[dataway]

I wonder how many HFT failures were using stock grind cams, or modern replicas of stock grind cams, as opposed to modern profile cams.

If you filter out high performance cams and high spring pressures I wonder what the failure rate would be.

I'm curious .... did high performance cams of 40 years ago use similar profiles to modern HFT cams, or are modern cams more abusive to the valve train?

[Formulas]

Originally Posted by dataway

I wonder how many HFT failures were using stock grind cams, or modern replicas of stock grind cams, as opposed to modern profile cams.

If you filter out high performance cams and high spring pressures I wonder what the failure rate would be.

I'm curious .... did high performance cams of 40 years ago use similar profiles to modern HFT cams, or are modern cams more abusive to the valve train?

There were failures long ago .... in 1983 i bought a 1970 espirit bird 350 4speed it ran ok but letting out the clutch i could feel a uneveness in the power did all the tune up stuff then got to watching rocker arms while running .... turned out the original 254 cam had 3 still operational but shaved lobes and concave lifters and the 254 cam has even less lift than std 4bbl cams


HP cams have had a sort of stepped evolution XE. was a step then a group before that and then 60s to early 80s time frame roughly each new generation has pushed lobe intensity higher in search of more overall torque and this stresses out the fragile lobe and lifter dance

[Formulajones]

Originally Posted by dataway

I wonder how many HFT failures were using stock grind cams, or modern replicas of stock grind cams, as opposed to modern profile cams.

If you filter out high performance cams and high spring pressures I wonder what the failure rate would be.

I'm curious .... did high performance cams of 40 years ago use similar profiles to modern HFT cams, or are modern cams more abusive to the valve train?

Hard to say if one is more prone than the other, I just haven't seen the failures with flat tappets. I run as much as 130 lbs. seat pressure on some flat tappets without issue, using modern grinds from Comp, while other cars here have stock camshafts or even 50 year old grinds from Isky that still work fine. There are some benefits however to the more modern lobes. But like I said, I go through extra lengths on mine with nitriding and pressure lube lifters etc... so a typical flat tappet for me runs about $1000. A hydraulic roller for me runs about $2000, sometimes more by the time I get the $1100+ lifters, etc... So the price difference is about double. Not horrible but not in the budget for many.

Like Mgarblik said, I really think these failures are just bad luck with a few other reasons mixed in, many of which aren't the cams fault.

[Ram Air IV Jack]

Originally Posted by Formulajones

Hard to say if one is more prone than the other, I just haven't seen the failures with flat tappets. I run as much as 130 lbs. seat pressure on some flat tappets without issue, using modern grinds from Comp, while other cars here have stock camshafts or even 50 year old grinds from Isky that still work fine. There are some benefits however to the more modern lobes. But like I said, I go through extra lengths on mine with nitriding and pressure lube lifters etc... so a typical flat tappet for me runs about $1000. A hydraulic roller for me runs about $2000, sometimes more by the time I get the $1100+ lifters, etc... So the price difference is about double. Not horrible but not in the budget for many.

Like Mgarblik said, I really think these failures are just bad luck with a few other reasons mixed in, many of which aren't the cams fault.

There are too many recent failure stories with flat tappet cams that you just can't ignore. I've seen this on cars owned by mechanics I personally know. Whether it is the chit overseas metal so many of these cams are made out of, and/or assembly issues, there are more failures of flat tappet cams reported today than ever before! Last year, one of the family members of Butler Performance sat for an interview with Smoke Signals. He claimed in their engine building service, they experience almost a 50% failure rate on flat tappet camshafts. Now since Butler is a renowned engine building company and known well by Pontiac enthusiasts, if that doesn't convince you something is horribly wrong with the modern flat tappet camshafts, nothing well....

[Formulajones]

I think people just like to complain more than ever before lol

[i82much]

Originally Posted by Formulajones

I think people just like to complain more than ever before lol

Back in my day, wiping a cam was like wiping your butt ... everybody did it, most people didn't feel the need to talk about it in public ...

[MrArt2u]

Originally Posted by Ram Air IV Jack

There are too many recent failure stories with flat tappet cams that you just can't ignore. I've seen this on cars owned by mechanics I personally know. Whether it is the chit overseas metal so many of these cams are made out of, and/or assembly issues, there are more failures of flat tappet cams reported today than ever before! Last year, one of the family members of Butler Performance sat for an interview with Smoke Signals. He claimed in their engine building service, they experience almost a 50% failure rate on flat tappet camshafts. Now since Butler is a renowned engine building company and known well by Pontiac enthusiasts, if that doesn't convince you something is horribly wrong with the modern flat tappet camshafts, nothing well....

Holy Smoke Signals, someone from Butler saying almost 50% failure rate on flat tappet camshafts is eye popping.

[PAUL K]

Originally Posted by MrArt2u

Holy Smoke Signals, someone from Butler saying almost 50% failure rate on flat tappet camshafts is eye popping.

It's not really happening. Just a figment of the imagination.

Many shops will not build an engine using a flat tappet set up.... Shops maintain this policy "for a reason".