Part one:
This one came about after a Mk2 block with a 998cc conversion, saw damage after various complications with both the height of the liners and a sport wills ringed head that was not as perfect as was thought.
Check the three welds on the top edge of the Hillman Imp alloy 998cc block. All pictures should enlarge when you click on them.
The new steel liners in the block looked great, done by a local machine shop, it was to become a learning curve for all involved, I later prooved the linings had not been glued in level, they were out of level from 0.0005" to 0.003". I had them pressed out and refitted them myself with Loctite 648 bonding liquid, using a bolted down 170 series sport cylinder head that had been faced skimmed as the press tool.
This method prooved to work and I found the liners were at the required plus 0.002" hight above the block face after doing it my way. However, this was not the end of the story and the engine never did get sorted in time to ship to Scotland with its sprint prepared body. I was left holding the engine parts as a buy back of what they would cost in the UK, a gamble if they prooved to be of no use?
The block had cracked in two places when the head was tightened down.
It became a long story and right now one I will not cover fully, the issue became more could I get the parts with what was by now a three times welded alloy block to work? The machine shop called to say that the loose liners would no longer fit the bores in the block they came out of, they were out by around 0.003", I called the job off and then collected the engine in bits and brought them back to my own workshop.
The second crack. A damaged block like this may just be dumped in the UK but not here in South Africa, they are very scarce and in the case of this 998cc block, a great deal of money has been invested in it already.
I then looked at the matter in a series of whats important (pun?) I fitted the crank, it turned ok but was less free than before welding, it will I hope bed in, we may end up doing a line bore job? I then needed to check the top landing, fitting a good cylinder head is a good way to start but there was excess welding on the top of the block that needed milling off, can I do that I thought!
Can this 998cc Imp block be made to run again?
Pictures (lots) and the rest of the story to follow in part two.
Roy
This one came about after a Mk2 block with a 998cc conversion, saw damage after various complications with both the height of the liners and a sport wills ringed head that was not as perfect as was thought.
The new steel liners in the block looked great, done by a local machine shop, it was to become a learning curve for all involved, I later prooved the linings had not been glued in level, they were out of level from 0.0005" to 0.003". I had them pressed out and refitted them myself with Loctite 648 bonding liquid, using a bolted down 170 series sport cylinder head that had been faced skimmed as the press tool.
The repair weld has been cleaned down with a disc grinder to clean it up but still requires a final milling to the level of the block, note the hard steel thread insert.
This method prooved to work and I found the liners were at the required plus 0.002" hight above the block face after doing it my way. However, this was not the end of the story and the engine never did get sorted in time to ship to Scotland with its sprint prepared body. I was left holding the engine parts as a buy back of what they would cost in the UK, a gamble if they prooved to be of no use?
The block had cracked in two places when the head was tightened down.
It became a long story and right now one I will not cover fully, the issue became more could I get the parts with what was by now a three times welded alloy block to work? The machine shop called to say that the loose liners would no longer fit the bores in the block they came out of, they were out by around 0.003", I called the job off and then collected the engine in bits and brought them back to my own workshop.
The second crack. A damaged block like this may just be dumped in the UK but not here in South Africa, they are very scarce and in the case of this 998cc block, a great deal of money has been invested in it already.
This was secondary welding, required as stop ends when we fitted the thread inserts, a few leaked due to thin metal on the inside of the block, so all thread ends were welded shut.
Can this 998cc Imp block be made to run again?
Pictures (lots) and the rest of the story to follow in part two.
Roy
