TECH? MORE POWER!

[BLUETHUNDER]

I own a 4.0ltr H.C and for a while now have considered upgrading the performance.The original intention was to supercharge the exhisting 4.0ltr unit,but after a little investigating i was looking at a bill in the region of £5,000.This was way above what i expected,so i considered option no 2.I can purchase a brand new 4.6 H.C RangeRover short block for £1,300.The idea was then to fit this to my exhisting heads from my 4.0ltr,with an A.C.T triple plenum in conjunction with an E.C.U re-map.The question is,is this feasible? what are the eventual costs?(they cant be anywhere near the £5,000 quoted for the supercharger work)and what are my likely power output figures likely to be?(B.H.P Torque e.t.c?.I was quoted figures of an extra 80-90 B.H.P with the supercharger fitted.Any help would be most appreciated. Thanks MARK.

[GreenV8S]

Have faced exactly the same problem in the V8S (now 4.6/big valve). Don't want to discourage you if you fancy having a go, but it is definitely NOT the cheap way to more power. Trading up is far, far cheaper. Also bear in mind that there are other ways to upgrade the car and more power is not necessarily the most cost effective way to make it go faster. In any case, with this sort of power rise you need to budget for a few thousand pounds of brake and suspension upgrades and expect the life of the standard transmission to be about 20-30k miles. The S Series and Griff/Chim bibles both cover this in some detail.

What s/c solution were you looking at by the way?

[BLUETHUNDER]

A freind of mine has a modified M90 Eaton supercharger fitted to his RangeRover.The work was carried out by Dennis Priddle of D.P.R super charger fame.This was the type of set up i was looking at.Its a plenum mounted blower with serpentine pulleys.Peter out of intrest,whats your views on the triple plenum?,i take your point about trading up to a faster car,but ive already carried out a bit of work on the car in regards of new wheels light mods e.t.c.I really wouldnt like to pass on what i have done to some one else,when if i bought another car i would have to do all the mods again.I would have gone for a cerbera,but what with the parts situation in regards to an engine rebuild if i needed one,then i think i will stick with what i know best. MARK

[2 sheds]

.I can purchase a brand new 4.6 H.C RangeRover short block for £1,300.The idea was then to fit this to my exhisting heads from my 4.0ltr,with an A.C.T triple plenum in conjunction with an E.C.U re-map.The question is,is this feasible? what are the eventual costs?(they cant be anywhere near the £5,000 quoted for the supercharger work)and what are my likely power output figures likely to be?(B.H.P Torque e.t.c?.I was quoted figures of an extra 80-90 B.H.P with the supercharger fitted.Any help would be most appreciated. Thanks MARK.

one of the limiting factors is the heads, i wouldn't fit tripple plenum system to standard 4.0L heads , stage 3 fully ported medium big valve heads are £750,
Have just finished a 4.0L upgrade project , which included Heads, twin throttle system, tornado chip & RR session , suggested cost would be £2,300 for parts &900 ish for labour & rolling road time, + VAT i would allow £4000.! for project.
Power increase would probably be around +40. maybe more i will have dyno figures soon, I would now describe the car as "urgent" , and now needs suspension work say around £1000, but this was the case with or without the engine upgrade, the point is don't all your dosh on the engine.
Hope this helps.
Tim
p.s edited twice due to bloody keyboard jam, i think i need to upgrade my PC..


>> Edited by 2 sheds on Sunday 27th April 12:44

>> Edited by 2 sheds on Sunday 27th April 12:57

[GreenV8S]

That's the sort of money Dennis quoted me for an Opcom conversion. He didn't think it was worth bothering with an intercooler at such low boost levels, but looking at the Eaton temperature plots I can't help thinking intercooling is the right way to go. Unfortunately this more or less rules out the easy installation option on top of the plenum.

