Jump to content
twodoorgaz

recipe for short, strong RV8 on carbs?

Recommended Posts

I'm obviously familiar with the installation of a V8 into a Series, but rather than find an engine and make it fit I would like to incorporate parts from a number of generations of the little lump to give the best possible fit for the application. Tracking down those trick little bits is one of my favourite past times and I have a year or so to assemble the engine.

I've got the difficult transmission aspects sorted now (thanks to a year of trading parts), the contents of the barn now offer a choice of modern (Short R380 + Milner-philips ring) or period (101 LT95) - both have their benefits. Axles are sorted (109V8 front, Ashcroft ATB and shafts rear). Brakes and steering have been decided upon.

Vehicle will look completely standard with original paint, except for the Def 130 rims I've been saving - and the gear lever position of course, but I'd like something a bit grand under the bonnet.

So attention turns to the exciting bit, the engine. I went through a phase of looking at the SBC or even the 4.3 Chev V6, but a few things just didn't add up, so I'm back on the venerable old Rover.

I could just stab any old RV8 one into place, but I'd like to gather bits for something special. The engine will be built and detailed on a bench, and I have the time and space to store and strip a few donor engines so I can select the best parts from each.

Damn Rick Voegelin and his book which I've read about a dozen times.

I would really appreciate some help in coming up with a recipe.

Aims are:

  • End up with an engine with the water pump nose correctly orientated in relation to the (custom) radiator to allow the option of a fixed fan or viscous. (the rust-free radiator panel I have will be stripped, the bonnet catch will go and an aluminium radiator will go onto the front crossmember so there will be more space at the front for a fan if I choose not to fit a kenlowe.)
  • End up with the shortest possible engine - focusing on the water pump nose. I'm aware the P6 nose was short, I'm also aware that the Serp pump (in isolation) is even shorter - see here. The part I get really hazy on is the timing covers and position of the water pump nose. I'm told the serps had a short pump, but a deeper timing cover that erodes the benefit.
  • I'm a big fan of the 3.5, but for this build I'd prefer to use a cross-bolted block (4.0 or 4.6) or at a push to have a late 3.9 drilled for cross bolts.
  • Any 3.9, 4.0 or 4.6 would get top hat liners during the rebuild as insurance, have already budgeted for that.
  • I am still undecided re: carbs vs EFI, Lucas vs MS. I know the pros and cons of each - MS wins in a big way in virtually every respect. Carbs can be a pain to set up and adjust, but replated and polished they look and sound fantastic. I'm leaning towards carbs for something of a showpiece. If I use my LT95 I'll probably stick with Carbs, If I assemble my Stumpy R380 it'll probably be MS.
  • The engine will be built for long life and reliability but aesthetics are important too (sorry). I love the look of SUs, but the Gems plenum can look pretty good as well.
  • Exhaust manifolds need to tuck in nicely.
  • It won't be going on LPG, so no concerns there.
  • Remote oil filter will b Mocal.

There are a number of options that would tick most of the boxes in one hit (the 3.9 intermediate is screaming at me here). Later oil pump and dizzy are big wins.

In an ideal world I would buy a 4.6, top hat liners and arb studs, balanced and rebuild with earlier SU carbs and intermediate timing cover for the short pulley and oil pump plus early RR manifolds - but I suspect its not that simple with no dizzy provision, etc.

Once I have the basic recipe I'll fatten it out with engine numbers, applications and part numbers if anyone else is interested. It'll take a few months to gather the bits but I can post the engine build here.

Really appreciate any help

Share this post


Link to post
Share on other sites

Sounds like your best bet would be to rebuild a 4.0 or 4.6 on carbs and then megajolt it. you lose the dizzy and gain the crank driven oil pump along with the cross bolted block

Share this post


Link to post
Share on other sites

Another vote for the above, JE Developements do a serp timing chest with P6 pump but not cheap.

Share this post


Link to post
Share on other sites

Loads more room with a serp front end, I personally wouldn't bother with a dizzy -just more to service and go wrong. Hide the coil packs and EDIS behind the engine/under a cover panel and you would never know it was on MJ (though of course I would Megasquirt it anyways.....)

