Leyland 4.4 VS Rover 3.5

Oldskoolrob

Oldskoolrob

Active Member
Curious to know if anyone here has experience with the 4.4 and how they stack up against the 3.5. Obviously capacity increase is always good, but being a longer stroke are they lazier than the 3.5? Worked to the same extent do you think the 3.5 would be a more lively engine or much-of-a-muchness in that area, and the 4.4's extra cubes would take the win?
 
Hello Rob,

Quite some years ago, Scott the owner of the Old Auto Rubber Company in Melbourne (Australia) had a P6B fitted with the Leyland 4.4 litre engine. I seem to recall he said his wife did a burn out at a Rover event which some Rover owner's possibly disapproved of. He said the 4.4 produced far more torque than the 3.5 but not that much more power. The 4.4 heads are pretty poor, possibly even worse than the Rover heads in terms of air flow.
Here is a link that I am sure you will find interesting.
P76 V8 4.4 litre Engine (Leyland Australia) | Rover P5 Club Forum (proboards.com)

Ron.
 
Thanks Ron - I've been checking because even though there's not many around they usually go for reasonable money (a 'good runner' near me for $600). But from what I've read I'd be better off putting the effort into the 3.5, unless a cheap 4.6RV8 intervenes :)
 
I have found the best 3.5 is one with 9.25/9.35 CR - rev MUCH better than 8.13CR version, and have much better torque curve (low down) than a 10.5CR when fitted with a manual box. Add the improvements provided by a 3.9l camshaft to put icing on the cake. Obviously a 4.0 or 4.6 would be even better, but IMHO the CR is important.
 
There was an SD1 in Christchurch in the 90s with one fitted, but as far as I'm aware, they never managed to get it running properly.
 
The heads are very similar to SD1 heads except they use pressed steel rockers on studs the block is noticably taller. the dimensions are 3.5 x 3.5 so dead square and they redline at 5500. Theychoke in the top end but you can get an edelbrock 4 barrel manifold that gives heaps more power. The front cover is very close to the SD1 cover but the water pump inlet faces the opposite side. Flywheel is the same as the 2,6 e series flywheel. They were very popular speed boat motors
 
I have a New old stock 4.6 short block lightened and balanced with pocketed pistons I got from Rover Tec in the 90s for my SD1 Vitesse which never got fitted.
Pretty tempted to fit it into my P6 at some point
 
clive P62 said:
I have a New old stock 4.6 short block lightened and balanced with pocketed pistons I got from Rover Tec in the 90s for my SD1 Vitesse which never got fitted.
Pretty tempted to fit it into my P6 at some point
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You wont be disapointed.
If I did another I would go for 10.5 :1 CR, a high torque cam, and the biggest valves available to fit the stock seats, 3500s manifolds, decent ignition, and probably use another Autolite 4100 carb. I cant get excited about EFI. With nice porting that should make circa 280 bhp.
 
Unfortunately being auto its got smaller manifolds, would have to have new larger bore downpipes made to fit my spare S manifolds.
 
corazon said:
Fraser has an F5000 engine for his replica racer, which I believe are based on the 4.4..
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It's very easy to make a 5 litre V8 out of a P76 V8, certainly in Australia anyway, just bore out the block to take Holden 'XU1' 'red six' pistons and fit them to the existing gudgeon pins on the stock bottom end. Making a 5.0 litre motor is, in essence why the 17mm taller deck P76/Terrier V8 was designed. Remember that the competing Holden V8 is available in 4.2 and 5.0 litre forms and that 5.0 litres is the size stipulated in Formula 5000 and Trans Am racing at the time. Certainly the F5000 development revealed some of the endemic weaknesses of the Leyland V8, (as well as the competing Chevrolet, Chrysler, Ford, and Holden V8s.) Given the taller deck height, it might even be possible to take the Leyland V8 out to 5.8-6.0 litres. Whether it would be reliable at those capacities is another matter.

It does lead to the interesting question of how a 5 litre Force 7 might have done, racing at Bathurst against the Holdens.Leyland-P76-5-600x440[1].jpg574ecfe4ad5054ea21b10495658b8687--vals-weird[1].jpg
 
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It depends a lot on what you are after. Pity the Force 7 was crushed...Hard to believe that car came out in 1973...The 4.4 came out in two compression ratios , those with red rocker covers were the truck ones and were lower than the blue cover car engines. If you are not going to race the car the 4.4 will give a nice boost in bottom end but it only has a two bolt main so isn't as stiff as the 4.6 X bolt block. That was what killed in in F5000 project but for road car it won't be an issue. While it chokes up in the high revs its still better than the 3500 and the 4 bbl manifold takes the power way up into 4,6 territory and over. Price wise i paid about AUS $200 for mine disassembled with one broken piston in the early 1980s. Back then you could buy the truck engines in crates for the same amount. Which is what the guy i bought it off did. The P76 used the same BW single rail gearbox as the ford and Valiant of the period so the bell housing is rather special.
 
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mikecoombs said:
It depends a lot on what you are after. Pity the Force 7 was crushed...Hard to believe that car came out in 1973...The 4.4 came out in two compression ratios , those with red rocker covers were the truck ones and were lower than the blue cover car engines. If you are not going to race the car the 4.4 will give a nice boost in bottom end but it only has a two bolt main so isn't as stiff as the 4.6 X bolt block. That was what killed in in F5000 project but for road car it won't be an issue. While it chokes up in the high revs its still better than the 3500 and the 4 bbl manifold takes the power way up into 4,6 territory and over. Price wise i paid about AUS $200 for mine disassembled with one broken piston in the early 1980s. Back then you could buy the truck engines in crates for the same amount. Which is what the guy i bought it off did.
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Not all of them were crushed, there are 10 left out in the wild. Eight were auctioned off and the other 44 made were crushed. It probably wouldn't have happened if Leyland Australia hadn't gone bust. The receiver wanted to get as much money for any remaining assets as they could and wasn't worried about things that an ongoing concern might have had about warranties and spare part supply. As it almost made production, like the Rover P8, many of the production tooling drawings are availableforce7post001[1].jpgforcedrawinga[1].jpgforcedrawinga[1].jpg
 
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It wasn't the receivers it was Leyland's then treasurer who was dead scared Leyland Australia would make it work and he would look like the goose he was. The floorplan went under the SD1 and the door design was used on the XJ40 (reshaped of course). The SD1 was actually modified so it could take the P76 engine in case they wanted to make it in Sydney. I have the owner's manual for the Force7 but I'd love to get hold of a factory service manual!
 
Some shots of the F5000 block. Note the modified 4 bolt main cap arrangement.
 

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