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Thread: main bearing clearances

  1. #1
    BLOWN88FRESNO MINI
    Clearances on the mains measure .001 on rear main, and .002 on the rest of the mains with std Clevite77 ,What bearings do I go with to loosen it up.
    This is a 454 9.8 deck int bal 4.25 stroke CAT 4340 crank with 6.385" CAT H-beam rods, SRP pop up pistons 10.25 CR, Alum pro topline 320cc heads with Manley severe duty valves, Comp Cams Extreme Marine 11-252-4 cam shaft, Weiand tunnel ram with 2 4777c Holley 650 dbl pumpers
    Also what kind of HP do you think this will Produce!

  2. #2
    sangervdrive
    I would say around 630 horse because its pretty similar to mine and thats what I got.

  3. #3
    BlueNun
    How do you like the CAT stuff??

  4. #4
    BrendellaJet
    Return the cam and have Straub spec one for you. Lots of power being left on the table going with an off the shelf grind.

  5. #5
    RICHARD TILL
    nice parts. it`ll be a good running engine with those ingredients. 252/264 @.050 and .575/.578 is a good hydraulic cam but if you really want to wake it up and do`nt mind adjusting valves try a roller. it do`nt have to be big, just roller. i`m running cat crank/rods too. 496 c.i.d. about 75 passes so far @6500 RPM.

  6. #6
    Senior Member
    Join Date
    Apr 2010
    Posts
    6,425
    How are you measuring everything?

  7. #7
    BLOWN88FRESNO MINI
    nice parts. it`ll be a good running engine with those ingredients. 252/264 @.050 and .575/.578 is a good hydraulic cam but if you really want to wake it up and do`nt mind adjusting valves try a roller. it do`nt have to be big, just roller. i`m running cat crank/rods too. 496 c.i.d. about 75 passes so far @6500 RPM.
    Thanks, Richard
    I'm not a drag racer by any meens but I do enjoy building my own motors. I think this motor will do what I want it to do
    be reliable
    turn every bodies head when I FIRE IT UP!!!!!!
    Have a little extra go.
    I like the reliability of the hydraulic cams. Were up at Bass Lake almost every weekend This motor may go in my Fresno Mini Cruiser or I might put the 'Joe Bagosian' Blown496 TD. Don't know yet.

  8. #8
    BLOWN88FRESNO MINI
    How are you measuring everything?
    I measured the mains using Plastiguage .

  9. #9
    YeLLowBoaT
    might want to take it to a machine shop that can mic them for you...

  10. #10
    Warp Speed
    Plasti-gauge can be amazingly acurate for a piece of plastic (wax, whatever the hell it realy is!?!) in a stock build, but won't cut it when looking for tenth's as you need to when building a performance engine.
    As suggested above, take it to a machine shop or experienced builder who can measure them properly with a dial bore gauge or air gauge. I believe the readings you are getting (rough) as the rear thrust is tight, and can get that way even if it has been line honed. If not done properly, the rear will always be tight as it is the widest main with the most material so it naturaly cuts slower.
    If the tight clearances are verified to be true, have them hone a few tenths out of the mains so you can at least get proper using "X" type bearings. If the crank is on the big side of spec, have them take the mains to the high side of the tollerance and you shouldn't have any trouble getting where you need to be. Most any experienced machine shop should know right where to put it for your crank size.
    Warp Speed

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