Hydraulic vs Solid Roller Cam - Nova Tech
Nova Tech  
Find Nova Parts at SS396.com     
GROUND UP & SS396.com         
Official Sponsor of Team Nova
   

Auto Insurance



Performance High Performance!

Novas.net is the premier Chevrolet Nova Forum on the internet. Registered Users do not see the above ads.
Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old Feb 11th, 12, 09:15 PM
brian oneil brian oneil is offline
Senior Tech Team *
Brian
 
Join Date: Oct 2006
Location: Smithfield, Virginia
Posts: 4,607
brian oneil has a positive reputation
Default Hydraulic vs Solid Roller Cam

This is an interesting article on how well it appears the the hydraulic roller cam and the solid roller cam are making almost the same numbers. This is a good read.


http://www.streetlegaltv.com/tech-st...raulic-roller/
__________________
71 Nova
SBC 427
238/256 Girly Cam
6.88 1/8th @ 100.00mph
Reply With Quote
Sponsored Links
Advertisement
 
  #2  
Old Feb 11th, 12, 11:13 PM
Big Dave Big Dave is online now
Site Moderator
Dave
 
Join Date: Mar 2006
Location: Tampa FL
Posts: 15,085
Big Dave has a positive reputation
Default Re: Hydraulic vs Solid Roller Cam

Two things wrong with the article. There is next to no splash lubrication at idle and low RPM which is why ed Iskedarian first created self oiling roller tappets which Comp and Crane and Crower have all copied. Second people who install a solid cam rarely shift at 6200 RPM. They are looking for a number closer to 7800 to 12000 which the hydraulic roller can not reach because the lifters are too heavy to maintain valve control. (it is the lose of control the allows the lifter to pump up).

I use a solid roller because I am not satisfied with the 6500 RPM limit imposed by a hydraulic roller. I have a chromemoly lighten bed crank, forged billet chromemoly H-beam rods, ARP bolts, and lightened short skirt forged aluminum pistons in the short block so that it will stay together if and when I decide to wrap it up. I have big heads and induction to reach my RPM goals that only the cam controls.

Big Dave
Reply With Quote
  #3  
Old Feb 12th, 12, 12:45 AM
Fold67 Fold67 is offline
Tech Team
Brian
 
Join Date: Dec 2011
Location: kennewick
Posts: 130
Fold67 has a positive reputation
Default Re: Hydraulic vs Solid Roller Cam

So when chosing a cam, solid vs hydro, What are your rpm limitations, is it the bottom end, the power band of the cam or is it some thing else?

Thank you
Brian
Reply With Quote
  #4  
Old Feb 12th, 12, 10:46 AM
Big Dave Big Dave is online now
Site Moderator
Dave
 
Join Date: Mar 2006
Location: Tampa FL
Posts: 15,085
Big Dave has a positive reputation
Default Re: Hydraulic vs Solid Roller Cam

You can take a stock cast bottom end to 10,000 grand. It is just as strong in measured tensile strength as the forged part is. The difference is in how they fail (as they all will fail when pushed that hard). With a cast part you get a great explosion with lots of engine carnage. If you physically survive the disaster (not hit by shrapnel, or a flying part cuts your brake line or the oil down causes lose of control and you crash), there will be nothing of value to rebuild (heads block cam and crank are generally destroyed). A forged bottom end bends rather than break. That is why you buy forged parts, so that when the crank bends you put new bearings in the block, straighten the crank and turn it down to reuse it again (or sell it on e-Bay as slightly used). A forged bottom end doesn't make horsepower it just adds reliability to your motor.

You can stick huge by large heads on top of your stock motor and it will crank up and run. It will be lazy and inefficient and it might be down a bit in power. Huge by large heads are only an advantage if you are increasing your displacement, or are taking the same displacement (ignoring the five extra cubic inches you get by boring it 0.030" over) and reving it higher in the RPM band. Then the larger ports can support the additional air flow required to feed a high reving engine or one that got significantly bigger.

The cam is ground to support a predefined RPM. This is because an engine is an air pump. We are pumping a fluid (air) that follows all of the characteristics of a highly viscous compressible fluid. That means it takes a finite period of time to pour the fluid into the cylinder, turn off the valve that controls the air flow, and open another spigot to pump the spent gasses out to repeat the cycle. Your added duration simply holds the valves off the seat longer allowing the fluid more time to flow.

