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

[Kern Dog]

She's ugly out there. So what lifters are you looking at ($$). Pushrods probably 3-400( smithbros) , cam button and shims fairly cheap

Dwayne likes the Comp Cams Evolution lifters. They have a hydraulic cylinder that is replaceable if it fails. I was told that this cylinder is an OEM part for some late model applications which means that it would comply with reliability demands and noise concerns.
The main reason that I chose a hydraulic cam was to reduce noise. I've ran solid lifter cams for over 10 years and it would be nice to reduce some of that clatter.

 

[gtxrt]

a tight lash solid lifter cam vs a roller. the only plus for a roller is the lifters can't go flat. I can't see any other advantages for a roller cam but a lot of disadvantages that are mentioned here already go back and look at the posts. I will add one more the roller has a slower ramp off the seat for less performance. A hyd roller will also lose lift at high rpms. a perfect spec out solid and a perfect roller you will see very little or no power gain.

 

[68 Sport Satellite]

So you're keeping your existing pistons?

 

[Kern Dog]

Sure, why not? I'm at 9.8 to 1 with aluminum heads. I could probably run mid grade in the engine now. The '528 cam I used to have was milder than this roller and I was at 10.12 to 1 with zero quench and didn't knock with that setup.

 

[6872n73]

FYI Back to back dyno runs with equivalent valve lift profile cams show a 1.6% increase in efficiency or power, due to the friction reduction of the roller.

 

[Kern Dog]

In 2022 when I wiped out the MP '528 cam, Dwayne said that it might be hard to get equal performance to the 528 in a roller without going bigger....and that would make it less streetable. (Think Vacuum & power brakes, idle quality)
I was considering a roller cam then but wasn't sold on it due to a less than confident view on the power level and the cost. I went with the Lunati solid FT that I had stashed away. It was the safe, easy and cheap option. I don't regret doing it. If the car was still an automatic and I wanted to drag race it, the cam does make great mid range to redline power.
The cam that he ordered is on a 112 LSA which will make it on par with the 528 as far as idle vacuum. The lift will be .581/.577 versus .532 after the .032 valve lash, the duration will be sort of close with 238/244 @ .050 versus a straight 242.
The Hughes intermediate shaft arrived today along with the valve spring height measuring tool. More stuff is expected in the next few days.

 

[1 Wild R/T]

Are you expecting to have this done before Spring Fling?

 

[Kern Dog]

Uhh, no. I didn't want to stack the deck against myself on this one.
I'm gathering stuff. The lifters are delayed along with valve spring shims. I plan to have the A/C system fixed for the Spring Fling event, then have the system evacuated later when I do the cam swap after the show.
It is spending money twice for the A/C but it sure makes for a happier spouse since she agreed to come along again.

 

[1 Wild R/T]

Wise choice... I'm working on a few cars trying to get them ready for the drive, got plans for another project on the Red Challenger but like you, I'm not gonna roll the dice on that working out..

 

[Kern Dog]

This project involves some things that I have never done. If I were not planning on taking the car, I'd jump in with the swap as soon as all the parts were here.
I've never measured for installed spring height. I've never shimmed the spring pockets. I've only replaced springs with the heads in place ONCE.
I've never installed a cam button nor have I machined one to achieve the proper camshaft end play.
I've only degreed a cam a couple of times.
I've swapped cams, heads, intakes, did several full rebuilds but the special stuff associated with a retrofit roller cam is new to me and I don't want to rush myself.

 

[gtxrt]

FYI Back to back dyno runs with equivalent valve lift profile cams show a 1.6% increase in efficiency or power, due to the friction reduction of the roller.

so if true on a 500 HP you gain 8 HP minus the HP loss from having to run more valve spring pressure.

 

[1 Wild R/T]

so if true on a 500 HP you gain 8 HP minus the HP loss from having to run more valve spring pressure.

The performance gains of a roller camshaft are less due to friction loss that how they are able to open the valve more quickly & hold it open longer with the same duration.... The friction gain is an added benefit along with reducing the risk of flat cams...

