Engine re-build....Hyper or forged pistons?
Thread Starter
Pro
Joined: Jun 2009
Posts: 613
Likes: 3
From: Fleetwood PA
Engine re-build....Hyper or forged pistons?
I know hypers have gotten some bad press, but are they really a problem on a street motor? I'm not throwing NO2 or a blower at it.
Its a 454 .030 over, 049 heads, mild cam, and about 10 to 1 CR.
I know forged are more forgiving and a lot of people say spend the money on them, but they come with their own problems. Piston slap, long warm up times,loser oil seal till warm, and price. The hypers seem to have the power adder restrictions, and are more brittle so you really have to watch detonation issues.
I think I'm leaning toward the speed-pro hypers, so if anyone has had any good or bad experiences with them, let me know.
Its a 454 .030 over, 049 heads, mild cam, and about 10 to 1 CR.
I know forged are more forgiving and a lot of people say spend the money on them, but they come with their own problems. Piston slap, long warm up times,loser oil seal till warm, and price. The hypers seem to have the power adder restrictions, and are more brittle so you really have to watch detonation issues.
I think I'm leaning toward the speed-pro hypers, so if anyone has had any good or bad experiences with them, let me know.
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Hypers are fine, but street-series forged are fine too. I have a set of forged pistons in my 454 and there is no piston slap and the oil seal is just fine. Street-series forged are not very expensive. I paid just over $300 for the set.
Melting Slicks
Joined: Sep 2005
Posts: 2,710
Likes: 901
From: Warminster PA
I used the Speed Pro hypereutectic pistons for my 71 LS5 rebuild. Since it was strictly a "factory specification" rebuild I thought I'd give these a try and I was very impressed with the quality of the piston.
From what you have described about your rebuild, I think that the hypereutectics would be a good choice.
Tom
From what you have described about your rebuild, I think that the hypereutectics would be a good choice.
Tom
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From: Millington Illinois
St. Jude Donor '08-'09
Drifting
Joined: Aug 2004
Posts: 1,883
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From: Lubbock TX
I'll generally step up to forged pistons before a forged crank. Watch sleazebay, I've scored several of my deals there by buying leftovers from abandoned projects. I have 3 brand new sets of big block pistons, all forged, and I didn't pay more than $300 for any of 'em, shipped.
Pro
Joined: Oct 2007
Posts: 587
Likes: 0
From: Overland Park Kansas
I've run my 383 for like 20k miles with KB hypers and OVER 11:1. I've had some bad pinging at times while it wasn't tuned right.
Never had a SINGLE problem. Took the heads off like 2k miles ago, pistons were still beautiful. While I'm sure detonation isn't good for them, (isn't good for anything), I don't think it's as bad as some people say.
If it's near the same cost and I was doing it again (AND the new forged ones don't slap), I'd still go forged tho just to cover my ***.
Never had a SINGLE problem. Took the heads off like 2k miles ago, pistons were still beautiful. While I'm sure detonation isn't good for them, (isn't good for anything), I don't think it's as bad as some people say.
If it's near the same cost and I was doing it again (AND the new forged ones don't slap), I'd still go forged tho just to cover my ***.
Le Mans Master
Joined: Feb 1999
Posts: 8,351
Likes: 75
From: Tampa Bay FL
Sealed Power/Federal Mogul (H345NP) hyper pistons in my rebuild 10 years ago. Hastings Moly Rings and no piston slap... approx $100/set for the pistons.
Running fine today. .020" overbore, 72cc DART Iron Eagle 180cc intake runner cyl heads, Crane Energizer (.454/.454) cam/lifters and an aggressive advance curve. I run premium fuel.
Jegs:
http://www.jegs.com/i/Sealed+Power/844/H345NP/10002/-1
NOTE: I bought my engine kit from Northern Auto Parts for under $400 ("Street Performance" kit if I recall). All name-brand parts (Fel-Pro, Crane, Melling, Cloyes, Hastings, Clevite, Mich 77, Speed Pro/Fed Mogul, etc.).
The NAP kit is still under $400 (EK1900). I note it uses Speed Pro cam/lifters now but the optional cam list is impressive. You specify overbore/oversize parameters when ordering. $540 (EK1901) includes Scat cast crank:
http://www.northernautoparts.com/Pro...tModelId=18322
OOPS! I just realized you are running a 454... mine was the '80 350 (5.7L). Of course, the price would be more for the 454... Your kit options at NAP:
http://www.northernautoparts.com/Pro...?ProductId=550
Running fine today. .020" overbore, 72cc DART Iron Eagle 180cc intake runner cyl heads, Crane Energizer (.454/.454) cam/lifters and an aggressive advance curve. I run premium fuel.
