Dont even waste your time with a flat tappet...About the only people that will argue to use them are cheap skate shade tree racers who own a car for all of 10 days, run it to death and then try and sell it for a profit.

Hyd roller makes it much easier to drive, more power, better cam selection off the shelf and custom, just all around better in every fashion. The only draw back is the cost in comparison to the flat tappet...But you also run a high risk of cam failure on break in and ruining the whole motor if its not shut down fast enough.

 

No way would I run flat tappets, it's too easy to convert to a roller.

 

i love flat tappet cams. They are lighter, they require less spring load, and can provide darn good ramp acceleration. they are old fashion in terms of valve actuation, but there are fully modernized lobe designs. Todays oils (although there are solutions) and the need for swapping in lightweight springs for break-in and quality components are the very real drawbacks and can be a deal breaker. Now days, I keep break in loads below 100lbs at seat and stick around 200lbs open. Then once broken in you can go on up to the cams needs 110/280, or whatever the needs. Yes, I have lost 3 cams since the early 80's to break-in. But now, I have a routine, and spring load at break-in is the key.

On my sons car (solid flat tappet), we look at the lash settings at the oil changes, and they are holding rock solid. The adjustability of a solid is perfect for the perfectionest tinkerer, like myself. Plus, from being around me and all the cam stuff I work, he is going thru the valves and reading plugs and adjusting carbs and timing adjustments like a banshee. Not many 17 year olds can boast of those experiences now days. He's newly old fashioned!

Are flat tappet cams a legit alternative? absolutely. They do have their break-in problems that need to be addressed and thought out. If you have any doubt, then you have to go to the hyd roller. I personally would not think twice about swapping in another flat tappet camshaft in a flat tappet motor; I am sure others steer clear for sure. But, on the other hand, I definitely would not go thru special pains to go to a flat tappet if a motor was running a hyd roller, unless there was some technical issue that just isnt working.

If I am dealing with a roller block, it will stay hyd roller for sure.

In swapping any cam into your 351W, I would be more worried about proper adjustability in the valvetrain first. a well thought out valve train and spring solution needs to be at the forefront, and if it is a flat tappet, there could be two different spring solutions are needed. (one break-in, and one running)

A hyd roller is definitely more troublefree because the break-in is a non issue, within that context is where flat tappets get their bad rap. It is possible to damage a motor during break-in, but if the proer precautins are taken, it is no more problematic tan it was in the 50's, 60's, etc etc.

With any cam, adjustability and proper valvetrain set-up needs to be thought out thoroughly.

Edited: my opening paragraph was intended as an attempt at being comical, but in hindsight read pretty obnoxiously. It really had no place in the post, so I deleted it.

 

Welp you guys affirmed my issue. I'll go hydraulic roller thanks guys. Now what nitrous can would you go with or within what specs should I go?

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How many first timers have you met that you would fully trust to install your flat tappet cam in your son's car without worry of proper break in and proper spring selection? Especially one asking on a public board which one he/she should go with and why...Not tryng to say you are wrong in any fashion Buddy, I know who you are and have personally seen several of your cams perform in person. This is just for arguments sake, nothing more.

Not a question if they can make power, its more for the end result which is a running car. I know myself im taking my time having a motor built properly with the lowest maintence cam I can possibly have. And of course im having a custom Hyd roller cam put in it, but ym heads are already set up for a PAC 1.300 spring with 140 on the seat. Why? Cause I want daly driver reliability, great performance and low agrivation if I want to drive stop light to stop light. My last car was a flat tappet cam car, huge cam and a whole 9" of vacuum and the car barely made 300rwhp. That was a whole lot of agrivation for something that didnt perform that well. Yes I didnt set it up, nor did I have anything to do with the assembly. But the end result for me was to never use a flat tappet ever again.

And the reason I said most shade tree racers use them is because they are super cheap to buy, so the out of pocket cost is low. They race them, do not maintence the thing, and then try and sell the car to unsuspecting buyers making the car sound much more agressive than it really is.

