Roller cam idea that I'm rolling around in my noggin....

[Kern Dog]

I had the engine out last year at this time....

I went through it.....new dished pistons to lower compression a bit, refresh the heads, some suspension and steering mods since it all was apart.
I pondered a switch to a roller cam at the time but kiboshed it. Cost was one factor. Another was that I had a good used Lunati solid flat tappet cam that I'd used before.
I don't necessarily regret using it but it clearly isn't an ideal cam for the combination.
Here is the cam card....

I have 1.6 ratio rocker arms so the lift is even higher than shown on the card.
This isn't a drag car. I am not a straight line racer either....My interests focus on strong street performance with an intention to make some laps on a road course.
The compression ratio is around 9.8 to 1 with Edelbrock aluminum heads. It idles okay and makes good power but I suspect that I could do better.
The idle vacuum from this combination is inadequate for the power brakes so I slipped in a vacuum pump. It works but it feels like a crutch.
I had a Mopar Performance 528 solid in the engine before. It wasn't quite as strong but it did run decent. It had great vacuum and worked great with power brakes.
Lately, I've kicked around the idea of actually making the leap to a roller cam IF one could be spec'd to improve power, vacuum and overall drivability. With the little that I know about roller cams, I have a feeling that it is all possible.
It seems to me that this Lunati is probably too much for this engine. I think this because the '528 was by comparison a LOT smaller yet not that much slower than it is now.
I just wonder if the Lunati specs are better suited for a larger engine with better heads and more compression.
The engine isn't soggy or sluggish but the low idle vacuum annoys me. It certainly isn't as snappy under 3000 rpms like it was with the '528.
My curiosity about how a properly chosen roller cam may deliver more vacuum, more power and maybe even better mileage creeps into my head sometimes.
This engine is a .040 440 block, a 4.15" crank and measures out at 495 cubes. 9.8 to 1 compression with 2" headers, 3" exhaust, 5 speed manual with 3.55 axle gears. The car is just shy of 4000 lbs plus me.
Does anyone have a car set up like this one with a roller cam you like? Care to share the details on your setup?

 

[kiwigtx]

I nearly got excited about going hydraulic roller a few years ago with my GTX. I went for a ride in a friend's Challenger with the same in a 512 engine. That thing pulled like a 14 year old school boy from about 15 mph in 3rd gear.....smoother than an automatic trans. I was tempted....but then I ended up selling the car.
He was also running the McLeod RXT clutch and a 4 speed.

 

[gkent]

That thing pulled like a 14 year old school boy

?????

 

[Dodge 330]

I had the engine out last year at this time....

View attachment 1503455

View attachment 1503456

I went through it.....new dished pistons to lower compression a bit, refresh the heads, some suspension and steering mods since it all was apart.
I pondered a switch to a roller cam at the time but kiboshed it. Cost was one factor. Another was that I had a good used Lunati solid flat tappet cam that I'd used before.
I don't necessarily regret using it but it clearly isn't an ideal cam for the combination.
Here is the cam card....

View attachment 1503457



I have 1.6 ratio rocker arms so the lift is even higher than shown on the card.
This isn't a drag car. I am not a straight line racer either....My interests focus on strong street performance with an intention to make some laps on a road course.
The compression ratio is around 9.8 to 1 with Edelbrock aluminum heads. It idles okay and makes good power but I suspect that I could do better.
The idle vacuum from this combination is inadequate for the power brakes so I slipped in a vacuum pump. It works but it feels like a crutch.
I had a Mopar Performance 528 solid in the engine before. It wasn't quite as strong but it did run decent. It had great vacuum and worked great with power brakes.
Lately, I've kicked around the idea of actually making the leap to a roller cam IF one could be spec'd to improve power, vacuum and overall drivability. With the little that I know about roller cams, I have a feeling that it is all possible.
It seems to me that this Lunati is probably too much for this engine. I think this because the '528 was by comparison a LOT smaller yet not that much slower than it is now.
I just wonder if the Lunati specs are better suited for a larger engine with better heads and more compression.
The engine isn't soggy or sluggish but the low idle vacuum annoys me. It certainly isn't as snappy under 3000 rpms like it was with the '528.
My curiosity about how a properly chosen roller cam may deliver more vacuum, more power and maybe even better mileage creeps into my head sometimes.
This engine is a .040 440 block, a 4.15" crank and measures out at 495 cubes. 9.8 to 1 compression with 2" headers, 3" exhaust, 5 speed manual with 3.55 axle gears. The car is just shy of 4000 lbs plus me.
Does anyone have a car set up like this one with a roller cam you like? Care to share the details on your setup?

