4.6L Project 110 CSW

[Simon B]

Hello LR Fora members,

I have a 4.6 V8 block which I had been going to rebuild with a webber 500, torque max cam and run it on LPG with an ignition module, however having read the comments on the weber I'm rethinking.

My desire is to make an engine that has some torque but can achieve a realistic level of economy (I driven v8s for a few years so know what what "realistic" is) It's use would be a towing and family drive.

So, in your opinnions what are the benefits of;

Staying with the SU/Stromberg type OEM carbs or going to Megasquirt/Megajolt (If this canb be achieved on a 4.6l

[western]

Welcome to LR4x4.com

I'm sure V8 Freak will be here soon, his 110 has a 4.6 V8 in it running with the Omax ignition system, sure he'll tell you all about it.

Please read the pinned info at the top of the thread listing, it will help you use the forum.

[letsgetdirty]

Hello LR Fora members,

I have a 4.6 V8 block which I had been going to rebuild with a webber 500, torque max cam and run it on LPG with an ignition module, however having read the comments on the weber I'm rethinking.

My desire is to make an engine that has some torque but can achieve a realistic level of economy (I driven v8s for a few years so know what what "realistic" is) It's use would be a towing and family drive.

So, in your opinnions what are the benefits of;

Staying with the SU/Stromberg type OEM carbs or going to Megasquirt/Megajolt (If this canb be achieved on a 4.6l

welcome to lr4x4...youll like it here,people are helpful and friendly....if your planning an engine with more torque is it wise to go lpg??? you might have run this before and been okay with it,but kinda sounds like you may as well leave it standard?ive heard all kinda reports off lpg vehicles being down on power,and ive driven a few which have been down on power to,understand for the fuel economy but just wonderded if its worth the bother with bigger carbs and highlift cam,i cant help you with anything else im afraid but as western said theres experts on everything on here

[V8 Freak]

I'm no expert and don't use the gas stuff.....

I would suggest people like Bull Bar Cowboy, Hybrid From Hell or Fridgefreezer can advise you better on the engine...

I just plugged one in and am learning in arrears.

I can tell you it makes a nice noise, drinks a few sips of fuel here and there but best of all. Makes me smile

Neil

[Simon B]

I'm no expert and don't use the gas stuff.....

I would suggest people like Bull Bar Cowboy, Hybrid From Hell or Fridgefreezer can advise you better on the engine...

I just plugged one in and am learning in arrears.

I can tell you it makes a nice noise, drinks a few sips of fuel here and there but best of all. Makes me smile

Neil

Thank you for the welcome, I looked at Omax, it's very expensive for my needs. My deliberation is due to not knowing what to expect from the weber in terms of economy, if it does not return better economy than the SU/Strom set up I may not bother.

I have the 4.6 block as stated plus all the other 3.5 ancilliaries it will need a top end rebuild and cam anyway, add to this a gas kit and we are talking some cash. I love the V8 burble, however, the lure of a very economic 200TDi is strong, factor in a bit of performance enhancement and it has much to offer - undeniably less power.

My 4.6 on SUs did about about 10mpg on LPG on the motorway less on short journeys. If the weber can take this to 15 it's a goer if not it's a lot of cash for more torque/bhp.

So to summarize my ramble what I want is my 110 to do towing speed in 5th with at about 15mpg (this would be 30ish mpg financial equivalent). I've never had a sports car so the 4.6 monster would be it! Mr Frugal is tempted by diesel though...

Help please!

[tacr2man]

For running on lpg what carb setup doesnt matter much as its the choke diameter that governs the air flow and your gas flow /mixture is based on that . To get the best you want to go to injection motor with switch over to liquid gas injection.

The vaporisor route is quite wasteful really. JMHO

[Simon B]

I was coming to this realisation yesterday and began to look at the ptracticalities of economically building up my 4.6 block with a fuel injection topend, though as yet I'm not sure if this will fit in a sensible way with the 3.5 heads. A 4.6 with a totaled block might be the way to go and salvage the parts from it.

This is a lot more of a project than I had planned, but 4.6 kit looks a lot cheaper than it did a while back, especially Efi.

[FridgeFreezer]

The weber you could replace with a hosepipe in terms of economy, it's a fairly OK setup provided you stick to tarmac, avoid slopes and vibration, and don't go far from the nearest petrol station. If you want a good carb setup, stick with factory. Except the factory fitted EFI 20 years ago...

With MegaSquirt I get about 15mpg most of the time, it's been known to get near 18 and my gearing is way too low for economy really, 70 is 3200rpm at the moment it could do with being half that. That's on a 4.6 with 3.9 heads and top end in a 109, so quite similar in aerodynamic quality to a 110

A full MS+EDIS setup will cost you similar to a Weber 500, and I happen to have a big box of EDIS-8's just turned up from the states here

The EFI parts you need can be picked up for about £10 as the bits that go wrong are the original ECU and Airlflow meter. The 3.9 injection setup is slightly nicer having clamp-down injectors but aside from that 3.5 or 3.9 will work fine.

