engine guys, #3 bearing cap won't seat ? **update**

Posted By: gregsdart

Re: engine guys, #3 bearing cap won't seat properly? - 09/07/09 06:03 PM

Thanks much for the idea. How much did you have to open the cap holes?
Will check it out and let you guys know what I found!

Posted By: RonP

Re: engine guys, #3 bearing cap won't seat properly? - 09/07/09 06:12 PM

I didn't have an exact amount. What I did (many times) is put some of that blue paste on the stud. I would seat the cap and then lok for contact spots. I took a small pencil grinder and just removed a little out of the hole. Did that many times until it fit. I probably don't qualify as an engine builder though having only assembled a few. Seemed to work ok for me though.
good luck

Posted By: 1_WILD_RT

Re: engine guys, #3 bearing cap won't seat properly? - 09/07/09 06:16 PM

My buddy had a 17/32 drill bit so thats what I used..

Posted By: CompWedgeEngines

Re: engine guys, #3 bearing cap won't seat properly? - 09/07/09 06:27 PM

Greg,

The best way is to use an adjustable blade reamer. Done many this way. Very common problem. Surprised you didnt have thrust issues with the cap like that. You CAN drill it, especially if you have a good solid Bridgeport or drill press, but I have done both and I prefer the "dial in" ability of the reamer. Technichally the bolts dont do anything but provide the clamping force, and shouldnt even touch the cap, but you dont want to over bore the holes.The cap register provides the right fit. Good luck, hope it works out ok.

Posted By: gregsdart

Re: engine guys, #3 bearing cap won't seat properly? - 09/07/09 07:29 PM

Went out and measured the studs, and cap holes. Studs, .497.
Caps, .530 . Plenty of room in all directions, no binding. I looked at # 1 with the dial bore gauge and came up with results that are similar but not as bad. Also the minimum diameter of the # 1 bearing bore is .0005 looser than #3. I wire brushed the cap to clean off the cap walk gunk but it is still out of tolerance in my mind. Think it is time to have this block line honed. What do you guys think? I don't want to spin a bearing.

Posted By: Cab_Burge

Re: engine guys, #3 bearing cap won't seat properly? - 09/07/09 08:00 PM

Quote:

Went out and measured the studs, and cap holes. Studs, .497.
Caps, .530 . Plenty of room in all directions, no binding. I looked at # 1 with the dial bore gauge and came up with results that are similar but not as bad. Also the minimum diameter of the # 1 bearing bore is .0005 looser than #3. I wire brushed the cap to clean off the cap walk gunk but it is still out of tolerance in my mind. Think it is time to have this block line honed. What do you guys think? I don't want to spin a bearing.

you have plenty of bearing to crank clearences and(if) it has been running okay so far so

it is uo to you, do what you thank is best

Posted By: emarine01

Re: engine guys, #3 bearing cap won't seat properly? - 09/07/09 08:14 PM

I had the same thing on my last small block,I could not get the center 3 to sit flush, ended up with pro gram caps and line hone to the new caps

Posted By: gregsdart

Re: engine guys, #3 bearing cap won't seat properly? - 09/07/09 08:20 PM

At this time I have more time than money, so I will do my best to get accurate data on where the bearing crush is, and decide from there. If that is in range or reachable I may try a back yard fix. Any input on that is appreciated!

Posted By: Ron Silva

Re: engine guys, #3 bearing cap won't seat properly? - 09/07/09 08:38 PM

The problem is not the actual clearance measured by the hole diameter vs stud diameter. The hole in the cap may not be consistent and it could be because the stud is not straight after seating in the block. It is very common to have problems when using studs. A bolt will not seat in the hole like a stud will. Think about it. The whole area in the block is threads and will come STRAIGHT out. A stud will not. My Machinist reamed out the holes in my main cap using a reamer. Makes a smoother hole but a drill would be fine. You have nothing to lost by drilling the hole one size larger. I bet that fixes it.

OR you can try intalling the cap temporarily with a BOLT and see what that does (re measure). If that fixes it then drilling the cap hole larger will almost for sure do it.

