Engine Building Tips - Roller or Flat Tappet Cam Pre-Lube and Break In - 440 MOPAR 512 Stroker 

As the owner of this build, I couldn’t have chosen a better builder to assemble it. Looking forward to firing it up, Pete!!!

I love the sewing machine sound of a nice flat tappet valvetrain.

Thanks Pete for this and your other engine building tips videos, many future engine builders will have a wealth of knowledge thanks to you and your videos!

When I built my 427 BBC back in 2000 with a comp cam flat tappet cam. I primed the engine on the engine stand using an HEI distributor with the gear teeth machined down. I Made sure all pushrods and rockers had oil coming out. Comp cams stated to take inner springs out, I said screw that. I used regular valvoline 30 weight oil to break it in. Cam many years later had a perfect pattern on the lobes.

Very good video to understand the different of both, flat tappet and roller cam. I am started my FE 390 rebuilt over one year ago. I need some time to decide what I want to do.....then I spend more money and go roller cam. I wont go the risk with flat tappet. So I get some help from Brent Lykins. And I ordered some parts from him. He create the profile for the roller cam which fits tobthe rest of the car/engine. And I also go with roller rocker. And some days ago the big day was comming.....First start, after priming the oilpump. The engine starts after some turns and yesssss, he is running good, without noise, no leaks. Now the second drive lap is done to settle the piston rings. I am very happy. It was not cheap, also because I am in Germany. So the most parts I have to order in the USA plus shipping, plus taxes. So I think it was the best way im my case.

As an aspiring novice, this sounds so helpful, and worth the money. You definitely earned my sub. I will double check you and get a second opinion, but i do feel far more in formed. Thanks.

I'm just starting a mopar, 400 to 512 stroker engine. I plan on going roller. Thank you for this. I am educating myself on what's necessary, i.e. bronze distributor gear, stronger timing cover, and thrust button. The latter two may be a good topic for a video.

Bottom line: Oil properties have changed over the years. YOU CAN'T RISK A FLAT TAPPET CAM FAILER! Play it safe and remove the risk factor and go full roller! It's just what you have to do now, face it!

When talking about the taper on the cam lobes, and saying the lifters will hammer down the high side, you forgot 1 very VERY important part. The lifters. The lifters must have a proper crown ground on the bottom that matches the taper of the cam lobe. This is a necessity for rotation, and it also keeps the lifter off the edge of the cam. You'll have half the lofter face in contact with half the cam lobe.

Success rate with roller, I agree with you but... You know you can open a valve riding a flat tappet lifter faster/longer than a roller, right? If you put a torque wrench on two valve trains, you'd never be able to tell the difference between roller and flat tappet valve train.

Can you discuss the roller rocker benefits in some future episode?

Just getting close to running my rebuilt 350 Chevy. I got to thinking, why doesn’t the “biggie” performance cam/lifter manufacturers set up a thermal cycling/oiling fixture, and using the fixture and simulated engine warm up thermal cycles, break the cam & lifters in, then package/ship a matched set to their customers, identifying which lifters go with which cam lobe? It seems, in today’s World, that would go a long way towards ending failures? And, my Comp Cam paperwork tells me of a nitriding process I could send it in to have done - too late, my cam’s in. It also talks of a lifter bore groove - but I can’t buy that tool & do it now, as I’m partially assembled and can’t risk shavings now. For a guy rebuilding a one-off motor (shade tree week-end guy, doing one motor) I wish I’d have known these details. Anyway - seems to me the aftermarket world is slacking a bit . . . And machine shops for not grooving the engine lifter bores at machining ( they never mentioned it). Thoughts?

Happy Thanksgiving 😊 😃

nice job Pete

Funny how the OEM's built flat-tappet engines for decades without all the break-in hoops to jump through. What changed?

During assembly make sure all lifters move freely

Sucks you have to take a loan out to stop camshaft destruction.

Thanks you for this video. Just preparing to break in a 340 flat tapped solid lifter cam and lifters. My question is using breaking valve springs(60-70 lbs). Currently on my speedmaster heads are some custom “ beehive” shaped springs rated at 230 lbs ( closed). As long as they do everything else correctly, lube, pre-oiling, ensuring immediate startup, is using a breaking valve spring worth the time and the money? Kirt

Well said, thank you.