Once again it is the valve timing that controls how the air enters and exits the engine, with a longer duration holding the valves open longer to allow the air more time to move at high RPM when things are happening faster (at 6,000 RPM the piston is moving so fast that you can write across the top of the piston as if it where stationary at the top of the bore instead of moving up and down leaving an open space). Of course at low RPM where street cars live your valves are held open way too long a period of time so you can not build compression because the air is being pumped out by the rising piston through the open valve. This is why it idles roughly. You are pumping air into a manifold that is supposed to have a vacuum in it. The carb sees the pulses of pressurized air and mixes gas according to what it thinks are a low vacuum condition which is why the motor loads up.

So what controls the engines RPM? The answer is the valve springs. They have to keep the tappet pushed against the cam and to hold the valve shut tight (without bouncing off the seat). They determine when valve float occurs. Valve float causes hydraulic lifters to pump up holding the valves off the seat (enough to actually bend the valve when it hits a piston). Valve float causes the motor to lay over and stop making horsepower (open valves defeats the purpose of internal combustion). It is the the thing that makes or breaks any build no mater how much money you put into an engine. Too much pressure and you wipe the lobe off the cam and induce valve bounce. Too little pressure and the valves float. Harmonics are also an issue as every spring has a natural frequency at which it fails to work (this shows up as dip on the dyno sheet) so you need a means of controlling spring harmonics as well.

Big Dave
Reply With Quote
  #5  
Old Feb 12th, 12, 02:32 PM
Norfolknova Norfolknova is offline
Tech Team
Matt
 
Join Date: Dec 2010
Location: 7th realm of hell , Va
Posts: 245
Norfolknova has a positive reputation
Default Re: Hydraulic vs Solid Roller Cam

I wpould say in simpler terms if you are building a street or street/strip car then use a hydraulic lifter cam. If you are building an all out race motor then go with the solid lifter cam.

Roller lifters and rollers rockers offer the advantage of less resistance and less head buid up. Several of the different magazines and tv shows have done dyno comparisons of roller and no roller motors, with the roller motors coming out with a small advantage given the rest of the engine being equal.

Most of the cast cranks seem to be rated to a max of 500 HP and then various sources say to go to forged. Like Big Dave said when the cast parts let go the tend to fail in grand fashion.

Match your valve springs to what is listed on the cam card, don't just use the old, they look good to me so I will not replace them theory.

Matt
Reply With Quote
  #6  
Old Feb 12th, 12, 03:33 PM
Fold67 Fold67 is offline
Tech Team
Brian
 
Join Date: Dec 2011
Location: kennewick
Posts: 130
Fold67 has a positive reputation
Default Re: Hydraulic vs Solid Roller Cam

Thank you. This clears up alot of what I had read in other forums and could not make sense of what they were saying. Also I now better understand how an engine will fail. So will bottom end generally fail before the push rods or at the same time generally speaking, if you manage to not screw up your valve train at such high rpms?

Brian
Reply With Quote
  #7  
Old Feb 12th, 12, 06:04 PM
Big Dave Big Dave is online now
Site Moderator
Dave
 
Join Date: Mar 2006
Location: Tampa FL
Posts: 15,085
Big Dave has a positive reputation
Default Re: Hydraulic vs Solid Roller Cam

Hydraulic lifters that get into valve float will pump up to the point that there is real risk of the valve hitting the piston. This will bend a push rod in a heart beat. Another issue is the rocker arm geometry. With a big block with it's multiple angled valve train this is a serious consideration where you have to move the center of the push rod pocket in the lifter and grind components to keep out of contact with a high valve lift cam. In a small block you have guides cast into the head that can get you into trouble at high lift. Hit the guide and you bend a push rod first time every time.

Finally if you're using stock parts (with a small block that is a 5/16 inch diameter mild steel part) you can buckle the push rod with just the spring pressure required to control the valve at high RPM. That is why you not only increase the size (going to a 3/8th inch push rod with a small block and a 7/16 to a half inch in diameter with a big block) but you use a thick wall chromemoly tube. You also need to have a push rod guide plate to fit the push rod that is holding the push rod as close to the rocker arm as you can get it (stock is flat, or none at all).

