Moparts
roller vs mechanical flat tappet cam?
Posted By: Jonnyj00
roller vs mechanical flat tappet cam? - 07/02/12 09:39 PM
Im trying to decide whether to keep with the old flat tappet cams or make the move to a roller. I dont need high lift at all around .590. So some pros and cons for each would be great. I have heard that rollers require more maintenance like valve springs changes more often and stuff like that but I dont know if thats because of the high lift that you can run with rollers? Another question I had was about cam additive for ZDDP whether you need it for rollers like you do for flat tappets and what kind do you guys use for your cams?
Thanks guys
Posted By: carolinacuda
Re: roller vs mechanical flat tappet cam? - 07/02/12 10:01 PM
Well i will give my two cents. Alot depends on your performance goals. Rollers do have its advantages but its hard to beat a good solid flat. Rollers are alot of extra $$ for a few horses. I used a hughes flat 572/579 for my 10.8 comp 446. Make sure you have good flowing heads or you will not gain much..I got Indy Ez's and a victor Int. topped by a 950 carb. Im happy so far with mine. I got it in a 74cuda with all stock susp and M/T Et's and i ran 7.22 in 1/8th. Thats with 3500 stall and 3.91 gears. Call hughes they will help you decide. I use Havoline racing oil which has zinc in it. Other than an occasional rocker arm adjustment ive had no issues.
Posted By: BigBlockMopar
Re: roller vs mechanical flat tappet cam? - 07/02/12 10:11 PM
You only have to wipe one lobe on the flattappet cam to remind you why you made the mistake of not going with a roller in the first place
A roller costs a good deal more, but it also takes away the annoying halfhour break-in period of a fresh engine or cam install. Oil selection becomes a little less critical aswell.
You can just start the engine, set timing and carb adjustments and then break in the rings during a couple of firm drives around the block.
Posted By: rickraw
Re: roller vs mechanical flat tappet cam? - 07/02/12 10:17 PM
what he said. at sometime u will have to change the bronze dizzy gear. rollers will have to be rebuilt at some point too. wish i went with a flat tappet cam. i'm runnin a 730lift roller on the street with some strip time. i just us delvac 15-40w oil, no additive needed.
Posted By: Cab_Burge
Re: roller vs mechanical flat tappet cam? - 07/02/12 10:25 PM
Posted By: gregsdart
Re: roller vs mechanical flat tappet cam? - 07/02/12 10:35 PM
There are street friendly grinds available that don't require race spring pressures and if i am right some that don't need the bronze gear? Call a couple of the cam company s and tell them what you want and you should come up with some solid advice and a setup that will last a lot of miles. You will like the extra power and roller cams have a little more bottom end torque because they have faster opening rates and don't need quite as much total duration for the same power band.
Posted By: Mr.Yuck
Re: roller vs mechanical flat tappet cam? - 07/02/12 10:37 PM
I'm pretty happy with the soild roller. It's a Comp cams 588/580. runs drives nice. Pulls hard and has better stret manners than a MP 509. Now the cost is 3x as much, so that is somthing to think about.
Posted By: Jonnyj00
Re: roller vs mechanical flat tappet cam? - 07/02/12 10:49 PM
Well this whole question was brought on becuase of the additive... We tried running a solid flat tappet with royal purple full synthetic and took some lobes off the cam
. Should have known better. This car runs the 1/8 and we shift at 5500 and runs 7.20 consitantly or should I say ran... Its just a 440 that had a .590 purple shaft. Ran good and consistant had no complaints with performance. We dont really wanna turn that many Rs because we dont wanna spend the money to do so lol. So it sounds to me like unless we wanna turn mor RPM stick with the flat tappet and just keep the cam lube in stock.
Posted By: Jonnyj00
Re: roller vs mechanical flat tappet cam? - 07/02/12 10:50 PM
BTW street drivablity isnt a concern. Race only car
Thanks guys!!
Posted By: gregsdart
Re: roller vs mechanical flat tappet cam? - 07/02/12 10:54 PM
Quote:
Well this whole question was brought on becuase of the additive... We tried running a solid flat tappet with royal purple full synthetic and took some lobes off the cam . Should have known better. This car runs the 1/8 and we shift at 5500 and runs 7.20 consitantly or should I say ran... Its just a 440 that had a .590 purple shaft. Ran good and consistant had no complaints with performance. We dont really wanna turn that many Rs because we dont wanna spend the money to do so lol. So it sounds to me like unless we wanna turn mor RPM stick with the flat tappet and just keep the cam lube in stock.
