P38 4.6 overheating

Can anyone help me on this one so i can go into work tomorrow armed with information.......

At work today he got a P38 4.6HSE brought in for overheating, this rang innediate alarm bells in my head because i remember something about the liners in the engine possible failing when overheated so I told the boss about it and he's to say the least a bit worried now because he might have to tell the customer that it might need a new engine!

Can Someone in the know expalin what CAN and may of hapened to this engine so i am a little wiser on the subject.

Many thanks

Mark.

Reply to
Mark C.
Loading thread data ...

Prone to cracked blocks between the cylinders I believe.

Reply to
Betabeta

Ok, what you are looking for is what looks like a crack running around the outer edge of the liner, between the liner and the block. This happens due to localised hot spots occuring that cause the alloy to expand more than the steel, more than normal and the alloy takes a permanent "set". Can be caused by a head gasket going or very hard driving or a lot of heavy towing. With the heads off, you need to check using a magnifier of some kind, I use a self-lit x10 handheld magnifying glass. I've been rebuilding these engines (rover V8's) for nearly 10 years now and personally I've never seen a cracked liner. It's always liner shift within the block in my experience. I've "repaired" a few 3.9 / 4.0 versions by dot-punching the ally around the affected area to "spread" it back in against the liner nice and tight then loading the surface with plastic metal and then re-machining square, but ONLY with the owner's consent first!!! It's worked on 2 out of 3 so far.... although it is a bit of a bodge to say the least. When playing with a 4.0 or

4.6, NEVER re-use the head bolts, they stretch, unlike the earlier versions of the engine. Best thing with a 4.6 is to fit a cylinder head stud kit (ARP) and follow the torquing instructions supplied with the kit. Badger B.H.Engineering, Rover V8 engine builders.
Reply to
Badger

Thanks badger , this is what i thought i had seen somewhere. Is the 4.0 the same design of engine with the liners in it? We have broken the news to the customer that the price will be a fair few quid for the new block. Think we got quoted £1500 for a block with pistons.

What are the chances of it JUST being a head gasket? or is it worth just slapping a block + prob a rad in it too? We tested the gasses coming out of the cooling system and it showed up as faulty :( but we havent taken the heads off of it yet.

When warm it pressures up and throws all the water out and when revved from idle it misses a beat or 2.

MC.

Reply to
Mark C.

4.0 is identical. I received a complete bottom end (block, crank, cam, rods and pistons) for a 4.0 recently, allegedly brand new never run, for £1500. The customer sourced it and had it delivered to me to complete for him. Came from the midlands somewhere. Problem was, it'd been heavily skimmed on the head faces of the block! Why? I don't know. Was it to machine all identifying numbers off? Who knows. Had the top face been repaired around the liners? Pass. All bits were absolutely brand new and when we went to fit the inlet manifold the bolt holes in the heads were 2mm out!! Inlet manifold and heads had to be port-matched and holes opened out in manifold to allow bolts to fit in! Engine ran perfectly under all conditions, giving some very good torque, no doubt due to the considerably higher than std compression.
50/50 chance in my experience. You've got to at least pull the heads off and have a look. I did a 4.6 hillrally motor once that was popping, farting and producing more steam than the flying scotsman. The temp gauge had been up past the top of the red zone for approx. 2 miles when it finally gave out and decided not to play any more. All it needed was new head gaskets, a 4thou head skim and reassembly with a stud kit! Lucky or what? The engine was alleged to have come from one of the better known landrover engine tuning firms in England, it had been built using the original head stretch bolts and excessive ammounts of silicon sealant on every other gasket face, normal silicon as opposed to the proper engine stuff as well! The right bank head gasket had a chunk missing between cylinders 2, 4 and 6, and the outside world! Both had blown into the water jackets at the front and rear and the plastic header tank had actually split!! The ally (read Expensive!) radiator had swollen it's core as well. Sometimes, you can be VERY, VERY lucky. This owner was.

Badger B.H.Engineering, Rover V8 engine builders.

Reply to
Badger

Thanks badger! much appreciated!

Badger '99 523iSE Scotland.

Is this you too?

MC.

-------

Reply to
Mark C.

Aaaargh! My secret's out! Yep, fraid so. Badger '83 110 3.9V8 4sp Auto, MSA licensed Motorsport Recovery Unit. '99 523iSE daily transport. '78 TR7V8 toy being rebuilt. B.H.Engineering, Rover V8 engine builders. Scotland.

Reply to
Badger

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.