If you want something special under the bonnet, have a look at the inlets here: http://www.mez.co.uk/ms12-new.html

If you really want chrome, I've not seen it done, but I expect you could get one of the 4.6 plenums and chrome it up...

Obviously... I'm not going to recommend carbs, you will likely chuck away 50+BHP, be less drivable, and worse on fuel.... but I do understand in a series you may want all those things :P

Share this post


Link to post
Share on other sites

Once last thought, get a yank manifold for it, and one of the multipoint throttle body injection types (at the bottom of the page) and a pancake airfilter, and you wouldn't know it was injected...

Share this post


Link to post
Share on other sites

I went with carbs on the 3.9 I put in my S3, and I'm very pleased with it. I have the serpentine intermediate front end, ditched the original dizzy and popped a Mallory with electronic points on, which has been fantastic so far. Megajolt not a bad option, though.

I'm not using the viscous fan - wasn't room with th V8 and LT8 in the 109 - but the crank nose sits about in the middle of my custom radiator. That setup was about the shortest I could find! Build thread here: http://forums.lr4x4.com/index.php?showtopic=95691&page=1

Share this post


Link to post
Share on other sites

4.0 or 4.6 bottom end, serp 3.9 timing cover if you want to keep the distributor, otherwise build it without and go with a megasquirt to run the fuelling and ignition.

A bit of porting work on the heads and a more lively cam would finish things of nicely.

I can't say much bad about the 14CUX efi setup either, although the newest setup on a vehicle will be at least 18 years old by now.

I wouldn't bother with carbs, despite them being 'simple and reliable', because to be quite honest, so's electronic injection when you understand it properly.

Also, it's said that the engines supplied to Morgan, Westfield etc were the top quality castings, whilst the lower grade ones were used for Land Rover products (work that out?) although the later -I think 2001 on- engines had the 'coscast' block which was reengineered to eliminate the porus block issues.

Might be a better start to build it round one of them if you can find one, or just spend the money on a Turner top hat linered block.

Share this post


Link to post
Share on other sites

Buy a TVR lump and then you get the modified heads into the deal, saves a load of dosh on the right deal :)

Share this post


Link to post
Share on other sites

Excellent - thank you very much guys, exactly what I was looking for.

I'll take the above on board and will start to gather parts.

I'll have to have a better look at Megajolt. MS I'm familiar with, but the MJ side needs some research.

Thought I'd be laughed at re: the aesthetic side of things - I'm aiming for classic-look black Samco hoses, black powdercoating and polished alloy, braided wiring loom, leather bonnet strap, etc. On my last build the detailing was the thing that griped me most - I want this thing to look like Jaguar helped Land Rover build a desert racer in the '60s (Tally-ho). Thats the only reason I've been toying with carbs - however much I hate setting them up.

Share this post


Link to post
Share on other sites

I rebuilt a new factory engine, (it was a bit rusty from sitting around in a warehouse), and did a little porting on the inlets to clean up the castings, got an H180 cam from Turner, and used those nifty twin-outlet EFI manifolds with the big exhaust that was already in the car. I kept the CD175s for simplicity. It's only a 3.5, but it goes well with an LT95. (Obviously, I really want a 4.6 but this is what I've got for now.)

If money ever allows, I'll Megajolt it, partly because it sounds like a beautiful system, and partly because getting decent ignition parts these days is laughably difficult. Rotors falling apart, no-name brand dizzy caps, it's just ridiculous.

I'm not so keen on Megasquirt because I'm not convinced it would survive long-term use on corrugations, and trouble-shooting in the bush would be very difficult, but for you, (assuming you're in the UK), I think it would be ideal in the long term.

Share this post


Link to post
Share on other sites

Carbs are easy - and I'm an EFI man! Get yourself a standalone wideband lambda jobbie and enjoy the simplicity. You might as well be reading tea leaves and chicken entrails trying to 'read' plugs.

