n/a piston to wall clearance.
#1
Registered
Thread Starter
Join Date: Apr 2013
Location: Lagrange ky
Posts: 309
Likes: 0
Received 0 Likes
on
0 Posts
n/a piston to wall clearance.
does this seem normal. im building a 489 for my pachanga. started with a 330. now its going to be a forged 489 with 781 heads. anyhow. i bought some 14cc dome 2618 diamond pistons. they want the piston to bore clearance at .0055. with open cooling marine motors adding another.002-.004. this seems like alot to me but ive only ever built car motors. i understand the block staying cold and the piston material growing. but this motor will be lucky to make 475hp and will only be WOT for about 5 minutes total a weekend.
is .0055 ok or should i have the machinist open it up more. im dropping the pistons off this week for the final bore and i need to know what to tell him
thanks, Brandon.
is .0055 ok or should i have the machinist open it up more. im dropping the pistons off this week for the final bore and i need to know what to tell him
thanks, Brandon.
#2
Registered
iTrader: (2)
does this seem normal. im building a 489 for my pachanga. started with a 330. now its going to be a forged 489 with 781 heads. anyhow. i bought some 14cc dome 2618 diamond pistons. they want the piston to bore clearance at .0055. with open cooling marine motors adding another.002-.004. this seems like alot to me but ive only ever built car motors. i understand the block staying cold and the piston material growing. but this motor will be lucky to make 475hp and will only be WOT for about 5 minutes total a weekend.
is .0055 ok or should i have the machinist open it up more. im dropping the pistons off this week for the final bore and i need to know what to tell him
thanks, Brandon.
is .0055 ok or should i have the machinist open it up more. im dropping the pistons off this week for the final bore and i need to know what to tell him
thanks, Brandon.
#6
Registered
iTrader: (5)
Call diamond with the job number off your piston spec sheet. Discuss the build and intended use with them and they will be happy to confirm. I built 2 pro charged 383's using there pistons. Marine required .005, add .002 for open cooling add .002 for boost. Well that adds up to a sh!t ton for a 4.030 bore! I called talked to a tech and he said go .0065 -.007 so that's where we are.
#7
Registered
iTrader: (1)
Call diamond with the job number off your piston spec sheet. Discuss the build and intended use with them and they will be happy to confirm. I built 2 pro charged 383's using there pistons. Marine required .005, add .002 for open cooling add .002 for boost. Well that adds up to a sh!t ton for a 4.030 bore! I called talked to a tech and he said go .0065 -.007 so that's where we are.
#9
Registered
Thread Starter
Join Date: Apr 2013
Location: Lagrange ky
Posts: 309
Likes: 0
Received 0 Likes
on
0 Posts
Piston slap when its cold doesnt bother me. I called diamond and got some girl who said i would have to talk to the distributor i got them from. Ill try again tomorrow and be more persistent.