6"Rod with 383 Q
Thread Starter
Instructor
Joined: Aug 2005
Posts: 105
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From: Nipomo CA
6"Rod with 383 Q
is it in my best investment to use a 6" rod in a 383 build up v.s. a stock length 5.7" rod?
the only real cost difference it the piston price from what im seeing. and a Keith Black set of pistons isn't too costly to begin with.
also would the 383 with a 6" rod be able to live at higher RPMs BETTER v.s. the 5.7" rod 383? the intention of the 383 is street and strip. 5-6K miles a year and will possibly spin RPMs as high as 5500-5800 depending on heads/cam/induction,etc. looking to use a 2800rpms stall and 3.54 gears so the rpms will mostly be around 3800-5800rpms during the 1/4 mile.
i know i won't feel the difference of a 6" over a 5.7" but i know the motors internals will so thats why i ask these questions. will the motors performance benefit from that length rod or to make it easier should i stick with a typical stock 5.7"?
the only real cost difference it the piston price from what im seeing. and a Keith Black set of pistons isn't too costly to begin with.
also would the 383 with a 6" rod be able to live at higher RPMs BETTER v.s. the 5.7" rod 383? the intention of the 383 is street and strip. 5-6K miles a year and will possibly spin RPMs as high as 5500-5800 depending on heads/cam/induction,etc. looking to use a 2800rpms stall and 3.54 gears so the rpms will mostly be around 3800-5800rpms during the 1/4 mile.
i know i won't feel the difference of a 6" over a 5.7" but i know the motors internals will so thats why i ask these questions. will the motors performance benefit from that length rod or to make it easier should i stick with a typical stock 5.7"?
Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
Either one will work fine, but the longer rod will reduce side loading (rod trying to push the piston thru the wall) which is supposed to free up a bit of power and give a bit more longevity. You;ll see many arguments on this. I personally prefer a long rod, IMO uses les energy at high rpm to overcome the rod angle thatn the shorter one.
Team Owner
Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
If you can afford too, I would avoid Hyper pistons. They have Feet Per Minute limitations. I would do cheap 6 inch forgings first
I found this out when the pistons were smeared in the bore of my 355 ci
I found this out when the pistons were smeared in the bore of my 355 ci
Last edited by gkull; Sep 28, 2005 at 10:58 AM.
Large Impressive Member
Joined: Jul 2003
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Here's some good reading on the subject:
http://www.stahlheaders.com/Lit_Rod%20Length.htm
I'm going with 6" rods for my (sort of) 383+, BTW.
http://www.stahlheaders.com/Lit_Rod%20Length.htm
I'm going with 6" rods for my (sort of) 383+, BTW.
Thread Starter
Instructor
Joined: Aug 2005
Posts: 105
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From: Nipomo CA
if i can have patience i'd prefer to buy Crower rods,SRP/JE pistons and a Callies crank.
I just have been hearing bad news about the so called "chinese brand" auto parts. i have only heard poor remarks about SCAT/EAGLE brands on this site but nowhere else in my area. i might settle for some SCAT/EAGLE parts due to the price and avalibility.
1 brand im gonna stay away from is SPEEDPRO/TRW pistons. the aftermarket name has been getting worse from hearing about plenty of failures. why are they failing? i don't know...maybe its the owner of the cars driving/abuse,improper assembly from machine shop? for what ever reason that brand aftermarket product piston is not gonna be put in my motors. it could happen to a SRP but i've never heard of it.....yet.
I just have been hearing bad news about the so called "chinese brand" auto parts. i have only heard poor remarks about SCAT/EAGLE brands on this site but nowhere else in my area. i might settle for some SCAT/EAGLE parts due to the price and avalibility.
1 brand im gonna stay away from is SPEEDPRO/TRW pistons. the aftermarket name has been getting worse from hearing about plenty of failures. why are they failing? i don't know...maybe its the owner of the cars driving/abuse,improper assembly from machine shop? for what ever reason that brand aftermarket product piston is not gonna be put in my motors. it could happen to a SRP but i've never heard of it.....yet.
Melting Slicks
Joined: Apr 1999
Posts: 2,010
Likes: 3
From: Moon Twp. PA USA
Originally Posted by Fancyazz
if i can have patience i'd prefer to buy Crower rods,SRP/JE pistons and a Callies crank.
I just have been hearing bad news about the so called "chinese brand" auto parts. i have only heard poor remarks about SCAT/EAGLE brands on this site but nowhere else in my area. i might settle for some SCAT/EAGLE parts due to the price and avalibility.
1 brand im gonna stay away from is SPEEDPRO/TRW pistons. the aftermarket name has been getting worse from hearing about plenty of failures. why are they failing? i don't know...maybe its the owner of the cars driving/abuse,improper assembly from machine shop? for what ever reason that brand aftermarket product piston is not gonna be put in my motors. it could happen to a SRP but i've never heard of it.....yet.
I just have been hearing bad news about the so called "chinese brand" auto parts. i have only heard poor remarks about SCAT/EAGLE brands on this site but nowhere else in my area. i might settle for some SCAT/EAGLE parts due to the price and avalibility.
1 brand im gonna stay away from is SPEEDPRO/TRW pistons. the aftermarket name has been getting worse from hearing about plenty of failures. why are they failing? i don't know...maybe its the owner of the cars driving/abuse,improper assembly from machine shop? for what ever reason that brand aftermarket product piston is not gonna be put in my motors. it could happen to a SRP but i've never heard of it.....yet.
