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-   -   forged or hyper (https://67-72chevytrucks.com/vboard/showthread.php?t=400658)

POPO1984 05-03-2010 03:48 PM

forged or hyper
 
guys im building a 383. my engine guy seems like he wants me to use forged pistons. the ones he wants will put me around 9.5:1 cr and are 450 bucks. do i really need forged or could i go hyper. i dont plan on spraying it or FI

swb85 05-03-2010 05:20 PM

Re: forged or hyper
 
If no power adders are planned, hyper is just fine. In all reality, you can even put a light power adder (100 shot or ~5lbs of boost) to quality hyper pistons so long as the tune is in order.

Ticker 05-03-2010 06:48 PM

Re: forged or hyper
 
The one thing to keep in mind that it's relatively cheap now to go forged...but hella expensive later (new pistons, rebalance, etc.)

If you think in your wildest dreams that you might user a power-adder later...spend the $$ now.

rjs53 05-03-2010 08:11 PM

Re: forged or hyper
 
It wouldn't bother me to go hyper if no power adders. I had a ZZ4 that i angled milled the heads .020 put the comp hr282 cam in and 1.6 rockers drove it like i stole it and had close to 200 1/4 mile passes on it. always ran 91 or 110 in it the one time i put 87 in it it rattled but didn't hurt it. wish i still had that motor but that's how wheelin and dealin goes

Alex1 05-03-2010 08:27 PM

Re: forged or hyper
 
Forged.

Marv D 05-03-2010 08:41 PM

Re: forged or hyper
 
No way would I build ANY performance or even a towing engine with hypereutectic pistons. Add a little detonation and they turn back to the sand whence they came. I have opened up more than one broken motor and found a hypereutectic piston GONE, no evidence at all it ever existed. Well,, except the big gaping hole in the cylinder wall where the rod beat the crap out of it with no piston to guide it's path.
Hypers are great for a driver / cruiser. Little thermal expansion means they have a tighter bore cold, are quiet as cast, great oil control, no scuffing if the motor overheats. They have their good points. but they also have their down side.

Ticker 05-03-2010 08:45 PM

Re: forged or hyper
 
I've built a bunch of hypereutectic engines - some that were pretty warm - and the only time I've seen 'em break is when more than a 75-100 shot of NOS is used, or when using Keith Black pistons without paying proper attention to ring gap.

NO engine is going to survive sustained detonation at speed...

ProStreet68SB 05-03-2010 09:33 PM

Re: forged or hyper
 
Quote:

Originally Posted by swb85 (Post 3955433)
If no power adders are planned, hyper is just fine. In all reality, you can even put a light power adder (100 shot or ~5lbs of boost) to quality hyper pistons so long as the tune is in order.

hypers can handle boost, just not spray. Remember the old GMC syclones and typhoons? I wanna say it was 11 or 13lbs from the factory on hypereutectic pistons. I know a guy here in cbus is a 5.0 mustang running hypers and 10lbs i wanna say he makes 435whp. So hypers can take boost, just not spray.

hotrod 80 05-03-2010 09:47 PM

Re: forged or hyper
 
Forged or cast for me .

POPO1984 05-03-2010 09:56 PM

Re: forged or hyper
 
Okay I got the forged srp 18cc dished pistons for $ 450.00 out the door. I plan on running 72 cf heads which should put me around 9.1:1. This is with a 6.0 rod. At least this is what my engine guy is telling me.

fiddy9apache 05-03-2010 11:21 PM

Re: forged or hyper
 
forged, spend the extra money now.

Ticker 05-03-2010 11:39 PM

Re: forged or hyper
 
Quote:

Originally Posted by POPO1984 (Post 3956007)
Okay I got the forged srp 18cc dished pistons for $ 450.00 out the door. I plan on running 72 cf heads which should put me around 9.1:1. This is with a 6.0 rod. At least this is what my engine guy is telling me.

Tough decision - but a good one. I personally like SRP and buy their pro kits for my builds almost exclusively.

I'm sure the engine guy has "done the math" and done it right...but ask him to lay the whole thing out for you - deck height, head gaset, quench, etc. You'll want that stuff later for sure. Generally you want to collect EVERYTHING you can and put it in a "build book", which is the "bible" (<- not capitalized, so everyone relax :)) for your engine. P/N, clearances, etc...get it all.

