Cracked block - anyone had this.

[SwedishTVR]

While rebuilding my Pre-serp 430, i started my engine in the chassis, as a quality-check before lifting the body back on.

The engine had not run during my ownership, since I bought the car from a guy that didn’t had the time to complete the rebuild.

now, i had taken the heads off, cleaned all faces, put new gaskets and many other bits on, and started the engine after putiing it back in the chassis.

the engine started, I adjusted the ignition-timing, but it started to smoke white smoke as the engine became hot. the hotter the engine, the more smoke. eventually, the fans came on.

As i suspect a coolant leakage, i pulled the plugs out, no clear difference in colour between them. I pulled one of the heads of (1-3-5-7) and cylinder 3 is clearly cleaner than the other three.

But, i can’t see any obvious reason for the coolant leaking into this cylinder. When searching the internet, I found this: http://www.cowdery.org.uk/cracks.php

Did any of you experience the type of crack and resulting coolant leakage? how did you solve it?

thanks in advance

[mcosh]

Seen similar symptoms from head gasket failure and warped heads. Have these been checked, skimmed.?

[LLantrisant]

cracked blocks can happen....the can be repaired with liners.

[Boosted LS1]

I'd pressure test the block to be certain. A head is far cheaper to replace or repair and you need a diagnosis.

[SwedishTVR]

I will take the other head off and have them pressure tested and machined the blockface

[MisterT]

SwedishTVR said:

Did any of you experience the type of crack and resulting coolant leakage? how did you solve it?

That looks like a typical case of porous block, just like the cowdery link you posted.

I’ve had two, one in a 4.6 Range Rover and then in my 5.0 Griff.

If it is porous (or cracked) block the only solution is top hat liners, assuming the block is reusable (machining the block face won’t fix it). My 5.0 Griff block was deemed scrap, but I had 6 liners slipped after an overheat on a Donington track day. I chose to replace with a V8D 5.0 short engine as the heads off my old engine were absolutely fine

[TJC46]

Could a slipped liner cause the problems you have ?

As you say the car was running fine until it started to warm up, and then your problems began.

Interesting reading on V8 developments web site

http://www.v8developments.co.uk/technical/liners/i...

[Pete Mac]

TJC46 said:

Could a slipped liner cause the problems you have ?

As you say the car was running fine until it started to warm up, and then your problems began.

Interesting reading on V8 developments web site

http://www.v8developments.co.uk/technical/liners/i...

I must admit, when I rebuild my engine I was planning to fit these to hat liners, particularly if the block needs reboring. It just seems a very sensible thing to do and makes the engine significantly more 'bullet proof. Pete

[phazed]

My original 5.5 block was top hatted.

That didn't stop a split forming in the casting behind the liner which is the outer case of the water jacket.

Water seeps out behind the liner and gets into the engine. This happened to me during a track day at the Lotus test site, ( brilliant day). and the whole radiators worth of water disappeared in an afternoon!

I did have the liner removed, block welded and a new liner fitted.

[Loubaruch]

Aluminium castings seem to suffer quite badly from porosity

I have a 1936 Morgan with an Ali sump that used to drip engine oil. A company "Impregnation Services" sealed it with some high temperature Polymer process. While at the company I noticed literally hundreds of Gearboxes and asked what they were doing there and was told they were for the BMW Minis as every one is sealed prior to installation. I am not sure if the process would stand up to the heat/stress in an engine block no doubt someone on here will know.

[SwedishTVR]

Thanks for all your comments and sharing your own experiences.

I hade the heads checked. The weren’t warped and pressuretest showed perfect results.
So, that makes me even more convinced that my block has porosity- or crack behind the number 3 liner.

I have been in contact with both V8Developments and Turner Engineering. I will take the engine out of the chassis, strip it and send it to one of them for relining.

Better safe than sorry...

Frank

[macdeb]

One word for you, 'Chesman engineering'. Ok, two words but they are the best imho.

[phazed]

macdeb said:

One word for you, 'Chesman engineering'. Ok, two words but they are the best imho.

They welded my block and fitted a new liner.

Also top hatted my later block.