High RPM isn't as popular today as it was back in the days of the 283 and the 327 because it costs an arm and a leg today (back then it was just another trip to the bone yard for another stock 283 and then poke your three quarter race cam back into it if it didn't break when you scattered the last motor you had all over the road).

Big Dave
Reply With Quote
  #8  
Old Feb 16th, 12, 09:38 PM
hardcoredarksky hardcoredarksky is offline
Tech Team
Adam
 
Join Date: Oct 2011
Location: Virginia
Posts: 319
hardcoredarksky has a positive reputation
Default Re: Hydraulic vs Solid Roller Cam

I miss those old days. I remember when my dad worked on all kinds of old cars all the time! We had so many of them I lost count.
Reply With Quote
  #9  
Old Feb 17th, 12, 04:27 PM
brian oneil brian oneil is offline
Senior Tech Team *
Brian
 
Join Date: Oct 2006
Location: Smithfield, Virginia
Posts: 4,607
brian oneil has a positive reputation
Default Re: Hydraulic vs Solid Roller Cam

Quote:
Originally Posted by Big Dave View Post
Two things wrong with the article. There is next to no splash lubrication at idle and low RPM which is why ed Iskedarian first created self oiling roller tappets which Comp and Crane and Crower have all copied. Second people who install a solid cam rarely shift at 6200 RPM. They are looking for a number closer to 7800 to 12000 which the hydraulic roller can not reach because the lifters are too heavy to maintain valve control. (it is the lose of control the allows the lifter to pump up).

I use a solid roller because I am not satisfied with the 6500 RPM limit imposed by a hydraulic roller.

Big Dave
I agree with you Dave. The article though shows that on the dyno, even the solid roller was falling off in power around the 6200 mark. I think they did the 440 CID engine a dis-service by limiting the carb to 750 cfm's. This engine probably needs 850-950 cfm's to feed more fuel to get more HP/TQ numbers. The added fuel and air should also increase the rpm potential a bit, especially the solid roller.

I posted this article though to show that with everything being equal, the hydraulic roller cam technology isn't that far off in producing the HP/TQ numbers of the solid roller cam. Of course we all know that the average HP/TQ over the rpm band within the rpm curve given would most likely go to the hydraulic roller, with the peak HP/TQ numbers going to the solid roller.

If this motor set up was to be put in a street driven car, the hydraulic roller probably would win out because of the ease of maintenance over a solid roller. We humans like to be lazy. Plus a little less valve train noise. With the numbers so close, it seems the best choice would be the hydraulic roller in a street application, as most street V-8's are not turning 7,000-7,500 rpm's even showing off to their friends.

If this were for a race motor a solid roller would be a better choice to take advantage of the rpm's (given more carb) and the flow numbers in cfm's that a good set of heads and intake can take advantage of to produce higher HP/TQ so as not to choke off the 440 cid.

Like I said, it is a nice comparison, and it shows the tinkers of the engine world are closing some of the performance gap between the hydraulic and solid rollers.
__________________
71 Nova
SBC 427
238/256 Girly Cam
6.88 1/8th @ 100.00mph
Reply With Quote
  #10  
Old Feb 23rd, 12, 12:32 PM
StraubTech StraubTech is offline
Tech Team
Chris
 
Join Date: Feb 2012
Location: Tri-Cities, TN
Posts: 116
StraubTech has a positive reputation
Default Re: Hydraulic vs Solid Roller Cam

The Morel hyd roller lifter on a BBC will easily go to 7000 rpm and make power. Not a problem. Lifter will need around 180 to 200# seat pressure and 450 to 500# open.

For a street car a hyd roller these days is a wise choice for most enthusist.
Reply With Quote
  #11  
Old Feb 23rd, 12, 09:51 PM
jmartorana jmartorana is offline
Tech Team
Joe
 
Join Date: Nov 2007
Location: Long Island
Posts: 49
jmartorana has a positive reputation
Default Re: Hydraulic vs Solid Roller Cam

Quote:
Originally Posted by StraubTech View Post
The Morel hyd roller lifter on a BBC will easily go to 7000 rpm and make power. Not a problem. Lifter will need around 180 to 200# seat pressure and 450 to 500# open.

