th February quote quote all
Yep, ARP bolts would be A Good Thing. With the big valves and ports on a 4.6 I would be inclined to save up my pennies for an ITB set up using the JED crossover manifold so I could take advantage of a reasonably naughty camshaft and still have good low-rpm driveability (it would take the brains of one Mark Adams to splice the input of two AFMs into one and program the CUX fuel chip accordingly - he once told me he's already done this on a 400 bhp Morgan Plus Eight yikes).

Seriously, you could end up with something that asks serious questions of large capacity Rovers and engine transplants as it'd deliver everything you could reasonably ask for within the limits of a Griffmaera.
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QBee

8,609 posts

29 months

[news] 
Wednesday 5th February quote quote all
900T-R said:
Yep, ARP bolts would be A Good Thing. With the big valves and ports on a 4.6 I would be inclined to save up my pennies for an ITB set up using the JED crossover manifold so I could take advantage of a reasonably naughty camshaft and still have good low-rpm driveability (it would take the brains of one Mark Adams to splice the input of two AFMs into one and program the CUX fuel chip accordingly - he once told me he's already done this on a 400 bhp Morgan Plus Eight yikes).

Seriously, you could end up with something that asks serious questions of large capacity Rovers and engine transplants as it'd deliver everything you could reasonably ask for within the limits of a Griffmaera.
Mark is a lovely guy, his phone number is there if you google him, just be patient as he tends not to answer his phone when he's away or working. He will happily chat for hours on the phone discussing your options with you, no commitment, and does a cracking job when he gets his mitts on your pride and joy hehe

900T-R

19,368 posts

142 months

[news] 
Wednesday 5th February quote quote all
QBee said:
Mark is a lovely guy, his phone number is there if you google him, just be patient as he tends not to answer his phone when he's away or working. He will happily chat for hours on the phone discussing your options with you, no commitment, and does a cracking job when he gets his mitts on your pride and joy hehe
Yep, all true that... sometimes you'll need a fair bit of patience to get an actual appointment with him to work on your car but he'll make sure you'll be very well informed beforehand, and when you have that elusive session he'll get to the bottom of things in double-quick time... thumbup

OleVix

Original Poster:

601 posts

33 months

[news] 
Wednesday 5th February quote quote all
db484bhpv8 said:
Similar spec to mine. It would be as it came from Peter a couple years ago.
4.6 tophatted, 4.0 pistons, ARP bolts and studs, 500 heads, ported inlet, blended trumpet base, typhoon cam,72mm plenum, full decat and running MS2. Drives lovely with good mpg and nearly 330 bhp.
Wow thats great bhp... My mc1 cam is new in the box and I'm wondering if I should make valve reliefs in the pistons and exchange it for a stealth cam with higher lift...

Blended trumpetbase is without trumpets? Does this affect torque? How do I get/make 72 mm plenum?

The long term plan is to get a full ms2/extraefi system on it, but in the beginning i'll stick to the upgraded chip and dizzy. My awesome mechanic friend is 59, he told me that in the olden days when you needed more advance you opened the dizzy and fiddled with the weights and springs inside... he knows his stuff so might try this smile

I will fit a wideband lambda in the y piece to see how its fueling.

Its full decat now, will try to get the manifolds and y ceramic coated.

OleVix

Original Poster:

601 posts

33 months

[news] 
Wednesday 5th February quote quote all
900T-R said:
Yep, ARP bolts would be A Good Thing. With the big valves and ports on a 4.6 I would be inclined to save up my pennies for an ITB set up using the JED crossover manifold so I could take advantage of a reasonably naughty camshaft and still have good low-rpm driveability (it would take the brains of one Mark Adams to splice the input of two AFMs into one and program the CUX fuel chip accordingly - he once told me he's already done this on a 400 bhp Morgan Plus Eight yikes).

Seriously, you could end up with something that asks serious questions of large capacity Rovers and engine transplants as it'd deliver everything you could reasonably ask for within the limits of a Griffmaera.
That ITB setup is so monstrously expensive! Will get the ARP kit though...

I'm hoping to get 300 bhp with this setup, still looking original in the engine bay. I think 300 is good power in a little chim... will leave most cars for dead and can hopefully keep up with 400hp porkers, new /M cars and RS Audis

QBee

8,609 posts

29 months

[news] 
Wednesday 5th February quote quote all
OleVix said:
db484bhpv8 said:
Similar spec to mine. It would be as it came from Peter a couple years ago.
4.6 tophatted, 4.0 pistons, ARP bolts and studs, 500 heads, ported inlet, blended trumpet base, typhoon cam,72mm plenum, full decat and running MS2. Drives lovely with good mpg and nearly 330 bhp.
Wow thats great bhp... My mc1 cam is new in the box and I'm wondering if I should make valve reliefs in the pistons and exchange it for a stealth cam with higher lift...

Blended trumpetbase is without trumpets? Does this affect torque? How do I get/make 72 mm plenum?

The long term plan is to get a full ms2/extraefi system on it, but in the beginning i'll stick to the upgraded chip and dizzy. My awesome mechanic friend is 59, he told me that in the olden days when you needed more advance you opened the dizzy and fiddled with the weights and springs inside... he knows his stuff so might try this smile

I will fit a wideband lambda in the y piece to see how its fueling.