Posted By: Hemiroid

Re: engine guys, #3 bearing cap won't seat properly? - 09/07/09 08:42 PM

Quote:

The problem is not the actual clearance measured by the hole diameter vs stud diameter. The hole in the cap may not be consistent and it could be because the stud is not straight after seating in the block. It is very common to have problems when using studs. A bolt will not seat in the hole like a stud will. Think about it. The whole area in the block is threads and will come STRAIGHT out. A stud will not. My Machinist reamed out the holes in my main cap using a reamer. Makes a smoother hole but a drill would be fine. You have nothing to lost by drilling the hole one size larger. I bet that fixes it.

OR you can try intalling the cap temporarily with a BOLT and see what that does (re measure). If that fixes it then drilling the cap hole larger will almost for sure do it.

Had problems lots of times with studs. I would approach it this way if it were me. No sense driving yourself crazy and spending money if you don't have to

Posted By: B G Racing

Re: engine guys, #3 bearing cap won't seat properly? - 09/07/09 08:56 PM

Before i would do anything I would check the bearing alignment in the block and cap for mislocated tangs before installing the crank and check for radius clearence on all the mains.Then install the #3 cap with the studs turned all the way in and backed out a 1/4 turn.Take a lead hammer and smack the crank for and aft checking the clearence at the main thrust on each side of #3 and check crank end play.Some times the thrust sides of the bearing need to be conformed to the cap and block.If this doesn't solve the issue then ream the cap holes as others have mentioned.

We found a similar problem at #3 thrust and it was actually cause by #5 cap that the bearing was riding on the radius and creating the issue,that's why I suggest you check all mains.

Posted By: gregsdart

Re: engine guys, #3 bearing cap won't seat properly? - 09/07/09 09:17 PM

I tried different bearings, swapping halves to see if it were a bearing issue. It is definitely not the bearings, as the measurements came out differing the same when I measured the bores minus bearings. The back side was still .0015 larger. Plenty of room around the studs, checked for that and found the holes all consistantly .530, studs .497. The studs are perfectly centered, allowing cap placement way forward or backward to get proper bearing alignment of the #3. Plenty of room side to side as well.
Any one have the specs for max minimum bearing bore diameter for proper bearing crush? Standard rb bearings.

Posted By: jamesc

Re: engine guys, #3 bearing cap won't seat properly? - 09/07/09 11:51 PM

Greg you make no mention of what block this is (one you've been running?), mega, stocker? as others have mentioned studs can cause issues even if they're loose in the cap. 25 years ago i had a 340 that wouldn't even turn with studs. not knowing what to do or having the $$$ to hone it i put the bolts back in it. engine ran 11teens and is still together and running this day. just because the engine was correct before and ran OK doesn't mean things can't or won't move some. if you've measured the bores without bearings and are getting bad readings might be time to hone it. also remember even if the numbers are good doesn't mean the bores are in a straight line. the stock FM "book" spec for the bores is 2.9425-2.9430

Posted By: Moparnut426

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 12:16 AM

I used a 17/32 reamer with a bridgport. all is good on mine...

Kasey

Posted By: gregsdart

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 12:26 AM

Jim the block is a megablock, the original block for this motor. Guess you are right, it may have shifted with use, especially with all the flex this thing has had. My biggest concern is I have fairly tight piston to head clearance as it is, and don't want to risk moving the crank up too much. I am at .046 with 6.965 steel h beams and about .001 oversize on piston to bore clearance with 4.500 pistons. I will have to call the shop tomorrow and see what they say. On the bearing bores, I was referring to the diameter without bearings installed. Looks to be about 2.940?

Posted By: Ron Silva

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 01:00 AM

Please stick a couple bolts in there and torque to specs and remeasure. Then report back what you find.

Posted By: jamesc

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 01:41 AM

sorry Greg i'm running around like a madman trying to get ready for a trip to CA and wasn't paying attention when i posted the numbers. the housing bore is listed as 2.9425-2.9430. i don't think you usually move the crank up too much just bumping the mains with a hone but i've personally never performed this operation or payed attention. obviously it depends on what it takes to get it straight/round and to size. on the piston to head i'd be interested to see what people have to say. of course there are a number of factors. bore size, piston clearance, RPM, rod type etc. i'm wrestling with this issue on a new build because the pistons are .005 taller than i wanted. i'm at zero deck with a 4.5 crank, 7.1 olivers and fresh 4.44 bore. this is an aluminum block so i'm wondering if it will grow some and open this clearance up a little. at this point all my piston to head is going to be in the gasket so i may be limited on what i can do.