As you know, I had stage III heads and cam fitted to my original 4.0 engine, together with an ACT single throttle plenum (and trumpets, manifold etc). This spec was the result of long discussions with Tim and Mark (thanks for putting up with me for so long guys) and I have to say it really seemed to suit the engine and went extremely well. Roughly 40 bhp up on the original engine if memory serves, slightly down on bottom end torque but the top end just pulled and pulled. Incidentally, Tim's predictions for the power/torque charactistics were absolutely spot on, very impressive given all the variables involved.

As far as the tripple plenum etc are concerned, I've met some very happy 5.0 owners with a tripple throttle plenum, and I seem to remember Tim saying the twin plenum was producing very good results on the smaller engines, but really Tim is the man to ask about the best over-all solution for your particular engine.

Cheers,
Peter Humphries (and a green V8S)

[BLUETHUNDER]

I was under the impression, that the heads fitted on the H.C engines,were of the bigger valve type?if not where does claimed extra 35 b.h.p come from over the standard models,or am i missing some thing.

[2 sheds]

BLUETHUNDER said: I was under the impression, that the heads fitted on the H.C engines,were of the bigger valve type?if not where does claimed extra 35 b.h.p come from over the standard models,or am i missing some thing.

Forget an extra 35 bhp, the heads are standard except polished , on rolling roads the difference between HC and "standard" is small if anything.

Tim

[BLUETHUNDER]

Ive taken in all your comments guys,and im on a bit of a downer.It seems that the costs of the engine mods are going to be roughly the same as the super charger option,so im down to option 3,and the last 1.Fitting a 4.6 to my exhisting heads with a 4.6 e.c.u obviously there will be a brake upgrade.Any comments....

[JonRB]

2 sheds said:

edited twice due to bloody keyboard jam, i think i need to upgrade my PC.

Well the trouble with upgrading your PC is that you upgrade the processor, which necessetates a new motherboard which often needs new memory. They you upgrade the graphics and the next thing you know is you need bigger brakes and uprated suspension.

Sorry, I seemed to have got confused somewhere along the way there.

[JonRB]

BLUETHUNDER said: I was under the impression, that the heads fitted on the H.C engines,were of the bigger valve type?

No, HC stands for "High Compression". You're thinking of the "BV" spec, standing for "Big Valve" (as in the Griffith 4.3BV)

[markh]

I thought that the 'HC' refers to the cam (Highlift Cam)

Mark

[2 sheds]

BLUETHUNDER said: Ive taken in all your comments guys,and im on a bit of a downer.It seems that the costs of the engine mods are going to be roughly the same as the super charger option,so im down to option 3,and the last 1.Fitting a 4.6 to my exhisting heads with a 4.6 e.c.u obviously there will be a brake upgrade.Any comments....

If you fit 4.6 bottom end but leave top end as is the power band would run out at lower rpm , expect max bhp to occur at around 4800-5000, it depends what your after , loads of low down torque or top end excitement, personally i like an engine to pull hard to 6000.
The £4,000 quoted is a realistic figure for a comprehensive upgrade and it includes the chip & Mark Adams treatment, it may cost less and upgrades can be tailored to suite budget. whatever engine modifications you do, allow at least £700 for the Chip & tunig process.
Tim

[BLUETHUNDER]

Can i be educated.By fitting the 4.6 short block to my heads,how does it change the characteristics of top end power,by bringing the power in earlier like you have said?I thought that a bigger bottom end would give me better low down torque,but top end power would remain the same as the original set up.Can you explain the change in power shifts? Thanks MARK

[2 sheds]

The larger combustion chamber takes longer to fill & empty unless you increase the porting accordingly.
Standard heads are designed to work with 3.9L in the Land Rover 4.6 standard heads are used but high rpm isn't relevant, the TVR 4.6 ( as Chimaera) has modified heads.
Tim

[shpub]

JonRB said:

BLUETHUNDER said: I was under the impression, that the heads fitted on the H.C engines,were of the bigger valve type?

No, HC stands for "High Compression". You're thinking of the "BV" spec, standing for "Big Valve" (as in the Griffith 4.3BV)

The compression ratio is the same, the valves are Vitesse and are the same... HC is for hign lift cam which is different.

Page 33 in bible 2.

Steve
www.tvrbooks.co.uk