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Connection Rod - 401 Stroker |
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SKeown 
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Joined: Jul/30/2009 Location: Texas Status: Offline Points: 3085 |
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 Posted: Nov/09/2014 at 11:05am |
That's not too bad for a 2" journal, but being you're dealing with Chevy bearings, there are .001 oversize bearings available. What compression were you shooting for? BTW, you'll have a better rod/stroke ratio with those longer rods, that's a good thing and will help stabilize the short pistons. I can't overemphasize the need to get the rods centered on the pins. Otherwise the pistons will cant in the wrong direction at the top of the compression stroke, that will cost you power and create unnecessary stress and wear. SKeown
Edited by SKeown - Nov/09/2014 at 11:23am |
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turvlo
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Joined: May/02/2010 Location: Norway Status: Offline Points: 28 |
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Posted: Nov/09/2014 at 12:15pm |
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Compression ratio is estimated to 10.5:1
Indy heads, Torker intake, Crane Cams Solid Roller http://s1355.photobucket.com/user/turvlo/media/camcard_zps1e4bb2c6.jpg. -  |
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gremlinsteve
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Joined: Dec/16/2008 Location: houston Status: Offline Points: 884 |
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Posted: Nov/09/2014 at 7:38pm |
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Good looking cam.
Should be a runner when sorted out. |
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SKeown
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Posted: Nov/09/2014 at 9:27pm |
The reason I ask about expected CR is because of the compression height and the -17.9cc piston volume. With the 4.195 bore x 3.900 stroke and assuming the block has been decked .010 you'll have 11.229 dynamic CR with Indy 61cc chambers and .040 gaskets. That's about half a point more than mine and I run more duration. Mine was designed to run on 93 pump gas, maybe you have better gas available? SKeown
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Boris Badanov
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Joined: Dec/14/2013 Location: NH USA Status: Offline Points: 4210 |
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Posted: Nov/10/2014 at 11:35am |
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Ok, I just inspected a 1974 401 rod, #5 to be exact against a Carrillo 2" journal SBC rod.
The 401 rod is offset away from cl by .075, this is away from the rod contact surfaces.
This gives, with clearances figured in a perfect 1" stagger. The beam of the rod is offset
but to the builder this means nothing.
Chebby Carillo rods are offset .05 twords the cl, the oppisite of AMC.
If my math is correct flipping the rods will give you a .025 "error" and should mean little or nothing.
I am sure some of you already know this.
Chamfering of the rod seems unadvoidable.
I did a little rounding of numbers by a few ten thousandths or so.
But the picture is clear, they gotta be flipped.
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Gremlin Dreams
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Boris Badanov
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Posted: Nov/10/2014 at 5:39pm |
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Photos of the sample rods and a CP Carrillo piston for good measure. 542 grams for the rod and 475 for the pistons. Not including rings, bearings and gungeon pin. The piston forging is originaly for a 421 Pontiac.  
Edited by Boris Badanov - Nov/10/2014 at 5:59pm |
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Gremlin Dreams
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SKeown
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Posted: Nov/11/2014 at 12:11am |
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Those are good looking parts. If the Carrillo I-beams are available for a 2" journal LS engine as they are in their H-beam design? Then you only need to remove .010 from the chamfered side to get them reasonably centered. I did that and by using off shelf bearings for large radii cranks mine cleared a 3/32 radii. Depending on the year of the OEM 401 rods, some are offset on the piston pin end too. I'm considering having Molnar design and make a 5 set run of 6" x 2" journal with the correct AMC offset. For the guys doing the 3.750 strokers, they can simply have them ground to a 2.100 journal and widen the journals by .020. That way off shelf LS rods can be used as is. If I had it to do over, that's what I would do. That creates 415 cid with a +.030 bore and a compression height of 1.224 in a 9.200 deck height (- .008 surface cleanup) a 1.62 Rod/stroke ratio using the 6.100 length rod and a stronger crank. SKeown
Edited by SKeown - Nov/11/2014 at 12:26am |
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Boris Badanov
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Posted: Nov/11/2014 at 5:36am |
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I am opting for the flip and chip as it will put the beam and small end dead nuts (within .025)
of theoritical CL of the piston. On a lathe it is pretty easy to cut a new chamfer. I got these on the cheap since they were 6.2" length intended for a long rod 302 or 283 Chebby. They have been on the shelf for many years... But the pistons were not cheap and the ring package is a bit tight. On the 401 rod the beam is centered on the big end. The thrust side is paralell and the anti thrust side is +.075"
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Gremlin Dreams
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crisd
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Joined: Jan/13/2020 Location: 28301 Status: Offline Points: 1 |
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Posted: Jan/13/2020 at 8:40am |
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In a search for stroker info this thread came up. If you guys are still on this website could you give us an update with how your strokers have performed over the years, and any suggestions on anything you would do different that I can incorporate in my build please?
Thanks in advance - Chris
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turvlo wrote: