Flat tappet cam breakin

[earlbrown]

Acceptable loss is ''zero''. Correct breakin is for work hardening the parts and marrying them to each other. If there's wear, there's grit. And when you have grit, you have wear......

On that groove, yes it's there and it's awful. I was told by a cam manufacturer years ago that flat cams have the groove and rollers don't. The only way to get a flat cam without the groove is to have it spray welded and reground (and hope the machinist does it right).

The bearing getting the raised channel is definatly a thing. And it's made worse by HV pumps, jacked up springs pressures, and people that feel the need to run 20W50.

 

[black owned]

Acceptable loss is ''zero''. Correct breakin is for work hardening the parts and marrying them to each other. If there's wear, there's grit. And when you have grit, you have wear......

On that groove, yes it's there and it's awful. I was told by a cam manufacturer years ago that flat cams have the groove and rollers don't. The only way to get a flat cam without the groove is to have it spray welded and reground (and hope the machinist does it right).

The bearing getting the raised channel is definatly a thing. And it's made worse by HV pumps, jacked up springs pressures, and people that feel the need to run 20W50.

So hardened foot lifters.Correct oil..and procedure hould be the key to flat tappet success.?

 

[earlbrown]

It also help to have burnished lifter bores and a vintage cam core that's made of good metal (and a ramp rate that's not stupid).


springs that aren't too stiff are also bonus points as well.

 

[Steve V]

So hardened foot lifters.Correct oil..and procedure hould be the key to flat tappet success.?

Yes. I have done several that way. And 85-90 lbs on the seat.

 

[black owned]

130 lb springs...don't do what I do.

Those springs are a benefit? If so please explain.Im ready to pull the trigger on a flat tappet cam.Need all the do's and dont's..

 

[black owned]

It also help to have burnished lifter bores and a vintage cam core that's made of good metal (and a ramp rate that's not stupid).


springs that aren't too stiff are also bonus points as well.

Who's making decent cams these days? Im looking at 206 or 208 cam and hardened lifters..Is this a good place to start and still leave room to grow?

 

[earlbrown]

Anybody that makes a roller


Cam selection isn't as important on these engines as it is on a high revving N/A engine. Plus if the heads aren't bowl ported and a couple flow mods, large cams don't give the same results as they will with the corks removed.

 

[ronviper]

Do yourself a favour and get a roller cam, you don't need the hassel of the break in procedure. My last flat tappet cam was in 1994 and it ran 10.16@ 132, now it's much faster without the worry of cam lobe wiping out. I had the motor rebuilt and the installer fired it up and the cam wiped out i had to pay for the re and re again, from then it was roller all the way without that problem ever happening again.

 

[Mr.Spool]

130 lb springs...don't do what I do.

i ran 100lbs on the stock cam back in the day,ran 10s at 125mph at 3800lbs.

 

[Mr.Spool]

Cam selection isn't as important on these engines

it depends on how fast you want to go.

 

[black owned]

My budget may only dictate a flat tappet cam..

 

[Mike T]

My budget may only dictate a flat tappet cam..

And a lot of of people are in that position. I'M sure that's why Steve has taken the time to show that it CAN be done.

I have a local friend who never post here but has been working on Buicks since day 1. He has built motors on all budgets and power levels .....told me he has not had a flat tappet cam fail at break in or suffer severe lobe loss in any motor he's built.

He has some very specific guidelines to his success and to say he's hyper vigilant would be an understatement.

 

[earlbrown]

My budget may only dictate a flat tappet cam..

Mine was like that too. My engine build got put off for two years until I could go roller. (and I'm one of the guys that can make a flat tappet cam live)

 

[Scarab]

what happens when a roller lifter turns sideways? Asking for a friend

 

[87GN_Bart]

Steve is good and can break the cam in before shipping but what happens if it's not broken in and you drop it in and have a problem with the flat tappet cam. You will pay for the re and re again, most builders rotate the engine to make sure everything is rotating smoothly however that is not holding the throttle for 15 to 20 minutes for breaking in the cam. There is an old saying you pay for what you get, cut corners and it generally

 

[SCOOBY DOO]

i ran 100lbs on the stock cam back in the day,ran 10s at 125mph at 3800lbs.

How many passes before they softened up?

 

[SCOOBY DOO]

Those springs are a benefit? If so please explain.Im ready to pull the trigger on a flat tappet cam.Need all the do's and dont's..

This is strictly a bracket engine...and sees a window of 5200-5800 RPM...and that's it. I don't recommend anything much over the stock spring pressure. Like I said...don't do what I do. I had approximately 1000-1200 passes on this engine between 6.8-7.2 at 100-102 MPH over four seasons. It was tore down and bored .030 over and a used set of TRW's put in it last year. The cam and lifters were mint...so they went right back in it again. Cam is a 212/212 CC with NOS GM lifters.

 

[Mr.Spool]

How many passes before they softened up?

i would have to look it was a long time ago,but i do remember a good amount of track passes and alot of street hits i wasn't upset at all about it.it was a pita to find though once it went away enough to see it on the slip.i was also running 1.65 rockers,ta49 turbo.i put another stock cam in after that and the motor ran fine.

 

[gunzandgearz]

I've never had any problems with flat tappet cams and breaking them in honestly I just use a lot of Cam Lube a good break in oil and make sure it's got plenty of zddp but I also will use the stock Springs to break the cam in if it's going to be a little on the radical side and then swap the Springs back over, I start out at 2000 RPM for 10 minutes go to 2500 rpm for 10 minutes and then back it Off to about 12 to 1500 for a few minutes drain the oil and install new good as gold, install a lot of these in the big and small block Chevy motors I do for customers also

 

[~JM~]

One of the Buick V-6 lifter bores is not aligned optimally to insure that the lifter rotates. Think it is the exhaust on #3 cylinder? Perhaps someone more knowledgeable could verify that.