machine shop vs parts counter(forged vs kb)

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Meet-Joe-"Dart"

Meet-Joe-"Dart"

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Re: Pistons.
The machine shop recommends Keith Black Hypereutectic Pistons, the parts guy says to me "errrrrrr wrong, that's your 1st mistake.... you have to go with forged ones" He says with any detonation the KB's will explode. Do I need forged sluggs with my combo ? (360, resized rods, Eddy magnum heads, doug's headers, etc...) I think I can fit them into my budget... but do I need them? Or is the parts guy just being a convincing sales man? He also mentioned that I'm wasting my money resizing the stock rods and replacing the bolts, that I could've bought new rods for only a little extra $$$. Are the stock rods really all that bad???

Any thoughts would be appreciated. THX:cheers:
 
it is true that hypers will explode if detonation occurs, or if you drop a valve...

forged will "absorb" a valve and deform, not grenade...
 
Explode?

Detonation is a bad thing with ANY piston. They DO NOT come apart with ANY detonation. Is it bad for them, yes. Forged are more resistant to damage. Get the tune up right and you don't have to worry about it.

Guys have run KB107's in stuff making 570+hp, some turning almost 7500rpm. They never came apart.
 
the parts guy says to me "errrrrrr wrong, that's your 1st mistake.... you have to go with forged ones" He says with any detonation the KB's will explode. Do I need forged sluggs with my combo ?
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Well, the parts guy MAY be making money n the sale, secondly, he may be of old school thought, forged or nothing, 3rd, he may also be going on what he has heard a lot of. Which would be poorly installed rings on the KB hypers, over N02 usage, poor timing and/or carb jetting. All of which will kill a cast piston.

The KB Hypers are absolutely fine. Just take the time to KNOW how your engine/carb is running and do not spray the engine with ridiculous amounts of N02.

He also mentioned that I'm wasting my money resizing the stock rods and replacing the bolts, that I could've bought new rods for only a little extra $$$. Are the stock rods really all that bad???
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He is correct on the price of "To much" on resizing stock rods and bolts.

He is incorrect on the price of new rods, there cheaper than resizing and there stronger.

There is nothing wrong with stock rods. They are strong and can take 7,000 rpm's w/good rod bolts.


And that's the fact jack!
 
Thanks for the info I'm going to go with Probe forged pistons, my shop told me go with the forged if you can. But that the KB's are a good piston at a value price. thx
 
I've always used Ross Racing Pistons and have never had any problems. I have forged aluminum piston in my 340 using 1/16, 1/16, 3/16 piston rings
 
I would take the word of a reputable machine shop over the word of a parts jockey. Who has more "real world" experience with these pistons? Who is going to be the 1 replacing parts if they are wrong? Who's reputaion is on the line? That, and I've been the parts jockey, and I've seen alot of mis-information.
 
Hyperutectic pistons are cast pistons. Cast with a good alloy, but still cast. They really should not cost more than 10% more than an OE cast piston. The rest is hype.

A forged piston is a different animal. Yes, a forging grows more so you have to run a little more clearance. They make a little more noise cold. They are stronger than a casting.

I had a problem with a turbo engine once. Forged slugs. The detonation was bad enough it smashed the clearance out if the top ring land, locking the ring in place. It still ran fine, but was blowing by more. I was actually surprised to see the top ring land look like that when I tore it down. Cast pistons would have been in pieces in the pan, and the rods would have been in the water jacket. The forged slugs saved me plenty of money. I only took it apart because I suspected broken rings from the detonation event.

B.
 
QUOTE..."I would take the word of a reputable machine shop over the word of a parts jockey. Who has more "real world" experience with these pistons?"
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Yeah good point... I think my shop was just trying to save me some money by offering the Keith Black pistons. However he did say if you can afford the forged pistons in your build then do it. He also said that he's running forged pistons in his Mopar.

