Motor clearance

[Stingpuller]

I think some have a miss conception of piston clearance in a running motor. Yes the aftermarket pistons run more clearance but that is because they grow more when they get to operating temp. Its not that they run loose in the motor(only when cold) they just expand at a different rate. Bearing clearance needs to be bigger if the power output goes higher. Things start to move more "flex" when you wick them up so a little extra is very much a good thing. I hope this helps some better understand whats going on in a race motor. I think a motor that doubles or more the output of factory rating is a race motor. Jeff

 

[sweetdiesel]

Jeff
I was a little leary when putting my motor together clearance was +++++

 

[malibu795]

ona DD i would have a tendacy to run on the tight side of the tolerances.... get more service life out of said equipment.. even in a street/strip setup.

all out race... bout midle of the road.. too loose things can get tooo much play and cause damage. ie running barely long enough to put heat in the oil will rob HP so loose clearance make sense.

flex "can" be a good thing and "can" also hurt things.

 

[JOHNBOY]

ona DD i would have a tendacy to run on the tight side of the tolerances.... get more service life out of said equipment.. even in a street/strip setup.

all out race... bout midle of the road.. too loose things can get tooo much play and cause damage. ie running barely long enough to put heat in the oil will rob HP so loose clearance make sense.

flex "can" be a good thing and "can" also hurt things.

The thing is like Jeff says. If your doubling the output of the engine you need to open the clearences up. If your putting rods in you most likely are at least doubling the output. Regardless of wether or not you daily drive it it should get more clearence.

 

[Kat]

I moved this here