Do you check for lifter rotation before you fire the motor? If any of them aren't rotating, put 500 grit sandpaper in the palm of your hand and rotate the base of the lifter in it till you can see that it is scuffed a bit. Test for rotation again. With the right oil, you should be fine.
Posted By: MR_P_BODY
Re: roller vs mechanical flat tappet cam? - 07/02/12 10:58 PM
Quote:
Well this whole question was brought on becuase of the additive... We tried running a solid flat tappet with royal purple full synthetic and took some lobes off the cam . Should have known better. This car runs the 1/8 and we shift at 5500 and runs 7.20 consitantly or should I say ran... Its just a 440 that had a .590 purple shaft. Ran good and consistant had no complaints with performance. We dont really wanna turn that many Rs because we dont wanna spend the money to do so lol. So it sounds to me like unless we wanna turn mor RPM stick with the flat tappet and just keep the cam lube in stock.
A roller will make more power and if you keep the
duration down you dont have to spin it higher and
no you dont need additives... if the bottom end can
turn higher and you have the flow I would turn it
higher... RPMs make HP if your set up for it
Posted By: Jonnyj00
Re: roller vs mechanical flat tappet cam? - 07/02/12 11:01 PM
Quote:
Quote:
Well this whole question was brought on becuase of the additive... We tried running a solid flat tappet with royal purple full synthetic and took some lobes off the cam . Should have known better. This car runs the 1/8 and we shift at 5500 and runs 7.20 consitantly or should I say ran... Its just a 440 that had a .590 purple shaft. Ran good and consistant had no complaints with performance. We dont really wanna turn that many Rs because we dont wanna spend the money to do so lol. So it sounds to me like unless we wanna turn mor RPM stick with the flat tappet and just keep the cam lube in stock.
Do you check for lifter rotation before you fire the motor? If any of them aren't rotating, put 500 grit sandpaper in the palm of your hand and rotate the base of the lifter in it till you can see that it is scuffed a bit. Test for rotation again. With the right oil, you should be fine.
Are you talkin about for engine break in? If you are thats the most pathetic part about our problem lol is this motor has been together for years we just didnt have any cam addative and decided to try and take a chance with royal purple with out the addative. If your not talking about break-in please elaborate im curious as to what you mean?
Posted By: FastOne
Re: roller vs mechanical flat tappet cam? - 07/03/12 01:50 AM
I'm going to try the new Crane steel oil drive gear with my roller, pn69970-1
Advice is to not use a high volume oil pump with this gear
Posted By: Crizila
Re: roller vs mechanical flat tappet cam? - 07/03/12 03:07 AM
IMO, rollers are over priced and over marketed ( Gods gift to performance ). For all out high end race engines, yes - other wise, they are just a bragging crutch. The additional weight you have to deal with offsets other advantages below .650 lift IMO. I have run a flat tappet cam with well over .600 lift for going on 4 years now ( using Royal Purple full synthetic BTW ) with zero problems. The larger .904 lifters used in Mopar motors is a real advantage for running aggressive flat tappet cam profiles also.
Posted By: 383man
Re: roller vs mechanical flat tappet cam? - 07/03/12 03:41 AM
I went with a solid flat tappet in my car. I use the EDM lifters with the small hole in the bottom for oil to the lobe. I checked all my lifters for rotation before I started it. I use Valvoline racing oil and a zinc additive. No problems at all. I did break the cam in on just the outer springs. With a roller I did not want to worry about valve float if it did not have enough spring pressure and I did not want to worry about a lifter breaking with the high spring pressure they use. I drive my 63 on the street alot and felt the flat tappet would be best for me. Ron
Posted By: J_BODY
Re: roller vs mechanical flat tappet cam? - 07/03/12 04:32 AM
Ran flat tappet in my RB 498 in the Mirada. Only two sets of valve springs ever and the car was still running 9.90's a couple weeks before I sold it. Same Ultradyne cam for 15+ years. New owner had been running 10.2-.3 at a couple different tracks at higher altitudes. 20-50 off the shelf racing oil for years, and then Shell Rotella since 08. I'm sure rollers have there place, but I sure see alot of people running them in dedicated race cars that didn't come close to the number I was running with my junk.
