[defman77]

I am starting up a thread on rollers vs non-rollers....I want to hear everyone's opinion on which one is better and why? Im rebuilding a mustang and cant decide so maybe some of you folks can convince me on which one to use. I tend to use non-rollers on my projects but i want to hear from you folks so shoot away!

 

[automotive breath]

Rollers have a huge advantage in the ability to lift the valve faster; this permits high lift possibilities with out extreme duration.

Flat tappets have a huge advantage in overall valve train cost.

 

[Henry Highrise]

Well now days with the government forcing the oil companies to remove the zinc from motor oil there is a very high risk of cam /tappet failure on break in. Shell Rotella oil still has some zinc in it and thats what the flat tappet cam folks are using for break in. Word is that in the next few months the Shell Rotella will have the zinc removed. The zinc as I understand it is a lubricant that the flat/tappet cams need...so I don't know...but if you do a search on the subject you can find lots to think about on this subject.

 

[Guy Hiltz]

Roller lifters have a definite advantage,especially as Henry pointed out with zinc being removed from oil,flat tappet cams are certainly at a disadvantage as far as accelerated wear is concerned.But roller lifters are not perfect either,I can tell you from my own experience at having a lifter explode and ruin a cam.What happens is that after time,especially if you are using high lift cams and heavy duty springs,the needle bearings in the lifters become flattened,or knife edged,because only one side of the needle bearings take a beating at a time,then there is more and more play in the lifter wheel and eventually they will break.When that happens,peices go flying everwhere.Joe Schubeck at schubeckracing.com has interesting theories on this matter.He also produces roller lifters that do not use needle bearings,they float on a film of oil much like crank and rod mains do,but they are expensive.Most cam companies also manufacture a higher end lifter that is supposed to supply more oil to the roller wheel/cam lobe area,but they still use needle bearings.Also, mods that work with flat tappet cams do not necessarily work with rollers.Thrust washers and cam buttons are needed.Windage trays and crank scrapers are not recommended,and oil restrictors are not a good idea either.Roller lifter oiling is mostly acheived from crank windage,this is very important!But let me also say that my first solid roller cam had been in this motor long before I bought it,I'm guessing at 15 years,lots of abuse and hard driving,and if I had of known at the time what that squealing noise really was,instead of tightening the alt/power steering belts I could have replaced the lifters and still be using that cam!

 

[rreruption]

For a street build I've I've never seen the need for a roller cam.It's just a lot of extra money.For a mild gain.Rollers do run better.And are probably more reliable in the high rpm range.If you got the money go for it.But I would spend the money saved for something else.

 

[KULTULZ]

I prefer the roller-tip style for the street as they take the side load off the valve stem, especially the canted valve styles.

Full roller for the street (unless HOT STREET) is a waste to me as to cost and roller bearing failure as previously mentioned.

 

[defman77]

Everyday?

So a roller would be ok for a everyday driver? As long as I dont push it too hard then the non- roller should be fine? I heard about non rollers wearing out quickly...if so how quickly are we talking about?

 

[Steve karch]

Manufacturers stopped using flat tappet style cams back in the 80's. Todays oils are not formulated for flat tappet cams and for that reason alone its a good idea to go to roller cams and rockers. Otherwise, rollers can give you more lift and duration than a comparable flat tappet cam, which means more horsepower and torque and better driveability. Less friction means lower oil temps and less side loads on valve guides are other good reasons to go with rollers. Cost, however, can be the deciding factor as roller cams and lifters are quite a bit more expensive than the flat tappet/stock style rocker. My engine is getting roller camed this winter (its at the machine shop now. I'll post the dyno results when its done.

 

[PapaWrench]

So a roller would be ok for a everyday driver? As long as I dont push it too hard then the non- roller should be fine? I heard about non rollers wearing out quickly...if so how quickly are we talking about?

