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main clearances and end play???? ..AND THE WINNER IS!!

Posted By: We The People

main clearances and end play???? ..AND THE WINNER IS!! - 09/29/10 12:02 AM

Just finished mocking up, checking clearances on my new eagle 4.15 crank that came in my Mancini 493 kit. after switching shells around from saddle to saddle this is the best I could come up with for clearances. #1 .0025 #2 .0025 #3 .0025 #4 .0035 #5 .0035 the end play came out at .004
What do you all think? should I get 3 half shells with .001 extra clearance or will .0025 be all right? is that end play right for that radiused crank?
thanks guys
Posted By: Monte_Smith

Re: main clearances and end play???? - 09/29/10 12:48 AM

If this is a race motor, the front 3 are too tight. That end play is also tight.

Is the crank off, or are the main housing bores tight?

Monte
Posted By: dusturbd340W5

Re: main clearances and end play???? - 09/29/10 03:23 AM

I know some people like more clearence on a race motor but my race only sb 416 has been very happy at .0025 on all 5 mains and the end play is at .006
Posted By: We The People

Re: main clearances and end play???? - 09/29/10 04:34 AM

Yes it is a race engine... but not extreme, stock block studded top and bottom, aluminum caps s/r heads. most likely about 650 hp.... no dynos around here.

I'd preffer .003 on the mains, thats why I posted. I can try to seat the thrust bearing a bit harder and see if the clearance grows a bit. at first it was about 0.
theres alot of opinion on main clearance, I'd like to hear some on this.
Posted By: We The People

Re: main clearances and end play???? - 09/29/10 04:45 AM

the Mains measured consistantly @ 2.75".
What is the main bore supposed to be? I havent run in to that spec before. This is the first engine I've Gone this deep into as far as clearancing and checking everything myself...there isnt a shop within 2 hours that is capable, and willing to spec stuff like this out so metticullusly..... sad I know...but I am better of doing it myself and investigating with all of you.
thanks
Posted By: 70Cuda383

Re: main clearances and end play???? - 09/29/10 07:16 AM

with tighter clearances, couldn't you just run a lighter weight/synthetic oil and save HP by not turning as much on the oil pump?
Posted By: JohnRR

Re: main clearances and end play???? - 09/29/10 02:16 PM

Quote:

Yes it is a race engine... but not extreme, stock block studded top and bottom, aluminum caps s/r heads. most likely about 650 hp.... no dynos around here.





What size are the holes in your main caps , mainly the #3 cap? With studs and stock caps you have to ream the holes to the next size up , not sure what's required with alum. caps .
Posted By: We The People

Re: main clearances and end play???? - 09/29/10 02:33 PM

The main bores were line honed for the aluminum caps/studs. and the engine was run with a factory .020 under steel crank, that crank had no main bearing issues....all though I dont know what the main clearances were in that setup.
thats why I believe the issue is with the shells , I pretty sure the clevite 77 series I am using can be ordered + or - .001" and that would set it up with .0035 all around. that seems like the easiest solution. but I'm still looking for ideas.
Posted By: CompWedgeEngines

Re: main clearances and end play???? - 09/29/10 02:55 PM

sent you PM.
Posted By: We The People

Re: main clearances and end play???? - 09/29/10 03:05 PM

thanks Todd
Posted By: Performance Only

Re: main clearances and end play???? - 09/29/10 03:25 PM

Quote:

there isnt a shop within 2 hours that is capable, and willing to spec stuff like this out so metticullusly..... sad I know...but I am better of doing it myself and investigating with all of you.
thanks



just curious, where in N.Y. are you ???
Posted By: We The People

Re: main clearances and end play???? - 09/29/10 03:31 PM

way up north on the St.Lawrence river. I can see Canada from my roof. Ottawa is only 50 mins away, I'm sure theres good shops there but crossing the border is a pain now.
Posted By: JohnRR

Re: main clearances and end play???? - 09/29/10 03:38 PM

Quote:

The main bores were line honed for the aluminum caps/studs. and the engine was run with a factory .020 under steel crank, that crank had no main bearing issues....all though I dont know what the main clearances were in that setup.
thats why I believe the issue is with the shells , I pretty sure the clevite 77 series I am using can be ordered + or - .001" and that would set it up with .0035 all around. that seems like the easiest solution. but I'm still looking for ideas.



Not asking about the main bore sizes but the holes that the studs go thru , if they are too tight on the studs you can't set the thrust properly.
Posted By: We The People

Re: main clearances and end play???? - 09/29/10 04:03 PM

I've never noticed them being snug, they slide right down, then I just tap them down in the block with a small plastic hammer. they are Muscle Motors caps made in '2000.
Posted By: JohnRR

Re: main clearances and end play???? - 09/29/10 04:31 PM

Quote:

I've never noticed them being snug, they slide right down, then I just tap them down in the block with a small plastic hammer. they are Muscle Motors caps made in '2000.



