Solid Mechanical Flat Tappet Cams

Decided to start new post on the subject of solid flat tappet cams.  

Typically these were used only in high RPM performance applications, however I am very curious how these cams would operate in a street driven low RPM Application.  

My car is 70 Lemans Sport (to be a GTO clone) with a 406 CI. I have #16 heads 2.11 /1.77 and cc'd them to 76 cc before a little deshrouding work the builder wants to do. I plan to run stock 4 barrel manifold and Q-Jet carb (or holley spreadbore equivalent)and hooker competition headers.  I have stock gears at 2.56, and plan to install a 3.23, 12 bolt. I also have a 4 speed muncie.  

Ive already ordered with help from an amatuer builder a solid cam custom ground from comp.  The cam is a single pattern 256 advertised duration 218@ 50 with .467 lift with 1.5 rockers.  Lift with 1.6 is .496.  I plan to use 1.6 roller rockers on my build, should add 3 degrees of duration @ 50.( not sure what that would change, power range?)

We ordered a lobe seperation of 105 degrees.  This builder wants to target the RPM range, and chose to do so by tightening the LSA to a number typically used in racing applications.  

If this builder chose a hydraulic flat tappet, he would have given me a 214@ 50 duration for my RPM range due to the typical 4 - 8 degree difference a solid cam will react in the same engine.

Comp has solid cams in lobe durations of 218@ 50 and 224 @50. I could have ordered a dual pattern, but not sure if that would benifit me at all.  Also, I could use two different ratio rockers and use various adjustment if desired.

I have more comments and a Sym that indicated 501 ft/lbs at 2000 rpm that was given to me in another post I will try to get added to this post.

Thanks  
Carlos
70 Lemans(GTO Clone),406,Solid Cam 218 single pattern, 105 LSA
Serious Hobbyist

I'd also like to get a SYM for a small off the shelf hydraulic to compare the two on the same engine. Note: I would still like this post to stick to a solid cams discussion and not take a left turn into hydraulics.  

Most likely somewhere in the 214 intake and 220 - 224 exhaust duration with 110 - 112 LSA and we'll see how the torque curve is affected.  
Carlos
70 Lemans(GTO Clone),406,Solid Cam 218 single pattern, 105 LSA
Serious Hobbyist

Sounds like an expensive and time consuming test, how would you know of any gains or losses without and track testing or dyno testing and the need for consistent weather conditions?  

Carlos, I'm going to move your stuff to this thread, OK.

CarlosCJ3B (208.195.70.39)
New User | Posts: 12 | Joined: 10/11 Posted: 10/12/11
09:00 AM
Hi,

just doing as much research as possible and was looking through this thread as many other people have.  Question; If it only took a couple of days to find out what roller cam this guy needed, why didnt anybody come up with a small solid flat tappet and run the numbers.  

I "google" small soild cam pontiac all the time and come up with nothing.  Most of the ones manufacturers sell are huge!?  Can someone  PLEASE run some numbers on a small solid for those nostalgic guys out there that want to run these cams.  I saw some TFX informatuion out there on solid flat tappets, but it was useless.

Also, most of the cams out there seem to have a wide lobe seperation angle 110-112.  Would it make more sense if these were tightened (105- 108) to flatten the torque curve if you can target the desired RPM range. I am working with a old Rod Shop/Builder and ordered a Comp custom solid grind 218/218 @ 50 with .467 lift w/1.5 (plan to use 1.6) with 105 lobe seperation to run in my 70 lemans 406 CI with 2.56 10 bolt (or 3.23 in my 12 bolt) gears and 4 speed muncie. I have 16 heads, (with bowl work and trick valve job) they are cc'd to 9.6:1 compression. 2.11/ 1.77 valves.

What is projected torque and horsepower?  Any help would be apprerciated.  


tuffnuff (207.6.156.3)
Moderator | Posts: 1415 | Joined: 12/09 Posted: 10/12/11
09:09 AM
I'll run a sym for you, if you give me all the specs on the valve eventing of that solid cam,,,,,,,,,,,, carb and manifold???


CarlosCJ3B (208.195.70.41)
New User | Posts: 12 | Joined: 10/11 Posted: 10/12/11
09:39 AM
Would that depend where we degree degree the cam to or are those numbers built into the cam? I 'll ask the speed shop/amatuer builder for the details.  

