V8 Build Quandary..

[Fatboy]

On my current project I'm going to fit a V8 avec le Megasquirt etc. The rolling chassis is almost done and I'm waiting on parts to rebuild the gearbox so I thought I'd turn my attention towards the power unit.

I've got three sources of parts:

1. An old "complete" V8, 8.13:1 compression. Engine No.27C00---B. I think this is a 3.5 from the late 80's.

Needs a chunk of work inc new big ends, at least a bore hone and rings, cam etc.

2. A more modern V8, 9.35:1 compression. Engine No.60D12---A. I think this is a 4.6....

Apparently had a water problem but not sure of detail so I assume its the block / liner.

This has complete heads on it, crank & pistons etc. Alloy sump & water pump.

3. Another modern V8, 9.35:1 compression. Engine No.42D22---A. I think this is a 4.0...

Also had a water problem, same as above.

This has complete heads on it, crank & pistons etc.

I believe the later engines with the crossbolted blocks have wider cranks. The pistons and rods are different so I suppose I can't use any of the lower end gear off the newer engines. Safest bet being the 3.5 and I'll have to live with the weaker crank / brgs. Upside being its less prone to using more water than petrol.

I am therefore only going to be able to use a pair of the newer heads unless I fork out a fortune on a new top hat block. (and I'll never get an AFE for that!! )

Anybody got any ideas about the front covers - should I aim to get serpentine ancilliaries etc or do I have to stick with V Belts. Does the serpentine crank pulley fit the earlier crank?

Nige - You found yourself a dodgy block yet? I know where there are a couple

As ever, thoughts, opinions and OT banter are always welcome.

[pugwash]

the 4.6 and 4.0 cranks are interchangeable as they had the same line bore.

heads are 90% interchangeable-there's list of head capacity (ie the cc of the valve bowls)- they vary from 28cc and 34cc which can have a big effect on compression.

serpentine front covers will not work with early cranks as they need a long nose to meet the oil pump- serpentine front ends are good though- i swapped to a serpentine front end and my oil pressure shot up- certainly more than a simple bottom end rebuild would suggest!

very early sumps don't quite clear the long throw of a 4.6 crank.

if you use a 4.0/4.6 block then get it top-hat linered first- Turners do good work, but you can get it done locally by other engineering companies.

if you rae going to build an engine you might as well build a 4.6 imo- they can be made to be totally reliable and powerful but you need to spend some time on them. Don't get in a mess about worrying about crossbolt blocks- i came across a couple of croxx bolters which didn't have the bolts in, unless of course you are using the engine in comp safari or other situations when you could frequently ping the red line.

If you sell bits then THOR inlet manifolds and serpentine front covers make good money- more so than 4.6 cranks in my experience.

take the time to get the rotating assembly properly balanced- it will pay dividends in the long run. If you want to get silly and build a 4.8 or larger (if you are going to get the block relined then you might as well think about getting the bore increased) there is a chevy piston that is available cheaply but which only needs the crown machining to fit- you get a bigger engine and choice of compression ratios. I'll look up the spec when i get a sec- it's in my build files at work.

Bull Bar cowboy knows a thing or two about V8s as does eliot mez at www.mez.co.uk- both worth approaching for info (although there are also innumerable others on the forum who have a lot of experience- it's getting them to admit it that's the key. Where's Paul Whiteman?)

[Bull Bar Cowboy]

Without a doubt I would use the 60D block (P38A engine)………… I assume that has the later front cover complete with the later crank driven oil pump and no dizzy hole…….. you are not going to need the dizzy anyway……………the 60D blocks (i.e. later blocks) have a better casting and that makes for a stronger engine

I will drop you a PM regarding getting that block top hat lined ……….. it’s a lot cheaper then you think…………..

I cant find any ref to a 27C engine …………. Are you sure it not 27G , as that would be from a disco (carb version)………

The 4.0L (42D – Range Rover 4.0L) would also make a nice engine, but like I said above the 4.6 is top choice.

Ian

[Hybrid_From_Hell]

I have added some thoughts below :

On my current project I'm going to fit a V8 avec le Megasquirt etc. The rolling chassis is almost done and I'm waiting on parts to rebuild the gearbox so I thought I'd turn my attention towards the power unit.

I've got three sources of parts:

1. An old "complete" V8, 8.13:1 compression. Engine No.27C00---B. I think this is a 3.5 from the late 80's.

Needs a chunk of work inc new big ends, at least a bore hone and rings, cam etc.

No point, its a 3.5 and its a low comp engine, the compression is in the pistons which is unusual for most engines, forget this one completely

2. A more modern V8, 9.35:1 compression. Engine No.60D12---A. I think this is a 4.6....

Apparently had a water problem but not sure of detail so I assume its the block / liner.

This has complete heads on it, crank & pistons etc. Alloy sump & water pump.

Water prob is dangerous, there is a real risk in spending loads of money on a rebuild and then to find the blocjk is still an issue, you can't detect liner issues much by eye, the only possible visual identity of poss problems are if you remove the heads, and one or more cylinders look like they have been pressured steam clean and are mint, this indictaes water steam cleaning that bore, the other visual is that the liners when the heads are removed you may find one where the liner top is not exactly flush with the top of the block.Not all water probs are liners, can be a simple as a head gasket and everyone then screams "Liners"

If you can see either of the above then you may need to have the block relinered, and best to use a decent engineering co that specialisizes in V8 and this sort of work, the one I recomendened to ian G he speaks highly of, and the work is superb - but its hundreds of £s not a few quid....no point spending a fortune on an engine where the rest of the copnents are not really up to it, so you need to think what exactly are you going to do rebuild wise, V8 rovers are NOT cheap, and thats excluding the liner issue ?There are a raft of mods I would suggest you look at on any rebuild, but thats a different discussion, here is more the base engine you pick on ? This sounds like a serp engine, again yopu need to decide what you are aiming for engine wise......... serps have plus and minus points.....

3. Another modern V8, 9.35:1 compression. Engine No.42D22---A. I think this is a 4.0...

Also had a water problem, same as above.

This has complete heads on it, crank & pistons etc.

I believe the later engines with the crossbolted blocks have wider cranks. The pistons and rods are different so I suppose I can't use any of the lower end gear off the newer engines. Safest bet being the 3.5 and I'll have to live with the weaker crank / brgs. Upside being its less prone to using more water than petrol.

Cross bolt blocks are stronger - mine is not one so you can get huge BHP without one, again build quality and components here are key, you can tell a cross bolt block from looking at the outside - look at the base just above the sump, see if it has a row of bolts down both sides yes = crossbolted no = not

Serp or non serp is another thought, you can have either, what ancillaries are you going for and there is much to discuss on either route but whilst you can have a old style front end on a serp engine you can't serp up a non serp as the crank is too short, whilst it can be done to an old crank (ie eales has remachined and lengthen some cranks that were worth it it isn't cheap )

The heads for 4.0 and 4.6 I think are the virtually same with minor differences , the 3.5s depend on the year,.... pre 77 ish heads have duel sping and small inlet and exhaust and are not much use also many people seem to think all V8 heads are ok on unleaded - not so pre 77 have the wrong value seats and unleaded cannot be safely used long term without having the special valve inserts shoved in them, not cheap and frankly not worth doing with the prices of late gheads and bigger valves.

In simple terms the later the V8 head the better, tho some belive the late late heads without the holes near the plugs for head bolts (which you don't use) are best, the heads that have these holes blanked (or not drilled) have some werid issues, therefore 3.9 heads asre quite sort, you could have a post on heads alone there is so much to discuss

I am therefore only going to be able to use a pair of the newer heads unless I fork out a fortune on a new top hat block. (and I'll never get an AFE for that!! )

Anybody got any ideas about the front covers - should I aim to get serpentine ancilliaries etc or do I have to stick with V Belts. Does the serpentine crank pulley fit the earlier crank?

Nige - You found yourself a dodgy block yet? I know where there are a couple

Yes I still need a knackered 4.6 block, for a mate that wnats it - for a 4.6 Crank and rods into a 4.0 block he has........... a thought for you in the above, ........

you can get a block "Checked" for liner issues - but the cost is huge, you more than half way to relinered tophat

Frankly if you don't want the cost of relinering I would use NONE of the above and go hunting for a known good 3.9 or 4.6 serp or non serp.

What is the finished applciation for, and what exactly are you hoping for, maybe then I can give you some more info ?...this should get you thinking in the meantime

Nige

[Bull Bar Cowboy]

Right…..…as Nige correctly says if any of the above engines are known to be ‘Coolant issues’ and if you don’t want to go down the TH liner route, then those will all be scrap……

However, as you know doubt saw by my rebuild…….coolant issues are not always evident. My engine came to me as an unknown……… I could find no evidence of a coolant problem, however the mains and bigends were shot and there was evidence of an oil burning problem so I assumed (wrongly) that it had been changed due to being wornout……..

My suggestion would be to get the 60D block TH lined ………. the process is as follows……… a machined bar is clamped by the main bearings to the correct torque……….then the old liners are CNC machined out to the correct size for the TH replacements, which IIRC is a 3 thou interference fit…………. the block is then evenly heated and the new liners are dropped in…………. once naturally cooled the new liners are CNC machined to your piston size and then the block is decked to ensure the liners are flush…………. the liners are then CNC plateau honed to the final correct size…….. the bar is removed and the main bearings are line bored to ensure concentricity (i.e. the ‘pinch’ areas are machined true)…………. Finally the original engine number is restamped……………

Remember if your block needs a rebore then that is half way or more to the cost in my PM……….

Other machining work can be included at no or little extra cost …………. You could have the block decked by 20 thou as it has to be decked anyway.

Also include your crank for a 10/10 regrind and the heads to be skimmed and get it done as a package………..again, if the heads are to be skimmed then have 20 – 30 thou removed to increase the CR (assuming you had the block decked) ………. Also get them check the valve guides and recut the 3 angle seats…………. If the guides are worn then they will be able to bore the guides and fit bronze liners ……….. allow about £75 - £100 per head (remember you have to get them skimmed anyway and that’s going to cost £30 - £50…….use the 4.6 heads as these later heads have much better oil seals ……… you can also get the machine shop to machine the guide bosses to be level with the heads in the above cost…….this will allow for a hotter cam to be used without risk of spring crunch. You can port the heads yourself, provided you have a die grinder and a compressor (or an electric die grinder)…….. I can point you in the direction of a suitable cutter for this exercise ………. all you need is patience

On any rebuild you should replace the cam and lifters ………… the cost of a hotter cam over standard is not a lot ………….. choose one that will enable you to use std lifters, although Roads bleed down lifters are not a lot of money……….

If you really want it bomb proof then consider fitting ARP bottom end and head studs, but be aware that you are looking at 4 times the cost of normal bolts………

Also use a quality timing chain set ………….. any decent set (cloyes) will be 4 to 5 times the cost of std ………… if you use std then be prepared to replace it every 20K.

For a standard rebuild I guess you are looking at the thick end of £800 ………… for a quality build then maybe £1000 ………… for some serious extra power and bomb proof then £1200 - £1800……….

HTH

Ian

[pugwash]

For a standard rebuild I guess you are looking at the thick end of £800 ………… for a quality build then maybe £1000 ………… for some serious extra power and bomb proof then £1200 - £1800……….

F**k me that's cheap- wish i'd spoken to you lot a few years ago as getting my block machined and rebuilt locally was a lot more.

Fatboy- that sort of money is a bargain for the work you will get done. With correct oil changes there's no reason why the rebuilt engine shouldn't be good for 150,000 miles or more. Power will be right up there as well- BBC how much power does your engine make- 320bhp? how much does a stock 4.6 make- 230bhp if you're lucky?

[Bull Bar Cowboy]

Jim,

Mine is a 3.9, so std they were 182 ………………… mine was doing 252 but being strangled at the top end by the snorkel…………………….however, the top end is of no concern as my build intention was to produce as much low end torque as possible………..

IIRC a std 4.6 is 223…………… so a little head work, hotter cam, different sparks/fueling, and some attention to detail will easily see 260 - 280 ………….. a general rule of thumb is that any std size RV8 with over 300 - 320 will be unpleasant to drive as a road engine……….but great as a track car………….

Those prices are close guesstimates for parts & machining …………..but yes its cheap because you are providing the labour and labour costs big bucks………….. its not rocket science, all that is needed is a fundamental understanding of engines, the ability to accurately read and interpret measurements, cleanliness, and attention to detail………..a lot of known engine builders seem to have a penchant for putting a premium on their prices

Properly built, with the right components, and fully maintained throughout its working life, then you will see big mileage from an RV8 ……….

Ian

[Hybrid_From_Hell]

IMHO a well done THL (top Hat Linered) block is BETTER than new.

The company I recomended to Ian G specialises in this sort of work, and other high end stuff

I know for a fact they do work for other machine shops - who sub out this work to them - Oh and then whack on a amount of £s for themselves - to do sod all work

Nige

[Fatboy]

Gents,

I really appreciate the help and advice.

