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full floating wrist pins

20K views 8 replies 7 participants last post by  rifraf  
#1 ·
i'm going to ask a stupid question. what is the purpose of full floating wrist pins? all the engine builder around here act like it's a big secrete or some thing. thanks
 
#2 ·
Full floating pins are commonly used on race engines, because they can be easily serviced, piston, rod eye and pin slide together and pin is retained with clips. The pin is free to rotate in all bores and this adds a little more surface area to act as a bearing. Press pins are harder to assemble. but add a little more latteral stability to the piston rod assembly and tend to be quieter.
 
#4 ·
406 ss monte said:
i'm going to ask a stupid question. what is the purpose of full floating wrist pins? all the engine builder around here act like it's a big secrete or some thing. thanks
One thing I love about oldsmobiles, full floating pistons/pins :thumbup:

The bad part is that even though many olds engines came with full floating pistons, no-one sells them after market.
 
#6 ·
IF this is a street driven car, I wouldn't get "floating wrist pins". As stated earlier, racers like them because maintenance is easier, but they break down an engine after every race ...sometimes. On the street you won't even come close to that. It adds no horse power, it's more expensive to do, AND if one of them retaining rings fail and the pin goes into the cly. wall ...kiss the block good bye! ...Stick with the pressed in pins! ...You won't be sorry! Good Luck! ...Mark
 
#7 ·
i wouldn't mind sticking with pressed pins but all the after-market h-beam rods i've seen have full floating pins. i bought a set of new 5.7" Cat h-beam rods to use in my 406. my pistons are set up to go either way so it's no big deal there. i'll make sure i have good pin retainers on them though. anybody got a preference on them?
 
#8 ·
If all you can get is full floating rods, I would not worry about it, go ahead and use them. Just about all hi po engines of the late sixties, early seventies used floating wrist pins. There is a very slight HP to be gained by using them. I have never heard of a properly installed retaining clip failing and destroying a block. If it is installed right and the clearances are correct, it's bullet proof.

Vince