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+--- Thread: Sleeved block for race engine (/showthread.php?tid=3345)
Sleeved block for race engine - shane - 25-09-2019
Hi
I have been advised against using a sleeved block for building a race engine. Is this the general consensus of opinion?
Also, does anyone know the weight of a stripped Austin seven-block without studs? Need the weight for a courier collection.
Regards
Shane
RE: Sleeved block for race engine - Spex - 25-09-2019
About 20.25 lb or 9.2 kg
Cheers, Peter
RE: Sleeved block for race engine - Zetomagneto - 25-09-2019
Definitely not, it's basically only the cylinders that hold the top to the bottom once bored to take liners the original cylinder walls are very thin.
RE: Sleeved block for race engine - shane - 25-09-2019
Thanks for the info
RE: Sleeved block for race engine - Tony Betts - 25-09-2019
If you are useing just the eight studs provided by austin, there is an increased chance of the block breaking along the base.
It's more of a myth not to use linners, because they will move when racing.
If you do use linners for tuned engines, then strap over the head into the crankcase from front to rear.
Tony.
RE: Sleeved block for race engine - Ruairidh Dunford - 25-09-2019
I don’t race but I have never ever had a problem with a sleeved block properly fitted.
RE: Sleeved block for race engine - Ian Williams - 26-09-2019
On a standard engine you won't have a problem Ruairidh
RE: Sleeved block for race engine - Tony Betts - 26-09-2019
Hi R,
The rumour has always been the liners moves. But that's not true.
The problem is, when you liner a block. It makes the walls thinner on the bottom half of the water manifold side. This is were the block is shaped around the bore.
There is NO problem with a standard engine.
But when tuning, and putting more force through the block. They can break around the base.
But good blocks are now very scarce, and even the best engine builders are useing linered blocks for tuned engines.
But they bolt everything over the head to reduce the upward forces above the 8 block studs.
Tony.
RE: Sleeved block for race engine - Ruairidh Dunford - 26-09-2019
I have had a number of engines come in (some sleeved and some not) which exhibit the damage you describe Tony. All of them had very high lift cams and very strong valve springs which I considered the root cause of the failure.
The blocks had lifted on the valve side and snapped the base off around the (normally number four) bore. In the cases of the ones with sleeves, these had certainly not moved and remained in position as you suggest.
Good blocks are indeed hard to find.
RE: Sleeved block for race engine - Zetomagneto - 26-09-2019
I would happily use linered block for standard engine, topic is for a race engine, as confirmed by Tony blocks are too thin at the base once linered