So I've Got This Old Rover 4.6 I Want to Use . . .

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Davo
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So I've Got This Old Rover 4.6 I Want to Use . . .

Post by Davo »

. . . and you know how it goes . . . what are the latest opinions on liners, cracks, etc.

My old Range Rover has a 3.5 with only 20,200 km on it, but I've got a camping trailer to tow so naturally I want more power. (Of course I do.) So I've got a used 4.6 and I was all set to get a Turner top-hatted block but now they're only doing customer's own units. Buying liners from them and getting a local knuckle-dragger over here to hammer them in is out of the question; businesses here are so bad I've given up.

Looking at this motor a bit closer it started to look like it could maybe-sort-of-be-okay after all, or maybe I'm just being stupid. It was used as an upgrade from a 3.9, so it's never been in a hot-running later Range Rover, and none of the liners have been leaking. I would crack-test the block with dye and also heat it up and pressure test it. Everything from the 3.5 would go on it, (it's got the later heads), including the ARP head studs. It would get a +.020" rebore, or just new rings, depending on how it measures up. I'd probably "pin" it, like you see on American sites. A couple of liners are just barely below the deck - I think the machining at the time was sloppy enough that the step at the bottom of the liners wasn't as accurate as it should have been.

It seems that these blocks had two main problems: liners slipping and making tapping noises but not leaking coolant, and cracks behind the liners, or both on the same cylinder.

So, is this reasonable or just desperately stupid?



garrycol
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Re: So I've Got This Old Rover 4.6 I Want to Use . . .

Post by garrycol »

Sorry I am a bit confused is this engine you are wanting to use a "genuine" 4.6 or a 4.6 that was made up from a 3.9 block - if so very much different engines in the bottom end with the 3.9 being a lot weaker.

Definitely do not pin a 4.6 liner as the area of the block where is has to be pinned will come come away sooner or later - get top hat liners. You may have to send the block down south but is still cost effective.

Garry

Davo
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Re: So I've Got This Old Rover 4.6 I Want to Use . . .

Post by Davo »

Hi Garry, and thank you, I didn't pick up on that point - it's a factory 4.6 that replaced a 3.9, so it had 3.9 heads, timing cover, etc.

There's no-one down south I would trust on this job. I would put using this block or getting someone in WA to fit top hats in the same category of risk. Some companies don't answer emails, and TRS don't even do blocks, just a short engine. Turner UK now only do engines and of course they are second-to-none, just too expensive.

I haven't heard of pinning leading to a broken block. Did you read that somewhere online?

garrycol
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Re: So I've Got This Old Rover 4.6 I Want to Use . . .

Post by garrycol »

Any engine rebuilding machine shop could do it - nothing special really.

Issues with pinning is quite common - the same issue that causes some cracking of block material behind the liners - hence the reason you will not see much on line about pinning the RV8 but plenty about top hatting. As I said nothing special really and any decent engine rebuilder could so it.

Davo
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Re: So I've Got This Old Rover 4.6 I Want to Use . . .

Post by Davo »

I've had some really bad and bizarre experiences with an impressive range of Perth businesses over many years. It's a complete gamble. I know a place in Perth was mentioned on aulro.com some years ago, but still nobody has the reputation of, say, Turner Engineering UK. There's a certain way to install these liners with heating the block, and using sealant, and there's an o-ring at the bottom, and holding the thing in a press while it cools. I remember your engine thread on aulro and you guys are spoiled for choice compared to us!

Oddly enough, I've had the opposite experience reading about pinning. Plenty on American sites about it, but nothing about blocks breaking. However, everyone who did it was just keeping their old Discos on the road, so no, definitely not ideal.

garrycol
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Re: So I've Got This Old Rover 4.6 I Want to Use . . .

Post by garrycol »

Davo wrote:
Sun Oct 14, 2018 12:00 pm
Plenty on American sites about it, but nothing about blocks breaking.
So that was on Rover V8s?

Noting the blocks do not break as such it is just the area where the pin is comes away sometimes. I didn't think the liners had an o ring at the bottom but I am not sure - there is certainly a lip in the block that the bottom of the liner can sit in and this can crumble away causing issues - it is in this area of the block that the pins have to go it.

Anyway if you are happy to get the liners pinned then get it done but if your local engine builder up north cannot do top hat liners then they certainly could not do pinning and you will have to deal with those businesses that you do not have confidence in anyway.

Good luck with it.

Garry

Davo
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Re: So I've Got This Old Rover 4.6 I Want to Use . . .

Post by Davo »

Yes, Rover V8s. Most US Land Rover forums have something about it.

The o-ring is part of the sleeves Turner sells, and they haven't had any problems with it.

And I'd do the pinning. All part of living in WA!

garrycol
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Re: So I've Got This Old Rover 4.6 I Want to Use . . .

Post by garrycol »

I assume you have seen this How To link http://www.landroverresource.com/docs/P ... _Liner.pdf

Let us know how you go.

PS - I just reread your original post - you haven't got anything in there about the 4.6 having any issues - infact you indicate the engine has not been over heated. Hmm as it is only a few hours work to get an engine in and out of a RRC - why not take a risk and buyng in the 4.6 as it is. Make sure your cooling system is in top condition - then down the track if there are issues pull the engine and do the mods you are talking about - all that will be lost is your time pulling the engine.

It is all about risk and its management - now if you think your 4.6 is dud now then that is different and I would do what you propose, but if you think it is actually Ok then I would take the risk.

Garry

Davo
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Re: So I've Got This Old Rover 4.6 I Want to Use . . .

Post by Davo »

Yes, I've seen that PDF, but thanks for linking it.

So, yes, that's what I was thinking about this engine, it wasn't in a P38a so it hasn't been run as hot and nothing obvious seems wrong with it. (Apart from #3 and #5 rods being swapped around! Probably a factory fit???)

The 3.5 in the car at the moment isn't an old one, it was a new factory engine built in the 90s and described by Des Hammill as guaranteed to slip liners! So you're right, it is a matter of risk management.

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Re: So I've Got This Old Rover 4.6 I Want to Use . . .

Post by SuperV8 »

I would hot pressure test the block. If fine then stick it in.
Mine leaked on three cylinders so I had the lot top hat linered .

Tom.
Dax Rush 4.6 supercharged V8 MSII

Davo
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Re: So I've Got This Old Rover 4.6 I Want to Use . . .

Post by Davo »

Yup, I hope to put it a big container of water, heat it up, and pressure test it. It's just such a weird gamble.

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