In an attempt to improve the power to weight ratio and the front to rear weight balance (and thus the front suspension issues), I've opted for fitting a Leyland 4.4 aluminium alloy V8 engine into my TC Cortina 6.  This page gives an idea of some of the issues involved in this conversion and how we've attempted to solve them.

First some pics, text on how (not why :-)) follows :
 

	Here we are back in the early days - basic fitment complete ie. engine mounts plus a few hoses, cruddy old rocker covers, no exhaust system, fan, radiator or electrics
	Same time, same stage but viewed from the passengers side. Note SD1 timing cover + accessories
	Weird angle shot here to satisfy artistic nature of photographer.
	Here is a nice view from the front - accelerator cable has been lengthened but is not connected, we were just getting ready to start the beast: exhaust is on, radiator in, fan on, electrics ready, electric fuel pump fitted and all kinds of fiddly things done. Radiator hoses are top: HZ top hose, bottom: EB Falcon bottom hose. Both hoses fit without cutting.
	Seems like we are hanging off a crane for this overhead view. It all fits in but only just.
	Side view - again, everything fits but only just.
Final picture - with powder coated orange rockers has yet to be taken because the car is always on the road and I cannot stop driving it long enough to take a picture :-).	On the road with transport department approval and insurance since February 25, 2002. So far no teething troubles. April 3, 2002 @ approx 3000 miles - secondaries will be tuned shortly so we should be able to get a better idea of performance.
	This is it! Errr, well not really :-) - but wrecking yards are fun places to go....
	Thats not it either - unlikely that this VW will ever see the balck stuff again though.....

Description of surgery required to effect this transplant

• Width of the P76 4.4 Block - the P76 4.4 block is wide - 515mm across the block from the exhaust manifold gasket surface on one side to the exhaust manifold gasket surface on the other side. This is much wider than the Ford Windsor 302 V8 and significantly wider than the Rover 3.5 block (which measures 465mm across the same dimension) and causes a number of problems.

 
• Fitting an exhaust manifold. I tried almost all the cast iron exhaust manifolds plus two different sets of extractors available for the P76 and Rover. This includes those from the Rover 3500 SD1, Range Rover, P6B, Range Rover 3.9 and the standard P76. Whilst some of these would have fitted on the passenger side head, they all clashed with either the crossmember or the intermediate steering shaft from the column to the rack or BOTH. Even the SD1 exhaust manifolds which have twin pipes at the rear and a fairly tight profile didn't clear the steering shaft! Only solution was a custom made extractor for the drivers side (I'm using a tri-Y setup). Definitely a challenge - the front two ports had to be routed through the wheel arch and over the front spring tower before joining the rear ports after the bellhousing. The new tri-Y extractor I had for the passenger side of the P76 needed to be shortened in order to clear the crossmember and avoid poking out below it.
• Wiring and clutch cable. The width of the block brings the exhaust manifolds close to the side rails of the chassis on which the wiring loom runs. This was a big deal after all - as mentioned above front two exhaust ports had to be routed through the front wheel arch to make room for the clutch cable etc.
• Booster Bracket - Standard Cortina brake booster unit would interfere with the rocker cover and head on the drivers side when the engine was revved up. Mine has been angled slightly away from the normal position by the use of some spacers at the firewall between the booster bracket and the pedal box.

 
• Clutch - Cortina 6 uses a clutch operated by a cable. So does the P76. Both pull the clutch throwout lever to the front of the car but the P76 system is quite different because the pedal cable operates a shaft which then operates another cable attached to the throwout lever. Keep P76 throwout lever, fabricate bracket to guide the Cortina clutch cable and its adjustment nut connect to the P76 throwout fork and its adjuster. Fiddle with throwout lever pivot point which (thankfully!) is adjustable without removing the gearbox.