I plan to run the stock 4 barrel manifold because I was told they flow just as good as anything else in my LOW RPM range.  I plan to use my slightly modified by the same shop stock 4 barrel Q-jet or a Holley DP spreadbore(650 CFM). I heard the small primaries may help produce more torque.  I have access to a larger carb than this if it is recommended. This is was what I had around, and I thought it was a decent choice for a car that lives under 4800 RPM.

Thanks  


tuffnuff (207.6.156.3)
Moderator | Posts: 1415 | Joined: 12/09 Posted: 10/12/11
09:49 AM
Indexing the cam centerline has no bearing on the actual eventing numbers that are ground into the cam profile.,. so get the numbers from your builder.
The Q-Jet is a 750 CFM carb.,. I doubt the smaller 650 Holley will offer any performance gains.
I would stay with the Q-Jet.



CarlosCJ3B (208.195.70.39)
New User | Posts: 12 | Joined: 10/11 Posted: 10/12/11
10:50 AM
Would there be any benefit to a larger Holley for any reason?

The advertised duration is 256, Comp Cams Solid Lobe number 6052. Not sure if this would answer your question combined with the 105 lobe seperation angle and single pattern.  I will contact the builder later today.  



CarlosCJ3B (208.195.70.39)
New User | Posts: 12 | Joined: 10/11 Posted: 10/12/11
11:03 AM
TAPPET LIFT @ TDC
           @ .050” @ .200”      106° 110°      1.5   1.6  1.7
6052   256      218    129       .057 .046       .467 .498 .529

lobe lift .311  



CarlosCJ3B (208.195.70.39)
New User | Posts: 12 | Joined: 10/11 Posted: 10/12/11
11:14 AM
Here are both of the small solid lobes that comp has available


Xtreme Energy Solid 6052
Advertised 256 @ .015
218 @ .050
129 @ .200
Lobe Lift .311
1.5 lift .467
Tappet Lift TDC .057 @ 106CL
.046 @ 110CL

XTQ Solid 6275
Advertised 248 @ .020
218 @ .050
129 @ .200
Lobe Lift .310
1.5 lift .465
Tappet Lift TEC .057 @ 106CL
.046 @ 110CL  



CarlosCJ3B (131.239.68.227)
New User | Posts: 12 | Joined: 10/11 Posted: 10/12/11
11:38 AM
Comp Cams says without any built in advance;

Intake opens @ 4 BTDC
Intake Closes @ 34 ABDC

Exhaust Opens @ 34 BBDC
Exhaust Closes @ 4 ATDC



tuffnuff (207.6.156.3)
Moderator | Posts: 1415 | Joined: 12/09 Posted: 10/12/11
12:53 PM
Carlos, I'll mull over the numbers tonight.,. kinda busy in the shop right now.
I'll do a sym on both cams, using the same parameters.
Hang in there.



CarlosCJ3B (99.56.230.252)
New User | Posts: 12 | Joined: 10/11 Posted: 10/12/11
05:14 PM
Also, let me know if your SYM will tell you where to index the cam for best results.  Do you usually build to dynamic compression or to cranking pressure, and what are the most ideal numbers for 93 octane pump gas?  



tuffnuff (207.6.156.3)
Moderator | Posts: 1415 | Joined: 12/09 Posted: 10/12/11
08:07 PM
Carlos, I just came in from the shop and I'm about to start plugging your numbers in.
Cams should be installed straight up because the cam manufacturers have done all the juggling already.,. IF, a cam needs more than 3 degrees advance or retard, it's the wrong cam.,. get a different one. I could go into detail why this is so,,,, but I'll leave the explanation for another day.



Pontiacman8 (184.32.138.158)
Moderator | Posts: 4425 | Joined: 02/08 Posted: Yesterday 06:40 AM
+1 tuff  



tuffnuff (207.6.156.3)
Moderator | Posts: 1415 | Joined: 12/09 Posted: Yesterday 10:24 AM
Got a sym on your 6052 and it's a nice cam.
Here are the numbers as follows;

First # is RPM.,. Power.,. Torque

2000.,. 188.,. 492
2500.,. 239.,. 501
3000.,. 285.,. 499
3500.,. 329.,. 493
4000.,. 368.,. 483
4500.,. 399.,. 466
5000.,. 418.,. 439
5500.,. 418.,. 399
6000.,. 397.,. 347
6500.,. 373.,. 301
7000.,. 336.,. 252

Hope this is what you were expecting.,. I'll do the other cam tonight.


