how do these main clearances look?
Thread Starter
TECH Fanatic
Joined: Jun 2011
Posts: 1,343
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From: Katy, TX
how do these main clearances look? Iron block 383.
11.3 CR street motor. No boost. No nitrous.
K1 4" crankshaft
Clevite MS-2199 H Bearings
Block was line honed at HKE with ARP studs.
I am using a mitutoyo dial bore gauge with an outside micrometer to come up with the following clearances. Measurements were taken at 90-deg from the parting line.
Some of what I have read leads me to believe #3 and #5 are too tight. A few others lead me to believe it will be ok. I tried removing the #3 cap, cleaning, and re-assembling with proper torque procedure. Dimensions did not change.
Should I get .001" undersized bearings for #3 and #5? Any help is appreciated!
No.____Min______Max_
#1___0.0024___0.0026
#2___0.0024___0.0026
#3___0.0017___0.0019
#4___0.0023___0.0025
#5___0.0019___0.0020
11.3 CR street motor. No boost. No nitrous.
K1 4" crankshaft
Clevite MS-2199 H Bearings
Block was line honed at HKE with ARP studs.
I am using a mitutoyo dial bore gauge with an outside micrometer to come up with the following clearances. Measurements were taken at 90-deg from the parting line.
Some of what I have read leads me to believe #3 and #5 are too tight. A few others lead me to believe it will be ok. I tried removing the #3 cap, cleaning, and re-assembling with proper torque procedure. Dimensions did not change.
Should I get .001" undersized bearings for #3 and #5? Any help is appreciated!
No.____Min______Max_
#1___0.0024___0.0026
#2___0.0024___0.0026
#3___0.0017___0.0019
#4___0.0023___0.0025
#5___0.0019___0.0020
Under sized bearings are smaller inner diameter and they don't make bearings that have larger inner diameter ( oversized ) . So You measured the main journals on the crank and measured the bearing with caps tqed without the crank ?
Thread Starter
TECH Fanatic
Joined: Jun 2011
Posts: 1,343
Likes: 8
From: Katy, TX
Thanks for the replies.
Main caps and bearings were assembled without crank for checking the dimensions.
The main journals on the crank are all within .0002 of each other (2.5584-2.5586), these were measured at 4 points each. This tells me that the tight clearance is a result of the bearings.
Main caps and bearings were assembled without crank for checking the dimensions.
The main journals on the crank are all within .0002 of each other (2.5584-2.5586), these were measured at 4 points each. This tells me that the tight clearance is a result of the bearings.
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Yep.... 
Thread Starter
TECH Fanatic
Joined: Jun 2011
Posts: 1,343
Likes: 8
From: Katy, TX
Thread Starter
TECH Fanatic
Joined: Jun 2011
Posts: 1,343
Likes: 8
From: Katy, TX
If I understand you correctly, you assembled your engine with 1 side regular, and 1 side "X" bearing for an increase of .0005 in clearance? If so, that sounds like a good solution for me on #3 and #5, as adding .001 seems too much.
Did you install the undersized half on the upper or lower?
I found them in the Clevite catalog as MS-2199HX. It specifies each bearing as .0005 thinner, for .001 more total clearance.
If I understand you correctly, you assembled your engine with 1 side regular, and 1 side "X" bearing for an increase of .0005 in clearance? If so, that sounds like a good solution for me on #3 and #5, as adding .001 seems too much.
Did you install the undersized half on the upper or lower?
If I understand you correctly, you assembled your engine with 1 side regular, and 1 side "X" bearing for an increase of .0005 in clearance? If so, that sounds like a good solution for me on #3 and #5, as adding .001 seems too much.
Did you install the undersized half on the upper or lower?
I don't remember which side they went in, I personally don't think it matters in 99.9% of the builds. The idea here is that the side with less load gets the thinner bearing and the side with more load gets the thicker bearing. We're only talking .0005", so unless it's on a BIG shot of nitrous or there is nitro in the fuel, I don't think it matters.