 
•  Gearbox - I'm using the P76 4 speed single rail which has slightly different ratios to the Cortina 6 single rail, a slightly longer extension housing and a much longer input shaft. Given the constraints of the firewall, the P76 block mounts further forward than the 250, so you need the extra length of the extension housing. Shifter hole in the floor pan needed to be enlarged approx 20mm to the rear so that shifter will clear the floor pan but no structural mods required and centre console still fits. Speedo cable is the original Cortina job with a P76 4 speed speedo drive swapped onto the end (cost $32).

 
•  Fan to Radiator Clearance - this depends on the front cover you use with the P76 block. You have a choice of using the original front cover and putting up with a worn out mechanical distributor and an oil pump which reportedly loses pressure occasionally [see here for some experiences on this], or moving to a more modern front cover like that used on the Rover SD1/SE/Van den Plas. I've opted for the latter because I can then also use the electronic distributor from these cars which still has a vacuum operated mechanical advance. The only problem is that Rover moved to a viscous fan drive for this cover and a longer front water pump shaft. Without a fan the clearance between the radiator and the end of the SD1 water pump shaft is 25mm which is too close to mount the big viscous fan. The solution here was to find a steel fan with a large centre and then spin the fan on a lathe to enlarge the centre hole until the fan can be moved along the shaft to bolt up to the water pump pulley.

 
• Gearbox Crossmember - Slight modification - move mounting section in crossmember back by cutting and welding, redrill to fit the two bolts from the P76 single rail gearbox mount.

 
•  Sump - standard P76 sump has its oil reservoir at the rear. Clears the front crossmember and thus does not require any cutting or modifications to the oil pickup. Yay! However a bit of heat and some hammering has been applied to the sump to increase the clearance to the front crossmember.

 
•  Starter Motor - mounts on the drivers side of the block. Standard P76 starter motor and almost all Rover starter motors have the solenoid poking out the side - too tight to fit an exhaust system on the drivers side due to the width of the block. Solution is to use a Rover SD1/SE/Van Den Plas (1978 on) starter motor, as the solenoid on these has been moved to the bottom of the starter. Its unfortunate that the Rover starter motor has a smaller locator diameter than the P76 starter - dealt with by having a 3mm piece of galvanised steel cut to fit tightly around the Rover starter locator and bolt pattern. The starter is a bit noisy due to the fact that the Rover and P76 ring gear is slightly different.

 
•  Tailshaft - Cortina tailshaft is approx the right length given the position of the engine as fixed by the new engine mounts. Transferred yoke from the P76 4 speed tailshaft to the Cortina tailshaft because the gearboxes have different numbers of splines on their output shafts. Balancing operation after cutting the Cortina yoke and welding on the P76 yoke is essential. Tailshaft yoke on the P76 4 speed single rail is the same as CM/CL Valiant with 4 speed single rail so if you can't get a P76 part these will also work.

 
•  Engine Mounts - Remove Cortina 6 cylinder capri style rubber, cup and bolt from existing mount plate. Existing mount plate bolts to the crossmember and has a "leg" extending down to the rear bolt of the U-clamp holding the steering rack to the front crossmember. P76 V8 engine mounts are forward of the crossmember so fabricate new mounts which use the P76 mount rubbers and which bolt up to the crossmember and which have a "leg" extending down to the front bolt of the U-clamp holding the steering rack to the front crossmember. This also keeps the mount out of the way of the exhaust. Pictures will follow shortly.

 
•  Radiator - if I'd stayed with the P76 timing cover I could've tried my 2 core standard Cortina cross flow radiator to see whether it had sufficient cooling capacity(ha!). However, since I switched to the SD1 timing cover, both hoses want to go to the drivers side of the radiator. This isn't a problem really as a  3 layer core (at least) radiator should probably be used anyway. I had the tanks swapped over on my Cortina radiator housing, a 3 layer core and a baffle plate fitted in the drivers side tank between the top and bottom hose outlets. Water will circulate from the top hose across the radiator and back again before leaving via the bottom hose. Radiator hoses - after a lot of searching through a Repco hose warehouse I've found that I can use the bottom hose from an EB Falcon and the top hose from an HQ-HZ Holden with a 1.6l Escort thermostat housing (needs slight rounding out of the bolt holes to fit the inlet). Both hoses fit without cutting and both are easy to find because the models are popular in AU.

• Standard P76 block with 20 thou oversize bore - I'm not trying to increase displacement here as that requires removal of the old cylinder liners, boring the block, then pressing in new liners. Due to the fact that there is not much metal around the liners on this block (in common with the Buick 215 and early Rover 3.5 up to 1983) you could drop a cylinder liner with potentially catastrophic results if you subject such an engine to higher than normal revs - not for me but seems to be ok for others - see here for example. I reckon that if you want to increase bore safely then start with a different block - 1983 and on Rover 3.5/3.9 or the newer Rover 4.0/4.6 have more webbing and more metal around the liners. Standard block and bore is fine for me because its cheap and it is going into a car that will weigh approx 1040kg with this engine so I don't need to rev it to get it going.

 

 

Mick Meaney (and others) also think that the P76 block is a really cheap way of getting extra grunt (and it is if you price a new Rover big capacity short block!). However, according to Mick, you should carefully check the 'cross webs' toward the rear of the lifter gallery: if the block is going to crack then you will see it in this area first.
 
 

Mick Meaney's pic of a cracked web. The bolt hole and machined surface on the right of the image is for the rear valley cover. Eeek!

• 1964 Buick 300 heads? - I was going to use the 1964 Buick 300 heads but these have a 54cc combustion chamber versus a 37cc standard head combustion chamber. Whilst this isn't usually a problem (just buy higher compression pistons), I already had a set of nice forged pistons with a 16cc dish (previous owner of this block had these as part of his uncompleted project). Using these pistons with the Buick 300 heads would have brought the static compression ratio down to approx 8.25:1. I've since heard others say that the combustion chambers can be welded up to reduce their volume but since the standard heads were already reconditioned by the previous owner and the Buick 300 heads should really be fitted with larger valves to make them worthwhile, I've decided not to use the Buick 300 heads for the moment and they are awaiting some future project. The advantages of the Buick 300 heads over the standard P76 heads are:

 
• supposedly superior port design (especially the inlet)
• size of the exhaust port outlets is larger by default
• has larger inlet valve (41.2mm versus 38mm standard) by default and can be easily modified for larger exhaust valves if required
• uses Buick/Rover shaft mounted rocker gear (which will accept oiling via hollow push rods so no need for oil passage drilling in P76 block) versus cheaper stud mounted rocker.

 
• Standard P76 heads with a few modifications?

 
• Holden V8 Valves: I've since heard from Mick Meaney that Holden V8 valves can be fitted to the standard P76 head which together with some nice porting can really improve things. According to Mick, the part numbers required are "EVL P/No 37062 (in) & 37065 (ex).  These are the biggest you can fit and don't require any mods to the valves themselves. You can match them with Holden collets and either a Holden or Chev retainer. The Chev retainers are good because they're available in different heights etc and you can get quality pieces for next to nothing. I used Ford Windsor guide plates which have to have .200 inches cut out to narrow them to match Leyland valve centres.  I wasn't able to find anybody who ever made Leyland plates and, apparently, the Leyland part no. that used to be listed by Yella Terra were one they cut and shut."

 
• Chev SB roller rockers in 1.6:1 ratio : another snippet of very useful info from Mick Meaney. Apparently these roller rockers are a straight bolt on replacement for the standard P76 parts. Mick also reckons that it is well worth checking your standard rocker posts for straightness as he has stripped some heads and found that the posts were bent (including low mileage standard heads). Problems that could result from this are increased valve stem and guide wear.

 
• Why? Although the P76 heads are obviously not performance pieces in stock form, it is clear from Mick's work that they can be made a lot better with the application of a few locally common (as in AU) pieces. Mick has also sectioned both the P76 and Rover heads of the time and actually thinks that the P76 head is superior to the Rover part.

 

 

	Mick's pic of a sectioned exhaust port on a P76 head.
	Mick's pic of a section inlet port on a P76 head.
	Mick's pic of a section through the spring seat.

• Wilpower single plane 4 barrel inlet and Rochester 4GC carburettor from a Buick 215 - Was going to use a Buick 300 dual plane inlet with some spacer plates from John Harcourt in New Zealand. However Bill Laney's Wilpower 4 barrel inlet is made for the P76 - no spacers required. The Rochester 4GC carb from the Buick 215 has fairly small primaries (which I like because overfuelling the engine is a big no no in my mind) but jets are fairly easy to obtain and the carb is simple and was as cheap as when purchased from the US: $40USD + postage with a reco kit included.






Left to right: standard P76 2 barrel inlet, Bill Laney's Wilpower inlet manifold and the Buick 300 4 barrel inlet with spacer plates for P76 - Thanks to Greg Williams for this photo!





NOTE: Other P76/Leyland people have commented on the strength of Bill Laney's Wilpower inlet manifold: it is a good quality casting which stands up well to port matching. I can also say that the lack of water heating on the hotbox in the Wilpower makes absolutely no difference to suburban driveability here in Tasmania! The car warms up quickly and I have no problems with cold idle etc. Its a great manifold!
 

• ARP main bearing cap studs and ARP rod bolts - overcomes another weakness of the P76 block (in common with the Buick 215 and Rover 3.5 up to 1983): crankshaft walk. The bolts on the bearing caps have a tendency to come lose over time with the result that the crank 'walks around' and the main bearing caps fret against the block - lots of expensive damage to the block and anything else in the way when something lets go. Not nice. ARP main bearing cap studs deal with this problem just fine. The new ARP rod bolts are supposedly much stronger than any of the stock stuff so might as well replace the old ones and do it properly.

 
• Balanced crank, pistons+rods, flywheel and front pulley - seems to make sense in any rebuild to me.

 
• Rover SD1/SE/Van den Plas front cover and electronic distributor - overcomes the problems associated with oil pump and worn out mechanical distributor on standard P76 front cover. Introduces a few extra though because of longer water pump shaft, water pump inlet on opposite side to P76 waterpump and enormous viscous fan (too large for my engine bay anyway) but these can be overcome.

 

 

More info has since arrived on the cause of the oil pump pressure losses in the original P76 front cover and oil pump. From the experiences of Mick Meaney: "The fluctuating oil pressure problem is, in my experience, down to two likely causes - the standard cylindrical relief valve has a tendency to cock or prop in the body and will momentarily stick. The pommies use a teardrop come tadpole shaped valve which eliminates this problem [you can see a picture of this in Hardcastle's book on pg. 125]. Other cause is, because the standard oil pump is of a decent high volume capacity there is a lot of oil passing thru it at higher revs and the gears can 'cavitate' so that oil within the pump body gets thrashed and delivery from the pump stalls. The fix is to mill or carefully die-grind two larger balance slots into the pump end plate - about 5mm wide x 3mm deep seems to be adequate. Any wear or grooving in the pump gear outer periphery or the pump body obviously makes it worse and correct gear end float is a must."
 

• Standard P76 4 Speed Borg-Warner single-rail - lots of people have recommended using a Toyota Supra 5 speed instead but I've always like the Borg-Warner single rail - seems tough and reliable. My only concern is the strength of the P76 clutch - previous owners I have known seem to think that it is a little too small for the job - shouldn;t be too bad for my application. For a 10.5" Chev clutch and a 5 speed box, Mick Meaney suggests using a Holden Commodore Borg-Warner T5. He has made up an adaptor for this T5 to fit the P76 bellhousing pictured below. Flywheel obviously needs to be redrilled as well.

Mick Meaney's pic of a P76 bellhousing and T5 transmission with adaptor plate mounted on the front.

