lol nice advertisement hope u aint leaving it on there when the head goes on

 

Is it just me or does that piston to the left look egg shaped? Is it the picture or the ring that makes it seem this way?

 

If you look closely at the left piston you will notice the ring gap at 7:00 o'clock.
That will give you and idea of how far the ring protruds from the piston, and that is what is casuing it to seem egg shaped.

JMC

 

all pistons are egg shaped and not perfectly round... with the angle u are looking at it u see it more definate

 

Faster,


If you were looking at a piston from the top and could not see the orientation of the pin could you actually tell which way it was ovaled?

JMC

 

You are joking right? How in the world would you machine a cylinder bore to match?? Maybe not perfectly round, i would expect cast pistons to be off by a couple of thousandths but to call it egg shaped and made that way......

 

Actually any "cam" ground piston will be oval in shape. The thrust area is made wider becasue the piston pin area expands more than the rest. So pistons are made in an egg shape so that when it heats up it becomes round. Also the piston head gets hotter than the skirt area so it is of a smaller diameter than the skirt. We are talking thousandths of an inch. Not visible to the human eye, except maybe Faster.

JMC

 

I can understand that, but as you pointed out... to the naked eye

 

you learn something new everyday, i love this sight, i am going to find out how many of my fello ASE certs. know about this, thanks JMC

 

Pistons have been 'cam' cut for a long time.
How much depends on the alloy composition of the alum that controls expansion rates.
They have to be designed for the specific engine family or there is risk of piston scuffing or excessive clearence when up to operating temp..
Fitting piston to bore clearence is critical and must follow the piston mfger. specs.
This is an area that will contribute to piston slap if there is excessive skirt clearence.
On the old 302 from back in the 70s, at high mileage, the skirts would start to colapse and get noisey. With continued use, brakege occurred and the engine was lost when a piston skirt broke up and the rod flailed in the cylinder breaking the cylinder wall/block and hurting the crank then it was all junk..
The usual signs of it are cold startup rap then it either goes away or reduces when the engine heats up. If it just reduces on an old engine then the danger zone could not far away for continues use.
I see people on this board that do not know what piston slap is but react with that label at every noise they hear.

 

again, agreed and nothing new but i wouldn't call it egged. and the way the one on the left looks is much more than cam'd but as pointed out, the picture and ring position could just through it off.

 

Neal,
The number on the original pistons match Mahle center pin pistons. The arrow on the replacement pistons indicate they are offset and the number indicates they are different then the others.
Do you think you will have any issues

 

HI!... WLF : I noticed the different # and called MAHLE on this. They told me the extra digits at the end of the identical stamping #'s are due to the 2 pistons I bought did not come from a matched set of 8 for a 5.4. Plus these particular two had to be custom matched up to the same weight as the ones that I originally bought. As for the arrow, on every engine I've every built, it just means that that ARROW has to point towards the front of the engine. Just a location arrow.

 

HI!... Well my custom grind COMP-CAMS cams and valve train showed up today from MIKE TROYER at PERFORMANCE PRODUCTS. As some of you might not know, Mike offered to pay for these parts out of his own pocket. He did not have to do this at all, but felt he wanted to, to help me out due to all the problems I had with the FOX LAKE heads I bought through him. This is customer service at it's best!!!!!!! Thanks MIKE!!!!!!

Well I took a few pics, so here you guys go :