 

Damn. Guess I need to go pull my flat tappet cam out of my 351w in my boat and swap to a roller since a flat tappet isn't reliable or ideal.


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It was reliable and ideal in the 80's...Can be today with the right installer and break in.

You probably run Pro Comp heads on that boat to right? But then you're going to argue about people ordering from JDSPerformance cause it puts local speed shops out of business. :shakehead

 

If you use an aggressive flat tappet cam, you will eventually have issues on the street. It isn't so much of an issue with mild cams and slow ramps, but aggressive cam profiles will eventually get you.

I got sick of having cupped lifters and flat cams, even after breaking cams in with inner springs removed and plenty of top end oil to the lifters. It was never an issue with mild cams, but high RPM cams would just eventually have a problem.

Of course I suppose I could have been getting bad cams, but I tried both Crane and Comp.

 

Yeah pro comp heads and pro form and professional products on everything possible. You are a bandwagon fan. Just because something didn't work for you doesn't mean the next person won't be able to make it work. Everyone has a budget to work with, and simple things work if it is done right. For this guy to swap to a roller cam you are either a looking at a retro fit cam,and a set of lifters and spider tray and new springs. or 400 dollar set of lifters and then another 150+ for a camshaft, and springs.


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$300-350 for a set of Link bar lifters, then a used cam shaft is from $125-200...

So $550 for a camshaft setup he can bolt in and never worry about....Or spend $300 on new flat lifters, springs, and camshaft...Have to break it in and risk the entire engine over $200 difference? Makes complete sense...

It doesnt work for alot of people, nor should a newbie try and tackle something so risky when budget is in mind. Not everyone can risk terminating a engine completely over something so cheap to avoid.

Are you denying your soap box preaching of the Pro Comp heads? And your local speed shops being put out of business by internet retailers?

And what am I on the bandwagon about here? Trying to save the guy a headache, possible ruined engine and alot of money for such a insignificant little price difference.

 

Where did I deny anything? Yes you are a bandwagon fan clear cut. And yes non brick and mortar ie dropship companies do put brick and mortar companies out of business. They sale products for next to no profit and never touch the item. It's great for the consumer until a problem a raises especially since according to you they are not at fault. Comparing pro comp heads to flat tappet vs roller tappet isn't a very fair, your talking a knock off vs a proven combo. Is flat tappet ideal? No but it will work and I am sure it will work as the op wanted. It is clear he isn't out to set any records as he is using a older motor and stock heads. I would be willing to bet that he is looking for the cheapest way to go as fast as he can which we all know isn't the correct way but I would venture to say more then half of the go fast world does. I am sure you are aware of the price of springs and machine work to have the pockets cut and the springs set up if you don't have the tools yourself? And the new dist gear he will need to install to run a roller cam, and pushrods since the lifter is longer. It all adds up very quick.

And I don't and haven't had any pro comp heads on any car I built. My boat has factory heads on it as you know the saying don't fix what isn't broken. I had some brand new ford racing heads and a rpm dual plane intake but didn't want to mess with something that ran so well all the time.

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There's nothing wrong with a flat tappet cam as long as the correct springs are used and the cam is broken in correctly and good oil is used, something like Rotella or Brad Penn. We just built an inline 6cyl stroker for a Jeep and it was converted to a roller cam setup and we just converted back to flat tappet due to a broke link bar, I guarantee the motor makes as much or more power than a lot of cars on this forum........

After all is said and done, a roller cam may be the cheaper more reliable option but there's absolutely nothing wrong with a flat tappet cam.

Wicked03gt, I'm not trying to flaming you man, I'm really not, but I've seen you give technical advise on here more than once that I can imagine leaves a person less knowledgable about the subject there inquiring than they originally had in the first place. Then you make posts about things simple enough that a person of any technical knowledge should know? I don't know everything nor do I claim to, but if I ever give false advise here I ask the forum members to please correct me. :salute:

 

There's nothing wrong with a flat tappet cam as long as the correct springs are used and the cam is broken in correctly and good oil is used, something like Rotella or Brad Penn.

