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#1 |
Senior Member
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Location: Northern Nevada
Posts: 7,224
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Could use some help for those who know OEM Cranks & Dampers on BBC
71 402, replacement parts. The crank wasn't changed.
I'm mostly sure this harmonic balance is a direct replacement. It's bottomed out. Seems the front surface on both should be flush, because it takes a 2" washer. Why wouldn't it be flush? No problem pulling the damper to double check it's a direct replacement, but can a new seal take it? The bolts on the timing chain cover were loose when I lined up the damper, so the alignment is dead-on and wouldn't change. Wish I had checked the original. Appreciate any input, thanks.
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Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assembly kit for restoring the (a) truck from the ground up. My build thread, and more on the assembly kit https://67-72chevytrucks.com/vboard/...d.php?t=730025 |
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#2 |
Registered User
Join Date: Jan 2017
Location: Larkspur, Colorado
Posts: 916
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Re: Could use some help for those who know OEM Cranks & Dampers on BBC
I've never seen a balancer flange that was flush with the crank snout, original or aftermarket. Rarely is that difference consistent either. If the differences were excessive I would sometimes machine the balancer flat washer to correct an excessive difference. Another thing I always checked once the balancer and heads were mocked up is to mock install the water pump, alternator and pulleys and check belt alinement with that new balancer.
Steve weim55 Colorado Last edited by weim55; 09-24-2018 at 02:16 PM. |
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#3 | |
Senior Member
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Location: Northern Nevada
Posts: 7,224
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Re: Could use some help for those who know OEM Cranks & Dampers on BBC
Quote:
I couldn't leave well enough alone, so I backed the damper out a pinch and reset with same results. Was tempting to install the old one just to see ![]() On a side, I don't know if this is a bad idea, I wouldn't think so. The threads in the snout could have looked better, so I cleaned the front end with a tap. Smooth as silk, the bolt screws in by hand and with good contact. The ARP bolt suggests using their high pressure grease only, no lock-tite. Some links: https://www.camaros.net/forums/18-en...-question.html Guy says a 350 balancer extends past the snout, post 13. He's a good source of info. Course mine is a BBC, but from what I'm reading this and elsewhere, yeah, they don't line up. May imply there's supposed to be a gap between the crank snout and washer across many applications. https://www.jalopyjournal.com/forum/...seated.980215/
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Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assembly kit for restoring the (a) truck from the ground up. My build thread, and more on the assembly kit https://67-72chevytrucks.com/vboard/...d.php?t=730025 Last edited by 71CHEVYSHORTBED402; 09-24-2018 at 03:19 PM. Reason: Add links |
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#4 |
Registered User
Join Date: Dec 1999
Location: Austin, TX, USA
Posts: 7,717
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Re: Could use some help for those who know OEM Cranks & Dampers on BBC
IMO, the crank should always be below the balancer. The washer is so thick because it is clamping the balancer. If the crank stuck out further, the washer wouldn't clamp the balance but would tighten on the crank leaving the balancer to move out whatever the extra distance might be.
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44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax |
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#5 | |
Still plays with trucks
Join Date: Jul 2009
Location: Spokane, WA
Posts: 3,556
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Re: Could use some help for those who know OEM Cranks & Dampers on BBC
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miSSed opportunity - ground up creation of an AWD 1994 454 SS that never was http://67-72chevytrucks.com/vboard/s...d.php?t=795577 69 C10 shortbed stepside 400 small block - built like what a super sport truck could have been 69 K20 lwb TBI 350 4L60E NP208 14-bolt Dana-44 w/disc 68 Camaro SS / RS 500hp 439 inch roller cam big block 4L80E 79 Malibu TPI 350 4L60 w/ Z28 steering & sway bars |
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#6 | |
Registered User
Join Date: Jan 2017
Location: Larkspur, Colorado
Posts: 916
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Re: Could use some help for those who know OEM Cranks & Dampers on BBC
Quote:
Steve weim55 Colorado |
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#7 |
Registered User
Join Date: Jan 2017
Location: Larkspur, Colorado
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Re: Could use some help for those who know OEM Cranks & Dampers on BBC
[QUOTE=71CHEVYSHORTBED402;8350787]Good to know, thank you. In your mind am I alright to go with what I got unaltered? The washer is fat and not going anywhere, so it's not going to contact the crank snout. Course I'll check the alignment when the pulleys are slapped on.
From the picture that you show with the new balancer I would say yes you were good to go. Plus you answered my other question that you're using a proper ARP balancer bolt and washer. What is actually more important for proper balancer retention on the crank is the interference fit between the balancer and the crank snout. A problem that people will run into are used balancers and cranks that I've had the balancer removed multiple times and the interference fit is now too loose and or the crankshaft or balancer keyway is not tight fit. Now you are trying to rely on the retainer bolt and washer to hold the balancer past the point it was designed for. Steve weim55 Colorado |
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#8 |
Senior Member
![]() Join Date: Feb 2009
Location: Northern Nevada
Posts: 7,224
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Re: Could use some help for those who know OEM Cranks & Dampers on BBC
Thanks a bunch, I think it's good to go. I sent a note to Summit. See if they chime in, but I won't hold my breath.
I did a mock-up of the crank & cam pulleys as suggested. Looks real good. Ruler says it's right too, or the difference is so small I can't see it. Should have mentioned, that's without gaskets. Torquing it down tomorrow. Currently juggling the rebuild with landscaping a new house. Too old for this, JK. Landscape is a passion, especially rock work. Go figure, this one is free, my ex-wife's place. Doing it for the dogs ![]() On another note, sure glad I don't have an HOA, screw those guys "we'd like the front yard done in a few weeks." Kiss my what? I'll finish the back first thanks. On Friday a 1000 Sq. Ft. of 3x8" river rock is going to be dumped on "their" postage stamp of a front yard. Hope they like it.
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Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assembly kit for restoring the (a) truck from the ground up. My build thread, and more on the assembly kit https://67-72chevytrucks.com/vboard/...d.php?t=730025 Last edited by 71CHEVYSHORTBED402; 09-24-2018 at 11:14 PM. |
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