FAQ |
Members List |
Social Groups |
Calendar |
Search |
Today's Posts |
#1
|
|||
|
|||
Can you run a 6.700” rod on an SGI 4.500” crankshaft?
Hey guys just needed to know if anyone is running a 6.7 rod on an Star Galaxy 4.5 stroke crankshaft? I’d like a little more Compression distance on my 490 build but I need to know if I have room for the shorter rod without having to cut down the counter weights?
I just haven’t used the sgi crank before Thank you
__________________
Build it Right Build it Once!!! Just another Engine Builder from the Northwest lol |
#2
|
||||
|
||||
Quote:
GTO George |
#3
|
||||
|
||||
Yes, for sure
|
The Following User Says Thank You to PAUL K For This Useful Post: | ||
#4
|
|||
|
|||
Thanks, I just wasn’t sure on the SGI crankshaft if they were any different
__________________
Build it Right Build it Once!!! Just another Engine Builder from the Northwest lol |
#5
|
|||
|
|||
__________________
Build it Right Build it Once!!! Just another Engine Builder from the Northwest lol |
#6
|
||||
|
||||
Quote:
GTO George |
#7
|
||||
|
||||
More about the counter weights than the block in this case
__________________
Dave Polichena |
#8
|
|||
|
|||
That’s my concern! Thanks
__________________
Build it Right Build it Once!!! Just another Engine Builder from the Northwest lol |
#9
|
|||
|
|||
FYI you can get SGI forged crankshafts for 621$ Shipped through their eBay store, best deal I could find
__________________
Build it Right Build it Once!!! Just another Engine Builder from the Northwest lol |
The Following User Says Thank You to Pontiac Derek For This Useful Post: | ||
#10
|
||||
|
||||
What's different about their counter weights? I have a Scat Forged 4.5" crank with 6.7" rods
|
#11
|
|||
|
|||
That’s what I’m trying to figure out SGI has a note under the Crankshaft saying you got to use a 6.8 inch rod and I don’t like using the 6.8” Rod with the 4 1/2 inch stroke crank because I think the Pistons too short so I want to use the shorter rod and so I figured I’d ask people here if they have any experience with this Crankshaft, I’ve ran shorter rods on the Scott cranks no problem and I believe that’ll be the same here it’s just good to ask before I order parts
__________________
Build it Right Build it Once!!! Just another Engine Builder from the Northwest lol |
#12
|
||||
|
||||
As far as pistons, is there a very big difference between the piston design for 6.7 vs 6.8 rod?
0.100" does not seem like much, but is it the difference between needing oil ring support or not? Or is there more to it? My machine shop was trying to talk me into going 4.5 stroke instead of the 4" I have waiting in the box, and while the extra cubes would be nice I just wasn't sure about it with a stock block build. I am thinking SGI says 6.8 rod just because the crank is 2.2" rod journal, but 6.7 should work also.... |
#13
|
|||
|
|||
Quote:
this is a street deal, unfortunately even at 1.3cd it will still have oil ring support rails but still I believe it’s better to get the pin out of the oil ring as much as possible, jmo
__________________
Build it Right Build it Once!!! Just another Engine Builder from the Northwest lol |
#14
|
||||
|
||||
Even my 4.35 stroke 6.7 rod Ross pistons use an oil ring support. No big deal to me, I wanted to keep more of the piston in the bore at the bottom.
__________________
Illinois Outlaw Gassers 6.27@107 9.97@131 |
The Following User Says Thank You to Bill Eveland For This Useful Post: | ||
#15
|
||||
|
||||
Really? I run a 6.7 rod in my 4.375 stroke motor with no oil ring support needed. Did the match on the combo before ordering the custom pistons from Diamond. The pin is close to the ring land, but no support needed. Maybe I have a hair more deck height than you.
__________________
65 Lemans Street Car - 521, T400, 3.70 9". 10.13 @ 135. 3770 lbs. Drag Week ‘14, ‘15, ‘17 63 Lemans Race Car- 8.81 @ 151, 5.60 @ 123(SOLD) 67 Bonneville ragtop 74 Firebird - 455, e heads, TK0600 in process |
#16
|
||||
|
||||
I got them thru Butler and thats how they came. I didnt ask before I ordered the rotating assembly so thats on me.
__________________
Illinois Outlaw Gassers 6.27@107 9.97@131 |
#17
|
||||
|
||||
I've built 2 motors with 4.5" stroke. Both with 6.7 rods. JE Pistons did not need a ring support. Diamond pistons did.
|
The Following 2 Users Say Thank You to Scott Stoneburg For This Useful Post: | ||
#18
|
||||
|
||||
depends on what its used for and where you want the ring pack --
|
#19
|
|||
|
|||
Im building my 496 with a 6.7 rod & 4.5 stroke crank.
SPEED SAFE, AIR RAM
__________________
"The grass is not greener on the other side, its just fertilized with different $h!t" |
#20
|
|||
|
|||
So after getting the Crankshaft today and doing some rudimentary measuring I think that there’s going to be plenty of room to run a 6.7 rod
piston should clear the counterweights no problem on this SGI crank There seems to be some confusion I’m only talking about the SGI crankshaft in this thread I was not talking about Scat, Bryant, muldex, or any of the other companies those are ones I’m familiar with this one I was not also hence why I asked but now that I have the Crankshaft I have the answer yes you can definitely run a 6.7 inch rod and probably a 6.635-6.66” if needed
__________________
Build it Right Build it Once!!! Just another Engine Builder from the Northwest lol |
Reply |
|
|