I run a Howards .545 lift, 234/241 @ .050 hydraulic roller in a 505. Absolutely love it! It makes great power but has good street manners, too, and is super quiet. It's been in for over 7 years now and virtually no issues.

 

[68 HEMI GTS]

I had the engine out last year at this time....

View attachment 1503455

View attachment 1503456

I went through it.....new dished pistons to lower compression a bit, refresh the heads, some suspension and steering mods since it all was apart.
I pondered a switch to a roller cam at the time but kiboshed it. Cost was one factor. Another was that I had a good used Lunati solid flat tappet cam that I'd used before.
I don't necessarily regret using it but it clearly isn't an ideal cam for the combination.
Here is the cam card....

View attachment 1503457



I have 1.6 ratio rocker arms so the lift is even higher than shown on the card.
This isn't a drag car. I am not a straight line racer either....My interests focus on strong street performance with an intention to make some laps on a road course.
The compression ratio is around 9.8 to 1 with Edelbrock aluminum heads. It idles okay and makes good power but I suspect that I could do better.
The idle vacuum from this combination is inadequate for the power brakes so I slipped in a vacuum pump. It works but it feels like a crutch.
I had a Mopar Performance 528 solid in the engine before. It wasn't quite as strong but it did run decent. It had great vacuum and worked great with power brakes.
Lately, I've kicked around the idea of actually making the leap to a roller cam IF one could be spec'd to improve power, vacuum and overall drivability. With the little that I know about roller cams, I have a feeling that it is all possible.
It seems to me that this Lunati is probably too much for this engine. I think this because the '528 was by comparison a LOT smaller yet not that much slower than it is now.
I just wonder if the Lunati specs are better suited for a larger engine with better heads and more compression.
The engine isn't soggy or sluggish but the low idle vacuum annoys me. It certainly isn't as snappy under 3000 rpms like it was with the '528.
My curiosity about how a properly chosen roller cam may deliver more vacuum, more power and maybe even better mileage creeps into my head sometimes.
This engine is a .040 440 block, a 4.15" crank and measures out at 495 cubes. 9.8 to 1 compression with 2" headers, 3" exhaust, 5 speed manual with 3.55 axle gears. The car is just shy of 4000 lbs plus me.
Does anyone have a car set up like this one with a roller cam you like? Care to share the details on your setup?

Pretty stout cam for a driver with 3.55’s and a 5 speed. I’d get away from that 108. Probably something on a 110 230’s/240’s duration with as much lift as possible for the lobe family (general of course). You leaning towards solid or hyd? Those new comp hyd roller lifters with the replaceable cartridges supposedly work well.

 

[BeepBeepRR]

?????

Things are done different there I guess.

 

[BSB67]

KD, I have run a solid roller cam in my 500 motor. But my motor is too different from yours to recommend it.

You didn’t ask for opinions, but I’ll give one. For your application I would recommend the Comp Cam’s Extreme Energy solid roller. It is advertised as a street roller, but it’s no lollipop either. It’s the XR286R. It 286/292 advertised and 248/254 @ 0.050. I think you’ll be close to 0.600” lift with the 1.6’s.