On the flip side we went roller with our W5 small block. After 50 passes we had to disassemble due to water seepage issues and found the bodies on at least 6 of the Comp Cam roller lifter bodies cracked. That was quite a bit of $$$ flushed... Ordered some new lifter from IMM and they lasted 150 passes until the engine expired....and of course hurt a cam lobe so you have to question the integrity of the lifters....so in 200 passes we have one set of junk roller lifters, and one set I probably would question on "re-using". We're in the planning stages for another 9 sec small block, and we'll most likely go with another set of "new" lifters..... but we're stupid like that
Posted By: poppaj
Re: roller vs mechanical flat tappet cam? - 07/03/12 04:34 AM
The advantage of a roller cam is you can use the stiffer springs which keeps the valve train under control at higher rpm. Plus roller profiles can be much more aggresive. poppaj
Posted By: Thumperdart
Re: roller vs mechanical flat tappet cam? - 07/03/12 04:46 AM
Been running an Isky roller for over 7 years now and I`ve changed springs once and had the lifters rebuilt once also and love it. Street lobes and revs like an animal past 7500 rpm`s w/ease......Don`t see myself ever going to a solid again........
Posted By: rebel
Re: roller vs mechanical flat tappet cam? - 07/03/12 05:39 AM
the first cam i used in my Indy Maxx block was a comp cams solid, 280/284 @ 050 650 lift, ran well but we only got 9.7 @ 137mph best at the end of the season. that was ok as we were running 9.90 so it suited me. then i came into some $$$ so i bought ICH's R1 cam, 272/276 @ 050 660 lift got us into the 9.5's but struggled with hardwear coming loose all the time, eventually we scored one of the lobes so i sent it to a cam man for analylist. he said that cam had harmonics & should be reground. so we did it. came back 272/279@ 050 650 lift. wow big improvement, nothing comes loose & with a little work on the bodys areodynamics we ran a string of 9.4's last season. the flat tappet was waay hotter at 050 but the lesser roller has us running heaps faster. on a race motor, i will only buy a roller from now on. the extra HP is so much cheaper buying a roller cam.
Posted By: gsmopar
Re: roller vs mechanical flat tappet cam? - 07/03/12 06:08 AM
Quote:
You only have to wipe one lobe on the flattappet cam to remind you why you made the mistake of not going with a roller in the first place
I lost a lifter and wiped out my roller cam. I don't think that this is a good argument for either cam.
Posted By: BIGSTROKER
Re: roller vs mechanical flat tappet cam? - 07/03/12 02:17 PM
i'm a roller cam fan but the bottom line is if your under .600 lift and you don't want to spin the motor over 7000 then a roller cam is a waste of money imo
Posted By: rickseeman
Re: roller vs mechanical flat tappet cam? - 07/03/12 02:20 PM
I've lost count of how many blown up roller cam motors I've bought in the last 35 years. Can't remember buying any blown up flat tappet motors. The lift you are asking for doesn't take much spring pressure over stock. It should last forever. Flat tappet motors also make their power at a lower rpm, which makes for a longer life engine. Nearly all drag racers think they have to have a roller cam. What a joke. You can make over 800 HP with a low rpm, low spring pressure flat tappet that will last a long time.
Posted By: SuperStock68Dart
Re: roller vs mechanical flat tappet cam? - 07/03/12 06:27 PM
If you're breaking roller lifters it's because you don't have enough spring pressure! To much is better than not enough. Any valve float, even if you can't "hear" it, will eventually take them out
Posted By: sshemi
Re: roller vs mechanical flat tappet cam? - 07/03/12 08:16 PM
I think that a roller is better for power in every way but i have seen a few roller lifter bearings fail and its not pretty.
Posted By: MR_P_BODY
Re: roller vs mechanical flat tappet cam? - 07/03/12 08:21 PM
Quote:
I think that a roller is better for power in every way but i have seen a few roller lifter bearings fail and its not pretty.