Smart man. A critical thinking man.

So half the cars that were manufactured with flat tappet cams back in the day failed their cams?

Great info

Hi Pete excellent informative video. I’ve watched a few machine shop videos and cams being ruined prematurely on Dyno or initial break in. Have you come across cam failure concerning Rockwell hardness on the cam or the lifter of flat tappet cams? You are using oil with zinc on break in do you used a zinc based oil as your primary oil after break in? My questions might be totally irrelevant if so tell me I’m no engine builder by any stretch of the imagination just a retired jet engine mechanic ( Navy ) I know you are ( Air Force ) but I’m interested in learning. Thank you for sharing knowledge . Artie. 👍🇺🇸

Flat tappet is quieter than roller? Hmm. Just broke in my Isky 570 lift on 1.5, break in oil and stopped 7 mins in to adjust lash. Cold lash estimate was wrong, started clacking when hot. Once lashed hot all good.

You don't Know, What you don't know, Until you have years/decades of experience, with anything mechanical. Thank god for RU-vid, Before that it was word of mouth & Information moved very slow...

Why wouldnt you pull the distributor and run the oil pump before you go to break it in, then at least the oil is there when you hit it.

Dumb question, but anyone ever wonder how it is a roller cam can be ground with such precision & surface finish it doesn't need break in, but a flat tappet cam "does"? If anything, a flat tappet takes up [minor] angular slop, whereas a roller needs lifter bore centers dead nuts square to cam tunnel or... axles don't load evenly, things can spread, and little bearings get scattered about after a time when it finally gives way. Either way, anyone building consider this: as the block goes, so can the cam. Obviously, no break in oil on earth will fix bad taper or crown, but it can burnish things/change ra.. There is no doubt initial lubricant applied to any machine parts leaves a huge fingerprint where longevity is concerned - I like something in the moly family for flat tappet cam lobes on first startup. As for that first ten seconds, a thing the marine world knows well: prelube pump. Needs its own pickup [I like about one inch off bottom], a lockout relay [fuel pressure switch control works most engines], and a check valve so main pump output feeds as designed/doesn't suffer bypass back to sump. Pressure? Just enough to get oil to the top of the block is fine.

Happy T-Day Pete! For clarification, i reverse the drill for oil priming on a Chevy small block? Thanks.

Thanks for the tips Pete! Aren't all the Jeep 4.0 and 4.2 I6 engines flat tappet?

Interesting information! I have a question for you, I have a marine 502, one day It would not rev up but to 2700 - 2800 RPM, there is compression, fuel pressure, power to the injectors, to the spark plugs, ECM checked good, dont know what else to think of. Now Im thinking about some bad lifters, could it be possible that one or more lifters went bad out of the blue? and the valve is not opening? I got #3 and # 2 cylinders dead. Thank you in advance

My flat tappet has been noisy for 6yrs.

Thanks for the info. What about using lighter springs on a high lift flat tappt cam for breakin?

11:00 very important information 🍻

Why choose a flat tappet over roller? For this moment it’s PRICE.

I guess for inline engines you can do away with the oil pump cranking procedure by pouring generous amounts of oil over the camshaft and tappets.

Sorry for my lack of understanding but isn't the oil pump connected to / driven by either the crankshaft or the cam? How can you spin the oil pump with a drill and not have it turn the crankshaft / cam??

How long I shoud run the SAE 30 Break in oil ?

great job pete, whats the 440 for ?

What about solid lifters with oil holes drill in the bottom?

50% cam failure rate?? Did I hear that correctly? If you’re having a 50% failure rate, you’re doing something wrong. Maybe 8%! If that! 2-5% would be expected.

Why then back in the 70 the factory never did this I put cams never broke then in mopar performance I think cheap cores china metal not pure back in the day everthing usa steel

None of this really makes sense. The world has hundreds of millions of cars running that have never had any cam, lifter problems. It looks like the big 3 don't know anything?