While that is true for smallish cams, that isn't always true for aggressive cams. Flat tappet lifters, either hydraulic or solid, do not like aggressive cam profiles.

I ran non-roller cams for years and never had problems (except in a stock 350 Chev that went flat in warranty from GM). When I started using aggressive cams that would run up to the 6000 RPM range and higher, it didn't matter what I did. They would go flat pretty fast on the street. I tried Comp and Crane.

I suppose the cores just could have been bad back then, but my headaches started when I started getting higher lift high RPM cams. I had so much trouble with street life I just quit using them. I pretty much think it was the aggressive cams, because of how the lifters have to work to keep from going flat.

Unless the money was not in the budget for a roller, I'd never use a flat tappet. Of course I don't use point type distributors either.

 

There's a lot of good info here but IMO it can be broken down this way:

1) in a maximum effort, minimum trouble, cost is not critical situation roller is clearly the answer. That being said, plenty of properly chosen solid flat tappet set ups will run awfully hard.

2) budget oriented, attention to detail builders won't think twice about using a solid flat tappet. There is the risk of wiping a cam, but if it is done right, this is a very infrequent occurrance

IMO the .01% of wiping the cam is the biggest reason to go with a roller. That being said, for a budget-appropriate decision, I'd not hesitate to run a non-roller.

I have a flat tappet hydraulic in my coupe bc it didn't make sense to spend the extra 400 or so to get a roller. Am I giving up some power? Maybe, but it still sounds nasty, gets sideways, and scares the hell out of plenty of people that have never been in a fast car

 

I think your summary is OK, BUT is missing.......

1.) The ramps on roller cams can be much more aggressive while having less wear. This means more available power, smoother idle and more vacuum for the same power.

The reason flat tappets cannot have such an aggressive ramp is the lifter has to be convex on the bottom, and offset on the lobe so only a fraction of the lifter bottom contacts the lobe. The cam lobe is ground at a slight angle down toward the lifter center. This spins the lifter around as the cam rotates. Wear is worse on a flat tappet even with mild ramps, and terrible with aggressive opening ramps. If the lifter bottom flattens or the cam lobe flattens, you are screwed. The lifter will stop spinning and the cam and lifter will wear right out. This is all aggravated by stiff valve springs, and none of it happens in the roller.

2.) No one knows the failure rate, but when I was running aggressive race cams on the street I had nearly 100% failure rate with flat tappet cams suitable for 6000-7000 RPM in less than 10,000 miles. I never had failures (except for one cam in a 350 Chev) with typical 5000 or so RPM cams with normal lifts. I worked with Comp and Crane on that, and they both told me to use a roller.

 

I think your summary is OK, BUT is missing.......

1.) The ramps on roller cams can be much more aggressive while having less wear. This means more available power, smoother idle and more vacuum for the same power.


2.) No one knows the failure rate, but when I was running aggressive race cams on the street I had nearly 100% failure rate with flat tappet cams suitable for 6000-7000 RPM in less than 10,000 miles. I never had failures (except for one cam in a 350 Chev) with typical 5000 or so RPM cams with normal lifts. I worked with Comp and Crane on that, and they both told me to use a roller.

Good points. I can't sPeak to the longevity so your experience is certainly useful info. I think a lot likely has to do with the spring pressure size of cam etc.

Also agree about the rollers being "more efficient". I think that it's good to understand the complete package of budget, use, and expectations for any build.

IMO there is a place for non rollers with the tight budget appropriate parts and reasonable expectations

 

Unless we are talking stock truck, flat tappet hydraulic, everything else pretty much needs a second set of springs. As buddy said, even with a slathering of break in lube, and getting Joe Gibbs or Brad Penn break in oil, you cant do a performance flat tappet cam on the "intended" use springs. Anything advertised 280 duration and up, going to need some break in springs.

The bigger stuff, (for 302's anyhow) 292 duration and a 305 advertised duration, didn't last long with street driving. Too much time with low oil flow, and lower (normal) oil pressure. The high spring rate, high reving flat tappet stuff does not like to sit at an 850 RPM idle..