My Turbo F22B2 - F22B DOHC hybrid - s16g

[bruno8747]

What was the total cost for the pistons and rings(set of 4)?
What Rod's did you get?
And whats the link to the pistons?

[Ilikebigbutts]

that deglazing job looks real nice but make sure you get piston to wall readings and tehy better be .002" or smaller.not trying to sound liek a smart ass just looking out for you.

ILBB

[mtnickel]

.002" or smaller!!! REally!? holy crap that's a tight fitting piston.


I'll give it a measure though for curiousity. I sorta just threw this together for as cheap as possible...not even decking it or the head (AHHH)! i was careful taking the head off with torquing out and whatnot, and it worked fine on the F22a block it's currently on. My only concern is that when i spun a rod in the current block that metal got into the head and chew up the bearings. i'm keeping my fingers crossed that the F22b head is still ok.

Mark

[Ilikebigbutts]

well i would deffinatly check it...you never know you might of actually taken more material than you had to and now the piston to wall is to big...i'm using forged pistons and i just measured mine and their at .005-.006" wich is ideal for forged pistons but i would deffinatly not want to run that much on pistons that dont expand after warming up...piston slap and motor go bye-bye...

ILBB

[Ilikebigbutts]

.002" is the service limit, thats teh biggest you can go on stock pistons when a rebuild is recomemded according to the manual.

ILBB

[mtnickel]

sons of pain in my assholes.

well it's not .002". and hypereutectic pistons expand even less than cast ones. crap...mhhhhh...well then. should have done more homework...i went with the 60 seconds recommended by the maker of the rings.

But even still,it could have been out of spec even before i honed.

well looks like i look for 85.5mm pistons and rebore/hone, or find a cheap block that's still in spec.
unfortunate.

Let this be a lesson to all those who want to rebuild an engine...research and tolerances are Key.

mark

[mtnickel]

i can't exactly measure because you're supposed to measure 3/4" from the bottom crown,
but when putting in the original piston with the ability to slide past the rings, i get a reading of around .0025 to .003.

these pistons actually work best with half the recommended service limit.

I think new plan will be forged and more power just have to save up now.

Mark


Mark

[Ilikebigbutts]

haha, don't get discouraged man shit happens and you learn from them...to be honest as soon as i saw you did the hone yourself i figured you had to go out of spec cause that hone looks like it took alot of material taken out, i just didnt wanna sound cocky...

out of curiosity what is the clearance at?

ILBB

[mtnickel]

well it's hard to tell the exact with the current pistons since it's all together, but with the stock F22B piston it's in the range of .0025 to .0035.
However, this is just on 1 side. is the clearance supposed to be all the way around? cuz in that case i might be okay since the actual clearance all the way around would be only about .00175 at the most.

mark

[Ilikebigbutts]

no thats with the piston skirt touching the cylinder wall on one side and getting the measurement on the other.

ILBB

[mtnickel]

well then i'm screwed.

Ha...well F22 blocks are pretty easy to come by. I'll see what i can dig up before i completely abandon this. But considering hypereutectic pistons need very tight clearances...any used block doesn't seem ideal.

Mark

[Ilikebigbutts]

unless you get oversized psitons?do they make them in over size?

ILBB

[mtnickel]

just checked with my friend...the clearance is actually divided by 2 if i measure that way.
and typically i should measure bore with outside micrometer or bore micrometer then measure piston and compare and divide by 2.

i'll keep you posted.

[Ilikebigbutts]

i'll have to check the manual again but i'm pretty sur ethe pic showed the piston pressed on one side and measuring from the other...if that the case then my measurements are to tight lol.

ILBB

[mtnickel]

no, you were right...friend recanted when i double checked with him.