SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: 78centurian on January 14, 2010, 01:14:36 PM
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i got a 460 and gunna put 40 over cast pistons in it. what the hell should i bore this thing to????
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STOP! Don't put cast pistons into anything, get some forged ones and come back
4.40 is your answer
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WHOA PUT ON THE BRAKES, call Dave at a&d NOW if for nothing else other than to talk to a real engine machinest
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yes, call this guy http://www.aanddengines.com/
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WHOA PUT ON THE BRAKES, call Dave at a&d NOW if for nothing else other than to talk to a real engine machinest
Did I do bad math? Stock bore= 4.36 + .040= 4.40. No?
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correct me if im wrong, but you dont want to drop off a block at a machinist and say "bore this to x.xx" ....you need to take your pistons to him with the block.
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correct me if im wrong, but you dont want to drop off a block at a machinist and say "bore this to x.xx" ....you need to take your pistons to him with the block.
you aint wrong sunshine :-*
i dont know about your math skipper, but, he needs to to it rite or he will be doing it over again. just ask brad (sorry hunny) why do you want to put the 40 over slugs in? instead of the off the shelf 60
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yea the block is just down there chilling waiting for me to get the pistons
the machinest sugested getting the 40 overs and my pops got a good deal for them off of ebay. brand new slugs with reconditioned rods with arp bolts for really cheap so thats the route we decided to go
he hasnt machined anything yet cuz he was waiting for the pistons but i was only asking cuz i wanted to make sure the clearence was right. dave at a&d set everything straight so i think i am good to go now. btw thanks dave for all the good info
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If you have a 4-5" micrometer, you can measure your own pistons and specify finished bore size based on specs that come with the pistons. For a normally aspirated marine engine, I normally add .001 since the block stays cooler than a street engine due to the constant supply of fresh cold water, and the pistons probably carry more heat due to running roughly double the normal rpm of a street engine. You could call the company who made your pistons and ask them as well.
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yea the block is just down there chilling waiting for me to get the pistons
the machinest sugested getting the 40 overs and my pops got a good deal for them off of ebay. brand new slugs with reconditioned rods with arp bolts for really cheap so thats the route we decided to go
he hasnt machined anything yet cuz he was waiting for the pistons but i was only asking cuz i wanted to make sure the clearence was right. dave at a&d set everything straight so i think i am good to go now. btw thanks dave for all the good info
cheap aint good and good aint cheap. :thumbup:
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yea the block is just down there chilling waiting for me to get the pistons
the machinest sugested getting the 40 overs and my pops got a good deal for them off of ebay. brand new slugs with reconditioned rods with arp bolts for really cheap so thats the route we decided to go
he hasnt machined anything yet cuz he was waiting for the pistons but i was only asking cuz i wanted to make sure the clearence was right. dave at a&d set everything straight so i think i am good to go now. btw thanks dave for all the good info
Your welcome :thumbup:
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cheap aint good and good aint cheap. :thumbup:
where have i heard that before
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where have i heard that before
this young grasshoppa heard it from my masta....
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this young grasshoppa heard it from my masta....
LOL grasshoppa, you have got your wings and are flying on your own :thumbup:
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from the guy who litterally folded a rod in half, invest in a good set of aftermarket rods too!!!
just my $.02
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how bout we got a set of "good" pistons for a "good" price
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how bout we got a set of "good" pistons for a "good" price
now i like that alot :thumbup:
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Whatever pistons you choose, make sure that the guy measuring them is the same guy machining the block. Measuring with precision tools has a lot to do with feel, and your number might be different than his number. Due to this fact, Micrometers and bore guages are most accurate when used as comparative tools than when used to determine the actual size of something. The number itself makes no difference in this case though...it's the comparison between bore size and piston size that matters, and if the same guy is measuring both and simply comparing the sizes of both, you'll be a lot more likely to hit the mark if you give him both the pistons and the block and call out the clearance spec than if you give him just the block and tell him how big you think the pistons are.