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Roller Rockers
https://slantsix.org/forum/viewtopic.php?t=48710		 Page 3 of 3
Author:  Dart270 [ Thu May 17, 2012 8:16 pm ]
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The early/mid RAS rockers have passages, but they are improperly made. The late ones appear properly made, but I haven't had the guts to test on the street.

Chuck, seriously, this is a waste on your car. Spend that coin on a good stall converter or a nice set of tires, or a suregrip if you don't have, or headers/big exh, or??? A modern stall converter is a wonderful thing on a street car. Happy to talk about options.

Lou
Author:  CNC-Dude [ Thu May 17, 2012 11:31 pm ]
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Quote:
I hear a lot of talk about how bad the ratio is on stock rockers, but if that is a bad thing, how come 1.6 rockers made no difference at all on a motor of mine versus RAS stock rebuilt rockers? Same motor, same car, same day, same track.

It probably did make a difference, just not enough to make a noticeable change once the drivetrain robbed some of it back.



400 miles on the street beat the crap out of a set of stems. :? Changing rocker ratios requires you to change pushrod length, it alters your valvetrain geometry by moving it closer to the rocker shaft
Author:  armyofchuckness [ Fri May 18, 2012 5:35 am ]
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Quote:
Chuck, seriously, this is a waste on your car. Spend that coin on a good stall converter or a nice set of tires, or a suregrip if you don't have, or headers/big exh, or??? A modern stall converter is a wonderful thing on a street car. Happy to talk about options.
Lou
Got it. Thanks, Lou! I'll hit you up for advice later. I do still need a stall converter. I think I've found a good 3.23 Sure-Grip for my 8.75 that a friend is willing to let go. I have to remind myself those and torque converters aren't cheap. Still need to get one of those.
Author:  Dart270 [ Fri May 18, 2012 6:03 am ]
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$400-500 for a good converter. I am about to stab one in my 64 Valiant (the "V2" for short), and expect to get this thing in the 14s in the 1/4...

Lou
Author:  armyofchuckness [ Fri May 18, 2012 8:05 am ]
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Cool. I'll PM you later about TC specs so we don't threadjack this any further than we already have. :lol: I'm very interested in learning how you spec out one of these. Since I'm loading mine down with creature comforts like heat a/c and power steering, I'm afraid I'm never going to break the 15s with a n/a engine, but I would like to get at least a good launch out of it.
Author:  slantzilla [ Fri May 18, 2012 3:38 pm ]
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Quote:
Quote:
I hear a lot of talk about how bad the ratio is on stock rockers, but if that is a bad thing, how come 1.6 rockers made no difference at all on a motor of mine versus RAS stock rebuilt rockers? Same motor, same car, same day, same track.

It probably did make a difference, just not enough to make a noticeable change once the drivetrain robbed some of it back.





400 miles on the street beat the crap out of a set of stems. :? Changing rocker ratios requires you to change pushrod length, it alters your valvetrain geometry by moving it closer to the rocker shaft
If it made more power the ET would have reflected it. The drivetrain would rob no more power than with stock rockers.

As for changing pushrod length, IF I would have had to end up with some weird adjuster length when setting lash I would agree. But when the lash adjusters come out in the proper place after changing rockers, how would shorter pushrods do anything?

The stems were beat from lack of oil anyway.
Author:  sandy in BC [ Fri May 18, 2012 4:18 pm ]
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Changing rocker ratios would not require a different pushrod length. If the pushrod was correct at 1.5...it would be correct at 1.6.
Author:  CNC-Dude [ Sat May 19, 2012 1:02 am ]
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Quote:
Changing rocker ratios would not require a different pushrod length. If the pushrod was correct at 1.5...it would be correct at 1.6.
That would be a fairly accurate assumption to make if you made a swap using similar design rockers(stamped steel to stamped steel, or even 1.5 roller rockers to 1.6 roller rockers), made by the same manufacturer. By going from a stamped steel, non-roller tip style rocker to a dissimilar style aluminum roller tipped rocker of a different ratio, you would be assuming all the critical dimensions are following the same path, like rocker shaft centerline height relative to roller tip heigth, pushrod cup heigth position relative to rocker shaft centerline height....and that just isn't going to happen. You will find that more times than not, when swapping dissimilar rocker like this, the same pushrod wont work in both.
Author:  CNC-Dude [ Sat May 19, 2012 1:18 am ]
Post subject: 
Quote:
Quote:
Quote:
I hear a lot of talk about how bad the ratio is on stock rockers, but if that is a bad thing, how come 1.6 rockers made no difference at all on a motor of mine versus RAS stock rebuilt rockers? Same motor, same car, same day, same track.

It probably did make a difference, just not enough to make a noticeable change once the drivetrain robbed some of it back.





400 miles on the street beat the crap out of a set of stems. :? Changing rocker ratios requires you to change pushrod length, it alters your valvetrain geometry by moving it closer to the rocker shaft
If it made more power the ET would have reflected it. The drivetrain would rob no more power than with stock rockers.

As for changing pushrod length, IF I would have had to end up with some weird adjuster length when setting lash I would agree. But when the lash adjusters come out in the proper place after changing rockers, how would shorter pushrods do anything?

The stems were beat from lack of oil anyway.
In a 1200 lb car like a dragster or a roadster, you might see a change in ET if you gained 8-10 HP, in a 2500 lb.+ you'll never see a gain with small an increase in power, or if you did it would be in the hundreths of a second, most people can't make passes that consistent to tell the difference. It also matters where in the RPM range the gain occurs. If the HP gain happens up at the top of the RPM range where you only spend a microsecond with the car pulling in that range of increase before you shift gears, again, you'll never see any ET increase.
Author:  slantzilla [ Sat May 19, 2012 6:05 am ]
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Then, in reality, they did nothing, correct?
Author:  sandy in BC [ Sat May 19, 2012 7:11 am ]
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Quote:
That would be a fairly accurate assumption to make
Thankyou!
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