Full Floating vs. Press Fit?
Thread Starter
|
Posting Guru
Joined: Nov 2009
Posts: 1,219
Likes: 4
From: Norton, MA
Full Floating vs. Press Fit?
So (for once) there is actually lots of info on this on my very first google, but I just want to make sure, before I make any decisions.
Most of what I've read has said that the two styles of pins, for all intents and purposes, are juuuuuust about identical. I've heard that floaters (hehe....) might help reduce friction losses juuuust a little bit, I know that they allow you to do the work without the machine shop, which is always nice, BUT I also read on one sight that floaters require some added means of lubrication, for the small end of the rod, and that the retaining rings can be problematic......
So what do you guys think?? My biggest question is the issue of oiling the small end, is that necessary? The retainers make me think, a little, but really they're so widely used I'm not too worried.
What can you guys tell me about these, on a 10.7 compression engine, that will never top 5000 RPM?
Hope everybody had a good day! AleX
Most of what I've read has said that the two styles of pins, for all intents and purposes, are juuuuuust about identical. I've heard that floaters (hehe....) might help reduce friction losses juuuust a little bit, I know that they allow you to do the work without the machine shop, which is always nice, BUT I also read on one sight that floaters require some added means of lubrication, for the small end of the rod, and that the retaining rings can be problematic......
So what do you guys think?? My biggest question is the issue of oiling the small end, is that necessary? The retainers make me think, a little, but really they're so widely used I'm not too worried.
What can you guys tell me about these, on a 10.7 compression engine, that will never top 5000 RPM?
Hope everybody had a good day! AleX
Lead Driver
Joined: Mar 2004
Posts: 8,922
Likes: 153
Full floating are most used in race engines that get torn down frequently to ease the process. IMO one is as good as another. Unless you have new rods that are set up for them, then there would be no reason to consider them in a street engine. I have never had a clip or spirolock come out of any piston I ever put in. There should be a oiling hole in the top of the rod to keep the pin oiled.
Hotshot
Joined: Apr 2009
Posts: 14,333
Likes: 247
From: Stanley, VA
FE's come stock with full floating wrist pins, small blocks, 335 and 385 series come with press fit pins.
On the FE's there is a small hole on the pin end of the rod to allow lubrication.
I've never had any issues with the pin locks but I know there have been cases where the lock ring breaks up or works loose and the pin comes out and destroys the cylinder wall, but I've also seen press fit pins lose their fit and do the same thing.
Personally I like floating pins but on a street engine I don't see any point in going to the expense of converting pressed pins to full floaters.
On the FE's there is a small hole on the pin end of the rod to allow lubrication.
I've never had any issues with the pin locks but I know there have been cases where the lock ring breaks up or works loose and the pin comes out and destroys the cylinder wall, but I've also seen press fit pins lose their fit and do the same thing.
Personally I like floating pins but on a street engine I don't see any point in going to the expense of converting pressed pins to full floaters.
Thread Starter
|
Posting Guru
Joined: Nov 2009
Posts: 1,219
Likes: 4
From: Norton, MA
OKOK, cool, both your answers pretty much back up the variety of different opinions I found around the web last night. Preferences swing both ways, which is a little confusing, but also means that both will do the job more or less the same. The oiling hole being adequate was one of my main concerns, but this backs up alot of what I found, which is that it is.
My engine DOES get torn down about once a year, but I'm hoping to end that..... eventually. But for now, floaters would help me out. On the same token though, I don't even know what I have in my engine right now for rods and pins, so that will be a major piece of determining what I swap to.
Basically I just wanted to be sure that they were infact essentially equal.
Two remaining questions though: did the FE's have bushings of some type in the rod ends, and if they DID, what's your opinion on just steel to steel? And, the one very troubling thing I read last night was that any kind of predetonation on an engine with floaters, for even a very short period, and you're pretty much assuredly sunk, is that true?? I only read that on one lone site, but that'd be enough to change my mind if it's true.
My engine DOES get torn down about once a year, but I'm hoping to end that..... eventually. But for now, floaters would help me out. On the same token though, I don't even know what I have in my engine right now for rods and pins, so that will be a major piece of determining what I swap to.
Basically I just wanted to be sure that they were infact essentially equal.
Two remaining questions though: did the FE's have bushings of some type in the rod ends, and if they DID, what's your opinion on just steel to steel? And, the one very troubling thing I read last night was that any kind of predetonation on an engine with floaters, for even a very short period, and you're pretty much assuredly sunk, is that true?? I only read that on one lone site, but that'd be enough to change my mind if it's true.
Senior User
Joined: Oct 2010
Posts: 254
Likes: 0
From: Hellertown,Pa
I'm partial to floating pin but that's my opinion
both have been doing the same job for years
I have seen floating pins walk out
in the turbo dodge world we had a sudden rash of pins walking
further investigation reviled an elliptical groove cut in some pistons and a groove not deep enough in others
JE was the culpruit for our failures
After a call out to them, they told my friend it should've been caught during assembly and its not their fault
I'm a big Wiesco fan , they come with spiral locks instead of c-clips, much better retainer
If your truly worried about pin walk some use teflon buttons instead of clips
Just some more food for thoguht
both have been doing the same job for years
I have seen floating pins walk out
in the turbo dodge world we had a sudden rash of pins walking
further investigation reviled an elliptical groove cut in some pistons and a groove not deep enough in others
JE was the culpruit for our failures
After a call out to them, they told my friend it should've been caught during assembly and its not their fault
I'm a big Wiesco fan , they come with spiral locks instead of c-clips, much better retainer
If your truly worried about pin walk some use teflon buttons instead of clips
Just some more food for thoguht
Hotshot
Joined: Apr 2009
Posts: 14,333
Likes: 247
From: Stanley, VA
As for bushings, FE's use a pressed in bronze bushing in the small end. Never run steel on steel when it comes to wrist pins.
While detonation isn't good for any engine, I don't see why it would be worse on full floating pins. I've never experienced any problems because of it.
While detonation isn't good for any engine, I don't see why it would be worse on full floating pins. I've never experienced any problems because of it.
Thread
Thread Starter
Forum
Replies
Last Post
Argess
FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
3
May 2, 2009 04:54 PM
PyroBob
Performance & General Engine Building
5
Apr 6, 2006 05:04 PM
Traderjoe28
Ford Inline Six, 200, 250, 4.9L / 300
3
Jan 30, 2006 06:49 PM
sancochojoe
Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
4
Jan 17, 2005 05:44 AM
