Lifters

With roller rockers is there any real advantage to solid lifters? I dont plan to change lash to do different things as i already have a cam that took care of that.

I to am curious about this.

powerstrokenstang said:

With roller rockers is there any real advantage to solid lifters? I dont plan to change lash to do different things as i already have a cam that took care of that.

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Why do you want to add roller rockers without adding solid lifters? What advantage do they give you by just adding that one part?

Hotrodtractor said:

Why do you want to add roller rockers without adding solid lifters? What advantage do they give you by just adding that one part?

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I would guess the same as a gas motor. Less friction, and 15-30 hp to the crank.

Hotrodtractor said:

Why do you want to add roller rockers without adding solid lifters? What advantage do they give you by just adding that one part?

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I know you are asking a question, but I think you may be making a statement and I'm interested in exactly what that is. I've run roller rockers on hydraulic lifters in gassers so I'm wondering what is the difference compared to our 7.3's. I may be wrong, but I'm inferring from your comment that the roller rockers are only effective when used with solid lifters in the 7.3. I'd like to know why.

SouthFlstrokin' said:

I would guess the same as a gas motor. Less friction, and 15-30 hp to the crank.

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Also strength at higher r's. Imho stock rockers are cheesy.

powerstrokenstang said:

Also strength at higher r's. Imho stock rockers are cheesy.

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Are we talking about rockers or lifters now?

Lifters to go w/ rockers....

Ah then wouldn't you want solid rollers?

Big Bore said:

I know you are asking a question, but I think you may be making a statement and I'm interested in exactly what that is. I've run roller rockers on hydraulic lifters in gassers so I'm wondering what is the difference compared to our 7.3's. I may be wrong, but I'm inferring from your comment that the roller rockers are only effective when used with solid lifters in the 7.3. I'd like to know why.

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Play along and come to your own conclusion.

SouthFlstrokin' said:

I would guess the same as a gas motor. Less friction, and 15-30 hp to the crank.

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powerstrokenstang said:

Also strength at higher r's. Imho stock rockers are cheesy.

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So you need some more strength at higher RPMs in a boosted motor - generally that means you need to be looking at your valve springs - can your valve springs handle say 50-60psi of boost at say 4500 RPMs and probably 60-70psi of backpressure for a pulling application now?

What kind of loading can the factory hydraulic lifters take before they collapse? Is it sufficient to be able to handle the valve springs and engine RPMs set forth in the first question?

What is the benefit of running a hydraulic lifter in the first place? How does that apply to the engine that we are talking about? Is there any pitfall to converting the rockers to solid - other than the minute cost of the components and the fact you need to remove the heads to swap them?

Hotrodtractor said:

So you need some more strength at higher RPMs in a boosted motor - generally that means you need to be looking at your valve springs - can your valve springs handle say 50-60psi of boost at say 4500 RPMs and probably 60-70psi of backpressure for a pulling application now?

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I attempted to address this awhile back, as doing the math for a situation you are suggesting, 910's had nowhere near enough seat pressure.

What kind of loading can the factory hydraulic lifters take before they collapse?

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Ahh that is a hydraulic pressure question, with some part of the equation being flow as well as pressure. I think. IOW at that rpm can the oil system feeding the lifters keep pressure up at higher rpms.

Is it sufficient to be able to handle the valve springs and engine RPMs set forth in the first question?

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Good question. Knowing what the oil pressure is at that rpm and the load on the pushrod would be a good place to start I'm thinking.

What is the benefit of running a hydraulic lifter in the first place?

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Decreased wear on parts and negates the need to adjust valve lash.

How does that apply to the engine that we are talking about? Is there any pitfall to converting the rockers to solid - other than the minute cost of the components and the fact you need to remove the heads to swap them?

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I'm assuming you meant lifters, not rockers, and yes, based on the prior questions I would say increased wear/shorter lifespan of cam, lifter and possibly pushrods.

who sells solid lifters and roller rockers? and do they require any machineing to the heads and or pistons?

My springs should handle that, and the lifter collapse was my biggest concern. I have nothing against solid lifters. The conversion kit is cheap and the heads would be off already. Adjusting valves is no biggy either. Basically i am curious on the benifits of both.