I went with carbs because I couldn't bring myself to put fuel injection on a 1973 vehicle. Info in my build thread.

Sounds like a lovely project :)

And agreed on the dizzy parts for the rover stuff being so poor these days. Another reason the Mallory is so good.

Share this post


Link to post
Share on other sites

Ever thought about a Ford V6 ?in particular the 24v 2.9 out of the Scorpio ,cracking engine .

Share this post


Link to post
Share on other sites

Oh, be sure to allow for a remote oil filter with a serp front end, they do like to touch the diff if the engine is in the wrong place.

Share this post


Link to post
Share on other sites

Most of a 4.6 or 4.0, whip the inlet off and drop carbs on (you filthy heathen), megajolt with the coil pack hidden - if you found small enough coils you could make a fake distributor to really confuse the rivet counters. The yanks may even do such a thing already, check out their hot-rod scene and Summit Racing.

As mentioned above, you can get throttle body injection units that look exactly like 4-barrel carbs and fit exactly onto 4-barrel manfiolds for the same reason. It wouldn't look standard but it wouldn't look injected and you'd have a chrome air cleaner to polish.

I'm not sure I'd jump at a TVR lump, I've heard they can be hit & miss bits-wise (as in they went through a period where they were fitting whatever they could find) and they're designed to pull an empty crisp packet up the road not a 2 ton brick so the power could be all in the wrong place.

Share this post


Link to post
Share on other sites

Thanks again folks - I've been on the hunt, buying the odd bit and measuring a lot more. After getting my copy of Des Hammil's book my understanding is a lot further on - but still a big vague on the MS/MJ options.

For the mechanical bits I'm looking at a 4.0 or 4.6 - already cross bolted & big journals - 10 bolt heads, composite gasket, crank-driven oil pump and I'll be adding ARP bolts, a remote oil filter and top-hat liners. Should give me the strength I was looking for.

A 3.9 intermediate is a close second - as above but with small journals (arguably no great loss as less friction and with more material in the block) and while not cross bolted, there is the casting provision to have it done during machining. Ancillaries may be a bit older to simplify the install.

 

I have a line on an interim 3.9 (serp + dizzy) as well as an already cross bolted 4.6 so will be picking them both up in the next week or two, I'll flog the bits I don't use. I'm not sure when I'll get round to stripping for machining and top hats but that gives a lot of options:

 

Option 1) CARBS: 4.6 block and heads, interim timing cover, SU carb setup (yes I know… but it will look fab. But will undoubtedly be a pain to set up the SUs/find needles, etc). Classic, beautiful, but usual clockwork-computer issues. Much shorter than v-belt front.

Option 2) CARBS:  As above - 4.6 with carbs, but no interim timing cover and simply use Megajolt instead of the distributor. No distributor. Fully waterproof. Easy. Shortest possible RV8 (20mm shorter than interim 3.9)

Option 3) EFI: 4.6 block and heads, interim timing cover, and Hotwire - chipped for 4.6 (Tornado or similar). OK, almost all Rover. Not waterproof. Much shorter than v-belt front. Shorter than V-belt, 20MM longer than MS/MJ.

Option 4) EFI 4.6 engine and Hotwire remains + Megasquirt . No distributor. Fully waterproof. Fully mappable injection and ignition. Again, shortest possible RV8 (20mm shorter than interim 3.9)

 

As explained I am rubbish when it comes to EFI. I have read the MS site and am getting a bit confused.

 

Am I right in saying:

  • Hotwire needs a distributor.
  • No MS/MJ setup needs a distributor. In fact, as the 3.9 and 3.9 intermediate has a hole for a distributor, you actually need to buy a 'dinky dizzy' plug to block this hole.
  • As I'm going for the shortest possible engine (and given that I am going to be starting with a 38A 4.0 or 4.6 block anyway), if I'm going to have MS or MJ, it makes no sense to include 3.9 intermediate parts and I might as well just go straight for the 4.0 or 4.6 with its extra-short, distributor-less timing cover?
  • WTF is Megajolt? I've seen a few people selling it but nowhere near the clear writeup there is for MS EDIT: I've just found FridgeFreezer's explanation on another thread. So - I could use either Hotwire or Carbs on the 4.6 engine and use Megajolt to replace just the distributor? i.e. I wouldn't need an intermediate Serp front end as I wouldn't need the distributor hole?