And in most cases(not all) the spring pressure was
too light OR the springs wore out... some cases the
roller lifter was just a inferior product ...JMO
Posted By: gregsdart
Re: roller vs mechanical flat tappet cam? - 07/03/12 10:32 PM
Quote:
Quote:
Quote:
Well this whole question was brought on becuase of the additive... We tried running a solid flat tappet with royal purple full synthetic and took some lobes off the cam . Should have known better. This car runs the 1/8 and we shift at 5500 and runs 7.20 consitantly or should I say ran... Its just a 440 that had a .590 purple shaft. Ran good and consistant had no complaints with performance. We dont really wanna turn that many Rs because we dont wanna spend the money to do so lol. So it sounds to me like unless we wanna turn mor RPM stick with the flat tappet and just keep the cam lube in stock.
Do you check for lifter rotation before you fire the motor? If any of them aren't rotating, put 500 grit sandpaper in the palm of your hand and rotate the base of the lifter in it till you can see that it is scuffed a bit. Test for rotation again. With the right oil, you should be fine.
Are you talkin about for engine break in? If you are thats the most pathetic part about our problem lol is this motor has been together for years we just didnt have any cam addative and decided to try and take a chance with royal purple with out the addative. If your not talking about break-in please elaborate im curious as to what you mean?
Yes,talkiing about breakin procedure. sounds like you want to stay with the 590 cam, and thats OK. Just wanted to help make sure you don't lose a new cam on fire up. Good luck with it!
Posted By: jyrki
Re: roller vs mechanical flat tappet cam? - 07/04/12 06:01 AM
I converted to a roller in a street car around 1994. The reason was that I wiped out three MP cams during a short period. I have used dozens of different cams since then in different build ups. In my opinion, there isn't an absolute truth here. There really is a reason why the OEM manufacturers use rollers nowadays too, it just makes more power than a similar flat tappet. It also accepts way more aggressive grinds, which requires and can use way stiffer valve springs etc. That of course stresses the other valvetrain components alot more than a flat tappet will ever do. However, a similar flat tappet would kill everything + itself there immediately. In a race car with frequent checking and maintenance, I would say go for it. And with an aggressive race grind. In a streeter, if you pick a "street roller" that doesn't require extreme spring pressures etc., I would say that the relaibility is at least as good as with a flat tappet, but the manners and power better. The real question is, that is the advantage for you worth the 1000$ or so you have to spend upgrading?
Posted By: 68 HEMI GTS
Re: roller vs mechanical flat tappet cam? - 07/04/12 06:07 AM
rollers work well, you just gotta suck it up and send the lifters back for a rebuild every few years. especially, if they don't oil the needle bearings directly. i send my comps back every 2 years that are in my Hemi, but it also see's tons of street miles and some stop and go traffic. think i idle'd more yesterday going 30 miles (one way) than i did all last year.........
Posted By: rebel
Re: roller vs mechanical flat tappet cam? - 07/04/12 07:58 AM
whats it worth to have your roller lifters reconditioned? being down under i don't want to waste $$ on a reco job when buying a new set is cheaper. freight can be a killer.
Posted By: jyrki
Re: roller vs mechanical flat tappet cam? - 07/04/12 08:48 AM
I believe it was 100-150$? I have never done that, for the very same reason
Posted By: cheapstreetdustr
Re: roller vs mechanical flat tappet cam? - 07/04/12 03:07 PM
ive been reading along...and if i base my conclusion on what has been stated here ...I would come up with the complete wrong impression of a roller cam.
the tradition for rollers in racing in the beginning was to fill the need for going ultra agressive...so that created the roller cams reputation..
however...if you get a cam turned for your specific application.
then throw this montra out the window "roller cams are best suited for high rpm application" that statement/mindset is misleading.
the roller lifter opens up the valve lift profiles to dimensions not avail in a flat tapit.
this means Torgue ..you can build in torque..you can build in low lift or low rpm performance.
id venture to say...take what you can do with a flat tappet for whatever your application...and add a %20 better results with the roller lifter over what you did with the flat tappit...its geometry and mathmatics plain and simple...
the only negative factor to add (as stated) is lifter weight...but honestly that only applies in higher or extreme applications...and can be designed around..
for what your doing...you will see definate gains..just dont base your new roller cam choice on flat tappit profiles...get a roler profile that best suits your heads flow graph and valve lift limitations..
fwiw..
my advice with your sinario is get a set of doug herbert roller lifters and do up a roller cam for your application get oil pump drive ..use the springs herbert recomends.
.and go faster than you went last yr....