They won't be snug , but they might limit front to back motion if too tight . But MM caps should have the larger holes .
Posted By: CDoering

Re: main clearances and end play???? - 09/30/10 04:06 AM

With the aluminum main caps I would believe there is going to be more clearance when the engine gets up to operating temp. I asked a question about main bearing clearances with aluminum caps a while back on another thread and didn't get an answer.

I had aluminum mains put on a 400 block earlier this year. I measured the line bore at 70 degree room temp then stuck the block in a parts washer at 170 degrees and then measured the main clearance again and it opened up .002. So if I had .0025 clearance cold I would now be at .0045 with the block at operating temp.

I didn't ever try measuring the block with iron caps to see the growth that the iron exhibits. Just thought I would post what I found.

My experiences with aluminum BBC marine motors was that we ran tight clearance of about .0015 cold because the aluminum block would grow so much. Different application though.
Posted By: Rapid340

Re: main clearances and end play???? - 09/30/10 12:40 PM

Quote:

I measured the line bore at 70 degree room temp then stuck the block in a parts washer at 170 degrees and then measured the main clearance again and it opened up .002. So if I had .0025 clearance cold I would now be at .0045 with the block at operating temp.





Dont forget your crank at 170 degrees would be larger also.
Posted By: 440Jim

Re: main clearances and end play???? - 09/30/10 05:10 PM

Quote:

What is the main bore supposed to be?

From Moparts.com, a member posted the main bearing cap dimensions:

B - 2.8175 - 2.8180
RB - 2.9425 - 2.9430
Posted By: We The People

Re: main clearances and end play???? - 09/30/10 05:29 PM

Thanks for the info guys. I'm going to recheck them tomorrow, along with the runout, and main bore.
when I did them the other day, my father opened the big over head door, and there was a big difference in the cool insulated garage air and the weird warm storm front that was rolling through. the block started to collect condensation during the process. not sure if it affected it or not, cause we kept rechecking and getting the same numbers over a couple hours. by the end the block had warmed a bit and was staying dry.
today I seated the thrust bearing a bit harder and I got .005"
Anyway I decided to go through a good recheck before making a decision. better to spend my free time and know for sure than waste cash blindly.
Posted By: Bob_Coomer

Re: main clearances and end play???? - 09/30/10 05:31 PM

You need to get it checked, how are you checking it? Its border line now and allows NO room for margin if the crank is out any at all.
I really like to know what each main bore, and crank journal measures though.
Thing is if your already boarder line tight, you cant afford any thing tighter, and I highly doubt the crank is perfect. If its out of round any could be a big problem.
Thats why I measure my main bores with a dial bore gauge, and measure the crank. I can then hone the block to correct and order the correct bearings is the last thing.
This doesnt cost much more money either.
Its exactly what I done with the Hemi. The #3 main bore was .001 tight, and #5 half a thou also.
I honed the mains, and ordered the HXN bearings etc.
Out of all the things that really need to be done correctly, the crank, mains, and rod sizing needs to be perfect or real close in my race engines. I set my rods and mains .003-.0035, .003 being minimal, but I know a few engine builder that like them at .0025 also...
.004 thrust is tight too. IMO if you could gain another .001 some how that would be great. .006-.008 is idea IMO.
Posted By: We The People

Re: main clearances and end play???? - 09/30/10 06:15 PM

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
Posted By: Bob_Coomer

Re: main clearances and end play???? - 09/30/10 06:39 PM

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.
Posted By: We The People

Re: main clearances and end play???? - 09/30/10 07:59 PM

thanks again Bob...good answer. gives me a bit more to think about. I may end up driving to syracuse with it yet.
Posted By: We The People

Re: main clearances and end play???? - 10/01/10 04:02 PM

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...
Posted By: 440Jim

Re: main clearances and end play???? - 10/01/10 04:10 PM

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?
Posted By: We The People

Re: main clearances and end play???? - 10/01/10 04:53 PM

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..
Posted By: Cab_Burge

Re: main clearances and end play???? - 10/01/10 05:30 PM

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
Posted By: We The People

Re: main clearances and end play???? - 10/01/10 05:53 PM

Thanks Cab, I finally figured it out...
Posted By: Performance Only

Re: main clearances and end play???? *DELETED* - 10/02/10 12:41 AM

Post deleted by Performance Only
Posted By: Performance Only

Re: main clearances and end play???? - 10/02/10 12:43 AM

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.
Posted By: We The People

Re: main clearances and end play???? - 10/02/10 09:53 PM

I saw King Bearings make Oversized OD main bearings for some Chevys. Are there any floating around for mopars, they would be useful in this situation.
Posted By: Sport440

Re: main clearances and end play???? - 11/23/10 04:44 AM

Just bumping this to the top because I think its some great info for some current posts and for any other review, mike
Posted By: sixpackbee

Re: main clearances and end play???? - 11/23/10 02:13 PM

Quote:

with tighter clearances, couldn't you just run a lighter weight/synthetic oil and save HP by not turning as much on the oil pump?


I run my stocker engines quite tight because I use nothing but zero weight oil. I would not suggest that pratice for a bracket engine but your theory is right.
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