 

Thank you very much for your patience.

 

 

Share this post


Link to post
Share on other sites

Mega jolt just controls spark, where as mega squirt controls spark and fuel injection. If you were to use the Devils trumpets then you would only require mega jolt

 

dont be put off by how complex it seems, it is deceptively simple. I had no experience with auto electrics before I fitted mine and found it relatively straight forward.

 

if I were doing it again I would get the later 4.0 to do away with the need for a dumpy dizzy as you say. The megasquirt/jolt does not need it, it is there to drive the oil pump on the v-belt engines and to just plug a hole on the serp engines

Share this post


Link to post
Share on other sites

Thanks again. Think I'm sorted here folks - off I go to start picking up bits.

 

One last, final thing if I may…….

 

Not sure if the 4.6 I'm going to look at is a Thor or GEMS. It only becomes relevant if I keep EFI and go with MS.

 

am I right in thinking that MS would make it irrelevant which system the engine was originally fitted with as the only thing retained is the injectors? I understand that THOR would be a preference due to extra torque facilitated by the plenum, but other than that it doesn't make a difference. Am I right?

If I bit the bullet and go for an EFI/MS setup, I admit that aesthetically at least, the GEMS plenum is my favourite of the three.

Share this post


Link to post
Share on other sites
On 19 June 2016 at 6:41 PM, Ozzy50 said:

Ever thought about a Ford V6 ?in particular the 24v 2.9 out of the Scorpio ,cracking engine .

Oh and Ozzy - I have given the ford V6 a lot of thought. With my Stumpy R380 its a real possibility.

 

I can pick up Steve Parker cologne adaptors off ebay dirt cheap (Series has same bolt pattern as Stumpy R380). That means I can use the compact little Cologne at full chat and make full use of it. I looked specifically at the dirt cheap 4.0 cologne in UK Ford Explorers (same engine offered in US Disco 3s). It is still a real possibility, but a RV8 just tickles my fancy that bit more.

Share this post


Link to post
Share on other sites

The Thor requires its own version of the megasquirt kit from nige, brackets are different and FPR is needed

 

 

i have Thor fitted to my 3.9 and am very pleased with it

Share this post


Link to post
Share on other sites

Just a quick update folks. Got the first pile of donor bits and got quite lucky: for a crate of lager less than a ton I picked up a 4.6 block and heads fitted with an intermediate serp front end. Still trying to work out the rest of the parts the PO used to build it though.

Share this post


Link to post
Share on other sites

Just worth mentioning, when I built a 4.6 using interim front end...you will also need an interim spec cam....they are longer to take the dizzy drive gear...I used a real steel viper cyclone if I remember right. Ran well with a green tune resistor and tvr chimaera 450 chip...

Share this post


Link to post
Share on other sites
On 11/09/2016 at 5:51 PM, twodoorgaz said:

Oh and Ozzy - I have given the ford V6 a lot of thought. With my Stumpy R380 its a real possibility.

 

I can pick up Steve Parker cologne adaptors off ebay dirt cheap (Series has same bolt pattern as Stumpy R380). That means I can use the compact little Cologne at full chat and make full use of it. I looked specifically at the dirt cheap 4.0 cologne in UK Ford Explorers (same engine offered in US Disco 3s). It is still a real possibility, but a RV8 just tickles my fancy that bit more.

There were two different 4.0 Cologne V6's. The early one was an OHV, but latter ones are SOHC. The SOHC used in the s197 Mustang (2005-2010'ish) made 210hp stock and is a good engine.

I've often wondered if the 24v heads from the 2.9 Cologne would fit the late 4.0's, but not heard of being done. I don't think the 2.9 was used in the US and not many 4.0 SOHC's over here.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy