Okay I am trying to install my Weisco piston on my new forged rods and the pistion wrist pin will not push thru the rod. Does this mean the rods need to be pressed? But the pistons are floating type with wrist pin clips. Can you uses a press fit rod on a floating piston?

 

some thing is not right

 

can you use a press fit rod on a floating piston?

 

Here. Go to the machine shop to have them put in. they will also use a special lubricant afterwards. Its not expensive, and it is done correctly so that you have a sound engine.

http://www.youtube.com/watch?v=H2YrL3k__dA

 

So since the wrist pin will be pressed on to the rod, does that mean I will not use the "C" clips on the pistons?

 

What rods you using? You shouldn't have to press the pin in on a forged piston/rod setup. Thake it to a good shop and ask them to take a look at it for you.

 

Forged pistons and rods should not use press fit pins. Look at the pin bore of the rods and if you see a bronze bushing, its meant for a floating pin.

Now if the pins won't go in the bores, find a machine shop that can pin fit the rods. Wisecos are usually pretty damn good about the pin fit on their pistons, but I don't know what rods you have.

Make sure they have this instrument so they can actually measure the clearance:



Notice the gold colored bushing in the pin bore. That's your bronze bushing.

 

Yeah my forged rods do infact have bronze inserts and they have 2 oil holes on the sides. See here.

 

They would simply heat it up slightly, push them in, and insert the c-clips.

Wiseco doesn't know what kind of rod you're using so they prepare it for both.

take it to a machine shop, let them do it for you. you're ok.. No blow to ego.

 

hahahah....just sucks I was on a roll putting it together until I rand into this....ugggg

 

Hang on a sec. With a press fit pin, you do not use the c-clips. There is no purpose for them when the pin has an interference fit with the rod.

With a floating pin, you absolutely should not have to heat up anything to get the pins in. They should have roughly .0009"-.0015" clearance at room temp and slid in with ease.

 

Its good thing you did. Inadequate pin clearance can lock up your engine in a heartbeat. Make sure when you put it together, you get some assembly lube on the pins so they wont start up dry. You can even use the ARP moly lube if you don't have anything else.

 

The wiseco pistons don't have an true interference fit once it is heated and pressed in. Blame wiseco if you wish, but this is what I did to about 3 engines when taking it to the machine shop. they then heated them, pushed them in (no real press) and left the c-clips for me to install.

Don't know what to tell you. Since this is debatable, again, I suggest he take it to a machine shop to be sure, and stop all the guess work.

 

I guess Monday morning Ill place a call to Wiesco and the con rod manufacture and make sure I can use them together. If infact I can, then Ill be taking them to a machine shop.

 

This isn't exactly debatable, there is a right way and a wrong way.

You should never have to heat up a piston to get the pin to fit. Not in a press fit pin application and not in a floating pin application either. At room temp, you should have about .001" of clearance, otherwise the pin can stick in the piston and completely lock up the engine. At best, you can lose a lot of power to friction. You only heat the rod with a press fit pin and using the c-clips is only excess weight and could possibly bind up in use. I highly recommend you find another machine shop if they advocate heating the piston to get the pins to fit and using c-clips with a press fit pin.

Regardless, I don't think thats the problem here, I think its the rod that doesn't have adequate clearance, which is common. Wiseco supplies the pistons with the pins so they're pin fit from them, and their clearance is usually consistent to a couple tenths. The rod manufacterers, however, don't see the pins when the rods ship so thet is usually where the issue is.

 

have a nice day

 

I know with je pistons and eagle rods and full floating pins, we put the pistons on the rods right there. With full floating, you shouldnt have to press anything

i've never heard of this issue with weisco pistons and eagle rods before

 

Fine. But I said the ROD needed to be heated. (as shown in the video) not the piston. Either way, he doesn't have the equipment to do it. So whether or not its .001" or .025", he still has to go to a machine shop to get it proper.

60K miles later, still rollin'. I'll trust the machine shop. But I do appreciate the input.

 

the rod bushings needs a light "hone" to make sure the pins fit in smoothly. if you have to force it in they are to tight. no need to heat or press them in. they should just slide in smoothly.

 

OP,

I'm not sure what pin or piston/rod combination you have but what others have stated is correct. The pins should slide in easily.

Do this for sure.

 

All the forged pistons I have installed onto aftermarket rods (about 20 sets) I have never ran into this...I just tried the next set I have sitting waiting to be installed (this is a wiseco/eagle combination) and they fit like they allways do nice and snug.

 

Shodan,

It sounds a lot like you are talking about the Wiseco pistons being heated in this post. Whether you meant the rods or not, I wouldn't want him or anyone else getting confused and asking their machine shop to heat the pistons.

 

My apologies for my lack of sentence structure at such a late hour. I would HOPE that any competent machine shop that deals with the installation of pistons would know not try and heat the piston. Again, the video was pretty clear as the reference.

 

I've had this issue with SCAT rods pin bores needed honed to fit. In the end I was happy that they were too tight (before honing) and not too loose.

No big deal.....

 

Yeah I talked to the rod manufacture and they said that sometimes the pin bore on the rod needs to be "adjusted" So Ill get it straitened out.