I need to know if my stroker, with Eagle crank and rods, and Speed Pro hyper pistons , is going to self destruct soon!
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Thread Starter
Instructor
Joined: Aug 2005
Posts: 105
Likes: 0
From: Nipomo CA
i've recalled 2 threads in C4 tech with broken speedpro hypers this year.(2 isn't alot but i've heard about more)
a friend locally had 1 break in the same way as the others did and he used the coated skit hypers by speedpro in his 355.
a friend locally had 1 break in the same way as the others did and he used the coated skit hypers by speedpro in his 355.
Melting Slicks
Joined: Dec 2001
Posts: 2,025
Likes: 1
From: Billings MT
I run a Scat 9000 series crank with 6" H-beam Scat rods and SRP pistons in my 406. This motor has spent 2 years and well over 100 passes at the drag strip along with over 10,000 miles of hard street driving. Rpm range at the track is from 6500-7300rpm, usually to 7000rpm on the street.
Still runs just as strong as when I built it. I had it pulled apart a few weeks ago and everything looks great.
Still runs just as strong as when I built it. I had it pulled apart a few weeks ago and everything looks great.
Melting Slicks
Joined: Apr 1999
Posts: 2,010
Likes: 3
From: Moon Twp. PA USA
Originally Posted by Fancyazz
i've recalled 2 threads in C4 tech with broken speedpro hypers this year.(2 isn't alot but i've heard about more)
a friend locally had 1 break in the same way as the others did and he used the coated skit hypers by speedpro in his 355.
a friend locally had 1 break in the same way as the others did and he used the coated skit hypers by speedpro in his 355.
BTW, what generation Corvette do you own? You are posting lots of stuff in C4 and C3, which do you have? Usually, if it's not listed in your profile, you own nothing. Which COULD mean you're a
Correct me if I am wrong, I can take it
.
Last edited by glen242; Sep 30, 2005 at 10:06 PM.
Team Owner
Joined: Oct 2004
Posts: 81,241
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From: altered state
St. Jude Donor '05
Nothing wrong with Scat products. Built a 6" rod 355 for a friend almost 2 years ago with KB hypers in it, he buzzes it on a reular basis to 7000 rpm with no problem. Most important thing is to find a machinist who is WELL INFORMED and make sure your tune is dead on. . Too many of these guys live under a solvent tank and aren't hip to the latest parts out there. There are many competent ones, just have to look to find them.
I don't believe the noob is a troll, seems he's just hunting for real info vs. the brand bashing he sees in C* section.
I don't believe the noob is a troll, seems he's just hunting for real info vs. the brand bashing he sees in C* section.
Melting Slicks
Joined: Apr 1999
Posts: 2,010
Likes: 3
From: Moon Twp. PA USA
Originally Posted by cuisinartvette
Nothing wrong with Scat products. Built a 6" rod 355 for a friend almost 2 years ago with KB hypers in it, he buzzes it on a reular basis to 7000 rpm with no problem. Most important thing is to find a machinist who is WELL INFORMED and make sure your tune is dead on. . Too many of these guys live under a solvent tank and aren't hip to the latest parts out there. There are many competent ones, just have to look to find them.
I don't believe the noob is a troll, seems he's just hunting for real info vs. the brand bashing he sees in C* section.
I don't believe the noob is a troll, seems he's just hunting for real info vs. the brand bashing he sees in C* section.
Large Impressive Member
Joined: Jul 2003
Posts: 65,811
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
The only negative thing about TRWs is their weight, I'm not sure about their (now) sister component, the Speed Pro. I have no experience with them. The TRW is fine otherwise, within it's limitations. It's not considered to be a weak piston.
The problem with the hypers is people not setting them up correctly. Top ring gap is very critical and if they're not gapped wide enough, they will self destruct in short order. Top gap is wider than conventional cast or forged pistons, second groove gap is important too. Also wall clearance is important for the given application and use. They are used with good results in lower buck drag and oval racing classes. I've had KB hypers in my engine for 20K miles now, through plenty of hard use, (frequently over 6000 RPM) racing and street driving w/ no problems. Like anything else, know what you're building and what you're building for. And yes, go with the 6" rod. There's really no downside to it and plenty of advantages.
The problem with the hypers is people not setting them up correctly. Top ring gap is very critical and if they're not gapped wide enough, they will self destruct in short order. Top gap is wider than conventional cast or forged pistons, second groove gap is important too. Also wall clearance is important for the given application and use. They are used with good results in lower buck drag and oval racing classes. I've had KB hypers in my engine for 20K miles now, through plenty of hard use, (frequently over 6000 RPM) racing and street driving w/ no problems. Like anything else, know what you're building and what you're building for. And yes, go with the 6" rod. There's really no downside to it and plenty of advantages.
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Originally Posted by glen242
Given this level of info, I would not blanket condem SpeedPro hyper pistons. "Break the same way as the others did", how did the others break?? Detonation, piston pulling top ring loose, etc.?? Before I condem a manufacturer, I would like to know all engine specs and under what conditions the failure occured!
.
.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
"i have only heard poor remarks about SCAT/EAGLE brands on this site"
The only bad raps I have heard was from my engine builder (builds HiPo racing boat engines)was that in extreme cases, the Eagle "H" beam will split lenghtways along a visible parting line that the SCATs don't have.
Rated Eagle / Scat the same for cranks .
The only bad raps I have heard was from my engine builder (builds HiPo racing boat engines)was that in extreme cases, the Eagle "H" beam will split lenghtways along a visible parting line that the SCATs don't have.
Rated Eagle / Scat the same for cranks .