[Orlando_87GN]

Ya, Ya, .. they are hypers... but hey, for $150 I'll take that chance and find out if they really split, crack, break, melt ect under detonation...

I have decided to put this 4.1 together, and not break the bank with the carrillo rods, JE pistons, girdle and $1500 in machine work to make it all happen.

I know some guys running them here locally, and I have seen there DS files.. I have seen plenty of detonation in their car, and no melted pistons yet...

Called Jack today. He said go for it, and should be good up to around 600HP.

Here's a question.. Has anyone used the hypers with BAD results? What was the scenario, and what was the out come?? Everyone you talk to says the Hyper's suck, but no one really has any first hand experience...

FYI - Federal Mogul Part Number:
H471P40 are the .040 over ones...$24.39 per piston !
E408K40 are the rings...$57.39

1.807 CH
~36 CC's in the dish, probably less.

I called around and Summit had the best price. 2 weeks to get here, $6 handling. What a deal.

I'l keep everyone posted..

------------------
Email Address: mailto:[email protected][email protected]</A>

Stock Turbo, Stock Heads, Stock CAM, V4, MSD50's, TH DP, JayJackson 62mm TB, 16position MaxEffort Chip. 3750# with Driver
12.35 & 108.39 Street Trim
11.92 @ 111.77 Race Ready

 

[Grannynational]

Run it!!

Joe
-----------------
1986 Grand National
13.22 @ 105mph
K&N and a paperclip

 

[HYPER-6]

Originally posted by Orlando_87GN:
Ya, Ya, .. they are hypers... but hey, for $150 I'll take that chance and find out if they really split, crack, break, melt ect under detonation...

I have decided to put this 4.1 together, and not break the bank with the carrillo rods, JE pistons, girdle and $1500 in machine work to make it all happen.

I know some guys running them here locally, and I have seen there DS files.. I have seen plenty of detonation in their car, and no melted pistons yet...

Called Jack today. He said go for it, and should be good up to around 600HP.

Here's a question.. Has anyone used the hypers with BAD results? What was the scenario, and what was the out come?? Everyone you talk to says the Hyper's suck, but no one really has any first hand experience...

FYI - Federal Mogul Part Number:
H471P40 are the .040 over ones...$24.39 per piston !
E408K40 are the rings...$57.39

1.807 CH
~36 CC's in the dish, probably less.

I called around and Summit had the best price. 2 weeks to get here, $6 handling. What a deal.

I'l keep everyone posted..

Ya might want to check out a recent thread on
the 'other' board before ordering the pistons
from Summit. Someone posted that Keith Black
pistons from a Ford <cringe> 351W engine are
able to be used in a 4.1L/4.0" bore and they are a better piston than the FMs. Both are
hypereutectics though.




------------------

 

[Orlando_87GN]

http://www.turbobuick.com/bb/Forum1/HTML/021337.html

You mean this one??

Ok, so why are the Federals supposedly inferior to the KB's?

The Windsor pistons will be about 8.4:1 (in my motor anyway) and the Federals will end up a hair under 8:1 .

That is my deciding factor on the Federals.

Again, anyone have any solid evidence that the hyper's are junk? Who has melted one?

I guess I'll be the guinea pig here.

------------------
Email Address: mailto:[email protected][email protected]</A>

Stock Turbo, Stock Heads, Stock CAM, V4, MSD50's, TH DP, JayJackson 62mm TB, 16position MaxEffort Chip. 3750# with Driver
12.35 & 108.39 Street Trim
11.92 @ 111.77 Race Ready

 

[GNXClone]

Ask Ken Mosher about his experience with hypers (not good).

In a different kind of turbo car, I broke the hypers into tiny bits like glass and ruined two engines. Not from heat but from detonation.

If you could find some diesel pistons that would be the bomb!

BTW: IMO 8.4:1 is better than 8:1. It'll give just a little kick down low and only require a fraction more octane or lower timing on the high end.