Its full decat now, will try to get the manifolds and y ceramic coated.
I have a similar spec, but a 5 litre running on the 14 CUX, mapped by Mark Adams, with a stealth cam. Gorgeous torque over a very wide range of rpm, but only 300 bhp..... Unless I am mistaken, the stealth cam gives you torque at the expense of bhp. So it pulls brilliantly out of corners on track days, but ultimately is slightly slower at Santa Pod.
72mm plenum is readily available. IIRC it is a 3.9 LR Discovery plenum, or something similar. Mine certainly has "3.9" cast into the top. Someone else will know for sure.

OleVix

Original Poster:

601 posts

33 months

[news] 
Wednesday 5th February quote quote all
A question about pushrods and rockers... can't I use the standards from my 3.9?

SILICONEKID346HP

11,759 posts

116 months

[news] 
Wednesday 5th February quote quote all
Ditch the MC1 and go for something a bit more radical, I have the Stealth but i could of gone for something even more extreme with the after market ECU .

The 72mm plenum is just a modified standard plenum . I think v8d sell them . Do you have the 38 or 45mm trumpet base .?

http://www.v8developments.co.uk/technical/inductio...

Edited by SILICONEKID346HP on Wednesday 5th February 22:30

Alexdaredevils

5,184 posts

64 months

[news] 
Wednesday 5th February quote quote all
You can get almost any cam to work with the 14cux with any chip, you need a adjustable fpr and a afr gauge, just keep tweeking everything until you get the afr you want

Downside my cold starts were iffy

900T-R

19,368 posts

142 months

[news] 
Thursday 6th February quote quote all
My choice fur running an RV8 on a plenum would be Stealth or TVR Power 885. With ITBs you can go a bit more aggressive.

A900ss

1,994 posts

37 months

[news] 
Thursday 6th February quote quote all
QBee said:
Unless I am mistaken, the stealth cam gives you torque at the expense of bhp.
That isn't what I've been told.

I thought the Stealth was a cam to deliver more mid and top end power over standard at the expense of low down torque. It certainly isn't the most radical of cams but is more extreme that standard.

I hope so as that's why I chose it frown



leerdam23

480 posts

146 months

[news] 
Thursday 6th February quote quote all
900T-R said:
...It would take the brains of one Mark Adams to splice the input of two AFMs into one and program the CUX fuel chip accordingly - he once told me he's already done this on a 400 bhp Morgan Plus Eight yikes).
Interested... I'm thinking that an 'easy' (read cheaper than ITB's, Xover manifolds and new ecu) way to reduce lairy cam shunting would be to fabricate a dual plenum for the RV8 by chopping and welding 2 so that 1 feeds one bank of 4 and one the other . I've seen twin plenums (2 chopped and welded together) but they seem to feed all 8 cylinder.

I also seem to remember several people doing this here on t'heads but not sure it they ever got off the ground so to speak.

Also Lloyds of canems fame have fabricated a duel plenum.

Anyone got this working at the moment?

QBee

8,609 posts

29 months

[news] 
Thursday 6th February quote quote all
A900ss said:
QBee said:
Unless I am mistaken, the stealth cam gives you torque at the expense of bhp.
That isn't what I've been told.

I thought the Stealth was a cam to deliver more mid and top end power over standard at the expense of low down torque. It certainly isn't the most radical of cams but is more extreme that standard.

I hope so as that's why I chose it frown
I could easily be wrong.
I asked for a car with driveability ahead of peak BHP. A stealth cam was specified by Rob.
My engine has most of the mods others with 330-360 bhp have (bigger AFM, smooth bore inlet hose, 72mm plenum, fully ported inlet manifold, stage 3 heads, lightened flywheel, fully decatted), but only makes 300 bhp. However, it does make 330 torques and is over 300 torques from 2000 rpm to 5000 rpm, which makes it a really flexible drive. For example, on track days I very rarely use second gear, even on pretty tight bends. The hairpin at Cadwell Park is about the only exception, and even there I sometimes use third.
The only mod I haven't had is an aftermarket ECU.
So that's why I jumped to the conclusion that it was the cam that was giving me the torque over bhp characteristic.

Come on guys - add your thoughts so we can resolve this one.

carsy

2,029 posts

50 months

[news] 
Thursday 6th February quote quote all
QBee said:
I could easily be wrong.
I asked for a car with driveability ahead of peak BHP. A stealth cam was specified by Rob.
My engine has most of the mods others with 330-360 bhp have (bigger AFM, smooth bore inlet hose, 72mm plenum, fully ported inlet manifold, stage 3 heads, lightened flywheel, fully decatted), but only makes 300 bhp. However, it does make 330 torques and is over 300 torques from 2000 rpm to 5000 rpm, which makes it a really flexible drive. For example, on track days I very rarely use second gear, even on pretty tight bends. The hairpin at Cadwell Park is about the only exception, and even there I sometimes use third.
The only mod I haven't had is an aftermarket ECU.
So that's why I jumped to the conclusion that it was the cam that was giving me the torque over bhp characteristic.

Come on guys - add your thoughts so we can resolve this one.
Always thought yours was a bit low on numbers giving the build.
Are you sure you`ve got a full 5 litres.

macdeb

4,953 posts

140 months

[news] 
Thursday 6th February quote quote all
OleVix said:
will try to get the manifolds and y ceramic coated.
If you do, DON'T get 'cermakrome' by camcoat. The finish on mine is appalling and the only thing worse was their attitude to it. Terrible service.
Go the extra expenese and get 'Zircotec' I wish I had.

phazed

10,083 posts

89 months

[news] 
Thursday 6th February quote quote all
carsy said:
Always thought yours was a bit low on numbers giving the build.
Are you sure you`ve got a full 5 litres.
laugh Those are genuine numbers. We used the same rolling road at the same time iyswim.
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