Posted By: dvw

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 01:47 AM

With Cometics or copper gaskets piston to head shouldn't be an issue. Chose the right thickness and your good to go.
Doug

Posted By: JohnRR

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 02:08 AM

Greg , is this still on the factory provided main line machining or did you have it redone ? I had a similar issue, stock 440 block , added studs and linebored for the studs because the torque spec for studs is greater than bolts. I put in the crank and it would lock up when #3 was torqued to spec, I hadn't opened the cap holes on #3 BEFORE the line bore, I ream to 17/32nd, I did it afterwards.

I finally figured out the cap was cut crooked by the shop , they all were, and it allowed the studs to straighten out the cap when torqued because the block side of the cap wasn't parallel to the spot face where the bolt/nut clamps against the cap.

Posted By: ccdave

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 02:25 AM

I agree, with studs sometimes you need to clearance the bolt holes to get the caps to seat properly & with #3 being the thrust bearing it's more critical...

Had to do exactly that on mine. Been 3 years of beating since. Chuck at Best (his caps) had me open the holes in the cap some and all was well.

Yes indeed

Sometimes you can get away with it and other times

At this point it should be manditory when studs replace the factory main cap bolts, the block be line honed and the #3 thrust cap be drilled out with a 17/32 drill. Chuck Senatore taught me this trick 15 years ago.

Posted By: gregsdart

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 04:18 AM

Quote:

Greg , is this still on the factory provided main line machining or did you have it redone ? I had a similar issue, stock 440 block , added studs and linebored for the studs because the torque spec for studs is greater than bolts. I put in the crank and it would lock up when #3 was torqued to spec, I hadn't opened the cap holes on #3 BEFORE the line bore, I ream to 17/32nd, I did it afterwards.

I finally figured out the cap was cut crooked by the shop , they all were, and it allowed the studs to straighten out the cap when torqued because the block side of the cap wasn't parallel to the spot face where the bolt/nut clamps against the cap.

Caps were drilled to 17/32 by RBRE when they put in the stud kit, apparently. They did the original machine work. All holes are .531, which is 17/32.
DRAGRACER97 could not find any bolts to fit. This has been a studded block from day one. Hemi style bottom end, so it has to have longer bolts than I have in my possession.
Am going out to see what measurements are now on all main bores.

Posted By: gregsdart

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 04:34 AM

Found these numbers.
Factory specs 2.9425 to 2.9430
Mine are;
#1 front side, 2.9425 back side 2.9431

#2 front side, 2.9427 back side 2.9430

#3 front side, 2.9421 back side 2.9428

#4 front side, 2.9434 back side 2.9427

#5 front side, 2.9434 back side 2.9435
Too much variance for my new crank to come home to. I think it is time for a line hone. The bearings always did come out of this motor with odd wear patterns, maybe this is why.

Posted By: Monte_Smith

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 05:07 AM

Was this block line honed or checked when it was new? Sounds like it was not, or whoever line honed it did a poor job. If it has taper now, it had it then.

Monte

Posted By: JohnRR

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 05:09 AM

Quote:

Found these numbers.
Factory specs 2.9425 to 2.9430
Mine are;
#1 front side, 2.9425 back side 2.9431

#2 front side, 2.9427 back side 2.9430

#3 front side, 2.9421 back side 2.9428

#4 front side, 2.9434 back side 2.9427

#5 front side, 2.9434 back side 2.9435
Too much variance for my new crank to come home to. I think it is time for a line hone. The bearings always did come out of this motor with odd wear patterns, maybe this is why.

