LS3 1.85 Rocker Test

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Sep 19, 2018 | 11:16 PM

#21

kinglt-1

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From: Ft. Wayne, IN

Quote:

Originally Posted by ddnspider

It didn't nose over with stock rockers....so what's the difference if its not rocker weight, simply the increased ratio?

Icreasing rocker ratio increases lift and duration at the valve along with jerk rate intensity...It most likely needs more valve spring pressure.

I ran SLP 1.85 rockers for 9yrs...they are identical to stock rockers other then the push rod cup is relocated to increase the ratio. I will say I am surprised the PSI springs are not keeping things in control with that setup.

Sep 20, 2018 | 06:51 AM

#22

ddnspider

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From: FL

Quote:

Originally Posted by 8.Lug

....But what are your cam specs? ....

That reading comprehension though

Quote:

BASICALLY A MAX EFFORT STOCK HEADS CAM CAR

Quote:

Originally Posted by kinglt-1

That's why its interesting to me....everyone sings the praises of the PSI1511's, yet it can't handle a stock cam with 1.85 rockers, especially with Ti retainers?

Sep 20, 2018 | 08:34 AM

#23

big hammer

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From: over dere

Quote:

Originally Posted by kinglt-1

it only increases duration when measured at .050. Seat to seat it makes no difference.

Also so I’ve read that Stock rockers are actually a rising rate ratio and YT’s are a constant ratio. So the valve acceleration near seat would be faster with the rollers than the stockers. I’d like to see this re done with better valve control and see what happens

Sep 20, 2018 | 08:52 AM

#24

kinglt-1

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From: Ft. Wayne, IN

Right...duration increases at the valve @ .050

My mistake, I thought OP was using SLP 1.85's. Didn't realize Yella Terra made a 1.85 ratio. Yella Terra are heavier then stock for sure. I would be interested to see what set of SLP 1.85's look like in comparison on the Dyno. On my LS1 w stock cam it made more power and torque through the entire curve over stock 1.7's.

Agree on further testing with better valve control.

Sep 20, 2018 | 09:35 AM

#25

G Atsma

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From: Central Cal.

Yella Terras are aluminum. Are they still heavier than the steel rockers?

Sep 20, 2018 | 10:23 AM

#26

kinglt-1

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From: Ft. Wayne, IN

over the tip of the valve they are.

Sep 20, 2018 | 11:02 AM

#27

lazerlemonta

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From: VA

I dropped almost a pound out of swapping springs and retainers. These are the ultra light version. Really it is a combination of valve control and the stock cam just saying screw you i dont want the air. Needless to say with the mid length runner fast it still increased power from 6600 to 7100 by 25. Not sure what configuration the car will be ran at my rental on 11/6. I have .660 springs coming that are 155lbs on the seat compared to the 130lbs of the 1511s. I could shim the springs but I am not going to waste the time doing so. I just wanted to show my results and help anyone who was considering a high ratio rocker on a stock cam.

Sep 20, 2018 | 12:38 PM

#28

spanks13

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Will you dyno again with the new springs? Should be interesting to see if you gain more up top, or if it really is maxing out the operating range of the stock cam.