I too have a rebuilt 400 and it produces excellent power, especially after going full sequential EFI and replacing the distributor with EDIS8 coil packs. Mine has a flat tappet grind from Crane and it runs absolutely awesome. I have tuned the computer and timing tables, it achieves about 13-15 mpg in a '79 Bronco running 35" mudders and a 4" lift.

Regarding the roller vs flat tappet debate, there is one standout detail that is unrefuted: the mass of a roller lifter, whether it's hydraulic or solid, is significantly higher than a flat tappet and in the case of hydraulic roller tappets, limits the max RPM of an engine employing them accordingly. This handicap along with some supply chain issues that have resulted in substandard manufacturing quality of roller tappets in the last 5 years has changed their perception in the engine building community, for sure. I recently put in a set of Ford Racing hydraulic roller lifters into a built 302 and have my fingers crossed that they're durable pieces...

I got my hands on a set of these old school Crane roller rocker fulcrum retrofits and am considering installing them on my stamped rockers on the 400. Not sure what, if any benefit there is to doing this, but curious to hear opinions on that!

 

The benefit of roller rockers is less side pressure on the valve stems as the rocker operates through an arc, so the rollers let the rocker roll across the valve stem instead of sliding across it. Valve guides likely wear longer, but rollers have bearings. Higher lifts with stiffer springs swing the rocker arm further in the arc under greater pressure, so I expect roller tips make more sense there too.

 

Roller lifters will absolutely turn as high of RPM as a flat tappet. you run heavier springs to account for the weight.

Hydraulic roller cam and lifters are better in every way except price. end of story game over .

 

99.9% of the time people are going to go with what they had in mind from the beginning. I can count on one hand how many times someone has taken my advice that went against their own intuition, even when I could tell that they knew I was right. I’m with you 100% on the roller conversion, but it’s a waste of time debating the matter. One sentence is usually all I’ll spend my time on when it comes to a topic like this. Throw my fact based opinion out there and let it lie. Like I said, won’t matter anyway.

 

You can deny acceptance, but you can't defy physics. Hydraulic roller lifter simply has more mass and a hydraulic plunger that stops performing well at high RPM, both of which are detrimental to all aspects of high RPM valve operation, particularly in the case of overhead valve (pushrod) engines. The goal should be to reduce the reciprocating mass, not increasing it. You can increase the spring load, but you're crutching it at that point and durability of the valvetrain will suffer in other areas. Hydraulic roller cams work great in the typical 6000 RPM or less ranges, but for true high performance and high RPM operation it's solid roller lifter or solid flat tappet, mainly because those hydraulic plungers just can't keep up.

 

Regarding max RPM, how many people build a pickup engine capable of running past 6000 RPM?

Especially a 400.

Or even a 460.

 

Is the goal more power and longevity or who can brag about turning the highest RPM ? 6500 RPM just won't cut it? you might want to drive a roller cam performance engine.

And if for some reason RPM is your thing run Jesel solid rollers and have the best of both worlds. good enough for NASCAR good enough for a Ford pickup.

Roller cams are what's happening. unless your budget won't permit it there's no excuse not to run one.

 

The idea that people are arguing that a flat tappet is better than a roller at this point in time is like clownish bozo talk. Reciprocating mass difference is so minor it's not even a factor, but a roller does have less friction to deal with. There are so many modern engines with rollers that run well over 6000 RPM from the factory.

 

LOL yeah, for street performance, I've already been down this road... it's not a good financial decision to upgrade a 400 to a roller cam. Mine rarely sees anything past 3000 RPM because it's producing over 400 ft-lbs at 2000 RPM with a hydraulic flat tappet - there's no point in revving it out like a 289. For real high performance and high revving capability, check out some of the finger follower valvetrains on high end motorcycles. I have one that I've never even hit redline with because it is so overpowered!

Speaking of high revving in a Ford V8, though, I have a classic Mustang project on which I just installed a set of shaft mounted roller rocker arms. They were necessary mainly because the heads have a valve arrangement that is offset and nobody makes individual rockers in that configuration, but shaft rockers were available. I inherited this project, so did not build the long block up myself. I'm living with some of the decisions that were made before me. It's got a fairly radical solid lifter flat tappet cam however and revs out to about 7500 RPM. I thought about rollerizing it via lifters and cam, but that would require setting the heads up with different spring pressures and redoing a whole bunch of assembly that was carefully accomplished. So I decided to just upgrade the rocker arm situation since that had to be addressed and focus on the EFI conversion instead. We'll see how it turns out.

 

Lots of good information here, it is your truck and your money. I have seen caterpillar roller lifters dismantle themselves, and wreak havoc upon a perfectly healthy engine otherwise. Cummins went to an application in 2019 (I think) of roller cams and most of my customers have been converting these BACK to flat tappet due to reliability. A roller cam is going to run less friction boosting power availability, fuel mileage, and power.