Jegs:
http://www.jegs.com/i/Sealed+Power/844/H345NP/10002/-1
NOTE: I bought my engine kit from Northern Auto Parts for under $400 ("Street Performance" kit if I recall). All name-brand parts (Fel-Pro, Crane, Melling, Cloyes, Hastings, Clevite, Mich 77, Speed Pro/Fed Mogul, etc.).
The NAP kit is still under $400 (EK1900). I note it uses Speed Pro cam/lifters now but the optional cam list is impressive. You specify overbore/oversize parameters when ordering. $540 (EK1901) includes Scat cast crank:
http://www.northernautoparts.com/Pro...tModelId=18322
OOPS! I just realized you are running a 454... mine was the '80 350 (5.7L). Of course, the price would be more for the 454... Your kit options at NAP:
http://www.northernautoparts.com/Pro...?ProductId=550
Last edited by TedH; Mar 24, 2010 at 09:01 AM.
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From: Corsicana, Tx
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While I'm definitely a forged fan....I like a little insurance. But be VERY aware....there are Hypers and then there are Hypers. There are some very cheap *claimer* pistons out there that are junk. A GOOD hyper is a different item. As in Mahle makes the hypers used in the bad boy LS-7 Vette's......but Mahle knows what they are doing.
I think the issue is that by the time you spend money to get a GOOD hyper, you are very close to the price of a good street forged one. Piston design has come a long way and slap is a thing of the past if machine work is proper. I just tore down my 540 that has been running 4032 SRP's for 10 years and the pistons still look new. I used .0045 clearance which is a little loose in fact ( I shift at 7500 rpm) and had no piston noise when cold started.
For what you are planning a good set of hyper's would work fine, but remember to pay close attention the the ring clearance requirements and also remember that they are just a cast piston with some added silicon. That's why they are cheap.
JIM
I think the issue is that by the time you spend money to get a GOOD hyper, you are very close to the price of a good street forged one. Piston design has come a long way and slap is a thing of the past if machine work is proper. I just tore down my 540 that has been running 4032 SRP's for 10 years and the pistons still look new. I used .0045 clearance which is a little loose in fact ( I shift at 7500 rpm) and had no piston noise when cold started.
For what you are planning a good set of hyper's would work fine, but remember to pay close attention the the ring clearance requirements and also remember that they are just a cast piston with some added silicon. That's why they are cheap.
JIM
Drifting
Joined: Dec 2005
Posts: 1,360
Likes: 3
From: NORTHEAST
While I'm definitely a forged fan....I like a little insurance. But be VERY aware....there are Hypers and then there are Hypers. There are some very cheap *claimer* pistons out there that are junk. A GOOD hyper is a different item. As in Mahle makes the hypers used in the bad boy LS-7 Vette's......but Mahle knows what they are doing.
I think the issue is that by the time you spend money to get a GOOD hyper, you are very close to the price of a good street forged one. Piston design has come a long way and slap is a thing of the past if machine work is proper. I just tore down my 540 that has been running 4032 SRP's for 10 years and the pistons still look new. I used .0045 clearance which is a little loose in fact ( I shift at 7500 rpm) and had no piston noise when cold started.
For what you are planning a good set of hyper's would work fine, but remember to pay close attention the the ring clearance requirements and also remember that they are just a cast piston with some added silicon. That's why they are cheap.
JIM
I think the issue is that by the time you spend money to get a GOOD hyper, you are very close to the price of a good street forged one. Piston design has come a long way and slap is a thing of the past if machine work is proper. I just tore down my 540 that has been running 4032 SRP's for 10 years and the pistons still look new. I used .0045 clearance which is a little loose in fact ( I shift at 7500 rpm) and had no piston noise when cold started.
For what you are planning a good set of hyper's would work fine, but remember to pay close attention the the ring clearance requirements and also remember that they are just a cast piston with some added silicon. That's why they are cheap.
JIM
I have had guys call wanting to replace their Hypers with forged pistons because their Hyper failed.
So far I have never got a call guys wanting to replace forged pistons with hypers LOL