I am building a 4.2 liter v-6 in a 1997 ford f-150. The Haynes manual says to put the notch on the piston toward front of motor. the problem I have is that the piston does not have a notch on them. any one know another way of telling which way is the right way?

 

No other marks on piston? You might try the website of the piston manufacturer for info or the retailer to you.

 

I am using the original pistons

 

The original pistons, as in the old pistons?

Or original equipment pistons from Ford?

If you are using the old pistons, you should be putting them back in the same holes in the same direction as they were when you pulled it apart.

 

By notch i believe they mean the pin that is located where the rings are placed in the grooves everyone calls them different things anyways you want these notches facing the inside of the motor because you risk shattering them as the other side is your exhaust port and you would have where your rings come together traveling up and down a port opening, otherwise some are marked with a small dot or small arrow indicating directions if you are not sure just bring one to a reputable garage and they will assist you in the correct direction because you do not want to be wrong on this task i assure you. I just caught that you are putting your old pistons back in the motor i would be on the side of caution as you appear to not know what pistons came from where etc and you risk damage to your cylinders. Spend a little time and get a honer and spend a descent amount of time honing them to form nice clean xxx's on your walls and spring for a set of middle of the road pistons if your shy on cash and save yourself an entire rebuild later there not that expensive and if done right will last a lifetime.

 

Pins to locate rings and the risk of a ring catching a port apply to two stroke piston port engines.

Aftermarket piston with an arrow towards the front of the engine:

http://www.summitracing.com/parts/sl.../applications/

Hhmmmm, I can't tell if those are really 4.2 pistons or just a stock photo.

 

You are correct my friend should have went to bed sooner last night lol

 

No harm. I tried to find a pic of an actual Ford 4.2 piston, but I have given up. All were generic or aftermarket pics. IMO, OP should be using new pistons, not replanting the old ones.

 

Nothing wrong with original pistons if they are in spec. Many people hone a cylinder, install new rings on the original pistons. Some pistons have a notch on the top lip for direction and some it makes no difference. If your honing and installing new rings, it does not matter if original pistons are put into their original holes.

 

unless you removed the pistons from the rods,they will be pointed correctly when the rods are installed as removed....RODS MUST BE INSTALLED ON THE SAME CRANK JOURNAL FROM WHICH THEY WERE REMOVED .... UNLESS... rotating parts have all been machined.and new bearings installed. good luck...Dave