Guys I know this conversation has been had multiple times over the years. I have looked at many threads going through the ins and outs of working on these motors. Recently i have about a Disco with a blown head gasket. The guy got in the middle of changing the gaskets out and gave up due to other unforeseen issues. With that being said i bought it from him and i am looking into what do to make a good long term vehicle for excursions with my family. The options i was looking at was getting the heads surfaced, buying some good head gaskets (cometic), ARP head studs and putting it back together. Another option i had looked into was buying the ACE kit and putting a 5.3 in it. I am just wanting to know some recent opinions on that kit and that swap. I would also like to know if installing the head studs, surfacing and a good gasket would be an adequate repair. I read somewhere that the cometic gaskets can keep the sleeves from moving? I am not sure how accurate that is.

Thanks ahead of time

 

For every 10,000 post asking advice on a possible motor swap 1 or less is attempted.

Get the heads decked, valve job, order whatever parts you need and get the gasket job over with.

 

I do not recommend the head studs, but otherwise you are on the right path. What were the unforeseen issues that came up?

 

Don't go with studs. The stretch bolts are a far better design for a couple key reasons. Search around and you'll find the topic hashed out.

 

I just looked at the Cometic website and they only make gaskets for 2003, 1995, and1994

 

I’m pretty sure the HG’s are the same for any D1 or D2 V8 engine.

 

Cometic makes MLS head gaskets for Rover V8's in both a 96mm and 94mm bore as well as various compressed thicknesses last time I looked. You can look on the Summit website and see what all is available.

The 4.0 and 4.6 blocks, according to spec, use a 94mm bore. The liners also apparently sit on a lip at the bottom, preventing them from moving downward into block, but nothing preventing them from moving up to the top besides the head/gasket.

In theory, if the liner is already fully seated against the lip at the bottom, and you use a 94mm Cometic MLS gasket, it will prevent the liner from moving completely.

I have some Fel-Pro composite gaskets I just measured the bore size on, which are OEM style of course (8$ per gasket via Rockauto sale recently), and they come out to 96mm. So if the liner itself isn't that wide, which I'm not sure of the actual wall thickness of the liner myself, then there's little to no fire ring of the head gasket actually on top of it to stop it from moving. Even if there is, the fire rings look pretty weak on these composites and could still get beat up easily.

MLS gaskets are superior to composites in my opinion. They're definitely not gonna blow out at the back water passage and crap like composites always do at least. MLS are usually a little more picky when it comes to having a nice flat prepped surface compared to composites though.

I think Extinct presented this information first a while back, can't remember exactly before I looked into it myself.

I prefer studs over bolts, but that's just me. I hate torque to angle bolts the most.

I'm an LS engine guy (in my other vehicles, not in my disco. yet.) and we don't have to deal with BS like slipped liners, nor have I done it to my Rover (yet), so I guess just take this information as more of theory from me as I haven't put it into practice. With that being said, if you have a cracked block between sleeve and water jacket, nothing is going to fix it except a major rebuild or new engine, and at that point you would be better off going with an LS swap for many reasons, cost and reliability being the main ones.

 

Great responses from everyone. I appreciate all the insight into this subject. I am on the waiting list for an ACE kit for the 5.3. I might still buy the kit and see how things go with the head gasket repair. While the engine is dismantled this far is there anything else is should look at/replace? Besides surfacing the heads and a valve job is there any other machining work
that I might need to have done?

My buddies unforeseen issue was a need to buy a bass boat for him and his son 😂.

thanks

 

If you do the swap to an LS, they really recommend that you lift the truck as well.

 

The disco is already lifted. Some of the big reasons I bought it was that it has a lot of expensive parts already installed