How To: Install New Pistons and Rods


Most of you want to swap out your weak stock internals to be able to go above the 450rwhp mark but don't have the cash to shell out to pay someone to do it for you. This "How To" starts after the engine has been taken out, oil pan uninstalled, and the rod/piston assembly taken out. Taking these parts out of the vehicle is the simple part which is why I did not spend time and energy on how to take parts off. The rods will come already numbered for the cylinders. Remember that Ford numbers their cylinders like this:

Front of Engine:
5 1
6 2
7 3
8 4

To install the new piston on the new rod is pretty simple yet complicated when it comes to locking them with the clips. Wrist pins usually comes with the pistons already so all you have to do is get your new rod and piston, insert wrist pin, and install the locks. Some clips need to be squeezed in there while others (Like the ones I used here) needs to be inserted with the tip then you can rotate it and it'll go in by itself.

Wrist pin and locking clips installed. (Top)


Now that that's out of the way, lets start off by looking at your cylinder. You'll be able to see a nice reflection (Glaze) on the cylinder so you want to get rid of that so you can start off fresh. How do you do it? I buy these for the cylinders to deglaze it and get my nice cross hatches on the cylinder.

Brush Research Mfg BRMGB334 3.75 - 95mm Standard Duty Flex Hone (You can sometimes find them cheaper somewhere else).

What is cross hatch? Taken from Wikipedia: A "cross-hatch" pattern is used to retain oil or grease to ensure proper lubrication and ring seal of pistons in cylinders. A smooth glazed cylinder wall can cause piston ring and cylinder scuffing.

So now that you got the concept of getting your cross hatch, I recommend getting used to your trigger finger and maintaining a constant speed before going inside the cylinder. Make sure its not too high but not too low either. 600-800 rpms while going up and down consistently is ideal for the perfect cross hatch. You need to lube the cylinder and the flex hone as well before going in. Flex Hone sells their own oil so I would buy it while you are at it.

Now that you got the cylinders honed its time to install the piston rings. I bought my rings from Summit Racing and bought their rings that were already gapped for my application. They do cost a little bit more but if you want to do it yourself you need to place the ring inside the cylinder, push it in with a piston, get a gap gauge to see what your specific application needs and file as necessary.

There are many ways to position the rings on these engines but I will show you what has worked great for me. Here is a picture of how I position them.

The top ring is in the center while the top oil ring is 45* to the left and the bottom oil ring is 45* to the right.


On the other side, the second compression ring is in the center while the spacer is 45* to the right.


You then rent (or if you already own) a ring compressor. You can rent these at any auto parts store and they will give you your money back once you bring it back to them. Make sure that your rods that you labeled are in the correct position, the piston facing the right way (Front of engine is in fact front of engine) and your rings dont move while you are compressing the rings. Once that is achieved, you slide the piston inside the cylinder, grab a rubber hammer, and start tapping the piston with a little force making the piston go in. Make sure the rod does not scratch the cylinder wall or nick the crank either. To avoid this, it would be great if you have an extra person helping you by guiding the rod itself until it finally reaches the crank.

There will be times where one of the rings comes out and you will have to repeat the process again until the entire piston goes in. It'll look like this.


And like this once everything is done.


Torque everything down to specs, once everything is good to go turn the engine over without the fuel pump connected so you can prime the cylinders with oil. Sorry if I forgot something but I literally just got done doing these to my own engine.

*Note* Use proper assembly lube on rod bearings to prevent dry start.


No comments :( Took me a long ass time to write down everything as well document with pictures. As long as someone gets good use out of this it'll be worth it.


Hell of a write-up, for a new guy trying to build himself a decent shortblock, this would save his life. Thanks Ortiz!


lil mustang big heartbeat
It'd be good to add to use extreme caution when sliding the piston in. You wouldnt want the rod to scratch the cylinder wall, or worse, the crank!!

good job though!