Bearing Clearance Aluminum Hemi

I was able to do a quick check on one rod and one main bearing with my limited time and found .0026 on rod and .0038 on main. I will get to it this weekend with a new anolog and a digital gauge to get as precise as i can.

I am fine with 0.0026" on the rod bearings (2.2 Chevy right?). But if you want more, you can mix HXN and HN bearings to get about 0.0031", just HXN would go loose ~0.0036"
What were the journal diameters? For example 2.1992 rod, 2.7492 main

the journal specs are 2.200x2.750. I measure 2.199x2.749. The mic checks out correct.

Way better to have .001+ to much bearing clearances on any racing crank bearing than .00010 to little

I have a brand new anolog gauge that measures in .0001" increments with total measure of .050" and a digital i want to try this weekend.

i found the brochure that came with my rings. It has a chart for gap. street/high performance .0045 top, second .004-.006 bigger than top ring. Drag race .005 top, second .004-.006 bigger than top ring. min .015 oil ring. Should be able to get all bearings measured and crank bolted in tomorrow.

I don’t have any experience but this is relevant to how much an aluminum block grows

https://youtu.be/QLdkTkv0Qos

I’m not a metallurgist but, I wonder if a billet block expands more or less the a regular aluminum block.

Interesting video Thanks for the share.

Good video. I like Steve Morris. Down to earth guy and a wealth of knowledge. I watch alot of his vids and learn from much of them. In this video the main cap is aluminum and i think that is the reason for all the growth. Using steel caps i wouldnt think you would get that kind of growth on an aluminum block, But that it the reason for this post, i dont know for sure.

Just spoke with Ray Barton. He uses .0025-.003 on rods and no more than .004 on mains. All consistent info.

I ended up using the digital gauge on the bore gauge and measured the bearing clearances double checking it with a new anolog gauge. They both gave exact same numbers.
Rod
1 .0026
2 .0026
3 .0026
4 .0026
5 .0025
6 .0026
7 .0026
8 .0026

Main
1 .0036 2 .0034 3 .0034 4 .0036 5 .0036

Those are very acceptable numbers , rods & mains . What digital gage did you use ? The one I have been using made a bad fall off the bench & needs replaced . Thanks Gary

I bought a no name gauge online. All 5 indicators were very close to each other. I used the 2 I thought were the best of what I had. The analogue gauge I used was a old friend of mine that was a machinist on now no longer with use.

A good, decent, dial bore gauge is handy.
I set mine up with a old Craftsman micrometer and recheck it after each bearing check, learning on how to rock it to get the minimum bore size is fun
Left, right, up and then down, several times

I understand 100%. All i got done yesterday was the crank installed. Lots of measuring just to be sure.

Dave,
What main bearings are you using? Part number:

Pic

Good to go!