Manley Pistons, arrived with not much fanfare

[jdmage_mx5]

According to the sheet I got with the Pistons and rings it said to go bore x .007". I'm going off the 15-30psi street car row.

A) they call that for both top and 2nd ring.
B) seems odd to have both rings the same
C) bore x .007 comes out to like .024 that seems huge compared to other builds running .018 or .020.

And to note, I called Manley to discuss this and I got a generic response "if that's what the sheets says then that's right. Those measurements came straight from TotalSeal."

[Dano]

huge gap is huge. with a piston made from said material (between race and OEM) I would expect smaller gaps...but I am by no means experienced in this area. Smaller required P2W is a given but I don't understand the large ring gaps and especially 1st and 2nd rings being the same?

interesting.

[jdmage_mx5]

Pwc was like .0035 for coated.

Originally Posted by Dano huge gap is huge. with a piston made from said material (between race and OEM) I would expect smaller gaps...but I am by no means experienced in this area. Smaller required P2W is a given but I don't understand the large ring gaps and especially 1st and 2nd rings being the same? interesting.

I started to follow the directions and really did not feel comfortable with such a huge gap. I have since ordered new ring sets from Manley and now trying to decide what gap I actually need to run.

[Tokay444]

Bigger the better when it comes to ring gap.

Institution Of Diagnostic Engineers

[Justin@Freektune]

Originally Posted by jdmage_mx5 Would you mind sharing your thoughts on PWC and ring gap with these Pistons? I know you have installed a few sets. I'm just curious as to what the more knowledgeable are running spec wise with these.

Always use their recommendations as a guidleline and adjust each spec per customers engine use/goals.. Each engine is built to spec, so there is no one size fits all.

Originally Posted by acemanz So given that we are using what you consider to be a product that should really only be used in an engine with regular overhaul intervals, what is your thoughts about the realistic longevity of these in a Daily Driver car. how long do we got doc?.. give it to me straight..

I have guys that have 40k+ miles on their engines, and as lex mentioned, short of louder piston slap, haven't had any ill effects. But things that do occur is more blowby and oil consumption. The key with keeping her healthy starts with a proper break in, maintenance, and definitely a good PCV system. I like big ports to let that CC vapor escape whether 10an fittings to a vented can, or breather cap.

I think Manley really hit it on the head by using the thicker top ring as opposed to the other pistons that are available right now. Each motor that I have used them in, is running, and all were pulling crazy manifold vacuum within just as few miles. I gave one of the engines a little boost (1-2psi) about 5 miles into my road test and that thing just wanted to pull. Made me all giddy inside. lol

[Dano]

Originally Posted by Tokay444 Bigger the better when it comes to ring gap. Institution Of Diagnostic Engineers

interesting theory and testing results.

[EdgeAutosport.com]

Lots of good info going on in here! Thank you Justin, Alex, and Tokay! Oh and jdmage_mx5 as well!

[Tokay444]

Originally Posted by Dano interesting theory and testing results.

The absolute LAST thing you want, is ring butting. Then you get what happens to the stock motor, but with a lot more work and at a higher cost.
I went .020" top ring and .025" second.
Left the oil control ring as it were.

[Dano]

yup and IIRC I went with .018-.019 top and .022 2nd.

I just don't want oil consumption and with the above gaps on my 90mm wisecos, I have none, with a 5% leakdown after 4K miles on 28-30PSI tune.

I think it can be a balancing act for sure.

[Easter Bunny]

Originally Posted by Tokay444 The absolute LAST thing you want, is ring butting. Then you get what happens to the stock motor, but with a lot more work and at a higher cost. I went .020" top ring and .025" second. Left the oil control ring as it were.

You ever going to turn that motor on?

[Dano]

it won't build enough compression to start...

[Easter Bunny]

Originally Posted by Dano it won't build enough compression to start...

Lol..... If your first built motor ran he should be fine.

[Tokay444]

Shipping head for FreekBuilt this week.
The oil control ring is what keeps the majority of the oil out of the combustion chamber.
There isn't a lot left to get past a gap smaller than the thickness of a finger nail in two compression rings. Especially since there is more pressure trying to push past the rings in the opposite direction than there is pulling oil from underneath.

[Dano]

Originally Posted by Easter Bunny Lol..... If your first built motor ran he should be fine.

don't you mean 2nd? or 3rd? I lose track...lol

Originally Posted by Tokay444 Shipping head for FreekBuilt this week. The oil control ring is what keeps the majority of the oil out of the combustion chamber. There isn't a lot left to get past a gap smaller than the thickness of a finger nail in two compression rings. Especially since there is more pressure trying to push past the rings in the opposite direction than there is pulling oil from underneath.

I guess I should state my objections more correctly...I don't want consumption for sure but what I really meant was I don't want blow-by filling up my OCC and/or my VTA filter getting soaked. both my 2nd and 3rd (current) builds are as dry as a powder house...well not that dry but you get the point.

[Tokay444]

In that case, I refer back to the document I posted.
I even actually considered pinning the rings.
A differnce of a couple thou isn't going to be what pressurizes your crank case or not, but it can be the differnce between end butting or not.
We've seen broken lands on forged pistons.

[Easter Bunny]

Originally Posted by Dano don't you mean 2nd? or 3rd? I lose track...lol

2nd counting the drop and pop.
1st "virgin" even though we know now she was a slut.

Man I forgot how much fail you had.

[Tomas]

The words Dano and Virgin are equivalent to the words Anti and Christ.
As separate entities they are harmless.
Together mayhem ensues.

[alfre127]

so anyone push this pistons with more than 600whp, with stock wristpins?

[Tokay444]

Is there something inherently wrong with the stock wrist pin?

[Tomas]

The Pu wrist pins have a smaller wall thickness then the Gen1 pistons. They are also lighter.
None have ever failed however.

[bdm665]

the MSF3 coupon code isnt working. what am i missing?