Let the fun begin

 

[Kern Dog]

I admit that I am only basing my thoughts on what I have heard in terms of roller cam technology. There is so much that I do not know.
Here is what I want:
Better low speed performance. I know that a stroked big block is not generally thought of as a 7000+ rpm engine like you'd expect from a smaller displacement, overhead cam engine. With this in mind, why not use a cam that makes the power under 6000 rpms? Off idle torque seems to me would make for a better street engine.
Roller Cam and lifters for reduced anxiety for cam and lifter failures and the freedom to use easier to find modern oil.
I'm not certain on whether I'd want a solid or hydraulic setup. I'd take a little more noise to gain some reliability. I've heard pro and con from both sides.
Some have suggested a solid setup due to simpler and lighter lifters but I've heard some prefer to close the valve lash numbers to limit the smacking abuse to the lifter wheels and internals.
I've seen and heard videos of some hydraulic roller cams that are as clackity sounding as a flat tappet.
I ran a MP '528 solid that had that old school .028/.032 lash. The Lunati in there now is .020/.022 so I am used to hearing some clackity clack. A fairly silent old V8 seems weird in theory but I could get used to that.
Dwayne Porter and I spoke last year and he was careful to not force any opinion on me. He deals with Comp Cams and says that the main issue with running roller lifters in a big block is that the stock lifter bores are short because they were never designed for the taller roller lifters. They can work but often times, the better choice is a solid roller since they are shorter and some think that is a better solution than the taller hydraulic lifter. I didn't record the conversation and I may not recall everything exactly as he said but I got the feeling that he still likes flat tappet setups. He thought the '528 was still a decent cam despite the fact that it was designed so long ago. When I spoke with him, I was unsure about stepping up to the roller setup. It isn't as if I am completely SOLD on the idea today but it is tempting.
So often, price dictates my decision. It isn't like I'm struggling to support myself here....I just try to be reasonable and not spend money on stuff simply because I can afford to. I REused the Lunati because I had it and kept the lifters in order. The .050 duration numbers do seem to be far more than what the engine wants.
I do know that a swap like this will not be cheap. It is because of that that I want assurances that it will be worth it.

 

[Dodge 330]

I ran the MP .528 in a 440 back in the day. I ran .018/.020 lash. I believe it was Dwayne Porter that recommended that?! It sounded like a nicely oiled sewing machine. I'm personally much happier with the hydraulic roller. It sounds and acts like a stock 440 with a mild cam...until you mash the go pedal! No problems with the Howards lifters in the stock bores, either. The lifters are limited to 6500 rpm, but with a stroker that's a non issue. This car gets lots of HARD street miles and lots of dragstrip passes btw.

 

[Kern Dog]

I run a Howards .545 lift, 234/241 @ .050 hydraulic roller in a 505. Absolutely love it! It makes great power but has good street manners, too, and is super quiet. It's been in for over 7 years now and virtually no issues.

This is where I get confused.
On specs alone, that looks milder than the ‘528 aside from the lift. I would need help understanding how it might make more power.
My hope is to surpass the ‘528 in power but not be too rowdy for cruising.

 

[BSB67]

You cannot compare solid cam and hydraulic cam 0.050 and lift specs directly to each other because of the lash. Obviously you need to subtract lash from the lift. The MP 528 actual valve lift will be close 0.50" if adjusted to the recommended .028" lash.

For 0.050" duration, the lifter on the solid cam is really at 0.030", if the lash is adjusted to 0.030" (assuming a 1.5 rocker ratio (0.030" (lash) divided by 1.5 = 0.020" subtracted from 0.050")). A general rule of thumb is you subtract 8-10 degrees of duration off of the solid cam when comparing to a hydraulic. In the case of the MP 528 cam, it will likely be about 10 degrees because the lash setting is so large.

