Solid roller vs. Solid flat tappet

After adding up the cost of going roller vs solid I need to decide if the gains are worth the significant cost being that I already have crane ductile rockers, pushrods, and springs.
Have any of you switched from solid to solid roller? If so what was the et or horsepower gain?

My machinist told me that a solid roller is worth 15 hp over a solid flat tappet (in a race application).
That is at same specs. A solid roller would allow you to maximize lift and duration over a flat tappet, though.

And no chance of a cam not broke in properly.

The best and biggest thing I found on switching from a solid flat tappet cam to a solid roller cam with similar or the same lift and duration was the roller cams all had a lot more piston to valve clearances from 20 BTDC to 30 ATDC
The lobe designs help the motor make more power

If you have all of that stuff and want to use it, solid flat tappet. If you don't mind spending some money and want to put a larger cam ( >.700ish lift) you will want to go roller ,aside from all of the other flat tappet break in issues.

It all depends on displacement, cylinder head capability, and what you are looking for out of your engine package. If you are running a 350+ CFM head the characteristics of the solid roller lobe (faster valve movement) and added lift might surpass the output of the biggest solid ft cam when it becomes unstable due to the lower spring pressures.

Whatcha building anyway?

I am building a 512 low deck.
11.7 to 1
Sidewinder heads ported will flow 300ish.
Mostly strip car, some street.
I plan to optimize the combo for bracket racing. But within reason so that it's a reliable combo.

If it was me I'd roll with what you have a keep some cash set aside for something else, like good shocks. 11.7CR will help things along. With the right cam you can run that thing on 93 with a splash of 110 for safety margin.

I figured since my car was a street car and I am not out to set a world record I would use the solid flat tappet. One reason is that its a cheaper setup and cash is always needed around me. And the second reason is I dont want to pull the lifters every few years to check them. I have heard of roller lifters loosing a needle bearing and wasting an eng. Now I know many guys do run them but I figured I would want a nice one and it would need good spring pressure. Who knows I could have run a roller and got away with it for many years but I would feel better pulling the lifters every few years and check them for piece of mind since I put a good amount of miles on my car each year. Like Dwayne Porter told me that valve float is bad with roller cams so you need to run much more spring pressure with a nice size roller you plan to race some. Valve float can let the cam hammer the lifter some which is tuff on the roller needles. So you do want to be sure you run the proper spring pressure with the roller. Yes it will make some more power but I have no complaints with my flat tappet cam. And I am not trash talking rollers as tons of people run them and do fine but I just would not want to be the guy that has a roller lifter come apart because I did not pull and check them every few years. Good luck which ever you choose. Ron

i'm agree with Ron on the subject. i'm building 511 as well but mine will see more street than strip. I had the cam nitrated and i'm using the EDM lifters that oil directly to the lobe. will break in on single springs with good oil. wont have to pull roller lifters every 5 yrs to have rebuilt or worry about losing bearing out of them any more.

I'm also with Ron on this. It's the classic trade off of performance vs cost vs reliability. If I had everything but the cam in my posession, and money isn't hanging from a tree in my yard, I would be looking seriously at a solid flat tappet. You're looking at around 2k for the entire roller set up incl rockers and pushrods or 300 for custom solid flat and lifters. If starting from scratch w no money concerns, roller all the way.

I have both set ups right now.. normally
I would run a roller but I went with a SFT
a couple of months back so I could run less
spring pressure.. I have the EDM hole in both
set ups.. the reason I did go with the SFT
was because the injection didnt like the roller
set up... but I'm finding out it really wasnt
the cam that was the issue... I think if you
were to look back you might find that SFT cams
fail far more often than roller cams.. so far
I have not had a roller cam/lifters fail in over
20 years of running a roller cam...I will see how
it goes with the SFT

Looks like solid flat tappet it is. Thanks for the reassurance. About the roller I do like the idea of no break in. I added the cost and it would cost me roughly 2k to go roller vs 5-600 solid lifter.
Jeremiah my thoughts exactly on running pump gas. When i race I will use some 110 but for cruising around I'll try pump fuel with a splash of 110.
I thought there was a chance this could be a more controversial choice, but it appears solid is the clear winner dollar for dollar. There are other areas I can use the money difference that will be better performance wise.

My Isky solid roller has been awesome for years mostly street which makes it more impressive w/gentle lobes but VERY nasty when stomped. Solid body lifters rebuilt once and still rockin.............Do it........

There for a while we didn't seem to have many (if any) good choices for flat lifters. But now we have a couple of good choices. The EDMs have gotten good reviews. And Barton has a tool steel lifter that I have had good service from. So, I think we have some choices now for flat tappets that can rival or exceed rollers for dependability and longevity. At least in some applications.

I normally run the purpleshaft solid flat tappets but my '69 Dart had a 706/661 lift solid roller, raced it for 5 years without doing any roller lifter maintenance although I probably should have.

I have never heard of a roller cam being wiped out upon startup. Yesterday at the track a guy was telling me about his experience of tearing down his new built engine to clean out the metal. I myself have did the same over the years. I'd look at the cost of pulling the engine and tear down and rebuild in your decision . Cheaper ,not that anything is nowadays as they say is not always the best way to go. From running flat tappet cams from the start in the 60's I now have a roller kit on the shelf for the next rebuild.