Posted By: Darryls-Demon
Re: roller vs mechanical flat tappet cam? - 07/04/12 04:37 PM
I have two street cars with solid roller cams and so far I think they are great. The stock stroke 440 I have has almost 2000 street miles on it I have checked the lash two times and nothing has moved but I did break a Erson 1.6 roller rocker at an idle at a stop light.
The other motor is a 408 W2 headed SB, this motor has over 2600 miles on it the lifters where checked a 100 miles ago and they look great and they are Comp lifters. I drive the small block everywhere, back and forth to work- 24 mile round trip round trip to Vegas all around the valley. I will be doing DragWeek this year with the car plus Iam thinking very hard about running the car in a true street challenge race next month in Pomona California.
Now my personal opinion on using a roller cam is you need to use very good valve springs, rockerarms and good pushrods you do not want to have any thing flexing in there.
Posted By: emarine01
Re: roller vs mechanical flat tappet cam? - 07/04/12 05:01 PM
Friction is friction... anything that rolls is better than something that slides.... Anything mechanical can fail..... and you don't get a lot for your money
Posted By: Crizila
Re: roller vs mechanical flat tappet cam? - 07/04/12 05:16 PM
The OEM's went to rollers to be able to meet the EPA standards ( and a good portion of that was to cut friction losses ), not for performance reasons. Street grind flat tappet cams can easily duplicate roller performance with a lot less valve train stress - and BTW, those high load valve springs needed with rollers affect valve train longivity at ALL rpm's - all the time. That equates to not only higher initial valve train $, but higher $ throughout the entire life of the valve train( and only the valve train if you are lucky ). The point I have been trying to make here is not that rollers are a bad thing, but that they are mismarketed by many cam manufacturers ( for obvious reasons - $$$ ) and sold to the ( to be kind ) less knowledgeable as a major performance gain when in most street and mild performance appications they are not. JMO. My suggestion is that before you pop for a roller cam, take a good look at your particular application. Don't just jump in to a roller because " all performance engines gotta have one".
Posted By: A57_RT
Re: roller vs mechanical flat tappet cam? - 07/04/12 05:59 PM
Its funny this comes up every so often. For years now ive been using the Beck/SM solids in both the std and leightweight version.
Even there heavy one is lighter then most anything offered.
On cams under .650 lift I can use modest (far less then a roller needs) springs, good quality rockers and pushrods and run to the chipped 7600 limit, one set is on the 5th cam, testing/dyno now in a car so that makes the cost worth it imo vs comps pig heavy edms thay call lightweight.
I do have one motor with the comp edms, never broke the cam in as by the book, just used rot. one can of old stp and I use a hp spring in the pump with the thoughts the edms will oil more at idle????
Never an issue if the lifter will spin in the bore, if the lifter is tight, try a different hole, if its the hole hone it.
When I was younger and took blocks to one of the better shops I used they always wanted the lifters and the pistons I was going to use, each time the block came back with a small cross hatch pattern in the lifter bores
Who knows.
Posted By: cheapstreetdustr
Re: roller vs mechanical flat tappet cam? - 07/04/12 06:05 PM
Quote:
The OEM's went to rollers to be able to meet the EPA standards ( and a good portion of that was to cut friction losses ), not for performance reasons. Street grind flat tappet cams can easily duplicate roller performance with a lot less valve train stress - and BTW, those high load valve springs needed with rollers affect valve train longivity at ALL rpm's - all the time. That equates to not only higher initial valve train $, but higher $ throughout the entire life of the valve train( and only the valve train if you are lucky ). The point I have been trying to make here is not that rollers are a bad thing, but that they are mismarketed by many cam manufacturers ( for obvious reasons - $$$ ) and sold to the ( to be kind ) less knowledgeable as a major performance gain when in most street and mild performance appications they are not. JMO. My suggestion is that before you pop for a roller cam, take a good look at your particular application. Don't just jump in to a roller because " all performance engines gotta have one".
i dont mean to digress but HUH?
frictional losses at the lifter ? = emission output?
more like valve events..that allow for a longer burn cycle to take place before exhaust valves open sending incomplete combustion gases out the tail pipe. that constitutes emissions..
holding the valve closed longer in degrees of crankshaft rotation extends the burn cycle..then having an opening ramp rate faster so the valve opens to the same lift rate later in crank rotation..achieving the same or more optimal max open rates in relation to crankshaft degrees..is more likely...
or Intake valve events that prevent reversion and egr issues.
seems more likely the causation..
now if we where talking oem extending the oil changes to 10,ooo miles.because of rollers..you may have causation to justify that one...?
