Do I really need a roller cam?

[slayer021175666]

I bought a lunati voodoo flat tappet with the lifters a while back. It's been sitting around a while and as the weather warms up I'm thinking about getting around to installing it along with the new set of ATK heads on my old 327. I've been looking at the prices of retrofit roller cam kits and reading all this scary information saying that hydraulic cams get wiped out these days. I'm just having a hard time justifying spending 800 or more bucks or so for the roller. I guess I'm old. I've had hydraulic flat tappets my whole life and it's been a while since I have done a cam swap but, maybe the roller is too far above my budget and, I don't know if it really makes sense. Such a mild street performance build. Why would it require a roller cam? I love the idea of rolling valve trains. I have roller rockers on it now. but, the expense to retrofit a roller camshaft is outrageous. Am I not seeing this for what it is or am I just overthinking it and should I just put in the hydraulic flat tappet cam that I already got recommended and bought from lunati or???

 

[1978 Z/28]

Flat tappet lifters only need 2 things to survive. A quick startup and propper brake in and oil that is zddp enhanced I use driven HR 6 https://www.summitracing.com/parts/jgr-03906

 

[cadillac_al]

I think the mild builds with regular Z28 springs will survive just fine. It's the hotter cams with stiffer springs that are most likely having the problems.

 

[1978 Z/28]

If you buy the proper springs for the cam and follow known break in procedures. All will be well
I used comp cams beehive springs to get away from having to remove inner spring used with old style valve springs.

https://www.compcams.com/pub/media/wysiwyg/CompCams/FlatTappetCamTechBulletin.pdf

 

[CorkyE]

I've broken in several hydraulic cams and they all survived, just follow the procedures and put a big fan on the radiator. Last was a Lunati, albeit that was several years ago. I've since gone roller, mainly for performance.

What is the p/n on the ATK heads? I know that Profiler used to make them but that business deal went south a few years ago. Seems Profiler promised ATK a number of heads and then couldn't come through. Put ATK in a big bind. Last I knew, they were using Dart heads on their performance engines.

 

[slayer021175666]

ATK part number is ATK64185, Corky.
I need to find out the ATK valve spring rates and ask Lunati what they think of them. I've tried a little bit to find that info but, maybe I need to dig a little deeper.

 

[G72Zed]

I go through the same thing up here with customer builds......but it's a 1,400$ difference going roller once you take everything into account.

Is a "Roller" cam nice, yes, is it required in a mild street build, not really.

Is it a requirement to hit certain HP-RPM goals, yes, but it depends on those targets/goals.

Budget, expectations are the 2 main drivers of choice. Budget being number 1.

Just did my 9th engine this year last Saturday, most were new GM 350 Crates with hyd flat cams, springs in the 90lbs range, and lifts in the .430-.460 range. Making 390+hp and turning 6k with ease, 91 pump fuel, none Ethanol. All done on the dyno.

As mentioned, break in procedures are critical, dyno or in car, including the oil used. I have been using the BR30 Driven break-in oil for quite a few years now, really like this oil.

Take your time, prepare accordingly, you may need to check spring pressure so as to help you break in those lobes correctly.

 

[CorkyE]

Everything I'm seeing is that head is set up with roller cam springs, 1.47" od. Seat pressure is 135lb, which is a bit much for flat tappet hydraulic. You need to call ATK to confirm.

 

[1978 Z/28]

I paid the price for break in on a dyno. Worth the price carb and timing set up for max HP. When all said and done 452 HP and 480 FT/LBS flat tappet with 1980 Chev "292 turbo" heads unported and not polished. Camashaft XE284H and valve springs 26986-16 Beehive valve springs 1.7" installed height 284 spring rate.

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[G72Zed]

I paid the price for break in on a dyno. Worth the price carb and timing set up for max HP. When all said and done 452 HP and 480 FT/LBS flat tappet with 1980 Chev "292 turbo" heads unported and not polishe

Yep, very much worth it when everything is said and done.