I know forged pistons are a better choice... but there's always going to be a better option(for more $$$$). Anyhow I'm gonna go with the Probe Forged slugg's I'm sure I'll be happy with my choice. :)
 
Whats the general feeling of hypereutectic pistons? Better then cast, not as good as forged? I find it funny that the Turbocharged Fords from the 80s used Forged up until the end, but the Supercharged Thunderbirds went Hypereutectic starting in 89. The Turbo cars used 8.0:1 and the SC cars went 9.0:1. They must know something.
 
None2Slow said:
Whats the general feeling of hypereutectic pistons? Better then cast, not as good as forged?
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Yes

I find it funny that the Turbocharged Fords from the 80s used Forged up until the end, but the Supercharged Thunderbirds went Hypereutectic starting in 89. The Turbo cars used 8.0:1 and the SC cars went 9.0:1. They must know something.
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I'm sure they do. But what they did when the changed it around is something entirely different. Perhaps less boost? IDK what they did.

The Hypers are plenty strong. You can even take a regular cast piston pretty far. IDK about adding 22lbs. to a regular cast piston, but 7 - 10 should not be an issue.
 
rumblefish360 said:
Yes



I'm sure they do. But what they did when the changed it around is something entirely different. Perhaps less boost? IDK what they did.

The Hypers are plenty strong. You can even take a regular cast piston pretty far. IDK about adding 22lbs. to a regular cast piston, but 7 - 10 should not be an issue.
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With any type of boost I always spend a little extra to get forged pistons. I just can't see me pissing away a few grand over an extra couple hundred bucks, but that's just me.
 
LOL, no doubt. Then again, were not building mild pedestrian rides with a minor WOW factor.
 
Meet-Joe-"Dart";1569798 said:
Yeah good point... I think my shop was just trying to save me some money by offering the Keith Black pistons. However he did say if you can afford the forged pistons in your build then do it. He also said that he's running forged pistons in his Mopar.

I know forged pistons are a better choice... but there's always going to be a better option(for more $$$$). Anyhow I'm gonna go with the Probe Forged slugg's I'm sure I'll be happy with my choice. :)
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You do know KB also make a Forged slug, don't you?

It's released under the "Icon" name now -

http://kb-silvolite.com/icon/index.html
 
What's funny is that I have KB forged pistons in an old FE motor- the machine shop I use got the task of re-manning an engine for my '72 F250. I got a engine out of a backwoods yard, originally I thought it was a 390 4-bbl- turns out to be a Super Marauder 410 (the recipricating portion, the block is a '73 reverse '105', 'TE' block). The machinist tells me," ya know my buddy over ay Brennen's has a set of KB forged pistons on the shelf with Speed Pro rings that is new in the box. I can get it for $250, they've been there since the mid-'80's." So that is my first set of forged pistons, don't need them to be forged, but hey- they were cheaper than anything else.
 
Rat Patrol said:
You do know KB also make a Forged slug, don't you?

It's released under the "Icon" name now -

http://kb-silvolite.com/icon/index.html
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Yeah funny you mentioned that.... I looked at the Keith Black Icon's, but they were about $200.00 more than the Probe Pistons. Parts store also had a set of JE Pistons that they had brought in for another customer (who never showed up) But again $120.00(sale's price) more than the Probe's. So I'm thinking I wasn't going to go with forged piston's at all, but now that I am... I gotta draw the line somewhere. Right?:D
 
Fair enough - If you can get the Probes for that much less - why not?

(Probably all from the same Chinese factory anyhow...)
 
I guess I should have mentioned that the Turbo cars were 4cyl and the Supercharged were V6. The turbo cars had an Iron block and heads wherer the V6 had Iron block aluminum heads. I ran the Turbos to 18lbs boost daily on the street and with good gas to 24lbs no problems. The v6 at 15lbs can pop a gasket unless you do some exhaust mods. Don't really hear of piston problems with either engine though. I'm running 10.0:1 on my 360 and was thinking about throwing a turbo on it. I can do it cheaper than buying a set of TTIs and would probably have more clearance for the pipes :bootysha:
 
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