I'd agree with you on that , something is just not right with those numbers

Posted By: Al_Alguire

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 05:14 AM

I agree looks like it had taper from day one...Dont think you can do anything to cause that problem other than mis machined

Posted By: gregsdart

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 12:47 PM

Thanks for the input , guys. Monte, this block was ordered with the stud kit installed, so a guy would hope they did it right. The caps and bores all show consistent hone marks. That would lead me to believe the stud kit may have been put in without a re hone?
Yep, it will get a line hone. Troubles that will pop up with that are loss of piston to head clearance, not a super big issue but another $150 for new gaskets. The milodon gear drive may be an issue though. Will have to check with them and see what can be done to make that fit again, as the holes for alignment are already in the block.

Posted By: The Shadow

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 12:55 PM

Did you ever try checking it with a feeler or even torquing it with some shim under one side to see if it gets worse?.
I would verify that it was seated correctly before line boring.

Posted By: gregsdart

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 01:01 PM

Quote:

Did you ever try checking it with a feeler or even torquing it with some shim under one side to see if it gets worse?.
I would verify that it was seated correctly before line boring.

I checked and rechecked the mating surfaces, cleaned and double checked them. Numbers are from a very good dial bore gauge, all consistent after being checked multiple times.

Posted By: The Shadow

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 01:21 PM

If your happy with your results.

I was just offering a solution to check a stud bind issue.
How many years have you run the block?
Did it have oiling issues?

Posted By: gregsdart

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 02:55 PM

this block has been around for a while, only 100 passes on it though since new. Thanks again, will re post after the trip to the machine shop with new numbers.

Posted By: Cab_Burge

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 04:19 PM

Hopefully the machine shop will only remove the minmum(.002 to .003?) needed to make all of the mains rounds and straight

Posted By: JohnRR

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 08:53 PM

Quote:

If your happy with your results.
I was just offering a solution to check a stud bind issue.
How many years have you run the block?
Did it have oiling issues?

Stud bind issue should be easy to spot , if you have to tap the cap to one side to pull the studs , I had to do that on the block I described above , the caps are cocked .

It's quite possible that somone swapped in the studs and didn't bother to rehone the block ?

Posted By: 602heavy

Re: engine guys, #3 bearing cap won't seat properly? - 09/08/09 09:03 PM

Had this same problem regards crank endfloat on the megablock , drilled #3 cap & all was good.

Posted By: gregsdart

Re: engine guys, #3 bearing cap update - 09/08/09 09:33 PM

It's quite possible that somone swapped in the studs and didn't bother to rehone the block ?
I don't want to throw anyone under the bus, but that thought crossed my mind. The other possibility is due to severe usage, stuff just moved. The problem with that idea is, I have two opinions i trust that don't think that happens.

Posted By: S/ST 3040

Re: engine guys, #3 bearing cap won't seat properly? - 09/09/09 12:57 AM

Quote:

Greg , is this still on the factory provided main line machining or did you have it redone ? I had a similar issue, stock 440 block , added studs and linebored for the studs because the torque spec for studs is greater than bolts. I put in the crank and it would lock up when #3 was torqued to spec, I hadn't opened the cap holes on #3 BEFORE the line bore, I ream to 17/32nd, I did it afterwards.

I finally figured out the cap was cut crooked by the shop , they all were, and it allowed the studs to straighten out the cap when torqued because the block side of the cap wasn't parallel to the spot face where the bolt/nut clamps against the cap.

Same here. I even sent the #3 bearing back the first time.
I finally figured it out. Caps weren't trued up on the faces
before the caps were cut. When I'd torque #3, it would pinch
the crank between the thrust surfaces.

I pulled the bearing halves out, installed them, one at a time in the
cap and lapped them with 600 grit on a granite surface plate.

Posted By: gregsdart

Re: engine guys, #3 bearing cap update - 09/15/09 01:09 PM

Got the block back from the machine shop, and all bearing bores check within .0001 to .0002 on all five bearing bores, front to rear, and all are nice and round.
One discrepancy- my dial bore gauge was set to zero off a good mike, at 2.9425. Block came back tagged 2.9427 . I checked all bores, all measured +.0011 to +.0013, or a total of 9.436 to 9.437. I pulled another brand new mike out of its packing to double check my dial bore gauge, and came up with the exact same reading as the first mike. By setting the new mike to 9.425, it reads zero on the dial bore gauge same as the first mike.
Any input on the difference of measurements?

engine guys, #3 bearing cap won't seat ? **update**