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Main caps and 2 steps
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DRR Sportsman
Picture of Ron Gusack
posted
I was thinking about trying a few laps with a delay box for the first time but I'm having second thoughts after reading a Facebook thread about main cap breakage. The thread makes it sound as though breaking caps is fairly common when running a 2 step. I'd like to hear first hand knowledge of this being an issue that you or a buddy of yours has experienced. I'm running a 2 bolt main 433 BBC that runs low 6 teens in good air. I'd be using a 4 wheel line lock instead of a trans break and launch rpm would probably be 25-2800.

If you've never heard of this problem it would be helpful to know too. Thanks for your insight.
 
Posts: 459 | Location: Maryland | Registered: January 23, 2007Reply With QuoteReport This Post
DRR Sportsman
Picture of NEMO963
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I ran a 2-bolt 476 for a lot of years (like 6-8) running low 8s in a SC dragster using a two step. That was before SLE and cross over delay boxes so that was on the 2-step for a while every pass. Never broke a main cap for what its worth.


2015 M&M T/D
Nemo
Duty-Pride-Tradition
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Posts: 313 | Location: Firehouse 10 Wichita Ks | Registered: February 15, 2005Reply With QuoteReport This Post
DRR S/Pro
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All T-brake cars leave off the two step. Not saying I never heard of a busted cap but it's not common. And who's to say it broke because of the two step!

I will add this also, if you set it up right it's only on the two step for a short time but I have seen some drivers jump in first and slam that thing wide open before the other racer is staged! Not the smartest thing to do IMO.
 
Posts: 2161 | Location: Tewksbury, MA,USA | Registered: November 03, 2000Reply With QuoteReport This Post
DRR Trophy
Picture of ytoddmalibu
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>030 over 454 two bolt main bbc over 800 passes with annual tear downs checking bearings caps and everything else never an issue. 540 and 565 bbc hundreds of passes each never and issue. The only racer I've heard of breaking caps was a stock block 400 sbc with 600 or more passes and he never knew that the caps were broken until he tore it down for regular maintenance. I would not worry in the least about a bbc and two step.

Todd P


3/28/2014 RIP Juli Pasch the love of my life for ever
 
Posts: 29 | Location: MidMichMotorplex | Registered: December 13, 2007Reply With QuoteReport This Post
DRR S/Pro
Picture of Eman
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Have you ever played the drums? That's the best way to envision what running 2 linelocks is like, I've done it and yes I played drums. If you're the slower car and 2nd to stage you have to get in and get set quick and pump the brakes. If you're the faster car it's not as bad. As far as the 2 step goes I'd rather not think about it with my 2 bolt 355 and cast crank!
 
Posts: 1488 | Location: E TN | Registered: February 13, 2009Reply With QuoteReport This Post
DRR Sportsman
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I have fun a 2bolt 400sbc with stock main caps for 10/15 years never broke a cap. I am also one who will mat the gas when 4 stage lights are lit never a problem. I know most people cringe at my way of running the car on the line but it works for me. Detonation and pre ignition will break caps as will a bent or twisted crank. Another but less likely way is to flood the engine with fuel or water.
 
Posts: 508 | Location: Going to or returning from the chipmine. | Registered: July 01, 2011Reply With QuoteReport This Post
DRR Pro
Picture of Mike Beck
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quote:
Originally posted by ytoddmalibu:
>030 over 454 two bolt main bbc over 800 passes with annual tear downs checking bearings caps and everything else never an issue. 540 and 565 bbc hundreds of passes each never and issue. The only racer I've heard of breaking caps was a stock block 400 sbc with 600 or more passes and he never knew that the caps were broken until he tore it down for regular maintenance. I would not worry in the least about a bbc and two step.

Todd P


I had that happen once. Engine was running perfect, had the typical 400 or so passes on it so time to freshen. Couldn't believe it when I pulled a main cap off in two pieces! And the bearings were still perfect.

Never saw a 2-step with that combo, was a sub 7000 rpm engine at that time. Bought some nice billet caps (only for the center three) and ran that thing for years afterwards before buying a good block.
 
Posts: 1444 | Location: South River, NJ | Registered: June 19, 2007Reply With QuoteReport This Post



DRR Top Comp
Picture of wideopen231
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Have heard of more than one breaking main caps,but they where all blown alky setup with big boost numbers and large 18 to 21 gpm pumps. Can not say I have ever heard of NA motor breaking main cap because of 2 step. As most here know I am far from fan of 2 step in lot os situation but on NA and with carb even I can not say I see a problem.




America home of free. Brought to you by 2nd amendment.
 
Posts: 4239 | Location: Greensboro NC | Registered: May 24, 2011Reply With QuoteReport This Post
DRR Trophy
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I would be more worried about a burnout limiter hurting the valve train than a two step hurting a main cap.
 
Posts: 36 | Location: Bradenton | Registered: August 21, 2010Reply With QuoteReport This Post
DRR Sportsman
Picture of Ron Gusack
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Thanks for all the responses.
 
Posts: 459 | Location: Maryland | Registered: January 23, 2007Reply With QuoteReport This Post
DRR Sportsman
Picture of Bad News
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quote:
Originally posted by RyanNorton1:
I would be more worried about a burnout limiter hurting the valve train than a two step hurting a main cap.


yup, 3 step. guys stay on that at 5-6 k rpm. No good. Learn how to do a burnout with your foot.
 
Posts: 868 | Location: ft laud | Registered: September 02, 2004Reply With QuoteReport This Post
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