richStroking a 3.5
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atleast im not the only one having trouble with stroking a rover, hope this helps abit, example using my maths and my set up which is different to yours, half stroke 1,595+, rod 6,000" + piston down bore 0.040 add them up = 7.635" to get to deck height of 8.960 you need a piston height of 1.325,you just need to use your measurements, does this help rich
richNightbreed racing, http://www.youtube.com/watch?v=NJoUTZ8UUps
Phew I'm not on me own then! Have been informed that with 4.2 crank, pistons would probably need the skirt machining as well as the top to clear the crank. That's gonna be pricey i reckon. Bah, looking lik e a 3.5 engine is all i can get 
If it's built right tho, it should take a fair whack of boost and be pretty reliable with the block/girdle set up i have.
If it's built right tho, it should take a fair whack of boost and be pretty reliable with the block/girdle set up i have.
Machining the skirt of a piston should not be expensive 
of all the jobs you could get done on an engine the tollerances are about as wide as the can be and set up is "reverse the jaws in a 3 jaw chuck and quickly true it up on a dial gauge" chop it off with a parting tool, 2 minutes for reversing the jaws 15 seconds to set the speed, 10 seconds to find reverse and the parting tool on the back of the cross slide, 60 seconds to set the piston in the chuck with the DTI and 60 seconds to part off a 1/4 inch off the piston(or however much you want). Stretched out its 30 minutes work.
Mike
of all the jobs you could get done on an engine the tollerances are about as wide as the can be and set up is "reverse the jaws in a 3 jaw chuck and quickly true it up on a dial gauge" chop it off with a parting tool, 2 minutes for reversing the jaws 15 seconds to set the speed, 10 seconds to find reverse and the parting tool on the back of the cross slide, 60 seconds to set the piston in the chuck with the DTI and 60 seconds to part off a 1/4 inch off the piston(or however much you want). Stretched out its 30 minutes work.Mike
poppet valves rule!
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CastleMGBV8
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Olly,
Topping and tailing was necessary on the rover pistons but may not be necessary with the ones you have.
What compression height are they.
The Rover 4.2 pistons have a compression height of 1.763" as aguide.
By the way although the 4.2 cranks are stated to be 77mm they can be a bit less, my data sheet give a manufacturing tolerance of between 76.222mm - 76.759mm. mine certainly wasn't a full 77mm.
Kevin.
Topping and tailing was necessary on the rover pistons but may not be necessary with the ones you have.
What compression height are they.
The Rover 4.2 pistons have a compression height of 1.763" as aguide.
By the way although the 4.2 cranks are stated to be 77mm they can be a bit less, my data sheet give a manufacturing tolerance of between 76.222mm - 76.759mm. mine certainly wasn't a full 77mm.
Kevin.
