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Post by enigmas on Nov 26, 2014 2:53:12 GMT
Does anyone have this information or perhaps an old piston in their stash of parts that they can measure the volume of in Milliliters. (You'll probably find a small dosage cup for dispensing medicinal mixtures in the bathroom cabinet or something similar in the wife's cooking stash.  So if you (?) can do this, use vegetable oil or something non toxic and not water, as a miniscus won't then be created resulting in an incorrect volume measurement. 1 milliliter = 1 cm3 so the conversion is straight forward. www.metric-conversions.org/volume/milliliters-to-cubic-centimeters.htm |
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Post by johnwp5bcoupe on Nov 26, 2014 13:35:49 GMT
Does anyone have this information o r perhaps an old piston in their stash of parts that they can measure the volume of in Milliliters. (You'll probably find a small dosage cup for dispensing medicinal mixtures in the bathroom cabinet or something similar in the wife's cooking stash. So if you (?) can do this, use vegetable oil or something non toxic and not water, as a miniscus won't then be created resulting in an incorrect volume measurement. 1 milliliter = 1 cm3 so the conversion is straight forward. www.metric-conversions.org/volume/milliliters-to-cubic-centimeters.htmHi Vince I emailed Paul at V8Tuner this was his reply  Sorry John Do not have any info on those or have seen one for some time. A 4.0 Litre LC engine has a bowl volume of approx 22cc so the 3.5 should be possibly around about 15 - 18cc ish Regards Paul |
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Post by enigmas on Nov 26, 2014 20:45:18 GMT
Thanks John, I appreciate your efforts to help me. The reason I asked, is that the engine in my coupe is a P76 V8 4.4 litre and when I rebuilt it many years ago I used the 8.13 pistons which were the best option at the time. Even so the compression is very high. As it primarily runs on LPG this was fine at the time but the octane rating of the fuel has been progressively reduced over a period of 20 years. I have a spare set of heads at a shop currently and if I know the volume I can extrapolate the difference between some old P76 pistons that I have and remove the extra volume from the cyl head.
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Post by djm16 on Nov 27, 2014 4:27:24 GMT
I think what you want to do is dip a piston into a graduated vessel (wife's measuring jug) up to a fixed point such as the middle of the gudgeon pin. Checking to the piston skirt is not going to work if pistons have different length skirts.
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Post by enigmas on Nov 27, 2014 12:28:32 GMT
I think what you want to do is dip a piston into a graduated vessel (wife's measuring jug) up to a fixed point such as the middle of the gudgeon pin. Checking to the piston skirt is not going to work if pistons have different length skirts. Unless I'm missing something...I don't get your comment. It's quite straight forward to burette a small quantity of ATF into the piston bowls, then subtract the lesser amount from the larger, which is the volume to be removed from the combustion space in the cyl head. |
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Post by Steve P5b on Nov 27, 2014 15:04:57 GMT
Thanks John, I appreciate your efforts to help me. The reason I asked, is that the engine in my coupe is a P76 V8 4.4 litre and when I rebuilt it many years ago I used the 8.13 pistons which were the best option at the time. Even so the compression is very high. As it primarily runs on LPG this was fine at the time but the octane rating of the fuel has been progressively reduced over a period of 20 years. I have a spare set of heads at a shop currently and if I know the volume I can extrapolate the difference between some old P76 pistons that I have and remove the extra volume from the cyl head. Thicker head gasket? |
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Post by enigmas on Nov 27, 2014 21:15:15 GMT
Hi Steve, the engine capacity is 4.4 not 3.5...same bore but a longer stroke ( 3.5 x 3.5). It runs a composite gasket not the tin one. The push rods would be loose and the fit of the inlet manifold affected.
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Post by Roy of the Rovers on Dec 1, 2014 13:55:48 GMT
Maybe someone at Rommer Bros can help? They sell pistons of various CR's..
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Post by guidedog on Dec 1, 2014 15:02:02 GMT
Roy I think you mean Rimmer Bros. Looks like a mispell.
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Post by Roy of the Rovers on Dec 2, 2014 14:03:53 GMT
fat fingers on an Iphone for you..  |
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Post by guidedog on Dec 2, 2014 16:33:54 GMT
I have the same problem with my mobile  |
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So if you (?) can do this, use vegetable oil or something non toxic and not water, as a miniscus won't then be created resulting in an incorrect volume measurement.
