408 LA main bearing clearances

[Radarsonwheels]

Howdy

Im trying to set my oil clearance on the mains. I have a scat cast crank and a set of standard bearings. I am using plastigage and I checked all the bearings three times to torque and got the same result: 0.0009 or 0.00085 every time. Needs more clearance!

I think I could run x bearings (.001 extra clearance) but I don't know- I'd rather have .0025 than .0019. I don't know if clevite even makes xx (.002 xtra) for the LA 360. I think flirting with .003 might be a better idea than flirting with .002? This is on a stock block scat cast crank/scat Ibeam/ KB forged piston motor with stage II shady dell edelbrock heads. I'm shooting for a 6200 redline and hoping for like 480hp @ the crank. So it's a serious street engine (in front of stickshift) but no race job or max effort.

What do you all think? -0.001 bearings? Or just haul the whole mess to my local shop to get measured and cut 10 under with new bearings for a perfect fit?

 

[sbmmustang]

did u have the mains checked on the block and then checked the crank to see what they were? I would run .0028-.0035 on clearance. Make sure the rods are good to for clearance.

 

[Radarsonwheels]

did u have the mains checked on the block and then checked the crank to see what they were? I would run .0028-.0035 on clearance. Make sure the rods are good to for clearance.

Ryan at Shady Dell is porting my heads and sold me the scat crank and rods, and balanced them. He measured and ordered me proper rod bearings. Its up to me to check main journals and thrust. Of course I'll double check rod clearance and side play when I put it together but so far I only measured the mains. Thrust was right on @ .005 but the bearings are all .0016-.0021 too tight if I'm going for .0025-.0030 clearance.

I never align honed this block but it lived for seven hard years with an eagle 4" crank and standard bearings redlining at 6k and running around 410hp

 

[sbmmustang]

Yes checking the clearances should be done but he should of checked also before he sent them out to make sure that way he could of ordered the correct bearings also for the mains. yes you can order a .001 extra clearance main but hope its enough. What brand of main bearing are you ordering?

 

[sbmmustang]

sorry you said Clevite so here is the part# MS1266HGX full groove main or MS1051P but they don't show a .001 extra clearance bearing. Might have to call Clevite.

 

[mini]

Had the exact problem with my 390 stroker. Went with .001 extra clearance and netted .0025

 

[Radarsonwheels]

I dropped the crank block and bearings off at the machine shop today to be measured. Once I find out the actual #s I can decide if I want/need an align hone, -.001 bearings, crank polished, or some combination of the above depending on which part or parts are causing the tightness.