Gm and the lifter failures, lately, yes. more bad ones than good ones I guess. Some going bad several times. How about the dodge hemi prone to roller cam and lifter failure.

Many flat tappet engines I have witnessed being assembled and started and ran without good practice to prepare a new engine. First most are not even oiled that I have seen, oil dumped in but the oil pump never rotated until oil is entirely throughout. I recommend rotating oil pump until engine is fully oiled before even attempting to start. Next problem is I have seen numerous engines, assembled from mechanics to machine shops to DIY ers all with such poor valve train geometry that the extra load on the cam lobe is severe from a taller valve, heavier spring, shorter lifter from a smaller base circle in the cam, causing lots of issues. Cam shafts Are certainly not as good as they once were, and more inconsistent. I have used lots of flat tappet cam shafts in many many various assemblies from jeeps, pickup trucks, fork lifts, boats, and I have not had a high attrition rate to speak of. I verify that geometry is not visibly wrong upon install and do my procedure with oil pump before start up.

I have personally seen many many many failures in both types at early mileage and also seen many many successes. Airplane engines get rebuilt regularly with flat tappet and I have never even heard of a failed camshaft in an airplane. I am certain it happens, but the cams in majority of those rebuilds are REUSED. They get frequent oiil changes and regularly inspected.

I have been very very happy with the flat tappet engines I have built over the years in every aspect. A roller may well have done better, however in my eyes, if the engine does a good job and lasts reliably for decades, what exactly is the benefit of retro fitting a much more costly apparatus? I can't see how my own builds are going to benefit in any way from a more expensive cam shaft. The only way to truly know would be to swap the exact same engine and vehicle from flat tappet to roller and evaluate. The rpm curve from roller is wider, and maybe for some instances that benefits. In my boat, I run it from idle to 4200 rpm and most rpm is 3800-4000 rpm a "wider" rpm range is of no use. In the trucks that pull my boat I tow down the hiway at 2500 rpm and in the mountain passes I go down one gear and rev to 3500 rpm respectively, When I go to the boat ramp I idle up and down the boat ramp in low gear. outside of getting up to speed from a dead stop, the wider rpm range seems negligible unless your vehicle has way more ratios to select from than mine to use that lower rpm more effectively. Furthermore, I like to use the rpm as the fan is pulling more air for cooling and the water pump is pumping more and the oil pump is pumping more, so I am not really a fan of seeing how low of an rpm range you can keep your engine to do the same work. Possibly in an overdrive on the hiway and being able to get lower rpm and still retain w better power but that is a very occasional circumstance for the pickup trucks I see in my community. these were always work vehicles and hauling boats, wood, lumber, trailer, fuel, farm implements, horses, cattle, construction equipment. THere are a few ladies that drive around in 4 door 1 ton trucks just to run around town, Why I will never know.

Finally, Last but not least, I have been made aware that in certain circumstances, Mainly marine, an engine running at too low rpm under load sustained is attributed to many burnt valves. I feel after seeing how certain people (and even certain relatives of mine) would always try to get the most they could out of the lowest useable rpm that could be gotten by with. many repairs were made due to this negligence. My thought sides slightly that there is some concepts that roller cams can allow you to utilize the powerplant in this manner further motivating you to try for more out of less; My experience from farming to vehicles to heavy trucks to marine and boats to performance to harvesting equipment to power generation and more abroad does not lead me to believe to condone this theory. Again, your truck, your money, your build. Build it your way.

 

IF , you could still buy flat tappets of the same quality the OEM ones were there could be a lame argument made for sticking with them today. you cannot. this is not a debate it's a waste of time.

 

Can not agree more, along with almost everything else. I take great care in the engines I work with to be very very careful to eliminate any extra stress within the valve train, Most engines get assembled without any cause for concern for issues needing addressed, just assemble it and run it. Manifolds and fuel pumps and brake boosters and brake mastercylinders and slave cylinders new distributors with no springs to control the cintrifugal advance, None of the parts are being made with any quality control, obviously for even the new vehicles, just look at GM and all of their engine issues that seem to be doing it because replacement parts are exactly the same as the ones that failed. make all with tremendous problems, like sideways installed cups and so on. With brand new lifters, one can check all of the lifters and see if the convex is properly manufactured into the lifter, the ones that are not correct; need to be replaced BEFORE install. Unfortunately I have only known of 3 individuals whom are familiar with how to actually verify this characteristic. An argument it is not, a cautious examination is in order for ALL new parts.

With all do respect, when a parts supplier sends defective merchandise brand new, they would be able to stand behind that merchandise, before install. When a builder installs defective merchandise for outlying reasons as time is too valuable to do it right or we do not have any idea how to check, that accountability falls on the guy turning the wrench.