That is definitely one reason that I love roller cams is no more fear of failure at break in. And if I were starting from scratch it would be roller all the way. And that's what I have done in the past. But in my current case it appears the $ to hp gain etc. won't be worth the extra 1400 cost.

What are you looking at for lift and duration
on your cam.. what kind of HP are you thinking
and is it a SB or BB.. you have to take into
account the rpm you will run

If I ever get my Dart out of paint jail, I'll let you know how my mushroom cam is working. Very similar rates of lift/duration to a moderate roller (mine after minimal regrinding to restore lobe taper is 272@.050, .652 gross lift) without the "extra 1400" for valvetrain

Although I was extremely nervous breaking it in! Outer springs only, good oil, lots of zinc. It's a trade off for sure...

After rolling a cam on a 360 I vowed never to run a flat tappet again. Still no idea what caused it. Chased down all the obvious stuff and never found anything.

Current motor is a mild 512 low deck build. Already bought a Comp XR280 roller setup.

Ive been running a hughes solid flat tappet for 8 years now, using their cool face light weight lifters, ive gone 9.79 at 139 with it shifting at 7000 crossing about 7300 in a small block, it has lived so far,use the right oil and you shouldn't have a problem, I change springs once a year just for peace of mind, ive considered going roller but I don't want to have to grind my rocker arms for the bigger springs, plus the bigger springs take horse power to compress,

I went from a .650 lift flat tappet to a more aggressive roller but also went from 12.5 to 14:1 compression at the same time. Went from low 9.80's to low 9.60's.

I also use the EDM lifters on mine. And I had no problems breaking in the cam as we left the inner springs off to break in the cam. I used Valvoline VR1 racing oil and a bottle of the Comp Zink additive. I also used the cam break-in lube on all my lobes. No problems at all and its been in the car since 2011. Dwayne Porter speced me a custom grind cam and it was no more then an off the shelf cam was. He has good prices and does awesome work. I wanted a custom grind since I run 92 pump and I wanted some power but had to keep the cyl pressure below 190. And it has never pinged with 37 total timing. Ron

i have been running a predator solid cam. been in the mix for 17 years. different blocks same everything else. moved the cam from 104 in steps to 110. took it from 10.70s to best of 9.89@134mphit was 262 265 with about 620 lift at 1.6 and it lasted a good many seasons. it just got freshened up due to me taking it to him and pitting on the lobes. but i now have a new modern fast ramp lobe cam to put in. with a little less duration at 258 but i am told it will act like a bigger cam. so we shall see. i did not want the cost of roller either and i am at the limits of the rules on time and my chassis.

Wait. What are you saying here? Are you talking about the cam ICL?

An "extra" $1400 to run a roller cam??

I guess I don't see how the math works out there.

Solid flat tappet cam, nitriding, edm lifters = about $525

Mild roller cam, mid-level lifters, price of bronze gear over iron gear = about $1200

Looks like about $650-700 difference to me.

If you were okay with more entry level lifters(which are fine for many mild roller race applications), then the cam and lifters are under $750.


Comp Cams 23-758-9 cam = $337
Howard's 91727 roller lifters = $380

Mid-level upgrade lifters:
Crane 66542-16 Ultra-pro = $788
Comp Sportsman 96829-16 = $689

We should call this section "practical hotrodding" lol

Thanks for the perspective Dwayne.

Dwayne, I already have ductile rockers that would work for a solid flat tappet and correct length pushrods.
Therefore I added the cost of roller rockers and pushrods on top of everything you accounted. If it were a fresh build and I already needed rockers and pushrods, your thinking is correct. The difference is much less in that case.
Thank you for your input.

In 2 cases I pulled a Comp Cams solid roller cam from customers engine and installed a Racer Brown STX-22 SFT cam. 1 was a small block 408 and the other was a big block 512. Both were low 10 second cars and ran some high 9s with the flat tappet. One has since switched back to roller and runs exactly the same, no gain over the SFT. My Demon also has a STX-22 and has gone in the 9.60s. Stroker small block with production iron heads. 2150+ passes with only 2 spring changes, 995-16 comp. $100 a set. Also my lebaron has the same STX-22 cam in a 512 BBM with Indy SR heads. 1300 passes with 1 spring change 928-16 comp. $150 a set. Been 5.40s 1/8th mile and 8.50s 1/4 mile.

just curious to what the lobe sep is on the stx-22 BB cam and where you installed it? thanks

I don't remember exactly. But most BB STX-22 are 106/108 and intake C/L 103/104, but I usually set them at 101/102. IIRC the Lebaron cam is 107 LS.

Thanks

"Equivalent grinds" between FT and RT, as in, the same valve curtain area at all points of lift, is physically impossible unless both are so mild you would never use them. Even similar average areas will not have the same vacuum, inertia load, and reversion characteristics.
The maximum acceleration and velocity are different, and especially different between roller at low lifts (which has the dangerous side thrust vector) and higher lifts (where the FT is limited by its contact length).