[Simon B]

Cheers Mr Fridge,

Looks like I've some reading to do, EFi seems the way forward at my budget level. I'll need a bit of help working out compatibilities and then make a shopping list.

I was very happy with LPG and had planned to use it again, there was a little drop in power less punch on acceleration but other than that it started better, warmed up faster and smelt better!

See you all soon!

[Hybrid_From_Hell]

Hiya.......Right

My 2p worth (which with inflation running as it is is prob more like £1 50 )

I would say MS

I would say this as I have been the Flapper, Hotwire, adjustable ECU, rechipped ECU and Rolling Road and 'wallet' routes, .....and the MS is by far the winner.

One of the real attractions (other than waterproofness off road) is its flexibility in tuning.

lets say you take your 4.6, and add std heads std inlet manifold and std trumpet and plenum , you just fit MS run, and then tune the fuel requirements.

If you then decide to fit Big valve heads massively ported,

with a a ported inlet and short HUGE trumpets and say a twin entry plenum,

or any other tuning bits you fit, start and then simply retune the fuel.

When you see that a EPROM for a Hotwire ECU is £250-£350 work and item and then you can have MS for less than that it sort of limits things doesn't it ??

You prob couldn't have found a more cynical member re MS than me,

some 20 months later I am a "born again Megasquirter" -

yeah lord I haaaave seeen the liaght yeah hallleaalulah

There are also some seriously knopwledable members here who will help,

I am not one of them, but BBC Bill S, Fridge will see you right if you get stuck,

Fridge nadgered me for ages to MS the Eales,

wish I had done it sooner,

I had a quick but tempermental rich running often misfiring Race V8,

MS later ........I have a rip roaring thing that takes my breath away (and my wallet for fuel but better than the webber 4 barrel I tried that was worse !)

Go MS you won't regret it - read here :

http://forums.lr4x4.com/index.php?showtopic=15317

Nige

[Simon B]

OK, chaps so can I use my 3.5 heads and stick the Efi kit on top of that or do I need to use 3.9 Efi heads?

There seems to an amount of 4.6 stuff around stripped out of Rangies like a 4.6 plenum and other bits. I assume that this will only fit a 4.6 manifold/head set up so would not be suitable for my build?

Lastly (for this post) with MS fitted would I run the risk of doing my block in via the liners loosening route as seen in a number of non-carbed v8 failures, if so is there a fix to prevent this?

[FridgeFreezer]

OK, chaps so can I use my 3.5 heads and stick the Efi kit on top of that or do I need to use 3.9 Efi heads?

You can use any heads, the EFI ones have a tiny notch in the port for the injector spray pattern but in reality I doubt it makes any great difference.

There seems to an amount of 4.6 stuff around stripped out of Rangies like a 4.6 plenum and other bits. I assume that this will only fit a 4.6 manifold/head set up so would not be suitable for my build?

It depends - the 4.6 plumbing is all different, I have a 4.6 plenum but none of the mounting hardware so stuck with the 3.5/3.9 one, the only difference (apart from where thing are) is the 4.6 one has 4.6 cast into the top. The throttle size is the same.

Lastly (for this post) with MS fitted would I run the risk of doing my block in via the liners loosening route as seen in a number of non-carbed v8 failures, if so is there a fix to prevent this?

A popular theory is that Rover ran the 4.6's very lean to pass emissions, which aggravates the liner slip issue. All 4.6's left the factory on EFi. Any carbed 4.6 is going to be an aftermarket job so probably a Weber, which means the likelihood of running lean is somewhat reduced due to the aforementioned hosepipe effect Whereas an EFi one will either be running the original tuned-for-emissions GEMS/Thor setup or, knowing LR & racing types, have some horrible bodge such as a ratty old flapper or hotwire system bolted to it, which is going to do no favours for anyone even if it is an adjustable one.

With an MS (or any mappable ECU) you tune the engine with feedback from the lambda sensor to ensure it doesn't run too lean - hell, you tune it right, that's the whole damn point. MegaLogViewer's auto-tune (datalog analysis) will get you to a pretty good state of tune on its own, you just need to do a bit of smoothing out and a bit of richening off idle.

If you're worried about the liner slip issue you could make the map (or MLVV's target tune) a bit richer but realistically top hat liners are the only guarantee. As I said, a carbed one is unlikely to suffer as it's constantly being drowned in fuel whereas even a ropey old flapper system will at least get the fuelling within a barn door's width or so.

[Simon B]

Having looked at MS in marvel I'm not sure if I can fit it to an LPG system unless I can make it run liquid injection (separate set of LPG injectors) so evapourator back on cards, I may still use the Megajolt concept and run my ignition via MS/J and EDIS8.

The alternative is run on stock SUs, fogger ring in each for lpg and stay with my old dizzy but have it rebuilt. The jury is still out on the weber 500. £500 for a carb and manifold that may not give me much more when on lpg is lot of cash.