P38 worry 4.6

BIG BILL · Feb 3, 2012

I have a friend that has a Disco 4.0 V8, it is lubbly with a new engine fitted.
I also have a friend who has had sports V8's

The top friend has had V8's for years and has just told me not to buy a 4.6 V8 as they have thin block walls ( a bored out 4.0 ) and can blow the engine through wear. ( is this true???)

My other mate says as long as it's serviced you can do multi miles??

Help.. mine has 80,000 and a full service history.
Do I need to change the gasket on the head?/

Cheers BIG BILL

wammers · Feb 3, 2012

BIG BILL said:
I have a friend that has a Disco 4.0 V8, it is lubbly with a new engine fitted.
I also have a friend who has had sports V8's

The top friend has had V8's for years and has just told me not to buy a 4.6 V8 as they have thin block walls ( a bored out 4.0 ) and can blow the engine through wear. ( is this true???)

My other mate says as long as it's serviced you can do multi miles??

Help.. mine has 80,000 and a full service history.
Do I need to change the gasket on the head?/

Cheers BIG BILL

No that is not correct. 4.0 is a bored out 3.5 with thin block walls. 4.6 is a stroked 4.0 with thin block walls.

MikeV8SE · Feb 3, 2012

As wammers said, the 4.6 is not a bored out 4.0 - it was stroked to increase capacity. Like stroking a cat.

dougdotcom · Feb 3, 2012

So a 4.6 is a 4.0 with a longer stroke but will still have the thin walls just like the 4.0? so still could have the block/liner/headgasket problem then?

Flipin hek theres no chance for us with the petrol engines then. DOOOOOMED

StuckAgainSteve · Feb 3, 2012

BIG BILL said:
I have a friend that has a Disco 4.0 V8, it is lubbly with a new engine fitted.
I also have a friend who has had sports V8's

The top friend has had V8's for years and has just told me not to buy a 4.6 V8 as they have thin block walls ( a bored out 4.0 ) and can blow the engine through wear. ( is this true???)

Cheers BIG BILL

It just shows you can have Rover V8s for years and still not know WTF you're talking about! :doh:

eightinavee · Feb 3, 2012

Any of the Rover v8's over 3.5 ltrs can suffer block problems,the earlier 3.9 RRC's and D1's and then the 4.0/4.6 in DII's and P38's are all 94mm bore.It leaves too little material to support the liners to be long term reliable - esp when poor quality control and indifferent build quality come into it.
The 3.5 was the reliable one,or the Aussie JRA 4.4 version used in Leyland Terrier trucks and the P76 car.
LR needed to make a bigger block with larger bore centres and longer crank etc,but being strapped for cash they never did it.Shame really that a unit that was excellent in 3.5 form should cause so much grief and scrap lots of otherwise useful cars - they even made the sump smaller on the bigger engines....

davef2901 · Feb 4, 2012

Keep an eye on your coolant and oil, use quality of both and pray. Although i've got to say that my 4.6 has 180K on it and it's the original engine, used a pint of coolant and oil in 3500 miles, doesn't smoke and performs like a 4.6 should. My 3.9 classic used no oil between services at 160K and my 3.5 classic used about a pint between services at 210K (god I've racked up some miles!). Am I just lucky? Between the 3 of them only the 3.5 had probs-head gaskets at 170K-so far!! Simple, if (or when ) they blow up either bite the bullet with a top hat linered engine, or get a jaguar 2.7 diesel conversion (LRO article). Sorry, the reliable diesels just don't do it for me, gutless wonders (cue storm of posts-my opinion and I'm entitled to it(( and the v8 repair bills)). Just do it

StuckAgainSteve · Feb 4, 2012

I heard that many of the 94mm blocks were reworked 3.5 blocks depending on who did it, including Rover and several outsourced engineering companies, they were all done to differing standards. Perhaps that's why some last forever and some are junk in quick order.

Rover V8s are simple engines, anyone handy with a spanner could rebuild one to a reasonable standard, unlike with many modern engines you can get big-end and main-bearing shells easy as pie for a pittance. I'd quite like an excuse to tear my motor down, port the heads, fit top hat liners and a 260i cam.

Stufer · Feb 4, 2012

my block cracked at 76k so recon block fitted, still love it!

davef2901 · Feb 4, 2012

I think stuckagainsteve is right cos I've seen mega miles on good rangie v8's and major low miles on bad ones. I've always been skint so I've got high milers( maybe that's the answer) and not had the problems so many others have. It is right that taking the engine to bits is easy, there's just a lot of it All I'd say is keep an eye on coolant and oil levels and strip when they shoot down, that old v8 really is a cracking plant.

P38 worry 4.6

BIG BILL

Member

wammers

No longer with us, RIP

MikeV8SE

New Member

dougdotcom

Active Member

StuckAgainSteve

Well-Known Member

eightinavee

Well-Known Member

davef2901

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StuckAgainSteve

Well-Known Member

Stufer

Well-Known Member

davef2901

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