CarlosCJ3B (99.56.230.252)
New User | Posts: 12 | Joined: 10/11 Posted: Yesterday 05:23 PM
Whoa! In a 406?  So what did you have to plug in the SYM?  Intake, carb , headers, compression, solid cam? I plan to use 1.6 roller rockers.

Does it give you a dynamic compression?  Want pump gas.

Still not sure if he ordered advance in the cam, couldn't contact him, I called comp with lobe and seperation specs to find the info I gave you.  

Is there any theory that single pattern cams make more torque?  

Sorry for so many questions, but I would like to understand why someone would want an off the shelf cam instead of getting a custom cam??

Thanks  



tuffnuff (207.6.156.3)
Moderator | Posts: 1415 | Joined: 12/09 Posted: Yesterday 06:22 PM
I plugged in all the numbers that you gave me Carlos. There are free compression calculators available and all you have to do is plug your own numbers in. Cams are ground on centerlines.,. the engine builder does the juggling.
No theory at all, newer split patterns have superseded the single pattern cams, from 40 years ago, it only stands to reason, progress.
Going with a higher rocker ratio may or may not work.,. you do the experimenting, then let us know if your combo gained or lost.,. it's a throw of the dice.
I think you should start your own thread.,. cuz this one belongs to Rum Runner.



fastoneefi (70.127.64.253)
User | Posts: 150 | Joined: 01/10 Posted: Yesterday 09:47 PM
Most cam companies only have solid lift lobes in higher durations because, when compared to a hydraulic they don't "seem' as big. For instance, a 220 at .050 solid lobe is typically equal to about a 208-210 hydraulic lobe. And your solid lift flat tappet advertised durations are normally taken at .020, not .006 like hydraulics so they look "faster".
Also a single pattern will generally make more low to midrange power because you're not bleeding off pressure on the exhaust side and you've reduced your overlap as compared to a dual pattern cam. On the flipside it will fall off sooner because of the same reason.
The most important event is intake closing, that determines alot.
Not sure why you're looking at a solid lift for your application but I do custom grinds as well. Let me know if I can help.  
Mark
Engine builder, Erson Cams Dealer and Accel DFI Tech and host of their "How-to DVD", located in Central Florida



tuffnuff (207.6.156.3)
Moderator | Posts: 1415 | Joined: 12/09 Posted: Yesterday 10:35 PM
Thanks for chiming in Mark and shedding light on the cam discussion.,. it's an endless topic that is much misunderstood by most.
Volumes could and have been written on the subject.
Carlos, here's the man you need to talk to.
Have at er Mark.



CarlosCJ3B (198.228.197.47)
New User | Posts: 12 | Joined: 10/11 Posted: Today 05:28 AM
I guess I could have went hydraulic. Is the only reason to go solid to prevent lifter calapse at high RPM?  I chose to do a solid to try to gain more lift at a lower duration to target my lower RPM range with as much flow as possible. I'm also hoping that the 1.6 roller rockers add duration, which I thought was typically 3 degrees, bringing the RPM range up a little.  

The builder did want me to go hyd roller, but we ultimately decided to go solid.  I know the final cost may be a wash, oh well.    

Anyone else out there with small duration solids in pontiacs, or am I out on a limb here? (TFX?) I seen several posts on this, but no one ever seems to pull the trigger to buy and test a small street driven solid.  Are we just getting lazy with yearly adjusting or is the hydraulic flat tappet that much more superior in my RPM range? Anyone out there driving with one of these??

Thanks  



I may have misunderstood the original post. Was he looking for a solid  or hyd roller or solid roller or hyd roller.  If you want to move this to a new post that someone can find and benefit from, that would be good.  See my questions above.  Thanks


tuffnuff (207.6.156.3)
Moderator | Posts: 1415 | Joined: 12/09 Posted: Today 09:29 AM
Roger 10-4 consider it done


 
When The Flag Drops,,,



The Bull Chit Stops,,,


P. Engineer, Engine Builder

I waqs referring to a simulator for expected results differences.  Below are specs I took from my other post to help explain what I ordered for a custom cam.

