small block hyd. roller lifters

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Confusedcuda

Confusedcuda

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Hello, If you switch to a hyd. cam and hydraulic roller lifters, do you need to switch the rocker arms? Thanks
 
Confusedcuda said:
stock 340 rockers?
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Not these.

Screenshot_20220906-125501.png
 
The stamped arms are weak for much over a true .500 lift 'the pressure required for the lift'...probably end up spearing one or more. But technically Dion R is right, the pushrod length is all that makes the diff within the rockers noted limitation.

The issue comes from a variable.. where...say you have heads that don't have the tips all even , or when the deck are off and canted end to end...and that's where an adjustable rocker arm works best so you can get about the same with all of them and not have various length push rods. That's just the objective way to look at it in a general sense.
 
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The rocker will break under the load required to control the heavy hydraulic roller lifter. Spring pressures are much higher than a hydraulic flat tappet. Also depending on the lifter you will need to bush the lifter bores or the lifter will leak and the motor will have low oil pressure.
 
You will need heavier springs for a roller cam. You could use beehive or conical springs which require less pressure on the seat & a lower spring rate. Bottom line is using these springs you might end up with the same load on the rockers or any only slightly more than with stock springs. Stock rockers would be ok. Comp Cams & others now have a wide range of these springs to choose from.
 
turbodart68 said:
The rocker will break under the load required to control the heavy hydraulic roller lifter. Spring pressures are much higher than a hydraulic flat tappet. Also depending on the lifter you will need to bush the lifter bores or the lifter will leak and the motor will have low oil pressure.
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I know what you meant.

To be realistic...a stock stamped rocker could handle a stock magnum hyd roller cam with its 80lbs seat and 200lbs open...but that's nothing anyone would go backwards to do.
It's the 300+ lbs open pressure that would kill a stamped rocker, be it roller or flat tappet. Bb or sb stamped rockers...they both give out with repeated high rpms and near 300lbs or more open.
 
turbodart68 said:
The rocker will break under the load required to control the heavy hydraulic roller lifter. Spring pressures are much higher than a hydraulic flat tappet. Also depending on the lifter you will need to bush the lifter bores or the lifter will leak and the motor will have low oil pressure.
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You're right, the heavy valve springs that are required for Hyd rollers will break stamped rocker arms.
There are hydraulic and solid roller retrofit lifters that you can use without bushing the lifter bores, I've run both in my stock block LA 340 on the street without any oil pressure issues.
Ya just gotta do your homework and run a high volume oil pump.
That being said I will never run any type of hydraulic lifter again.
 
Confusedcuda said:
Hello, If you switch to a hyd. cam and hydraulic roller lifters, do you need to switch the rocker arms? Thanks
Click to expand...
I mean.... 318's and 360's cam with roller cam/lifters and used the stock stamped steel rockers/shafts. Only need to switch is for strength, depending on how much spring pressure/lift you are using. I have over .500 lift on a 5.9 magnum and using the Hughes spring kit with the stock rockers, no issues yet
 
318willrun said:
I mean.... 318's and 360's cam with roller cam/lifters and used the stock stamped steel rockers/shafts. Only need to switch is for strength, depending on how much spring pressure/lift you are using. I have over .500 lift on a 5.9 magnum and using the Hughes spring kit with the stock rockers, no issues yet
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Same here 318willrun. I have 50k miles on a 5.9 with a Hughes cam over 500 lift with their springs on some EQ heads with nothing but the stock magnum rockers.

If the op has an LA style head mopar performance used to make some "heavy duty" stamped steel rockers that were slightly thicker than stock.
 
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