[Bigmant773]

Well… this happened last night, about 20min from home.

That’s not supposed to be there!

Needless to say, I don’t have high hopes for the engine at this point. I’m going to pull the pan to see the extent of the damage, but I think at 165k miles, she might be due for a new engine anyway.

 

[masantschi]

Ouch

 

[Redrover NC]

How?

 

[V50_M66]

Oof that's no bueno. How did that happen?

 

[Bigmant773]

Just driving home on a 200 mile trip, going about 65mph. Looks like the engine threw a rod

 

[Bigmant773]

Oil pan removed!

Connecting Rod snapped, right above the collar that connects to the crankshaft. With that said, there doesn’t appear to be a whole lot of extra damage.

Can someone talk me off the ledge of potentially pulling the heads and replacing broken rod and piston and just reconnecting it to the crank shaft?

 

[V50_M66]

Oil pan removed!

Connecting Rod snapped, right above the collar that connects to the crankshaft. With that said, there doesn’t appear to be a whole lot of extra damage.

Can someone talk me off the ledge of potentially pulling the heads and replacing broken rod and piston and just reconnecting it to the crank shaft?

Wow. Got any pictures of that?

I wouldn't do that. If one went, who's to say the others won't follow suit, especially if the new rod isn't balance matched to the rest of the rotating assembly.

 

[Bigmant773]

 

[Bigmant773]

Wow. Got any pictures of that?

I wouldn't do that. If one went, who's to say the others won't follow suit, especially if the new rod isn't balance matched to the rest of the rotating assembly.

Just posted above!

I was thinking the same, but I dunno, I was thinking $500 for a new rod and a head gasket kit sounds a lot better than $7700 for a new engine from Atlantic British

 

[V50_M66]

View attachment 94993
View attachment 94992

Just posted above!

I was thinking the same, but I dunno, I was thinking $500 for a new rod and a head gasket kit sounds a lot better than $7700 for a new engine from Atlantic British

Wow. Looks like a spun rod bearing, probably from low oil pressure. The crankshaft is done too, and who knows what else. Unfortunately looks like a new motor is your best bet. I’d personally try to fund a junkyard or used engine. A couple grand and you’ll be back in business. Rebuilding it properly is going to be more than just getting an engine for it

 

[Bigmant773]

Two more pictures just for funsies. You can see almost a 1/3 of the piston is missing. Crazy stuff!

What issues do you think there will be with the crankshaft?

 

[V50_M66]

View attachment 94995
View attachment 94994

Two more pictures just for funsies. You can see almost a 1/3 of the piston is missing. Crazy stuff!

What issues do you think there will be with the crankshaft?

Oh wow
You can see if you zoom in on the crankshaft photo that the bearing surface is messed up. This is likely what caused your failure - low oil pressure meant that the connecting rod bearing fused to the crankshaft because of excess heat from contact, which caused it to lock up and shoot the rod through the pan. At the very least, you'd need to resurface that bearing surface. Additionally, since the piston is so messed up, I'm willing to bet that cylinder liner is also messed up. It's simply not worth the money with the risks associated with it unless you wanted to rip it out and fully rebuild it on a stand, but by the time you do that you're looking at the pricing for a new engine anyway. Engine tolerances have to be crazy tight, and everything has to be balanced perfectly so it doesn't shake itself apart.

 

[Bigmant773]

Oh wow
You can see if you zoom in on the crankshaft photo that the bearing surface is messed up. This is likely what caused your failure - low oil pressure meant that the connecting rod bearing fused to the crankshaft because of excess heat from contact, which caused it to lock up and shoot the rod through the pan. At the very least, you'd need to resurface that bearing surface. Additionally, since the piston is so messed up, I'm willing to bet that cylinder liner is also messed up. It's simply not worth the money with the risks associated with it unless you wanted to rip it out and fully rebuild it on a stand, but by the time you do that you're looking at the pricing for a new engine anyway. Engine tolerances have to be crazy tight, and everything has to be balanced perfectly so it doesn't shake itself apart.

Given that I have fully rebuilt the auto transmission in my dodge Cummins, I am now beginning to think a full rebuild of this engine will be not only a few grand cheaper, but also not a terribly hard project, as long as I have the time to do it.

I think I’d be looking at rebalancing the crank shaft and putting in some Atlantic British flanged cylinder liners anyway. For the price of a AB engine at $7700, I think I could rebuild the whole thing and upgrade it with a Turner cam shaft ECU, deck the block and heads and all new accessories and still be under that price.

My wheels are turning, pun intended! We’ll see what I decide to do to get this ol girl back on the road

 

[V50_M66]

Given that I have fully rebuilt the auto transmission in my dodge Cummins, I am now beginning to think a full rebuild of this engine will be not only a few grand cheaper, but also not a terribly hard project, as long as I have the time to do it.

I think I’d be looking at rebalancing the crank shaft and putting in some Atlantic British flanged cylinder liners anyway. For the price of a AB engine at $7700, I think I could rebuild the whole thing and upgrade it with a Turner cam shaft ECU, deck the block and heads and all new accessories and still be under that price.

My wheels are turning, pun intended! We’ll see what I decide to do to get this ol girl back on the road

I mean if you're willing to do it and spend that kind of money, go for it. I was thinking you could get a used motor for 2 or 3 grand, which is probably the direction I would go, but that would be a cool project if you are up for it

 

[discovering]

Have you considered an LS swap? If you're skilled enough to rebuild the engine, swapping in the LS shouldn't be a big problem for you. I'm about two weeks from the completion of my L33 swap. It's already running, just need to build the air intake, connect the exhaust and service the tranny.

Many Disco IIs are at the junkyard because of slipped liners. A junkyard engine would still need a complete overhaul. It'd probably have less holes in it though

 

[Bigmant773]

Have you considered an LS swap? If you're skilled enough to rebuild the engine, swapping in the LS shouldn't be a big problem for you. I'm about two weeks from the completion of my L33 swap. It's already running, just need to build the air intake, connect the exhaust and service the tranny.

Many Disco IIs are at the junkyard because of slipped liners. A junkyard engine would still need a complete overhaul. It'd probably have less holes in it though

I’ve thought about it, but I’ve decided I prefer to keep it a 4.6 for ease of maintenance. At least if I know the flaws I can plan for them, with the LS that’s not necessarily the case haha.

I am planning some upgrades however. Like a hotter cam and an ECU flash from turner, so the goal will be to correct the typical issues and give it a little more power. We’ll see how it goes

 

[discovering]

I am planning some upgrades however. Like a hotter cam and an ECU flash from turner, so the goal will be to correct the typical issues and give it a little more power. We’ll see how it goes

Cool - are you going with top-hat liners?

 

[Bigmant773]

Cool - are you going with top-hat liners?

Abso-damn-lutely!

 

[Bigmant773]

Hopefully going to be turning this into a build thread!

Parts ordered from Atlantic British, I found it hard to justify $7700 on a new engine setup from them, and TWS motors was somewhere in the $12,000 range for a similar setup but with a 300hp rating. Needless to say I am officially doing it myself.

Parts from AB include all the new engine goodies, plus a new oil pan, piston and connecting rod.

Turner in the UK will be providing their street cam.

Q&E machine shop in LA will be decking the block and heads, and putting in flanged and O ringed sleeves from LA sleeves. They will also be port and polishing the heads, and grinding and balancing the crank to .020.

I plan to send in my flywheel to TWS to get it lightened by about 10lbs which is cheaper than a new one.

And lastly I’ll be sending off the ECU to Tornado in the UK for a flash, mostly due to TWS wanting roughly double for the same thing.

All that put together should make for a highly reliable engine build for the next 200k+ miles, and add some much needed torque and hp in the 3k and 5k+ RPM range. Couple that with less rotating weight from the flywheel and crankshaft, and this should be an engine that really has some good power.

 

[YETIX]

Wow! Definitely will be following along