Comp LOBE number:
Xtreme Energy Solid 6052
Advertised 256 @ .015
218 @ .050
129 @ .200
Lobe Lift .311
1.5 lift .467
Tappet Lift TDC .057 @ 106CL
.046 @ 110CL

Comp Cams says without any built in advance and 105 LSA, the following are the valve events;

Intake opens @ 4 BTDC
Intake Closes @ 34 ABDC

Exhaust Opens @ 34 BBDC
Exhaust Closes @ 4 ATDC  

TuffNuff came up with the following results on a simulator;



2000.,. 188.,. 492
2500.,. 239.,. 501
3000.,. 285.,. 499
3500.,. 329.,. 493
4000.,. 368.,. 483
4500.,. 399.,. 466
5000.,. 418.,. 439
5500.,. 418.,. 399
6000.,. 397.,. 347
6500.,. 373.,. 301
7000.,. 336.,. 252  
Carlos
70 Lemans(GTO Clone),406,Solid Cam 218 single pattern, 105 LSA
Serious Hobbyist

Those numbers are with iron heads and your solid cam with 1.5 rockers.
These numbers are about 20 short of what Steve was getting with his original iron head 406 and hydraulic cam that had more lift and duration.

 
When The Flag Drops,,,



The Bull Chit Stops,,,


P. Engineer, Engine Builder

I came up with between 7.8 and 8.2 on a dynamic compression calculator with the intake closing event of this cam and the cam installed straight up assuming head volume ends up at 78 cc after all head modifications are complete.

Not sure what equates to in cranking pressures, and if pump gas will work?  
Carlos
70 Lemans(GTO Clone),406,Solid Cam 218 single pattern, 105 LSA
Serious Hobbyist

Hi There,
 I don't know how a 20/60 mech cam with 260*@ 50/1000"

 lift and only 420/1000" @ THE VALVE on 1.5 rokas would
 suit this agenda..Cam grinders out here once threw cam
 numbers around like politician's promises..
 Most of the differences that were advertised were B/S
 as they all came off the leased or purchased copies of
 the SAME Master...Blah Blah to the shonks!!!!!!!!!!!  

I'm not sure what the question is?  That cam size doesnt seem right!  

The advertised duration of the cam I bought is 256. with 218 @ 50/1000

On your last statement,  I believe there are so many combos and RPM ranges and engine sizes, especially Pontiac, that when it comes time to pick a cam people commonly choose too large, looking for a wild idle.  The power, espcially average power will suffer severely and result in a turd of a car. I would rather favor the smaller cam and develop greater torque for fun street driving.

I also questioned why people dont chose a tighter lobe seperation angle in street driven cars. My own answer to that is, if people cant chose the right cam, the companies have to compensate by widening the RPM power range of the cam.  If you look at my SYM, the good power range is 2000 wide , while other cams are 3000 RPM wide.

I know some effects of tight LSA, idle, vacuum, but not sure exactly how it reacts with the lower duration?  Maybe someone can answer that.  What is estimated vacuum for this cam vs. a 230 @ 18 solid with 105 LSA?  
Carlos
70 Lemans(GTO Clone),406,Solid Cam 218 single pattern, 105 LSA
Serious Hobbyist

The only way to know for sure is to just build an engine and find out. The rest is just a guessing game.  

Boy Carlos you're all over the place with this. In one post you mention using a tight lobe sep because you're looking for low rpm power. In another post you mention you didn't want to go hyd because your were afraid of potential high rpm problems with a hyd lifter, which is it?

People do mostly hyd today because of the flexiblity of that setup. They are virtually maintenance free and give you a good stable valvetrain past 6000 if everything is right and you use good quality pieces.

Solids are normally for higher rpm/limited use applications.

And most off the shelf cams are done on wider lobe seps for a better idle, driveability, and to fit a broad range of applications.

When in doubt, a good rule of thumb is to go smaller on the duration and tighter on the lobe sep, that'll typically give you more power sooner (right where you drive it) and if the durations are reasonable, still give you good overall manners as well. But that will make the torque curve peakier, not flatter.

One more thing, you normally don't want to maximize lift for "as much flow as possible" on a low rpm application. With a wider valve opening you lose velocity, especially when using stock or nearly stock 60's and 70's era iron heads. In that same post you say you're looking for low rpm power yet you're going to use 1.6 rockers in the hopes of "bringing the rpm range up a little", huh? Again you're all over the place here. If you want to raise the rpm range just retard the cam a bit. You have enough compression and displacment to do that.

