leyland P76 pistons

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jrv8
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leyland P76 pistons

Post by jrv8 »

Does anyone know if rover V8 pistons can be fitted to the P76 rods and used in the 4.4 litre engine , or does anyone have a spare standard size piston for a P76 V8 ?
Jim



garrycol
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Re: leyland P76 pistons

Post by garrycol »

Jim - I cannot answer your question but I am sure people on the AULRO (www.aulro.com) forum will definitely know. I would ask in the Technical Chat section.

Good luck

Garry

jrv8
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Re: leyland P76 pistons

Post by jrv8 »

Hi Gary,
Thanks for the link and I've applied to join . All the measurements I've made say that it should be ok , but it would be nice to talk to someone who has actually done it.
Regards
Jim

garrycol
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Re: leyland P76 pistons

Post by garrycol »

What car have you got the engine in? and why pick that particular engine - not the greatest iteration of the RV8 and I guess pretty rare over there - less rare here but getting that way. Was used as a conversion to the 3.5 RV8 but proved less reliable - many old Range Rovers have them and of course the P76 car and Terrier Truck through there virtually none of them left.

Garry

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Re: leyland P76 pistons

Post by jrv8 »

Hi Gary,
It's for a customer who has imported a P76 into the UK and is restoring it . He supplied main bearings with thrusts and gaskets sets which was good as these are unique to this engine , but when I went to reassemble the unit , I discovered that one of the pistons had a hairline crack in it . The Rover V8 piston is identical in size , but has a different crown design , so I thought that I would ask before starting to fit a set of RV8 pistons to the P76 rods. I'm thinking that a set of the low compression 8.13:1 Land Rovers pistons will leave me with the correct compression ratio for the P76 .
Regards
Jim.

garrycol
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Re: leyland P76 pistons

Post by garrycol »

Jim - I dont know how long it will take for you to get onto AULRO so I have cut and pasted the information you have asked for here into a Thread in the Tech area of AULRO.

Will see what comes back and you can add to the thread if needed when you are registered.

Cheers

Garry

PS - I have always had a softspot for the P76 as I considered to be a pretty good car - just the wrong type of car for the times when they were produced in the mid 70s - most other car makers here were downsizing and along comes Leyland Aust going against the grain of typical Brit small cars and builds the equivalent of a Aust designed "Yank" tank - they were loved and despised at the same time. Leyland folded here shortly after and the P78 came to an end. I have to say that the 6 cylinders that had the Morris Marina 6 cylinder engine was absolutely horrid.

Garry

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Re: leyland P76 pistons

Post by jrv8 »

Hi Gary,
Thanks for that , much appreciated.

Regards
Jim

garrycol
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Re: leyland P76 pistons

Post by garrycol »

Ok - two responses.

From PLR
Rover pins in Rover pistons the little end clearance would need checking for the piston type (8.13 , 9.35 narrow top ring ).
Rover pin .0041" smaller diameter than P76/Terrier from the books i have .
Earlier Rover ( 8.5 , 8.25 ) pins .0003" small dia than P76 , an 8.13 with the thick top ring may have the same pin size as these ( don`t have specs for 8.13 thick ).

From Bee Utey
I fitted a new set of 8.13:1 thick ring Rover pistons to a P76 engine last year, no dimensional problems at all. The compression ends up at around 9.5:1 so it'll need premium fuel, otherwise it will be fine.

Now the information from PLR is technical but I assume it is all correct.
I know Bee Utey and he is a top operator - he is a mechanic with extensive experience with Rovers - however more importantly he is right into the P76 and indeed owns an ultra rare P76 Station Wagon (Estate) - these never went into production. He has one of two Ford roof prototypes (fitted a roof from a Ford Falcon) and these are different again (and earlier) from the one remaining final prototype wagon that never got to production.

So if Bee Utey says says the pistons work then I would believe that.

This site lists 4.4 pistons and rings http://www.roverparts.com.au/piston___r ... p76_4_4_v8 also http://www.precisionintl.com.au/Engine. ... 5&EID=2090

This link on P76s and the various versions might be of interest, noting that only the 4 door sedans got into production and all the rest were protypes including the Force 7s.
https://www.streetmachine.com.au/events ... berra-2013

I hope this helps.

garry

Oh - just remember that the 4.4 is a different casting from the other RV8s - it has slightly larger crank journals (big ends are the same), the block has a higher deck height, the valves are a little smaller and there are a number of other minor changes which if you need to put in other RV8 bits will need to be accounted for - however most can be worked around. it has all been done before.

Garry

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