
rebuilding 1969 383 charger engine
Moderator: Moderators
- pete walton
- Posts: 1401
- Joined: Mon Jan 16, 12 4:18 pm
can i suggest,if you have the option, that you stick in the old bearings
get the crank in and mount up two pistons and rods
one on each side
see how far the pistons are down the hole at TDC
rod length from manual + the distance from the top of the pin hole to the top of a piston + 1/2 the pin bore + the bit from piston crown to top of block
will give you you deck height
once you have that you can look at pistons try to get some that fill the hole up to the top.
aim for a flat top piston if you can and try to get some quench when you get you head done.
saves having masses cut from heads and block which saves cash.
summit has a piston selector remember that you don't have to get mopar pistons...
any piston of appropriate deck height, an oversize mid way through the range that kinda fits with your Bore and pin bore can be used
i wouldn't use the biggest oversize from 1 model of engine to build another engine it leaves no scope for mistakes or rebuild
but i might use a +10 or +20 thou piston from a car with just short of 4 inch bore in a 4 inch bore block i.e i might need it bored 4.005 to take the +10 thou piston from brand X engine. aim to do the smallest cut on the block you can get away with in all aspects.
I only strayed to Jeep for mine, would have had chevy pistons if they had done anything more than standard cast.
its easier to bush a rod for a smaller pin or a floating pin but you can also ream out the small end for a slightly bigger pin but i'd stick with the push fit pin in that case no space to alos fit the flaoting pin bush. mopar rods are forged, see what your engineer thinks.
remeber for flaoting pin you need a littl oil hole in the small end
suggest ARP rod bolts are good insurance
smain studs and head studs nice to have on a street motor but not essential
if you get the heads and block machined flat descide before you do it if you are going to use Cometic style MLS steel shim gaskets
the finish on the heads and block is different smoother for them over the standard gasket.
you can Add static C/R by getting valves with no dish in the head
if you need to get the guides done you can go down a size in valve stem size making a smidge more space in the port and less restriction
be sure to specify if you get crank regorund that you are building a street motor or a race motor
you manual will specify something like 1.5 thou clearance on the mains as standard
if you say race motor you will end up wityh 2- 2.5 thou clearance which may not be what you want
don't bother getting any work done on the block if the main caps do not take a decnet whack with a wooden mallet to fit them in the register.
any that just fall in are stretched and being cast iron can't really be helped its been weakend
unless you are going to new ductile caps and the attendent expence of a full align bore and hone
Mopar lifters and AMC lifters are the same 0.904 inch size and have the oil band round them in the same place. AMC lifter howver have a lower seat for the pushrod. spending on new pushrods can be avoided after a big head and block cut if you use AMC lifters.
Dave
get the crank in and mount up two pistons and rods
one on each side
see how far the pistons are down the hole at TDC
rod length from manual + the distance from the top of the pin hole to the top of a piston + 1/2 the pin bore + the bit from piston crown to top of block
will give you you deck height
once you have that you can look at pistons try to get some that fill the hole up to the top.
aim for a flat top piston if you can and try to get some quench when you get you head done.
saves having masses cut from heads and block which saves cash.
summit has a piston selector remember that you don't have to get mopar pistons...
any piston of appropriate deck height, an oversize mid way through the range that kinda fits with your Bore and pin bore can be used
i wouldn't use the biggest oversize from 1 model of engine to build another engine it leaves no scope for mistakes or rebuild
but i might use a +10 or +20 thou piston from a car with just short of 4 inch bore in a 4 inch bore block i.e i might need it bored 4.005 to take the +10 thou piston from brand X engine. aim to do the smallest cut on the block you can get away with in all aspects.
I only strayed to Jeep for mine, would have had chevy pistons if they had done anything more than standard cast.
its easier to bush a rod for a smaller pin or a floating pin but you can also ream out the small end for a slightly bigger pin but i'd stick with the push fit pin in that case no space to alos fit the flaoting pin bush. mopar rods are forged, see what your engineer thinks.
remeber for flaoting pin you need a littl oil hole in the small end
suggest ARP rod bolts are good insurance
smain studs and head studs nice to have on a street motor but not essential
if you get the heads and block machined flat descide before you do it if you are going to use Cometic style MLS steel shim gaskets
the finish on the heads and block is different smoother for them over the standard gasket.
you can Add static C/R by getting valves with no dish in the head
if you need to get the guides done you can go down a size in valve stem size making a smidge more space in the port and less restriction
be sure to specify if you get crank regorund that you are building a street motor or a race motor
you manual will specify something like 1.5 thou clearance on the mains as standard
if you say race motor you will end up wityh 2- 2.5 thou clearance which may not be what you want
don't bother getting any work done on the block if the main caps do not take a decnet whack with a wooden mallet to fit them in the register.
any that just fall in are stretched and being cast iron can't really be helped its been weakend
unless you are going to new ductile caps and the attendent expence of a full align bore and hone
Mopar lifters and AMC lifters are the same 0.904 inch size and have the oil band round them in the same place. AMC lifter howver have a lower seat for the pushrod. spending on new pushrods can be avoided after a big head and block cut if you use AMC lifters.
Dave
The Greater Knapweed near the Mugwort by the Buckthorn tree is dying