Email or pm me if you like, I'd be happy to help.  
Mark
Engine builder, Erson and Lunati Cams Dealer and Accel DFI Tech/Dealer, located in Central Florida

I must have written it wrong. I was looking to target a specific range by tightening LSA, it minimizes your operating RPM power range, right?  

The low duration will give me my power at low RPM.  

I was also mentioning high RPM as typical use for solid cams, but that is not the reason I used it. I figured the higher lift would help, not neccessary total lift, but steeper ramp on the lobe.  Also, what I was saying in rocker arms, doesnt the 1.6 add duration @ 50(about 3 degrees), effectivly moving the RPM range up a little?

Alot of my posts were actually questions and open for discussion, but I think we're basically saying the same thing.

I would like to hit on the statement you said below;

One more thing, you normally don't want to maximize lift for "as much flow as possible" on a low rpm application. With a wider valve opening you lose velocity, especially when using stock or nearly stock 60's and 70's era iron heads.

So, what is the deciding factor on this, the maximum flow of the heads? I dont think I'll have the heads tested, but the builder is boing to do some bowl and valve guide area work, he did extra valve macining, (backcut?) He is also going to port match the intake and heads.

So how do you know when you are effectively huring the velocity, would this have to be a flow test before and after?

Thanks  
Carlos
70 Lemans(GTO Clone),406,Solid Cam 218 single pattern, 105 LSA
Serious Hobbyist

mb68bird:
The only way to know for sure is to just build an engine and find out. The rest is just a guessing game.

Bird,

both of your posts indicate there is no way to know how cams react without extensive testing.  I would think by now, experience or a computer/science we would know how a particular cam reacts or is supposed to react with given parameters, it can't be a total guessing game? I will post my complete build when complete and try to do some testing on a chassis dyno and at the track.

Will a car be faster in 1/4 mile with a wide LSA or narrow?  Doesn't this depend on average HP or torque during the run?  
Carlos
70 Lemans(GTO Clone),406,Solid Cam 218 single pattern, 105 LSA
Serious Hobbyist

CarlosCJ3B:
I must have written it wrong. I was looking to target a specific range by tightening LSA, it minimizes your operating RPM power range, right?  

The low duration will give me my power at low RPM.  

I was also mentioning high RPM as typical use for solid cams, but that is not the reason I used it. I figured the higher lift would help, not neccessary total lift, but steeper ramp on the lobe.  Also, what I was saying in rocker arms, doesnt the 1.6 add duration @ 50(about 3 degrees), effectivly moving the RPM range up a little?

Alot of my posts were actually questions and open for discussion, but I think we're basically saying the same thing.

I would like to hit on the statement you said below;

One more thing, you normally don't want to maximize lift for "as much flow as possible" on a low rpm application. With a wider valve opening you lose velocity, especially when using stock or nearly stock 60's and 70's era iron heads.

So, what is the deciding factor on this, the maximum flow of the heads? I dont think I'll have the heads tested, but the builder is boing to do some bowl and valve guide area work, he did extra valve macining, (backcut?) He is also going to port match the intake and heads.

So how do you know when you are effectively huring the velocity, would this have to be a flow test before and after?

Thanks

Typically .1 change in rocker ratio equates to about 1-2 degree duration at the valve. And .1 increase in rocker ratio change also reduces lobe sep about 1 degree as well.

Unless they're way off port matching is a bit of a waste of time. You're better to spend the time in the bowl and short side radius area.

Yes that will make a difference in how much lift you'll want. Beyond a certain point you'll lose efficiency.  
Mark
Engine builder, Erson and Lunati Cams Dealer and Accel DFI Tech/Dealer, located in Central Florida

I'm still with you guys on this thread.,. just been a bit busy in the shop.
Tonight I'll post some startling results that make direct comparisons of solid vs hydraulic vs roller and also subtle LSA changes from 110 to 108.,. and also rocker ratio, from 1.5 to 1.6.
Lift differences will also show some surprising results.
The test engine remains the same and only one thing gets changed with each sym.

 
When The Flag Drops,,,



The Bull Chit Stops,,,


P. Engineer, Engine Builder