Posted By: Crizila
Re: roller vs mechanical flat tappet cam? - 07/04/12 07:29 PM
I think we are kinda saying the same thing here re the emission thing - although a part of it was to cut friction losses. Extended oil changes came about by mostly better oil ( synthetic in particular ).
Posted By: cheapstreetdustr
Re: roller vs mechanical flat tappet cam? - 07/04/12 08:52 PM
you get more valve lift or gain a broader span of valve control across the lobe with a roller trunnion than you can physically achieve with a flat tappit..
so saying you can do the same thing with a roller just doesnt compute.
you can have a steeper ramp which speeds up lift.
or you can move the valve lifter earlier or later in the lobe position in relationship to crankshaft degree of rotation..fwiw..
there is an advantage here..you cant utilise with a flat tappit...
granted a .904 diameter lifter affords us mopars more options..but no where near what a roller offers...fwiw.
Posted By: cheapstreetdustr
Re: roller vs mechanical flat tappet cam? - 07/04/12 08:59 PM
its not just more lift..thats simple..its more lift earlier (intake lobe/tapit) or later (exhaust lobe/tapit) at points you cant achieve with a flat tappit...
you can get aggressive loge ramps with a flat tappit but at some point you put too much side load on the lifter..
and the lobe sweep across the tappit face you will find a numb spot...where the lobe moves/crankshaft degree of rotation moves..ie piston moves..
but the valve no longer does...
this is why the roller is superior.
Posted By: cheapstreetdustr
Re: roller vs mechanical flat tappet cam? - 07/04/12 09:11 PM
the best way to describe this is a flat tappit is lazy compared to a roller tappit.
Posted By: Sixpak
Re: roller vs mechanical flat tappet cam? - 07/04/12 09:16 PM
Quote:
I converted to a roller in a street car around 1994. The reason was that I wiped out three MP cams during a short period. I have used dozens of different cams since then in different build ups. In my opinion, there isn't an absolute truth here. There really is a reason why the OEM manufacturers use rollers nowadays too, it just makes more power than a similar flat tappet. It also accepts way more aggressive grinds, which requires and can use way stiffer valve springs etc. That of course stresses the other valvetrain components alot more than a flat tappet will ever do. However, a similar flat tappet would kill everything + itself there immediately. In a race car with frequent checking and maintenance, I would say go for it. And with an aggressive race grind. In a streeter, if you pick a "street roller" that doesn't require extreme spring pressures etc., I would say that the relaibility is at least as good as with a flat tappet, but the manners and power better. The real question is, that is the advantage for you worth the 1000$ or so you have to spend upgrading?
What I understood for the switch to roller cams by the OE's was that in the mid 70's when Catalytic converters and unleaded gas became the norm in the US, the converters started getting contaminated by the zinc and other oil additives that promoted better wear on bearing surfaces. When they started cutting the zinc in the oils to save the converters the cams and lifters started failing. I remember a rash of bad cam and lifter failures in a lot of 305 Chevy's in the early 80's that may have been partially due to this. So to get around the loss of wear additives, the OEs switched to rollers.
Posted By: cheapstreetdustr
Re: roller vs mechanical flat tappet cam? - 07/04/12 09:24 PM
Quote:
I think we are kinda saying the same thing here re the emission thing - although a part of it was to cut friction losses. Extended oil changes came about by mostly better oil ( synthetic in particular ).
to a large degree roller cams greatly reduce shear forces on oil...the rings and flat tappit camshaft contribute to most to oil break down..
think of oil like a mass or volume consisting of grapes...thousands of grapes together forming a liquid.sort of like an oil pan full of ball bearings...
the shear effect in a cam wiping across the lobe or rings scraping up and down the cyl walls break open the grapes...however areas like roller bearings and crank and cam bearings dont break the protective coating of the grape...
a grape being a oil molecule...with a outer shell.
once the shell breaks ...the lubrocity goes with it..
thats over simplified but a way to visualise it..
if you dont break the grapes/oil molecule..then it lasts longer...fwiw....but again ive digress from the OPs topic.