BossHogg69 05-04-2010 12:45 AM

Re: forged or hyper
 
Good call on the SRP's - I have a set of forged 23cc dome forged SRP's in my 468.

Hertzdaddy 05-04-2010 08:06 AM

Re: forged or hyper
 
Quote:

Originally Posted by Ticker (Post 3956312)
I'm sure the engine guy has "done the math" and done it right...but ask him to lay the whole thing out for you - deck height, head gaset, quench, etc. You'll want that stuff later for sure. Generally you want to collect EVERYTHING you can and put it in a "build book", which is the "bible" (<- not capitalized, so everyone relax :)) for your engine. P/N, clearances, etc...get it all.

Very good advice. I wish I had that info now on an engine I bought already assembled.

djracer 05-04-2010 08:44 AM

Re: forged or hyper
 
You made the right decision so now order that plate system to get that pig out of the hole! LOL :metal::lol::sumo:

POPO1984 05-04-2010 09:10 AM

Re: forged or hyper
 
Quote:

Originally Posted by djracer (Post 3956732)
You made the right decision so now order that plate system to get that pig out of the hole! LOL :metal::lol::sumo:

That was one of the reasons that I got the forged. If I want to spray it way later down the road ill be able to.

swb85 05-04-2010 10:51 AM

Re: forged or hyper
 
Quote:

Originally Posted by ProStreet68SB (Post 3955925)
hypers can handle boost, just not spray.

Tell that to all the ls1 cars that have a 150+ shot on them. Shoot there's some local guys around here that have been spraying 200 for several years on stock bottom ends.....they won't last forever, but if you keep it from detonating it won't grenade.

J_PEPIN87 05-04-2010 10:52 AM

Re: forged or hyper
 
Who's building your engine popo?

hotrod 80 05-04-2010 11:53 AM

Re: forged or hyper
 
Quote:

Originally Posted by j_pepin87 (Post 3956903)
who's building your engine popo?

x 2

POPO1984 05-04-2010 01:10 PM

Re: forged or hyper
 
This older guy in South Houston his buisness is called speeco. Ive heard really good things about him. Really nice guy he is also doing my rebuild on the differential. His name is Harold or Buddy

Ticker 05-04-2010 01:29 PM

Re: forged or hyper
 
Quote:

Originally Posted by swb85 (Post 3956901)
Tell that to all the ls1 cars that have a 150+ shot on them. Shoot there's some local guys around here that have been spraying 200 for several years on stock bottom ends.....they won't last forever, but if you keep it from detonating it won't grenade.

:agree: I have seen hypereutectics hold up under some brutal abuse...but in the end it becomes a risk management process :)

djracer 05-04-2010 02:32 PM

Re: forged or hyper
 
If my memory serves me right someone on here had a 305 with a bunch of spray and I think it had cast or hypers in it but I wouldn't try it. I always say I would rather be lucky than good. That guy was lucky.

Shon 05-04-2010 04:34 PM

Re: forged or hyper
 
local 135k mile STOCK Bottom end LT1 is running in the 9s (1/4 mile) on the hose so if you got the tune right, it will work....

hotrod 80 05-04-2010 06:08 PM

Re: forged or hyper
 
Quote:

Originally Posted by Ticker (Post 3957125)
:agree: I have seen hypereutectics hold up under some brutal abuse...but in the end it becomes a risk management process :)

Quote:

Originally Posted by Shon (Post 3957431)
local 135k mile STOCK Bottom end LT1 is running in the 9s (1/4 mile) on the hose so if you got the tune right, it will work....

If these are the Mahle pistons they will take quit a bit of abuse if the tune is right , but The popular name brand that first comes to mind you couldn't give me .

Captainfab 05-04-2010 11:12 PM

Re: forged or hyper
 
So the Mahle hypers are supposed to be better than the other brand? Can you elaborate?


Quote:

Originally Posted by hotrod 80 (Post 3957572)
If these are the Mahle pistons they will take quit a bit of abuse if the tune is right , but The popular name brand that first comes to mind you couldn't give me .



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