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Discussion Starter · #1 ·
Hi everybody, Long time reader, great forum!

Do you think this short will be reliable in a 1/4 mile drag, NA application.

-SBC 420" 4.155x 3.875 9.025" Dart Block
-3.875 Callies Magnum with 350 main & 2.0" small journal big end. Don't know the weight but it is a cheaper one.
-Carrillo h beam 6" rod, 7/16 carr bolt, 682 gm (487 gm BE, 195 gm PE)
-500 gm piston, 120 gm pin.
- ATI balancer

Heads have come in bigger than i thought and this might make peak power at about 8K, maybe needing 8.5K shifts. Will this be reliable or is it just asking for trouble?

If it won't live, What maximum shift RPM do you think it will be reliable to?

Thanks
 

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I don't see any problem with 8500 rpm. The short block will do it.

Don't worry about the short block, concentrate on your valvetrain.
 

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I don't see any problem with 8500 rpm. The short block will do it.

Don't worry about the short block, concentrate on your valvetrain.
With proper clearances and assembly no issues going a little higher than that. As Chris said, shaft rockers set up correctly, quality springs like PAC or PSI, and LARGE pushrods. I had excellent service and quality from Manton, I am sure Smith Brothers or Trend would be fine. Did I highlight LARGE!!! Use as big as you can fit. Valvetrain will be your friend or foe. Make sure you get a cam that is easy on valvetrain as well.
 

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With proper clearances and assembly no issues going a little higher than that. As Chris said, shaft rockers set up correctly, quality springs like PAC or PSI, and LARGE pushrods. I had excellent service and quality from Manton, I am sure Smith Brothers or Trend would be fine. Did I highlight LARGE!!! Use as big as you can fit. Valvetrain will be your friend or foe. Make sure you get a cam that is easy on valvetrain as well.


Yep, every bit of it.

Also, don't forget titanium retainers and light-weight valves if your combo allows for them. Anything to help keep the valve-side weight down will be a plus for an 8500 plus screamer. Shaft rocker arms - without question.
 

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Hollow stem stainless valves I feel are more reliable then Titanium valves.
 

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Discussion Starter · #6 ·
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Thanks for the info. This will turn about1500rpm more than anyting i have had to do with so it's all new territory.

I asked because i had someone tell me that the heavy rod will hurt that crank with its 350 main and small journat BE. Also the piston is about 20gm heavier than it needs to be.

Didn't want to go to an Alum rod because of the maintenance needed.

Valvetrain will be good stuff. Have new Del west 5/16 Ti intake valves and 11/32 Ti ex. Need to get the rest of the valvetrain.
 

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Hi everybody, Long time reader, great forum!

Do you think this short will be reliable in a 1/4 mile drag, NA application.

-SBC 420" 4.155x 3.875 9.025" Dart Block
-3.875 Callies Magnum with 350 main & 2.0" small journal big end. Don't know the weight but it is a cheaper one.
-Carrillo h beam 6" rod, 7/16 carr bolt, 682 gm (487 gm BE, 195 gm PE)
-500 gm piston, 120 gm pin.
- ATI balancer

Heads have come in bigger than i thought and this might make peak power at about 8K, maybe needing 8.5K shifts. Will this be reliable or is it just asking for trouble?

If it won't live, What maximum shift RPM do you think it will be reliable to?

Thanks
What heads? 15/18 deg. with >270cc intake port?
 

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Discussion Starter · #9 ·
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Would 550 gm aluminium rods produce a quicker ET than 680 gm steel rods? Might be worth it if i can run .05 or so quicker over the quarter. Or will the weight reduction do nothing?

Whats the life of aluminium rods these days? 3.875" stroke shifted at 8500 rpm with 620 gm piston/pin.
 

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Discussion Starter · #10 ·
Would 550 gm aluminium rods produce a quicker ET than 680 gm steel rods? Might be worth it if i can run .05 or so quicker over the quarter. Or will the weight reduction do nothing?

Whats the life of aluminium rods these days? 3.875" stroke shifted at 8500 rpm with 620 gm piston/pin.
I have been told the alum rod could come in at about 450gm.
 
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