Yes a roller cam would be ok for your everyday driver. The flat tappet or "non-roller" as you call it, will last 100K+ if broken in properly and the correct motor oil is used. The current trend in the petroleum industry of reducing the zinc, manganese and phosphate additives or ZDDP (prevents scuffing of metal-to-metal surfaces and an anti-corrosion barrier) are causing very early destruction of cams. Use a oil additive in the first oil used on new engines such as GM Engine Oil Supplement (EOS), in addition to the liberal use of molydisulfide assembly lube. As mentioned above, deisel rated oils such as Rotella and Delo have more ZDDP than most major brand oils. If the trend continues we'll soon see an end of flat tappet cam use.

 

[automotive breath]

I recently replaced a solid flat tappet camshaft for a roller in a super gas car 355 CI. The duration @ 0.050” of the two cams was identical; the roller has 0.630” lift compared to the 0.550” of the flat tappet. At the racetrack the performance has improved with the roller, two tenths of a second quicker and picked up 4 MPH in the 1/4. This comes at a cost, the roller cam and valve train cost about $1000.

Because of the cost difference, I don’t think flat tappet cams will be going away. Oil additives will likely be required.

 

[xxllmm4]

Just a quick note to add to what people have said about the ZDDP levels of oil, A low cost alternative to the GM EOS is the use Valvoline syn power oil treatment at 1-2oz per quart every oil change. I saw some new oil analysis at http://www.bobistheoilguy.com (theirs some smart guy on this board) Its pretty much ZDDP and Moly, both are high pressure friction additives perfect flat tappet cams. IMO its better than the EOS because it also contains Moly.

Jordon

 

[Aussie XAXB]

David Vizard wrote a really nice article for Pop. Hotrodding this year about camshafts. This is what he had to say about flat vs. roller....

"Because a flat lifter can initially accelerate faster than a roller, we find that with cams under about 270 to 278 degrees of off-the-seat duration, a flat tappet can produce as much or more area under the curve. It also used to be claimed that a flat lifter design was substantially inferior to a roller lifter in the friction department. Though this was, to an extent, correct 20 years ago, we find that new super oils have eaten substantially into whatever friction reduction advantage the roller may have had over a flat lifter."


Here's the link to the article.

http://www.popularhotrodding.com/tech/0607phr_camshaft_basics/


Steve

 

[IanRiordan]

Dave Vizard is fairly cluey for an Englishman. He made a lot of sense on tour over here in the 90s. Out here people are STILL boring Chevs & Fords to Chrysler lifter bores when the class demands a flat tappet grind.

 

[bigbadbowtie]

My opinion.

street duty daily driver......choice #1 newer roller block,#2 retro hydraulic roller ,#3 flat tappet.

Weekend toy or max effort street car .... aggressive hydraulic roller or solid roller.

I have ran a solid roller on the streets for years at a time with no issues. It just take more time/effort to keep on eye on wear.

 

[hotrodf1]

David Vizard wrote a really nice article for Pop. Hotrodding this year about camshafts. This is what he had to say about flat vs. roller....

"Because a flat lifter can initially accelerate faster than a roller, we find that with cams under about 270 to 278 degrees of off-the-seat duration, a flat tappet can produce as much or more area under the curve. It also used to be claimed that a flat lifter design was substantially inferior to a roller lifter in the friction department. Though this was, to an extent, correct 20 years ago, we find that new super oils have eaten substantially into whatever friction reduction advantage the roller may have had over a flat lifter."


Here's the link to the article.

http://www.popularhotrodding.com/tech/0607phr_camshaft_basics/


Steve

I also had a thread going about this - it has been discussed a bunch.

I was using Engine Analyzer Pro to analyze power gains, if any, based on cam lobe profile and such. The roller did offer performance gains all across the board on the cam I was testing, which was 230/236 @ .050, which is about a 280 or so adv. duration. But the gain was only 5 - 10 ft lbs most places, and the peak HP was up by about 10-15 HP, depending on LSA, etc.

If you have the cash, the roller is worth it. You get better idle quality (street car) and still have the top end charge of what would be a much larger flat tappet cam (and in some cases the flat tappet never could match the power of the roller). The bigger flat tappet may work for you, but the idle would be much more radical for street.

Like the article says, I think for aggresive cams, the roller can be a benefit, but for smaller grinds with good street manners, a flat tappet will do just fine if the right grind is picked out.