I'm getting close to switching to a roller cam in the big block!

[Mopar Hunter]

I can’t wait to read the before and after results of a roller cam.

 

[Hemirunner]

Once you go roller, you’ll never go back to a flat tappet. They have their place in low buck builds and restoration engines and such but in a performance engine, roller cam all the way. Sounds like you’re in good hands with this one.

 

[Kern Dog]

Since my other engines have held together with the milder cams and springs, (Also with vintage parts) they will stay that way.
THIS car has always had the biggest camshaft, stiffest springs and highest compression of the cars that I have. It is also the one that I drive the most and unfortunately, it has had 3 flat tappet cams go bad out of the 5 that I've used in this block. At a glance you'd think that there is something wrong with the block but you have to consider all the factors. High performance parts are under a lot more stress than 318 parts and that stress can reveal weaknesses that are not usually seen in milder engines. The roller design should alleviate the risks that I've dealt with for years.

 

[Kern Dog]

Summit racing has the lifters in stock but since I'm not in a hurry, I'm going to wait until Dwayne Porter can get a set to have sent to me. He has been a friendly and helpful Mopar guy and I want to do right by him.
There are all the other things to buy along the way which as weird as it sounds, the delay helps matters.
It is purely in my head but paying ONCE in a large chunk of money just eats at me. It defies logic to make 5 purchases that still come to the same total but for some reason, I don't feel as bad doing it that way.
Other car guys must have the same mindset too though. We all know (or ARE) the guy that buys an abandoned project cheap and spends about double to get it completed as it would have cost to buy a finished car.
I sometimes feel like in another life, I lived in the Depression where you had to be frugal just to survive.

 

[Hemirunner]

I’m not sure how you drive this particular vehicle, but we tend to be rough on things in my world. Have you considered putting solid lifters on the hydraulic roller cam and tight lashing it? If it’ll see some spirited high rpm action, it may be food for thought. I’m sure you’ve discussed it all with Porter.

 

[BSB67]

I’m not sure how you drive this particular vehicle, but we tend to be rough on things in my world. Have you considered putting solid lifters on the hydraulic roller cam and tight lashing it? If it’ll see some spirited high rpm action, it may be food for thought. I’m sure you’ve discussed it all with Porter.

For clarity, you mean solid roller lifts, correct?

 

[RemCharger]

For clarity, you mean solid roller lifts, correct?

I'll double down and ask what's the advantage over a solid roller cam?

 

[Curiousyellow71]

I'll double down and ask what's the advantage over a solid roller cam?

This is over simplifying, but roller cam failures happen when a lifters roller bearing gives up. When the rollers bounce it is hard on the needle bearing or bushing. If you run a solid roller lifter on a hr cam which has no lash ramp about the only lash the lifter will see is when the engine grows. So there is less lash. If we set a engine with aluminum heads to 0 cold..it is about .007 hot. Iron headed engine even less. Less lash is less lifter bounce. Hopefully prolonged lifter life more comparable to a hydraulic roller lifter.

 

[HawkRod]

Greg,

I'm sure you know this but you will most certainly need new pushrods as well - the roller lifters are much taller than the old ones. When you mock everything up, make sure your valvetrain geometry is where it needs to be, then measure and order your pushrods.

 

[Hemirunner]

For clarity, you mean solid roller lifts, correct?

Yes, solid roller lifters.

 

[Hemirunner]

I'll double down and ask what's the advantage over a solid roller cam?

The big advantage is less weight (depending on brand/style,etc) less complexity, and the ability to turn it a higher rpm without valve float and no concerns about failure of the hydraulic lifter or sticking lifter plungers. The HR lobes are usually less aggressive and require less spring. I shift my street car at 7600 so my viewpoint is considerably different than most on this site, so take that with a grain of salt.

 

[Kern Dog]

I called Hughes Engines today and ordered their Melonized intermediate shaft. Tom took the call and was a nice guy. They were in stock which is great since I heard they were sold out.

 

[Hemirunner]

I called Hughes Engines today and ordered their Melonized intermediate shaft. Tom took the call and was a nice guy. They were in stock which is great since I heard they were sold out.

That gear is the way to go. I’ve run one since 2019. It drives my dry sump which in turn runs my fuel pump.

 

[Kern Dog]

Dwayne Porter advised against the bronze gear based on rapid wear.

 

[Hemirunner]

Dwayne Porter advised against the bronze gear based on rapid wear.

Yes, they’re a consumable. Every year at a minimum is typical. We’ve found tips and tricks to extend wear, like bearings and shims underneath, but they’re definitely a wear item.