377 SBC is a 400 block with a 350 crank... but is it 5.7 rods or 6 inch rods?
I believe it depends on type of piston your useing ???
is that conciderd destroking a motor
yes on destroking
you can use wither a 5.7 or a 6.0 rod.... depends on the height of the wrist pin location on the piston your using..
but if your de-stroking a engine... build a 352..... they are nasty engines... you just use a 237 crank not a 350 crank
more rpm's
so you can buy a piston for a 6 inch rod and run it with no problems and the same with a 5.7 rod?
if you know any roundy rounders talk to them 377 was the engine to have in that sport for long time ;D
Quote from: bigmike on November 03, 2011, 02:28:04 PM
so you can buy a piston for a 6 inch rod and run it with no problems and the same with a 5.7 rod?
yes you can even use a 6.125 rod I think
unlce uses 283 crank on those...rods have no idea
there's really only 4 sbc cranks.. the 3 inch stroke 283 and 302 crank, the 3.25 inch stroke 307 and 327 crank the 3.48 inch stroke 262, 305 and 350 crank and the 3.75 inch 400 crank, the shorter the stroke the higher the rpms you can run withgiven parts, for sbc the best length rod you can use is teh 5.7 inch, especially with longer strokes, if you use the shorter 3 or 3.25 inch strokes than 6 inch rods would be alright too, but don't use the longer rods with the longer strokes, and the rod length is also crutical to your piston selection, they are designed to be used with a given rod length. also i would reccomend using full floating wrist pins if you want high rpm's,
so you are saying not to use a 6 inch rod with a 400 block and a 350 crank?
if u do u need the right piston so u dnt hit head
with the 350 crank you can get away with it, but it doesn't leave a whole lot of room for the oil rings, and with the 400 crank it's a very bad idea because their on top of one another
what? so the 350 crank and 6 inch rod is no good to use? so a 5.7 rod would be better?
yeah with a 350 crank the 5.7 is a better idea
That. .3 of a difference makes that much of a difference? Anything to watch out for?
that .3 inside a motor is a lot.. that's 300 thousandths , and that's that much more piston between your wrist pin and oil ring pack to think about that way... and a big thing to be carefull about is not to get carried away with your build, just because you spend top dollar on a bunch of parts doesn't mean their gonna work together...and watch your compression for iron heads and pump gas keep it around 9 to 1 and for aluminum heads keep it around 10 to one,, other wise your gonna have issues with pump gas... and there's a few different ways to get your compression up or down, i'd be glad to give ya some help or pointers during your build. there's a few guys on here that are running motors i built and their happy with them.
I'm running a 400 crank(3.75) with 6" rods with no prob, rev to 7000 rpms, if you use different rod length rods you have to use pistons for those rods. The wrist pin hole are located differently for the rod length
Quote from: Jr on November 03, 2011, 06:05:03 AM
but if your de-stroking a engine... build a 352..... they are nasty engines... you just use a 237 crank not a 350 crank
more rpm's
what is this a 283 crank in a 350 block
no 400 block
Quote from: 355REDNECK on November 07, 2011, 02:02:36 AM
Quote from: Jr on November 03, 2011, 06:05:03 AM
but if your de-stroking a engine... build a 352..... they are nasty engines... you just use a 237 crank not a 350 crank
more rpm's
what is this a 283 crank in a 350 block
no a 283 crank in a 350 block makes a 302 if it's stock bore
Quote from: Jjay78 on November 07, 2011, 02:40:11 AM
Quote from: 355REDNECK on November 07, 2011, 02:02:36 AM
Quote from: Jr on November 03, 2011, 06:05:03 AM
but if your de-stroking a engine... build a 352..... they are nasty engines... you just use a 237 crank not a 350 crank
more rpm's
what is this a 283 crank in a 350 block
no a 283 crank in a 350 block makes a 302 if it's stock bore
how do u get the 352 then
400 block with 283 crank
Quote from: bigmike on November 07, 2011, 09:37:27 PM
400 block with 283 crank
actually that's only 320 cid...with a stock bore.. and with a 327 crank it would be a 347, and a 372 with a 350 crank.. but a 283 with a 400 crank would be a 354
On the subject of 6.0" rods vs 5.7" rods they both have there up and down sides. My information comes from information I have gathered from planning my 383 build. I am not a professional engine build but the information I am giving came from some very well known builders along with my own hours and hours of research. If what I am posting is wrong please correct me.
The 2 best things about 6.0" rods are more rotating mass so more torque. The other is that a 6.0" rod will have a smaller angle of deflection on the piston to the wall. The 6.0" rod being longer does not put as much lateral (sideways) force on the piston into the cylinder wall. See the picture below. Nothing in the picture is to scale just a quick drawing I made to show what I am saying. This is over-exaggerated to show the difference. The red rod is the 6.0" rod and the blue rod is the 5.7" rod. If you picture the crankshaft rotating clockwise you will see how shorter rod puts more force shoving the piston into the wall than the longer rod.
(http://i775.photobucket.com/albums/yy34/bmx0964/Tech/RodSize.jpg) (http://i775.photobucket.com/albums/yy34/bmx0964/Tech/RodSize.jpg)
The plus sides to 5.7" rods is the already stated wrist pin locations (keeping the wrist pin lower and out of the piston rings). The other is less rotating mass so they spin up the RPM's faster and easier.
It all depends on what you want to do.
Gotta watch out for clearance issues with the crank/rod/piston skirt assembly when ya get to changin these things around. They dont always tell everything in the forums. Sometimes ya gotta do a little grindin in there 8)