 

[Kern Dog]

Thanks, I was aware of that.
I'm more confused about how the roller cam lobes ability to open the valves faster affects power. The opening and closing ramps of roller cams are so steep! I've read that comparing specs between roller and flat tappet cams is extremely difficult due to the effect that fast opening valves have on torque and HP.

 

[BSB67]

Thanks, I was aware of that.
I'm more confused about how the roller cam lobes ability to open the valves faster affects power. The opening and closing ramps of roller cams are so steep! I've read that comparing specs between roller and flat tappet cams is extremely difficult due to the effect that fast opening valves have on torque and HP.

Roller cams lobes look more aggressives, but the valve action might not be more aggressive. They look different because how and where the roller wheel contacts the lobe verses a flat tappet. The flat tappet cam exerts more leverage on the lifter at low lifts per degree of rotation than a roller. So for identical specs, the roller cam will look way more aggressive.....but its not.

You can compare them directly, but it is helpful to also have the duration at 0.200" as well as 0.020" and 0.050" and total lift, presuming they are both solid or both hydraulic.

 

[qkcuda]

I ran a Comp 236/242 duration 542/541 lift hydraulic roller in my 500 low deck with 1.5 rockers. That was plenty of cam, in fact my buddy ran the next size smaller 230/236 and it made more torque, and more vacuum. Torque is fun on the street and those will net you close to 650 lb/ft

 

[RemCharger]

This is where I get confused.
On specs alone, that looks milder than the ‘528 aside from the lift. I would need help understanding how it might make more power.
My hope is to surpass the ‘528 in power but not be too rowdy for cruising.

Compare them at .200 or more.
Old crappy cams were sold on huge duration #s that dwindled towards max lift.
Newer rollers have as small of an advertised duration as possible with more meat at higher lift.

Edit: I see this didn't post and others have elaborated

 

[Geoff 2]

Some misinformation here.
Roller cams are slower off the seat, not faster than FT cams. After the seat timing, the roller gets going.

If the car is used mainly for cruising, I would go for a solid roller. More reliable. Comp Cams charge the same for a shelf roller as they do for a custom grind. Contact Chris Ryan at Comp for a custom grind.

Comp has some really fast acting lobes that have relatively short duration & high lift. More area under the curve. Take the CSZ series. 248 @ 050, 276 adv & 0.603" lift.

 

[Mopar Hunter]

Engine Masters did a show on this very same thing, series 7 episode 6

 

[lilcuda]

Call Bullet Cams for a recommendation. I would avoid Comp Cams. I’ve heard of a lot of issues with quality control recently.

 

[coloradodave]

Call Bullet Cams for a recommendation. I would avoid Comp Cams. I’ve heard of a lot of issues with quality control recently.

Oh boy, here we go again! "I've heard" is not a good enough reason to diss possibly the best selling line of camshafts and related components on earth. Take a walk through the pits at any NHRA event and talk to the racers and engine builders attending. Sure, now and then you're going to hear a negative comment but who knows how the engine was built, broken in or treated? Do the same at local bracket races where a lot of street cars show up. My experience, both for my cars and those I talk to have been overwhelmingly positive when dealing with Comp Cams. And certainly, get professional opinions from all brands that interest you.
I don't want to say you don't have a right to your opinion, but "I've heard" is so not that...

 

[BSB67]

Oh boy, here we go again! "I've heard" is not a good enough reason to diss possibly the best selling line of camshafts and related components on earth. Take a walk through the pits at any NHRA event and talk to the racers and engine builders attending. Sure, now and then you're going to hear a negative comment but who knows how the engine was built, broken in or treated? Do the same at local bracket races where a lot of street cars show up. My experience, both for my cars and those I talk to have been overwhelmingly positive when dealing with Comp Cams. And certainly, get professional opinions from all brands that interest you.
I don't want to say you don't have a right to your opinion, but "I've heard" is so not that...

I was going to ask for specifics regarding Comp Cam roller cam failures. Then I remembered it’s the internet.