 
• Other stuff:
• Crane anti pump up lifters for Buick 300 (have hole for oiling the top via hollow pushrods)
• Mild (very nearly standard grind) new billet cam shaft - I like hi-torque, low revs and low stress - specs can be seen here
• Crow double row roller timing chain set
• Buick 300 side rear main oil seals
• Standard rear main oil seal (which is still available from Repco Australia)
• Ford clutch spigot bearing (not just a bush)
• Standard valve springs
• was going to use SD1/SE/Van den Plas alloy rocker covers to replace standard P76 tin rocker covers, but these turned out to be too tall (interfered with firewall, heater unit and brake booster) so I used powder coated standard P76 tin rocker covers.

 
• Rough performance comparison - Standard P76 with 2 barrel Stromberg WW carb made 143kw (192 HP) @ 4250 RPM with 393Nm (285lb/ft) of torque at 2500 RPM. The Ford 250-2V six, also with 2 barrel Stromberg WW carb, made 127kw (170 HP) @ 4400 RPM with 338Nm (245 lb/ft) of torque at 2400 RPM. Given that the car has lost approx 40-50kg from the front end, it is a lively little performer with understeer much reduced.

• Buick 215 sold to Rover in 1963 apparently because of high production costs (lots of blocks thrown away due to poor casting technology/metallurgy of the time).

 
•  Buick 300 replaces Buick 215 in 1964 but has cast iron block and for 1964 only the heads are aluminium and will fit Rover 3.5/Buick 215/P76 4.4 without modification. 1964 Buick 300 heads are considered superior to Buick 215 and early Rover 3.5 heads because of larger exhaust port outlets and ability to easily fit larger valves.

 
• Buick 300 gets cast iron heads in 1965 which can still be made to fit the Buick 215/Rover 3.5/P76 4.4 - but much more work required. See for example here .

 
• Leyland Australia P76 gets raised (approx 17mm higher) and stroked Rover 3.5 block+crank with same pistons but longer rods and bigger main bearing shells in 1973 - new capacity is 4.4 litres. Everything from Rover 3.5 except crank and rods can be used on the P76 4.4. P76 4.4 crank can be used on the 3.5 as a stroker crank. See for example here. By comparison, the stroked Rover engines (4.2 and 4.6) kept the same rods, block height and bore as the 3.9 but reduced the piston crown height to accomodate the extra stroke on the crankshaft. The Rover approach is superior because you get the capacity increase without having to change the block height, rod length, inlet manifold width and external dimensions as well as the crankshaft.

 
•  Rover 3.5 gets more webbing and more metal around cylinder liners in 1983 - result is known as the "stiff block".

 
•  Rover 3.5 "stiff block" gets bored out - 3.9 litre, and then stroked - 4.2 litre. These blocks can be retrofitted with stuff from the 3.5 such as the front cover, heads, inlet manifold etc. 4.2 would have different crank and pistons to the 3.9 to provide increase in stroke & capacity.

 
•  More stroking and addition of cross bolts into the main caps results in the 4.6. 4.0 is crossbolted 3.9 - apart from crossbolted main caps new blocks are much the same as the "stiff block" and can still be be retrofitted with old parts from the 3.5/3.9 such as heads, inlet manifold, front cover etc. 4.6 would use different crank and pistons to the 4.0 to provide increase in stroke and capacity.

 
•  Table showing comparisons between engines:

Engine	Bore x Stroke	Capacity
Buick 215/Rover 3.5	88.9mm x 71mm (3.5" x 2.8")	3528cc
Rover 3.9/Rover Crossbolted 4.0	94mm x 71mm (3.7" x 2.8")	3950cc
Rover 4.2	94mm x 77mm (3.7" x 3.0")	4278cc
Leyland Australia P76 4.4	88.9mm x 88.9mm (3.5" x 3.5")	4416cc
Rover Crossbolted 4.6	94mm x 82mm (3.7" x 3.2")	4554cc

Check out: "Tuning Rover V8 Engines" by David Hardcastle, 1993 (J.H.Haynes and Co. London)
 

• Thanks to Mick Meaney for passing on his experiences + pictures! Also to Simon Collins for taking the photos of the Cortina.