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Does this sound like a bulletproof bottom end??

B

ben427

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Got the frame and cage pretty well done for the race truck, now im geting around to the engine. I've built plenty of performance engines, but nothing to this caliber. I'm aiming for 675-700 hp, from a small block. Gotta keep it light. Gonna use a virgin 400 block with Milodon splayed main caps, Eagle 4340 4.00" crank, Eagle 6.0" H- Beam rods, and a set of JE forged pistons. It will be balanced (obviously) Does this sound like it should stand up to you?

If your interested, the top end will be a Brodix 18* Al head kit with a single plane and an 850 Demon. Cam is yet to be decided other than its gonna be a hydraulic roller with an AFR rev kit and shaft mounted roller rockers.
 
If you really want 'bulletproof' look into a Callies or Crower crank. I would go with Crower rods too....

Why waste some of that camshaft with a hydraulic roller? If it is going too be a race motor, put a solid roller into it.
Remember if you run a solid roller you can nooot use aluminum rocker arms. Comp Cams makes a very nice set of Stainless Steel rocker arms.

Weigh out the cost difference between upgrading your block with getting it machined and the splayed caps installed ooor purchasing a Dart or World Products block. When the block allows the crank to flex that is when they start coming apart.
 
the factory block is the weak link

eww hydraulic roller, that is street car stuff
 
you cannot get good heads for a Cad motor
to run big cubes and big power in a production based motor you need a Ford 385 series. 557" with a stock block and a 4.5" stroke that actually fits in the block
 
Yeah i get the picture, solid roller it'll be, I'll have to start looking for a block i guess.
/forums/images/graemlins/thumb.gif
 
i see no reason to go with such an expensive crank, when GM offered a very good one straight from the factory. cross drill the rod journals, this will take quite a bit of mass off the crank, then allow you to turn some of the counterweights off the crank. next take the crank and deburr all the sharp edges, maybe even massage the counterweights a little, like knife edging them, so that they cut through the air in the crankcase better. balance it all out, and call it good. might even be able to get away with a standard neutral balanced flywheel/flexplate then too.
 
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Yeah but i gotta run an SBC to stay in the class.

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Mud bogger?
 
Is there a displacement limitation, or is the only limitation that it has to be a SBC block?

I keep seeing ads for the World Products SMALL block 454s.... seems like starting with an extra 100 cubes would make it easier to get to the HP/TQ numbers you want??? /forums/images/graemlins/thinking.gif
 
Well Last time i checked, Gm doesnt offer a 4" stroke crank. So I will need to buy aftermarket, and if im gonna be pushin 675 + horsepower, its gonna need to be good.

Nevrenuf:
Not a mud bogger, but a pro stock sand drag-slalom racer like the ones seen here ( www.fullbore4x4.com ) I really wann keep outta the modifieds for now, may migrate there later.

Greg72:
Yeah i saw those and was contemplating doing one similar, but i dont like the way they in particular do it. they have a 4.25 bore smallblock. And IMHO, that is just too much for a smallblock to handle. I was thinking about getting a Dart Iron eagle tall deck block with a raised cam location and spread pan rails so i could run a 4.155 bore and 4.125 stroke, and get a 454 smallblock that way. But i think was 434 will be plenty for me, 4.125 stroke is getting way out there, and im not quite comfortable with it yet.
 
[ QUOTE ]
you cannot get good heads for a Cad motor
to run big cubes and big power in a production based motor you need a Ford 385 series. 557" with a stock block and a 4.5" stroke that actually fits in the block

[/ QUOTE ]

the engine is just 385" then you can make it 557"? yikes thats some serious stuff! /forums/images/graemlins/bow.gif
 
To run naturally aspirated or light nitrous, Eagle works well. Good rep. Blown, /forums/images/graemlins/screwy.gif go with the big dogs....(Callie, etc)
 
If you want to wind it up high for HP, then the bigger bore shorter stroke is the way to go. It helps with unshrouding the valves so they can breathe deeper.

The shorter stroke also helps with longevity as there is less side load on the cylinder walls. Shorter stroke and long rods = /forums/images/graemlins/waytogo.gif /forums/images/graemlins/woot.gif /forums/images/graemlins/waytogo.gif
 
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