Slant Six Forum :: 4340 Billet Crank

someone has made 630 HP at fairly low RPM with only 20 psi

Quote:

someone has made 630 HP at fairly low RPM with only 20 psi

I'm not at all sure I know what to do with 300HP in a 2500# car, let alone 630 HP!

Go radical on the rods using chevy bearings

Quote:

Go radical on the rods using chevy bearings

Is my memory serving me correctly that some of the billet cranks were standard stroke but had Chevy size rod journals?

Me thinks so, but me not sure!

Try to find the billet crank, that will be enough maybe adding steel mains and a girdle kit. If you want to spend money on custom bottom end part order a set of custom long rods and custom pistons... No K1 or Molnar.. Go radical on the rods using chevy bearings (you can offset grind the journals on the crank) maybe a 20mm piston pin and 190mm long rods and a piston matching that.

That is what i did to my slant. You get a killer rod ratio and a very ligthweigth rod-piston assy. Use TotalSeal gapless rings. And thats it, you get a killer bottom end.

Thats my sugestion! Hope it helps!

I read that you want to develop some oil squirt for the pistons and maybe valvetrain? If that is the case I will highly recomebd to run an external oil pump and at that point even consider a dry sump setup to reduce windage at a minimum. A 4bodies oil pump will be just ok for that.

I'm trowing all this because it seems that you want to address everything on this motor, so every little thing that comes to my mind ends up here. Hope it helps!

Be careful if you want to use Chevy bearings because the V8 bearing chamfers are asymmetric and can pinch the side of the journal. Better to use a 4cyl bearing that is not a "shared rod journal" engine like a V8.

Lou

Author:	Dart270 [ Tue Sep 01, 2015 12:53 pm ]
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Cool. Probably Clay City, KY or Bristol, TN would be the closest Slant races to you. Clay City is still to come this year - 9/25-9/26. There has been one near Joplin, MO in April for the last couple of years too - even closer. Welcome, Lou

Author:	Rick Covalt [ Tue Sep 01, 2015 12:53 pm ]
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Quote: someone has made 630 HP at fairly low RPM with only 20 psi I'm not at all sure I know what to do with 300HP in a 2500# car, let alone 630 HP!

Author:	Greg Ondayko [ Tue Sep 01, 2015 1:34 pm ]
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Quote: Quote: someone has made 630 HP at fairly low RPM with only 20 psi I'm not at all sure I know what to do with 300HP in a 2500# car, let alone 630 HP! I would.. Take 500 # out and go faster! Greg

Author:	Old6rodder [ Tue Sep 01, 2015 1:52 pm ]
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For what it may or may not be worth ...... In my light (1400 lbs) car with a medium build, the forged crank held fine, 'til the #3 main web gave it up. Admittedly, it took seven years (and I'm not sure what'd be the best way to address it), but that's how it went.

Author:	Landons65Dart [ Tue Sep 01, 2015 2:59 pm ]
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My car will weigh about 3500 pounds with the Jeffco and Dana 60. Also, I'm going for high boost and a possibility of nitrous, so I'm trying to build up for higher possibilities, not the least possible.

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4340 Billet Crank https://slantsix.org/forum/viewtopic.php?t=57536	Page 3 of 4

Author:	dartsport76 [ Tue Sep 01, 2015 3:04 pm ]
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3500?! Race diet man!

Author:	Polara1974 [ Tue Sep 01, 2015 4:01 pm ]
Post subject:
Try to find the billet crank, that will be enough maybe adding steel mains and a girdle kit. If you want to spend money on custom bottom end part order a set of custom long rods and custom pistons... No K1 or Molnar.. Go radical on the rods using chevy bearings (you can offset grind the journals on the crank) maybe a 20mm piston pin and 190mm long rods and a piston matching that. That is what i did to my slant. You get a killer rod ratio and a very ligthweigth rod-piston assy. Use TotalSeal gapless rings. And thats it, you get a killer bottom end. Thats my sugestion! Hope it helps!

