Some 15,000 miles after a proper rebuild. Running 340bhp and 400lbft torque. All running fine. Not pushing hard at all when steam plumed out from behind the car. Pull over, got recovered. And now diagnosed with a cracked engine block. Engine had been rebuilt and was running well. What causes this to happen? Just bad luck?

Regards
James

 

I don't think you should say who but was it a reputable garage that did the work? If so could be worth speaking to them to get they're opinion. 15000 miles might be a bit to much for complaints but a good garage should care.

 

What instance of cracked block ?
Did it throw a Rod
Liners fail
Bottom end let go
Seize etc etc
Be more specific then it will be easier to understand

 

Boost spike or high combustion chamber temps would be my guess.
They normally fail at the weakest spot which is where the liner is notched out on the coolant gallery side for access to the crankcase bolts.

Got any pics of the failure ?

Mick

 

Got a complete hawk sti engine coming out in the next couple of weeks of any good to you

 

Car has been off the road for nearly 4 months. Now back on the road with a new blocked and forged bits again. Here is a pick of the cracked old block. Not a great pic - but you can see where the crack starts.

 

What was it bored to?

 

It wasn't as far as I know. Had a cracked oil pick up pipe about 10k miles before it went pop. That might have been part of the the problem. Always burnt oil since the rebuild and the chap who did the latest rebuild said there was scoring on the pistons. Anyway have now done 500 miles on the new rebuild and all is looking OK. No oil consumption so far and no smoke on start up. Happy bunny for now. But have been in this place before, so not going to count my chickens. But if it goes bang again, then that's it. I'm gonna buy a Vectra - can't keep spending money on her.

 

2.5's are known to have problems with the oil pick up, the original builder should have upgraded when engine was built.

Have you spoken to the original engine builder, what did they say?

Its probably not a good idea to say who did it first time round but who did it this time?

 

That crack in that position is common on 2.5Lt blocks and is a well known problem.

Pics of mine below.





It never ceases to amaze me that people are spending small fortunes building forged SCD 2.5 engines when this is a known issue. Alyn at AS Performance has produced a closed deck insert which solves this issue. Its a very small price when you consider the overall cost of even a normal refresh rebuild.

 

Is that a closed deck??

What sort of price are we talking about for those inserts??

 

My pics are from my previous engine which was a SCD 2.5 forged. Same symptoms running hot. When I stripped it it had the crack in the liner as shown.

The closed deck insert that Alyn does resolves this issue. When I had the engine above the closed deck insert wasn't available.