Posted By: Crizila
Re: roller vs mechanical flat tappet cam? - 07/04/12 11:48 PM
Thanks, but I didn't really need an explaination of why a roller is better than a flat tappet cam. point is, if your application can't utilize the extra area under the curve, it's a waste of $. Yes, there is a point of no return in regards to aggressive lobe ramps, and it applies to roller cams also. With flat tappet cams, that point is usually determined by the lifter diameter. With rollers, the point is usually determined by how strong you can make the rest of the valve train. I still contend that if you are running a cam under .650 lift, the negatives to running a roller outweigh the positives. You pays yo money and you takes yo chances.
Posted By: jyrki
Re: roller vs mechanical flat tappet cam? - 07/05/12 07:28 AM
for me, running a flat tappet gave three negatives in one summer, wiped out cams and the consenquences. After that rollers in my own use, some occasional harm either from own stupidity or from the parts getting tired. I think I have hade maybe ten lifter failures, a couple from wearing out and some others loosing pushrods etc. The cams may have gotten some scars, but nothing you can't fix yourslef. Some rocker failures too, the aluminum ones get tired if you stress them and break after a lot of cycles, just like aluminum rods. Our stuff has been relatively low rpm, so the weight is not a huge factor. Although the current one has a red line of 7700, it has been together for three summers without problems. Forgot a couple of hurt valvepsrings during this time, but since switching to endurance springs, there hasn't been any problems. In an old Hot Rod magazine they compared similar grinds on hyd flat tappet, solid flat tappet and roller designs. The roller won clearly, they produced a broader tq curve. And that's also the reason the OEM went with rollers; while having the cam adv. degrees low to meet emissions, you still get more area under the curve and retain, or increase the performance. Like I wrote before, there is an advantage, but is it worth the 1000 or so in your case is the hard question. You might spend it elsewhere for even bigger advantage. My next engine, a 340 W2, will most likely use a flat tappet because it's a budget build. We'll see wether the decision is right or wrong.
Posted By: A57_RT
Re: roller vs mechanical flat tappet cam? - 07/05/12 02:20 PM
One set of these and you will never buy another set of solid lifters again and never eat a lobe.
These SM are the heavy ones at 73 grams vs a std old 828 comp at 88 grams and then the pig comp lightweight edm-s at 101 grams, just right with a johnson hylift hydro.
I use modest springs, middle of the road rockers, .116 walled pushrods and bang these to 7600 over and over.
As I posted one set is going on 4 flawless years in a street/strip car with comp rockers,springs and they are on there 5th camshaft.
So there are some flawless solid cam setups in use.
The only thing ive seen with these lifters is if you get near .700 more the spring pressure needed calls for a roller core with solid lobes, at least thats what the class racers are doing.
![Attached picture 7278231-DSC06388[1].JPG](https://board.moparts.org/ubbthreads/upload2/7278231-DSC06388[1].JPG "7278231-DSC06388[1].JPG")
Posted By: 68HEMIRR
Re: roller vs mechanical flat tappet cam? - 05/31/13 05:09 AM
Quote:
One set of these and you will never buy another set of solid lifters again and never eat a lobe.
These SM are the heavy ones at 73 grams vs a std old 828 comp at 88 grams and then the pig comp lightweight edm-s at 101 grams, just right with a johnson hylift hydro.
I use modest springs, middle of the road rockers, .116 walled pushrods and bang these to 7600 over and over.
As I posted one set is going on 4 flawless years in a street/strip car with comp rockers,springs and they are on there 5th camshaft.
So there are some flawless solid cam setups in use.
The only thing ive seen with these lifters is if you get near .700 more the spring pressure needed calls for a roller core with solid lobes, at least thats what the class racers are doing.
UNTIL THE GLUE SEPARATES AND THE LIFTER FAILS WHICH MINE DID.....700 SPRING PRESSURE I DID AND BLEW OUT 8 LIFTER CUPS.MY STAGE V HEADS WHERE BUILT BY FORHEMISONLY AND HE THOUGHT I HAD A ROLLER CAM....SO FORGET THAT IDEA
Posted By: 69dart
Re: roller vs mechanical flat tappet cam? - 05/31/13 08:24 PM
If starting from scratch the difference is only a couple hundred bucks. Herbert has good roller lifters, cams and springs. I'll probably never go solid again.
I have one custom ground solid roller cam that is really stupid as far as how high in RPM it will pull hard to 
) and the playback tach shows I shifted it out of first gear at 8100 RPM, it was still pulling hard