For a street car a hyd roller these days is a wise choice for most enthusist.
Hey Chris

Whats next.... a hydraulic roller BBC running 9.80's in Vegas?

7000 is easy with the Morels and the right cam and springs combination. Here's proof..



For those that don't know Chris he is the cam guru! No lie. If anyone is looking for a hydraulic roller set up look him up at www.straubtechnologies.com or just give him a call. He has made believers out of many.

I was amazed what he did with my motor.
__________________
1969 Nova SS 502 with a CStraub Big squishy Girly cam M23W 4.10 w/ Superior chromoly axles
Reply With Quote
  #12  
Old Feb 24th, 12, 08:48 AM
StraubTech StraubTech is offline
Tech Team
Chris
 
Join Date: Feb 2012
Location: Tri-Cities, TN
Posts: 116
StraubTech has a positive reputation
Default Re: Hydraulic vs Solid Roller Cam

Quote:
Originally Posted by jmartorana View Post
Hey Chris

Whats next.... a hydraulic roller BBC running 9.80's in Vegas?

7000 is easy with the Morels and the right cam and springs combination. Here's proof..



For those that don't know Chris he is the cam guru! No lie. If anyone is looking for a hydraulic roller set up look him up at www.straubtechnologies.com or just give him a call. He has made believers out of many.

I was amazed what he did with my motor.
You gotta post that over on Chevelles in the BBC hyd lifter thread!!!
Reply With Quote
  #13  
Old Feb 27th, 12, 12:24 PM
62novaSBC 62novaSBC is offline
Tech Team
 
Join Date: Jan 2011
Posts: 335
62novaSBC has a positive reputation
Default Re: Hydraulic vs Solid Roller Cam

I have a few girly roller engines and regularaly turn them 7000 - 7300.
its the lobes, lifters and spring pressure that makes it all work together.
__________________
62 Nova cruiser
383/200-4R/12-bolt w 373s
224/224 HR cam
1.57 10.97 @ 121.2
67 camaro
pumpgas 420sbc HR cam 641hp
1.39, 9.79 @ 137.5

Reply With Quote
  #14  
Old Feb 27th, 12, 07:03 PM
StraubTech StraubTech is offline
Tech Team
Chris
 
Join Date: Feb 2012
Location: Tri-Cities, TN
Posts: 116
StraubTech has a positive reputation
Default Re: Hydraulic vs Solid Roller Cam

Crazy's Morphed ZZ502 with a 244/248 @ .050" Hyd roller with a set of the Morel 4603's ran a best at vegas of a 9.86". After that they said no more as the car is legal for 10's. So with 100lbs of sand, 6 degrees less timing, and 2/3 on the throttle stop she ran 10.10's
Reply With Quote
  #15  
Old Feb 27th, 12, 07:15 PM
62novaSBC 62novaSBC is offline
Tech Team
 
Join Date: Jan 2011
Posts: 335
62novaSBC has a positive reputation
Default Re: Hydraulic vs Solid Roller Cam

lets not forget that girly roller BBC made 764HP on pumpgas
thats very impressive with that mild of a duration
great job on that stick Chris
__________________
62 Nova cruiser
383/200-4R/12-bolt w 373s
224/224 HR cam
1.57 10.97 @ 121.2
67 camaro
pumpgas 420sbc HR cam 641hp
1.39, 9.79 @ 137.5

Reply With Quote
Sponsored Links
Advertisement
 
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Solid roller lifters brian oneil Forum Classifieds 6 Jan 17th, 11 10:05 PM
Howards Hydraulic Roller Lifters Jackel Engine 2 Feb 9th, 10 11:25 PM
Harold need help! Ultradyne solid roller Q's zwuvlu Performance 17 Jul 11th, 09 09:42 PM
Lunati Voodoo Solid Roller COPO9560 Performance 7 May 5th, 09 11:12 PM
full roller or roller tip rocker arms i_dunno_09 Engine 9 Sep 16th, 08 09:09 PM


All times are GMT -4. The time now is 08:41 AM.


2009 AutoForums