Author:	Polara1974 [ Tue Sep 01, 2015 4:16 pm ]
Post subject:
I read that you want to develop some oil squirt for the pistons and maybe valvetrain? If that is the case I will highly recomebd to run an external oil pump and at that point even consider a dry sump setup to reduce windage at a minimum. A 4bodies oil pump will be just ok for that. I'm trowing all this because it seems that you want to address everything on this motor, so every little thing that comes to my mind ends up here. Hope it helps!

Author:	Rick Covalt [ Tue Sep 01, 2015 6:27 pm ]
Post subject:
Quote: Go radical on the rods using chevy bearings Is my memory serving me correctly that some of the billet cranks were standard stroke but had Chevy size rod journals? Me thinks so, but me not sure!

Author:	Polara1974 [ Tue Sep 01, 2015 7:43 pm ]
Post subject:
Quote: Quote: Go radical on the rods using chevy bearings Is my memory serving me correctly that some of the billet cranks were standard stroke but had Chevy size rod journals? Me thinks so, but me not sure! The good thing about the 2" chevy rod journal is less friction area, more readly available bearings options in different materials than std slant six, you can offset grind the crank to reduce or increase stroke. Also it takes a smaller rod big end when using chevy size bearing, thus less rod weigth. I know... I used th Shevy word to much... But its for a good cause!!! Lol

Author:	Landons65Dart [ Wed Sep 02, 2015 5:28 am ]
Post subject:
Quote: Try to find the billet crank, that will be enough maybe adding steel mains and a girdle kit. If you want to spend money on custom bottom end part order a set of custom long rods and custom pistons... No K1 or Molnar.. Go radical on the rods using chevy bearings (you can offset grind the journals on the crank) maybe a 20mm piston pin and 190mm long rods and a piston matching that. That is what i did to my slant. You get a killer rod ratio and a very ligthweigth rod-piston assy. Use TotalSeal gapless rings. And thats it, you get a killer bottom end. Thats my sugestion! Hope it helps! Well, I already got molar rods. For pistons I went with dished Ross pistons at 0.06 overbore.

Author:	Landons65Dart [ Wed Sep 02, 2015 5:30 am ]
Post subject:
Quote: I read that you want to develop some oil squirt for the pistons and maybe valvetrain? If that is the case I will highly recomebd to run an external oil pump and at that point even consider a dry sump setup to reduce windage at a minimum. A 4bodies oil pump will be just ok for that. I'm trowing all this because it seems that you want to address everything on this motor, so every little thing that comes to my mind ends up here. Hope it helps! Those were exactly my thoughts! I'm glad someone could verify that idea for me. Now I know it's not too radical of an idea. Since I'm blocking off the distributor hole anyway, might as well remove the ugly pump in the process and do a mice external setup! It'll make it easier to change the oil without making a mess with an upside down oil filter...

Author:	Dart270 [ Wed Sep 02, 2015 5:50 am ]
Post subject:
Be careful if you want to use Chevy bearings because the V8 bearing chamfers are asymmetric and can pinch the side of the journal. Better to use a 4cyl bearing that is not a "shared rod journal" engine like a V8. Lou

Author:	Polara1974 [ Wed Sep 02, 2015 6:25 am ]
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Ok on the rods and pistons. Thats is a good setup already and it will hold all together even with a stock forged crank. But think this for the future: if you are going to consider ordering a custom crankshaft dont fall short ordering a custom crank beeing tie to production or aftermarket readly available rods and pistons!!! If you do that you wil bel not taking all the advantages of a custom crank and you should since that is big money already. At that point consider a full custom bottom end!!! Were you chan choose journal size,stroke, rods size and piston size in every way!!! Maybe you can put together the bottom en wity the parts you already have for a start and prepare a custom short block latter. About oil mods great you think that way! Is the best setup you can have! Now how about camshaft and valvetrain? What type of parts are you considering?

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Author:	Polara1974 [ Wed Sep 02, 2015 6:36 am ]
Post subject:
Quote: Be careful if you want to use Chevy bearings because the V8 bearing chamfers are asymmetric and can pinch the side of the journal. Better to use a 4cyl bearing that is not a "shared rod journal" engine like a V8. Lou Here in Argentina we usually use Chevy 250 inline six engine rods bearings thus avoiding this problem.