Torque Honing Plate for our cars.
02-23-2018, 12:08 PM
#1
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Torque Honing Plate for our cars.
Porsche 944, 968 torque honing plate. Should fit the 928. Do we need it?
Åke
http://www.cylinderheadsupply.com/por-v8.html
Åke
http://www.cylinderheadsupply.com/por-v8.html
02-23-2018, 12:48 PM
#2
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I have a pair of torque plates that my machinist keeps at his place, which he uses for all boring and honing, when we are using an Alusil process.
The dimensional differences with and without either plate being installed are very significant....so much so that I initially wondered if we were doing the right thing....
I do know that my leakdown tests improved by a large percentage once we made these plates and started using them, however I have not had any engines back apart to see how the bores look after use.
Perhaps that, alone, is a good sign.
The downside is that using torque plates for all operations (including align boring) adds to the amount of time and effort require to do the actual machine work.....it adds to the cost.
The dimensional differences with and without either plate being installed are very significant....so much so that I initially wondered if we were doing the right thing....
I do know that my leakdown tests improved by a large percentage once we made these plates and started using them, however I have not had any engines back apart to see how the bores look after use.
Perhaps that, alone, is a good sign.
The downside is that using torque plates for all operations (including align boring) adds to the amount of time and effort require to do the actual machine work.....it adds to the cost.
02-23-2018, 12:51 PM
#3
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Porsche 944, 968 torque honing plate. Should fit the 928. Do we need it?
Åke
http://www.cylinderheadsupply.com/por-v8.html
Åke
http://www.cylinderheadsupply.com/por-v8.html
Always keen to learn something new- reading the link you sent I presume that such a device is intended as a tool to bolt onto the crankcase when preparing the bores- the intention being to distort the cylinders to the as built condition when the engine is assembled so that preparing the bores they end up with the roundness required rather than possibly being out of tolerance with no knowledge of such. Is that a reasonable interpretation of its functionality?
09-23-2018, 01:33 PM
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Porsche does not prescribe a torque honing plate. It is essential to tighten the bearing stud in bolts which hold the two halves of the crankcase together before honing. I can see the need of a honing plate for a closed engine block where the head studs are screwed into the upper part of the block. The 928 has an open block with the head bolts way down. Some time ago I honed a Volvo closed engine block using a honing plate provided by the customer. After finish honing the block I carefully measured the cylinders with the honing plate in place and after it was removed. I could hardly see a difference, maybe a difference of 0,01 to 0,02 mm which actually is within the given tolerances. Has anyone checked the cylinder bores the same way for a 928 engine block?
https://www.porscherepair.us/power-s...-gts-54-i.html
Aluminum honing plates for the 928 is available for the nice sum of $ 728.75
http://honingplates.com/index.php?ma...roducts_id=278
I have a scrap cylinder head laying around. It could be used for the making of a honing plate.
Åke
https://www.porscherepair.us/power-s...-gts-54-i.html
Aluminum honing plates for the 928 is available for the nice sum of $ 728.75
http://honingplates.com/index.php?ma...roducts_id=278
I have a scrap cylinder head laying around. It could be used for the making of a honing plate.
Åke
