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Re: main clearances and end play????
[Re: Bob_Coomer]
#816896
09/30/10 02:15 PM
09/30/10 02:15 PM
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Joined: Apr 2009
Posts: 190
Communist New York State, Comi...
We The People
OP
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OP
member
Joined: Apr 2009
Posts: 190
Communist New York State, Comi...
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Thanks Bob, I checked it with mikes and a dial bore gauge. The crank was extremely close on all the mains, I will check the roundness tomorrow. Heres a question for you... if I'm looking for .001" more clearance on three mains. wouldnt it be simpler and more efficient time wise to just get 3 x bearing with .001 more clearance? How far off could the main bore be to clamp .001 too tight? I deffinately agree that the mains and rods need to be perfect, and I am attemting to get them there. Thanks 
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Re: main clearances and end play????
[Re: We The People]
#816897
09/30/10 02:39 PM
09/30/10 02:39 PM
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Joined: Nov 2003
Posts: 6,293
Rock Springs
Bob_Coomer
master
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master
Joined: Nov 2003
Posts: 6,293
Rock Springs
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Quote:
Thanks Bob, I checked it with mikes and a dial bore gauge. The crank was extremely close on all the mains, I will check the roundness tomorrow.
Heres a question for you... if I'm looking for .001" more clearance on three mains. wouldnt it be simpler and more efficient time wise to just get 3 x bearing with .001 more clearance? How far off could the main bore be to clamp .001 too tight?
I deffinately agree that the mains and rods need to be perfect, and I am attemting to get them there.
Thanks
Good question, the + bearings might work, but in my case, and probably yours the whole main bore wasnt consistent. Im not going to say it wont work, but if the bore is egg shaped its just not a good fix. If the bore is egg shaped, you add the over sized bearings while it might give you some extra clearance, when you torque the cap down that saddle is now egg shaped also.
Talk to your machinist, and ask what it would cost to fix it properly. Heck a set of main bearings is $100 now. If I could have the block lined honed for a hair more that would be better. Talk to him get his take on what should be done.
[color:"red"]65 Hemi Belvedere coming soon [/color]
[color:"#00FF00"]557" Indy engine 1.07 60ft 144mph in the 8th 2100 lbs package [/color]
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Re: main clearances and end play????
[Re: We The People]
#816900
10/01/10 12:10 PM
10/01/10 12:10 PM
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Joined: Jan 2003
Posts: 16,925
NC
440Jim
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,925
NC
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Quote:
I checked the main bores today, and found they were .0025" fatter at the parting line. I only check#1... cause why bother continuing?
Good start. Was that just the cap and block or was that with the bearing in it? All bearings will be looser at the parting line.
What was the actual cap and block bore dimension?
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Re: main clearances and end play????
[Re: We The People]
#816902
10/01/10 01:30 PM
10/01/10 01:30 PM
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Joined: Aug 2003
Posts: 43,161
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,161
Bend,OR USA
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Quote:
just the empty bores. I dont have an inside mike, so I set the outside mike to the spec 2.9425", and zeroed the dialbore gauge. this would show me any out of round condition. and it did.
the vertical measurement was a half thou. big 2.9430" which is right at the big side of the range posted above. but like I said it was just showing the diff from the zeroing mike so that may not be the actual size.
I also double checked with a telescoping gauge, from vertical to parting line...it too showed the diff in the 90*.
Looks like I will be dragging it to Syracuse, to see Todd, and get some machining..
Good find
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: main clearances and end play????
[Re: Performance Only]
#816905
10/01/10 08:43 PM
10/01/10 08:43 PM
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Joined: Jul 2010
Posts: 2,091
Delray beach, Florida
Performance Only
top fuel
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top fuel
Joined: Jul 2010
Posts: 2,091
Delray beach, Florida
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Quote:
BOB COOMER wins the why are my clearances messed up contest!!!!!!!!! 
I checked the main bores today, and found they were .0025" fatter at the parting line. I only check#1... cause why bother continuing?
It didnt occur to me to to start there, cause I had the block line bored for the caps before...or so I thought. remember what I posted about no good shops around here...  
just a little information for you. if the bores at the parting line are .0025 big as you describe, you only have three choices.
1, either bore the blocks mating surface to close that gap, (which would take a lot of work) cut the caps and align bore it again,
2, cut the caps and bore/ hone for proper vertical sizing and don't worry about the out of round.
3, toss that block and start with a better one.
align boring a block does not make the parting line wide, or bigger. align honing almost always will. boring a block doesn't always look as pretty because it'll leave a shadow where it doesn't cut. a hone will hit the wide area and make them even wider.
from what i've seen, most factory blocks are already wide at the parting line from the factory, but typically only .0002-.0005, not .0025
take it to Todd and let him decide the best course of action.
Last edited by Performance Only; 10/01/10 08:47 PM.
machine shop owner and engine builder
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