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Roller vs flat tappets

Started by Matt13, September 13, 2020, 03:27:23 PM

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Matt13

Rebuilding my 340. Are roller tappets worth the extra money?

Brads70

I used a hyd roller in every engine I build, to avoid the possibility of wiping out a cam. There can also be some performance advantages also... IMO yes it's worth the extra cost to use a roller cam/lifters 

B5fourspeed



Brads70

Quote from: B5fourspeed on September 13, 2020, 04:50:23 PM
How much is the extra cost?

Just looking on Summit racing site, cam 3-400 lifters 500


https://www.summitracing.com/parts/lun-20200712lk/make/chrysler

https://www.summitracing.com/int/parts/hrs-91764/make/chrysler


My thoughts choosing a roller was more like.... what will it cost to rebuild if I wipe the cam....

7212Mopar

Camshaft and lifters are usually not too much more. The roller rockers can be expensive with some of the name brand aluminum rockers. Few of us use the less expensive stainless steel PRW rockers. Also it is what my engine builder recommended. Some say rockers with needle bearing are not reliable and should stay with sleeve bearing.
1973 Challenger Rallye, 416 AT
2012 Challenger SRT8 6 speed Yellow Jacket

RUNCHARGER

I go roller all the time now. I lost a flat tappet a few years ago. Cost me a crank grind, bearings and a lot of time I didn't have.
Sheldon

Chryco Psycho

Flat tappet cam & lifters $250-300
Roller cam & lifters $1000 so 3-4 x the price & generally you need better valve springs too .
you want EDM style roller lifters actually all lifters in EDM , rollers can starve for oil if they idle a lot as the only oiling is trickle down from the heads & spray from the crank , so make sure you are not shy with the RPM with roller lifters !
Every type of cam has advantages & disadvantages none are perfect .


tparker

I went with flat tappets. I'll let you know if I wipe out my cam. LOL.

Not sure I'd let the possibility of wiping out the cam be a driving factor in a roller vs tappet. What percentage of the cars left the factory with Tappets? I could be wrong, but I think 100%. I didn't hear of too many recalls on this. Is the issue in installation? It's probably not break in, cause most of the cars were sold to avg Joe's that may or may not properly break in the car. Or am I wrong on this? Just thinking this one through without actual experience.

In any case, I'll let you all know if my cam goes south. :)

Chryco Psycho

Follow my initial fire up thread in the reference section for the best chance of not hurting the cam , the most important factors are good / proper oil & immediate start up .
things have changed a lot over the years , you often hear of the 3 rd gen Hemi tick which is lack of oiling to the roller tappets , oil additives have changed , most flat tappet  cams survive in my experience , I have had a couple fail , most new engines are using roller tappets now

RUNCHARGER

Oils have changed and that is the biggest reason we are losing camshafts now. I also wonder if QC is a factor in the manufacturing of lifters and aftermarket camshafts as well. Absolutely follow CP's instructions and use oil that is designed for flat tappets (like Joe Gibbs racing oil or something similiar).
Sheldon

Burdar

Roller is very tempting especially since you are in the rebuilding process right now.  Roller will always outperform a flat tapped cam.  However, I've been reading a LOT of posts about failed small block roller lifters.  It seems like the choices on the market are limited and the ones that are available have a high failure rate.  I would not go roller right now.  The only exception is if you are using a factory roller block where you can use a low mile set of factory magnum roller lifters and "dog bone".   It seems like a lot of the failures have to do with the link bars.  The link bars are breaking, the lifter is turning in its bore and eating the cam.


HP2

At the power levels the OP is targeting, there is no real noticeable, seat of the pants performance benefit of using a roller over a flat tappet.  Even at the OEM level, the move to rollers was driven more by fleet mileage figures combined with changing oil formulas than it was for any power or longevity benefit. The high performance world is a whole different animal.

Of course with a flat tappet, one must be mindful of the oil used in it to ensure it starts well and lives a long life.  There are oils out there with higher levels ZDDP than most commercial parts store oils and there are additives if you prefer to use the more commercially available oils. Just develop a routine and then stick with it.

Shane Kelley

I have had good luck with flat tappets. Personally I have never had one go down on any engine I have built. While I haven't built a massive number of motors it's still 30-40 I have done. Quality parts and break in along with the correct oil with Zinc is the key. I have been using the Crower cam saver lifters in that last few builds and I really like the added oil they put on the cam surface. Simple but effective design.

Chryco Psycho

40 years ago companies were making 1000s of lifters / day for the factory assy lines , now flat tappet lifters are made in small batches as modern cars all use roller lifters so I too believe that the lifters are not as good as they once were , Johnson make the best lifters so I always try to source those or use the Mopar lifters which are probably made by Johnson anyway . You can get very close to roller performance using agressive solid flat tappet cams

floorit426

Do machine shops still resurface flat tappets?