full floating pins / bushed rods

I just ordeded a set of JE dished pistons from MIke for my 200 Turbo build. I will be using a set of polished, shot-peened, and ARP'd stock C3 rods. My question is???? do I use the std. pressed pins or install bushings for floating pins? Not sure , but I am headed to the machine shop tomorrow and was thinking of leaving the rods as they are. Thanks for all the helpful info--Lee

full float for racing and press for mileage and performance is what I have been told.

IMHO...

If using press fit pins only use a shop that has a rod furnace. I have had problems with shops using a press to force the pins in and causing galling and very stiff moving pistons.

With a rod furnace the pin end of the rod is heated and the pins are cooled and the piston is sitting in a fixture that controls how far you can push the pin in.

The rod is heated, the pins cooled and the rod is then set in place in the piston and the pin slides into place very easily. No galling and when it cools its done and locked into place.

The guy who runs the shop Im using said he doesnt understand why in this age anyone would still try to press fit the pin over a rod furnace.

Full-floating!

From what we've found, the higher cyl pressures caused when using power adders, causes the piston to gall up with the wrist pin.

At the very least have your machine shop take just a bit more out of the wrist pin "hole" in the piston if you plan on pressed in pins. They seem to come to tight from JE.
At least for our application.

Later,
Will

Broncitis":3rx3yjlm said:

full float for racing and press for mileage and performance is what I have been told.

Click to expand...

Does not compute...

Most VW racers use full floating pins and Teflon buttons, this creates a full floating operation so the pin can float between both the piston and rod...this allows the the piston to move almost separately from any rod twist under severe boost conditions which will avoid a piston from being shoved out the cylinder walls...I know this has nothing to do with Fords but the technology is still the same.

From a practical point I can understand racers using full floating pins because the assembly would be easier to tear down and reassemble in the pits. Snap a spiral lock in and use the pliers to remove and you can carry a bag of spiral locks.

In the big drag teams they might tear an engine down and put it back together several times a week.

I have heard several horror stories about the rod pin bore not being sized properly and the wrist pin sliding out in to the cylinder wall. Happened on my friends Uncle's 428CJ Torino.

I prefer bushed rods. The spiral locks that come with the JE pistons will not come out of the piston.
I recomend using some Manley or Carillo or similar bushings. They are thin bushings and they hold up better than most. This must be done by a good shop with good equipment or it will cause more problems than it solves.
If the shop uses good equipment, you will get the added bonus of equal length rods. 8)

Hey listen to does 10's he's much more experience than I, I am using cast pistons and the fit was perfect to me, moved very freely, but does 10's does 10's, so listen to him, theirs alot of talk out there, I like experience in my corner, you go WILL.

Anlushac11":wuy3zg08 said:

Snap a spiral lock in and use the pliers to remove and you can carry a bag of spiral locks.

Click to expand...

I believe you are thinking of Tru-arcs, they are similar to snap rings, and require pliers to install/remove them. A spiro-loc is a very secure fitting retention device, that does just as its name implies. It spirals into the lock groove about 2-1/2 to 3 times, and has a 360 degree contact surface with the lock groove. The JE pistons are supplied with this style of lock, and I have never experienced one failing in the many circle track and extreme duty forced induction engines I have assembled. They do require a little technique to install/remove with 2 thin bladed screwdrivers, but as already has been mentioned, they are a very good design and you just aren't going to have a problem with them coming out or failing. The down side to a press fit piston, is that they make the wrist pin wear in on the same spot because it can't rotate independent of the rod and piston, especially as the cylinder fires time and time again under the added cylinder pressure of a turbo. Also, you stand the risk of damaging the pistons if they ever have to be removed from the rods, you will always have metal transfer from the pin to the rod as it is pressed out, and that will scar the pin bores of the pistons. I would have to give a thumbs up for floating pins, but only if it involves using spiro-lok's, I would have to just flip a coin if it came between Tru-arcs or press fitting however....

Dont get me wrong, I support full floating pins and spiral locks.


This is the design I am familiar with and was thinking of.
http://store.summitracing.com/partdetail.asp?autofilter=1&part=JEP-094-050-CT&N=700+400110+316124+115&autoview=sku


I just saw where someone makes a tool that you put the spiral lock on the tool and literally just rotate the tool counter clockwise and it spins the spiral lock in place. Not sure how you get them out.

http://www.lockintool.com/how-to-use/

Broncitis":3symfsky said:

but does 10's; does 10's...

Click to expand...

Sorry for the interruption...but this cracked me up!
Thanks!!
Will