FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: TimeWarpF100 on April 07, 2015, 11:13:24 AM
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Just curious what people are seeing on a FE with crank installed along with rear seal and all mains torqued.
Assembly of my 418 (finally) and with crank installed it seemed to spin as easy or easier than any other I can recall.
The lowest setting on my inch lb wrench is 23. That is enough to spin the crank with ease.
What kind of torque to turn with all pistons in along with cam? Basic short block . .
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There is no specification for that given. However, many folks building SBFs strive for 8-10lbs for the crank, and <14lbs for the BBF, with rings, rods, etc SBFs 14-17lbs, BBf <23lbs. Each engine builder will have their own "pet" figures they try to achieve, but a lot depends on the final usage of the engine. Dyno queen requires less, tolerances on high side to reduce friction. Street another requirement. What is important is if you tear it down in a year to refresh, how does the crank, bearings look, and how does it spin now. That will tell you if you need more, or less clearanaces on the refresh. Joe-JDC
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Also depends on what assembly lubricant you use. Straight motor oil will seem like the rotating assembly wants to whiz over, while some of the more viscous assembly lubes will feel like the crank is rolling through syrup.
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Lowest I've gotten with a 427 was a loose std bore (about .010 clearance!) with factory small dome TRW's, std $ steel crank about .003 and .0025, and a Milodon gear drive turning the cam, 7 lbs on a pretty accurate beam torque wrench- I could spin it with my little finger. More normal clearances would have no doubt brought it up a bit- but it did spin smooth and easy
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Thanks for the comments!
I was not trying to obtain a certain torque but upon having crank installed it seemed easier than most so I checked it. Under 2 ft lbs is pretty easy spinning . .