When considering how much a roller cam costs perhaps considering how much having a cam go flat & destroying an engine costs should be part of the consideration....

 

[gtxrt]

The performance gains of a roller camshaft are less due to friction loss that how they are able to open the valve more quickly & hold it open longer with the same duration.... The friction gain is an added benefit along with reducing the risk of flat cams...

When considering how much a roller cam costs perhaps considering how much having a cam go flat & destroying an engine costs should be part of the consideration....

yes big advantage with cam and lifter wipe out. but no advantage over a solid tight lash fast ramp cam. and a hyd cam flat or roller will lose lift at a high rpms. hyd roller lifters still have the same problems as the hyd flat tappets.

 

[BSB67]

FYI Back to back dyno runs with equivalent valve lift profile cams show a 1.6% increase in efficiency or power, due to the friction reduction of the roller.

Can you be specific on exactly what “equivalent valve lift profile” means?

Do you have the cam and testing data that you can share, or a place we can get it?

Thanks

 

[BSB67]

so if true on a 500 HP you gain 8 HP minus the HP loss from having to run more valve spring pressure.

One would assume that you would use the same valve springs if the “lift profiles” are equivalent.

 

[RemCharger]

The performance gains of a roller camshaft are less due to friction loss that how they are able to open the valve more quickly & hold it open longer with the same duration.... The friction gain is an added benefit

Exactly. A roller lobe clearly shows where the extra power comes from. I was stuck In the flat tappet book club for years but finally gave way to the advice of others who had made the jump. Now all I have to worry about is the needles falling out

But 10.50s so far with a 440/ all steel Charger, it's a screamer

 

[Kern Dog]

yes big advantage with cam and lifter wipe out. but no advantage over a solid tight lash fast ramp cam. and a hyd cam flat or roller will lose lift at a high rpms. hyd roller lifters still have the same problems as the hyd flat tappets.

The high rpm advantage of a solid flat tappet is lost on me. The Tremec 5 speed that I have does not like to shift at all when I'm over 6000 rpms. I've tried numerous times and the shifter feels like it hits a wall. No grinding, no noise at all, it is just as if a blocker lever moved in front of the shift gate. Once the rpms drop, it shifts fine.
Secondly, while I do like a car that pulls great at all rpm ranges, I drive the car entirely on the street and freeway where torque and mid range power is what works best. I don't care to go through the transmission to modify it for shift quality for a high RPM shifts, at least not now.
I wiped a cam in 2006, one a few years later, then another one in 2022. Of the classics that I have here, the Charger is the one that I drive the most miles and have wiped out camshafts. The reason for the failures has not been pinned down 100% but given the witch's brew of high spring pressures, a variation in oil quality, possible issues with lobe and lifter taper and/or metal integrity of the failed lifters, I decided to play it safe here.

 

[BSB67]

Now all I have to worry about is the needles falling out

IMO, just another myth perpetrated buy internet misinformation.

Is there a point they will fail under a certain set of conditions. Sure. But if you buy good lifters, very, very few folks will ever come close to the conditions that would result in failure. The devil is in the details.

 

[RemCharger]

IMO, just another myth perpetrated buy internet misinformation.

Is there a point they will fail under a certain set of conditions. Sure. But if you buy good lifters, very, very few folks will ever come close to the conditions that would result in failure. The devil is in the details.

I wouldn't call it a myth.. I've seen it more than enough in real- time. Good lifters, but very high hp motors. Check lash, check lash, then check again

 

[BSB67]

Ca

I wouldn't call it a myth.. I've seen it more than enough in real- time. Good lifters, but very high hp motors. Check lash, check lash, then

Can you share the details?

I know of one: Red Zones, 900 hp, 900 lbs and 0.90” over the nose, 350 passes.

And my point is that just about everytime the subject comes up with running a street roller on a lolly-pop street cam lobe the fear mongers come out and talk about filling your motor up with needles. You’d never guess that we used them for 40 years before the days of: “you have to use bushed rollers.”

Also, word of bushed roller failures are popping up.

Again, buy quality.