-Mike

 

[Orlando_87GN]

GNXClone - What were the circumstances with your pistons coming apart? What brand were they? What application? Extremly lean condition? Too much boost? I think any piston will give out due to stresses like that.. maybe the forged are more forgiving..



------------------
Email Address: mailto:[email protected][email protected]</A>

Stock Turbo, Stock Heads, Stock CAM, V4, MSD50's, TH DP, JayJackson 62mm TB, 16position MaxEffort Chip. 3750# with Driver
12.35 & 108.39 Street Trim
11.92 @ 111.77 Race Ready

 

[kenmosher]

I have one that I use for a coffee cup holder. It cracked at the wristpin and the skirt. Eventually, it cracked all the way to the ring land and then it broke (as in a pie shaped piece missing from the crown). Pretty spectacular as it pressurized the crankcase and blew oil on the downpipe, causing a "jet with an afterburner" look as it went down the track at night (a quote from someone who saw it).

The car spun hard in second gear about 100-150 feet out (something was spilled or wet...Friday night grudge night where they don't prep the track).... car hit the rev limiter, bucked and then started to miss. Coasted to the shutoff lane and about fainted when I saw the fire truck come barrelling up to me! Fortunately, they used Halon or some other dry gas and no damage (didn't even burn the paint on the underside of frame).

Ruined #3 bore ... would need a sleeve to correct it. That block is now sitting in my parts cache as a "maybe some day" project. The wierd thing is the other 5 pistons actually looked almost brand new! I could wipe the top with a rag and they shined right up! I wonder if this one either saw a little detonation, or cracked due to the over rev, or was faulty. Regardless, it's either stockers or forged for me from then one!

------------------
==========================
Ken Mosher http://www.turbo-link
Co-moderator: GN/TType Enthusiast Organization

 

[Orlando_87GN]

What brand was this? How long ago as well. Thank you.

------------------
Email Address: mailto:[email protected][email protected]</A>

Stock Turbo, Stock Heads, Stock CAM, V4, MSD50's, TH DP, JayJackson 62mm TB, 16position MaxEffort Chip. 3750# with Driver
12.35 & 108.39 Street Trim
11.92 @ 111.77 Race Ready

 

[GNXClone]

Originally posted by Orlando_87GN:
GNXClone - What were the circumstances with your pistons coming apart? What brand were they? What application? Extremly lean condition? Too much boost? I think any piston will give out due to stresses like that.. maybe the forged are more forgiving..

Circumstances: No audible detonation, no overboost, not lean. Just all of the sudden a loose rod comes out of the block (because the piston has shattered leaving the rod to fling around).

Brand: Mazda OEM [I did say different]

Application: Turbocharged '99 Miata.

Not lean at all. O2 volts in the mid 900's!

Too much boost? I don't think so. Had been running 15 PSI for 3000 miles then poof!

Second engine, ran 12 PSI for another 3000 miles then poof again!

I think maybe the timing spiked up a hair too high or something. It was on the edge and a little over pressure made the high silicon content pistons (hyperuetectic) break like glass. Again, I never heard any detonation at all, and this engine was VERY quiet. (No ricer exhaust! Sounded stock).

Similar to what Ken wrote above, all the other pistons looked perfect as did the spark plugs. No visible sign of detonation anywhere!

I gave up on forced induction on that car.

Forged pistons ARE more forgiving. I've heard the stockers are even more forgiving than forged because they are modeled after a diesel engine application. Almost anything from a diesel app. is built to take alot of abuse.

I'm not telling you not to use them, just relaying my experience. I too will never use a hyperuetectic piston in a F/I app again. Many others have great success, but I would rather spend a little extra and over engineer. Build it to take 200% of what you throw at it is my new philosphophy.

-Mike

 

[kenmosher]

Brand: SpeedPro (bought out by Fed. Mogul)
Happened in 1993 (I think)
20-21 psi of boost and a "normal" timing chip (Red's 107).

------------------
==========================
Ken Mosher http://www.turbo-link
Co-moderator: GN/TType Enthusiast Organization

 

[JohnH]

here you go. fm hyper.