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Old 01-24-2013, 12:22 AM   #26
steves1967
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Re: Anyone no what pistons these are??

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Originally Posted by RWB-713 View Post
Four words.. Rocker. Arm. Stud. Girdle. Stud mounted rockers always flex quite a bit at high RPM, which cause improper valvetrain geometry & mis-alignment. In the 6500+ RPM range, oiling becomes an issue as well, it's flying all over the place, quite frequently not where it needs to be.

I'm just trying to give some advice to protect your investment man! I'm not saying don't give er hell, that's why we build what we do. Most of us abuse the crap out of alot of our stuff, because we built it for that reason. It's fun to be throttle happy. I'm just givin ya a heads up of the possible consequences, I was in high school once I know how it is. I just don't want ya to be the guy with the oil trail followin him out of the parkin lot waitin on a tow truck!
.508 lift cam? I wouldnt worry about stud flex unless you are over .600 lift/ solid roller cam/ or 7000 rpm...
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Old 01-24-2013, 01:30 AM   #27
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Re: Anyone no what pistons these are??

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They flex? Didn't realize that lol I thought they were the best that could be done. Thanks for that heads up. One day I want to get out of the 40 something year old heads and go to aluminum or at least newer flow patterns and stuff.

I know man, No offense taken what so ever. I know what you mean. The more opinions, and information the better. This forum has really helped a lot. I have another small block and a big block sitting outside that'll be the next build, so trying to take in all the information I can :P
Yeah, even the finest ARP studs will flex to some extent. Yes it does help quite a bit to use good studs, but it's still there, and it intensifies the higher the rpm. You're off to a good start for sure, do all the research you can, there is TONS of information out there for building SB & BB chevy's. But motor building is a fine art, and high horsepower/ high rpm engines are an even finer art.

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Originally Posted by steves1967 View Post
.508 lift cam? I wouldnt worry about stud flex unless you are over .600 lift/ solid roller cam/ or 7000 rpm...
Yes, it does itensify with higher lift, higher valve spring pressures, and higher RPM. But it's always there. Bolt a set of splash gaurds on a set of rocker studs sometime and watch, you can see the gaurds twist even while turning the motor over with the starter. I've seen many "stock valvetrain", vacuum rule limited, circle track motors flex the studs like that. And we couldn't run anything more than a .510" (hyd flat tappet) lift cam to meet the vacuum rule in most cases.
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Old 01-24-2013, 02:03 AM   #28
70c10stepside
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Re: Anyone no what pistons these are??

Thanks for all the tips RWB! I've found out there is an art to it lol My father use to build a motor weekly. He built them around sound and not performance though. I ask him rpm questions or strength questions. His answer is normally around, when it comes to rpm, and strength, you no you went to far when it blows. Or when you here a bang lol
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Old 01-24-2013, 02:23 AM   #29
RWB-713
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Re: Anyone no what pistons these are??

Quote:
Originally Posted by 70c10stepside View Post
Thanks for all the tips RWB! I've found out there is an art to it lol My father use to build a motor weekly. He built them around sound and not performance though. I ask him rpm questions or strength questions. His answer is normally around, when it comes to rpm, and strength, you no you went to far when it blows. Or when you here a bang lol
Anytime man! I'm no expert by any means, but i've seen a whole lot of what not to do along the way, and I've researched & learned a large amount from it. Anything I can pass on to save someone some agony just feels like the right thing to do!

Lol, I had a buddy who used to say something along the lines of "You wanna know how fast it can turn? Stand on it til it blows up. It was 1 less than that."
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Old 03-06-2013, 01:07 AM   #30
steves1967
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Re: Anyone no what pistons these are??

Yes, it does itensify with higher lift, higher valve spring pressures, and higher RPM. But it's always there. Bolt a set of splash gaurds on a set of rocker studs sometime and watch, you can see the gaurds twist even while turning the motor over with the starter. I've seen many "stock valvetrain", vacuum rule limited, circle track motors flex the studs like that. And we couldn't run anything more than a .510" (hyd flat tappet) lift cam to meet the vacuum rule in most cases.[/QUOTE]

Might want to check your valvetrain geometry- if you are flexing studs with a .510 lift cam something is off.... or maybe you were using the short thread ARP studs, ARP has several different thread lengths available.
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