I've been having main bearing clearance issues. I need to get a set .001in. undersized X bearings but from what I'm finding they're a special order part. Has anyone else run into this and what kind of turnaround time did you have to get your bearings? Clevite says their X bearing wouldn't ship until 12/11/17 and Sealed Power says theirs won't ship until 9/4/17. Any info or experience you've had getting undersized bearings would be appreciated.

Have you callled callico or king to see if they have them, usually there is one or two sets on ebay but a quick look didnt have any pop up.

But I think if you search the web and make some calls you can find a set sooner.

King doesn't offer .001in undersized mains. My hands are also slightly tried to what bearings Summit sales because they will be supplying them to me for free. I bought this supposedly bolt in ready stroker kit from them.

Wow, I looked more and found the same thing, actually I think its hit and miss on who has them in stock and who dont.

I got a set of the MS1266HGX in Feb and although I dont recall if it was summit or jegs they had them in stock.

Of course you can find the 318/340 ones now.

Its cool summit is going to cover the cost as most bolt in kits are known not to be bolt in kits.

Shoot me a PM, I'm pretty sure I have a couple sets in the garage.

Are you still running the stock magnum block?

I sent you a PM with a couple questions about your combo.

I had Summit place the order for the Sealed Power set. We'll see how long they actually take to get here. They're "backordered" with an est ship date of 8/30/17

Ok I'm at my whits end, I can't seem to get this clearance where I want it. The Sealed Power mains came in earlier this week and I got around to checking the clearance yesterday. Turns out I missed the fact that these are.001in undersized, not .001in not more clearance, so they're tighter (less than .001 in.) compared to what I had (.0015 in.). When I had Summit order these, I also had them send me a set of Clevite "X" rod bearings. When I checked those the clearance was the same as the standard King rod bearings I had before (.0015 in.). Any guesses what gives? Is my only option to have the crank polished to get it to spec (.0025-.003 in.)? Should I even bother having Summit send me a set of the Clevite X mains to try?

I built a 340 stroker motor (4 inch stroke) earlier this year with a Scat Brand cast steel crank, I ask for the smallest size rod and main journal they had in stock, they where not on the small size when I measured it
I had to have .001+ removed from the crank journals at the customers expense to get .002+ oil clearance on the rods and .003+ oil on the main clearances
This was not a kit either so I went through a bunch of different brand and part number bearings before giving in on having the crank ground down to the size I needed
Good luck on your deal, take your time and get it exactly where YOU want them

This is also a Scat 4 in cast crank, I bought it as a balanced kit from Summit. So far both Scat and Summit have been great to deal with. Summit has sent me 3 sets of bearings at no cost to me, and Scat sent me some mains as well. My guy at Scat seemed receptive to possibly covering the cost of polishing,but recommended trying the X bearings first. Hopefully between the 2 companies we can make something happen. Thanks for the info Cab you've been very helpful when I have questions.

Your learning about all the fun an engine builder has on just about EVERT engine these days. Let's clear a few things up. ( not being critical, rather just providing information)

1) You CANNOT Polish a crank to accomplish what you need here. It can't be done.

2) Most of the case cranks come grind too fat.IE 2.8105,2.5004 etc. They really need to be smaller

3) Its not Summits fault the bearings aren't sizing right. To be honest, I am shocked they are just blowing thru sets of expensive bearings like that.

4) Your need to understand there are oversize bearings, ( X) and undersized bearings -1 etc. Your are intermixed the terminology.

5) The closet sizing you will get, are going to be MS 1266HGX. With any luck you`ll get -.0025 to luckily -.003. Rods will be easier to find. Quite often, you'll need two sets of bearings to get clearances right.

6) If X bearings don't work, then there is a good chance you'll need to get the crank ground. Many shops won't grind only .001, it's not fun. Again, you cannot Polish a crank more than a tenth or so without creating an issue.

What does the housing bore measure? Have it taken to the big number. If you're using Clevite H bearings, you can realistically get away with going a few tenths over the big number and still have plenty of bearings crush.
Again, as stated earlier, X bearings will give you more clearance, 1s will take it away. You can also save yourself some time by getting a bearing micrometer and measuring the thickness prior to installing.
Not the cheapest route, but if you build a lot of engines, it's a worthwhile investment.
I usually like to hone the main housing to the big number just for this reason. It's easier to take clearance away (in most cases) than it is to gain it.