I've done a number of builds on 3.5's including a total strip / rebore / ground crank so am familiar (ish) with them. Ian's thread is an aspiration I don't think I have the ability to achieve but nothing ventured, nothing gained as they say so I'm now seriously thinking of giving the 4.6 a go.

I'm not really constrained by time as its not a daily drive.

The suggested total cost is a chunk less than my previous major rebuild although for me, carriage may be a cost.

I'll re-read the replies when I get home and formulate a plan. My starter being a proper stripdown of the 4.6

Thanks again,

[FridgeFreezer]

All this is over my head a little but I'm using a stock 4.6 block with 3.9 heads and the composite head gaskets, on paper it'll have lost some compression but I can't say I've noticed it plus it runs happily on Russian petrol. If I had spare cash I'd get the heads skimmed and the block THL'd. I did stick a slightly fruity cam in it, duplex chain and ARP head studs when it was built.

BTW you can buy two different ARP head stud kits, one for older engines and one for 4.0/4.6 which doesn't have the outer row of bolts and is therefore cheaper.

While you're on the phone to Real Steel, their rubber rocker cover gaskets are good.

All this said, if I thought I was gonna have to spend more than £1500 rebuilding a Rover V8 I'd be on eBay looking at LS1's

[pugwash]

All this said, if I thought I was gonna have to spend more than £1500 rebuilding a Rover V8 I'd be on eBay looking at LS1's

don't go to ebay- contact http://www.clevelandpickapart.com/ based funnily enough in cleveland. Top people, couldn't be more helpful, and prices are ridiculously low. I got a firebird LS1 for £1350? i think which with shipping and taxes was more like £1800 or so, but that was allin with ECU, and all relevant parts (including Cats). Shipping took 7 days door to door.

Of course it leaves you with a drive train problem as it's difficult (and pointless) to mount a LS1 to a ZF4 box. Can get cheap 4L80e and 4L60e for not much, and you just buy TCI software to control the shiftpionts- or drop the bottom end off and go fully manual valve conversion!

[Fatboy]

I cant find any ref to a 27C engine …………. Are you sure it not 27G , as that would be from a disco (carb version)………

Ian

Aye indeed.... 27G it is. Just checked!

I'm going to need to do some sums and have an Ebay frenzy I think!

[FridgeFreezer]

I'm going to need to do some sums and have an Ebay frenzy I think!

eBay?

[Fatboy]

eBay?

... to try and raise some funds and create some room....

[FridgeFreezer]

... to try and raise some funds and create some room....

Aaah, thought you were about to buy vital engine bits off eBlag

I would ask if you have any good stuff for sale but I'm so skint it's not funny

[Fatboy]

I would ask if you have any good stuff for sale but I'm so skint it's not funny

Theres good cash in scrap at the moment... A mate who runs a local garage was telling me that he got £12 each for some old three spoke Rangie alloys. I've got at least 10 of them... Then there is a couple of old chassis, (is the plural of chassis, chassi ? ). The old leaf springs off the 2a, gear box casings, a couple of old pairs of V8 heads and a front cover or two..

[TheRecklessEngineer]

Aaah, thought you were about to buy vital engine bits off eBlag

I bought a V8 from eBay...true it was in bits, but didn't you once describe it as "Rather pokey?"

[Fatboy]

This mission may be getting out of hand...

If I bolt a Megasquirted, rebuilt 4.6 infront of my rebuilt Series gearbox I'll probably die of shrapnel wounds to the lower body or impact damage due to brake melt.

However, I've put a ZF 4 speed into my 3.5 V8 90 which also has Rangie axles and has been running well for a while. I rebuilt that V8 from scratch and it is probably a wiser choice for the Series IIa as its not quite so powerful as the 4.6 will be .

So: I'm toying with the ideal of pulling the 3.5 out of the 90 c/w SU's and Tubular Manifolds and putting it into the Series IIa. Then rebuild the 4.6 for the 90.

Am I in the process of qualifying for a vapour build?

[Hybrid_From_Hell]

Am I in the process of qualifying for a vapour build?

IMHO only if you pratt about and / or dismantle a working series to a pile of bits and then procrastinate about putting either back together

Nige

[Fatboy]

IMHO only if you pratt about and / or dismantle a working series to a pile of bits and then procrastinate about putting either back together

Nige

I'm in the clear then.... it wasn't working before I took it to bits..