[Dick Boneske]

Regarding the failure of the hydraulic roller lifter in Pontiacs. Isn't it true that the aftermarket hydraulic rollers for Pontiacs today are actually GM LS engine lifters--which is why the oil band is too low for Pontiac engines?

If it's true that these are LS lifters, it seems odd that there are actual failures of the lifter body itself. Most LS motors run well beyond 200,000 miles without lifter failures. Why do they fail in Pontiac engines if the problem is not lack of oil flow while the lifter is on the base circle of the cam?

I have heard that hydraulic roller cams for Pontiacs today have a smaller base circle than OEM cams had, by significant amount, worsening the problem of the low oil band.

I'm concerned about this because we're having a Butler 468 stroker built now. The engine shop wants to use Comp Cams solid Extreme Energy flat tappets because of the trouble he's seen with retrofit hydraulic rollers. I just can't see the logic in using a solid flat tappet cam in a street engine. The 20 HP gain means nothing compared to the noise, need for adjustment, and risk of cam failure as so many see with flat tappet lifters, solid or hydraulic.

Help me understand this right way to go.

[i82much]

Originally Posted by Dick Boneske

Regarding the failure of the hydraulic roller lifter in Pontiacs. Isn't it true that the aftermarket hydraulic rollers for Pontiacs today are actually GM LS engine lifters--which is why the oil band is too low for Pontiac engines?

If it's true that these are LS lifters, it seems odd that there are actual failures of the lifter body itself. Most LS motors run well beyond 200,000 miles without lifter failures. Why do they fail in Pontiac engines if the problem is not lack of oil flow while the lifter is on the base circle of the cam?

I have heard that hydraulic roller cams for Pontiacs today have a smaller base circle than OEM cams had, by significant amount, worsening the problem of the low oil band.

I'm concerned about this because we're having a Butler 468 stroker built now. The engine shop wants to use Comp Cams solid Extreme Energy flat tappets because of the trouble he's seen with retrofit hydraulic rollers. I just can't see the logic in using a solid flat tappet cam in a street engine. The 20 HP gain means nothing compared to the noise, need for adjustment, and risk of cam failure as so many see with flat tappet lifters, solid or hydraulic.

Help me understand this right way to go.

I mean honestly, there's no perfect answer right? I lost a solid flat, lost a solid roller, now I have a hydraulic roller with the Comp lifters. So far the hydraulic roller has held up better than the first two, but then again the current engine was built by a different shop than the first two.

It's hard to say what approach is going to be most reliable because you've got so many different variables when you read these threads. If you see a broken lifter from one guy and another guy says he has 50k trouble-free miles with the same lifters, is that dumb luck? Spring pressure? Oiling issues? Cam bore alignment? Lifter bore clearance? Proper valvetrain geometry?

[Formulajones]

There is no real need to worry about flat tappet cam failure or even periodic adjustments on a solid flat tappet.

If everything is built properly, good oil, correct springs, geometry, etc... a flat tappet works perfectly fine.

I have 2 of them in daily driver service and one is a solid. I've put just over 30k miles on the solid flat tappet engine in the last 3 years. At first I checked the lash 2-3 times the first year and it never moved, so I Iet it go a full year. Checked it again, It was perfect. Another year went by and I checked it last fall, again perfect. We'll drive it all summer, and throughout next winter and into next year before I'll even consider pulling the valve covers for another check. It's just not a big deal.

It's a tight lash solid flat tappet, and I took extra precautions with nitriding the camshaft as well as using Comps EDM hole on the face of the lifters to squirt oil directly onto the lobes of the camshaft. I run a good set of Crower roller rockers with poly locks as well, and always run Amsoil with the added flat tappet cam protection they offer in their hotrod oil. It's been an excellent setup. I don't know if it's one or two things I've done here to make this behave as nice as it does, or if it's a combination of everything, but the old wives tail is just that. If everything is happy they don't need to be adjusted every few thousand miles.

Engine builders like the solids because they tend to make a bit more power than a hydraulic, in similar comparisons. So you'll see the push towards that scenario if they are into squeezing power. But nothing wrong with hydraulic if you don't care about that.

[PontiacJim1959]

Originally Posted by Dick Boneske

Regarding the failure of the hydraulic roller lifter in Pontiacs. Isn't it true that the aftermarket hydraulic rollers for Pontiacs today are actually GM LS engine lifters--which is why the oil band is too low for Pontiac engines?

If it's true that these are LS lifters, it seems odd that there are actual failures of the lifter body itself. Most LS motors run well beyond 200,000 miles without lifter failures. Why do they fail in Pontiac engines if the problem is not lack of oil flow while the lifter is on the base circle of the cam?

I have heard that hydraulic roller cams for Pontiacs today have a smaller base circle than OEM cams had, by significant amount, worsening the problem of the low oil band.

I'm concerned about this because we're having a Butler 468 stroker built now. The engine shop wants to use Comp Cams solid Extreme Energy flat tappets because of the trouble he's seen with retrofit hydraulic rollers. I just can't see the logic in using a solid flat tappet cam in a street engine. The 20 HP gain means nothing compared to the noise, need for adjustment, and risk of cam failure as so many see with flat tappet lifters, solid or hydraulic.

Help me understand this right way to go.

I think it is like all things, everyone has an opinion, experience, "knows a buddy who....," read it in a book, or googled it on a forum.

I don't know why people complain about solid lifter noise/tick, but are OK with headers and/or a loud/performance exhaust. I've had 1 engine with solids and don't recall much ticking with the hood closed, but then again, I ran a 3" exhaust system with Corvair turbos and the car had a very choppy idle to begin with and was loud.

As pointed out, once set-up, you do not really have to be adjusting them all the time. Maybe if you used self locking nuts as found on a Chevy which can back off, poly-locks seemed to work. The factory 3/8" bottleneck studs from what I read have a bit of a crown and not the best for keeping poly-locks locked down - maybe that plays into the problems people speeak about in always adjusting them. If you replace with the BB aftermarket ARP 7/16" rocker studs, they have a flat top and hold the set-screw in the poly-lock far better. You also have to develop a "feel" to using the poly-lock and I am sure some don't snug it up enough fearing they will break/strip out the set-screw, and maybe some do do this. I never had an issue. The poly-locks also come in differing lengths. Wonder how many purchased the wrong length and where too short and did not grab as they should and didn't hold or were too long and bottomed out before tightening and didn't adjust as they should. Just something to think about.

Using a Crower flat tappet in my 455 because I want one and like the sound of solid lifters as anyone who is a car enthusiast and knows engines, knows what that sound is and recognizes the engine is "built." If you are not a car enthusiast or know much about engines, then you would think the lifters are noisy, but so would the loud exhaust. In my book, a solid lifter/sound carries a bit of respect for the car because solid cams in my time meant horsepower.

With solid lifters, you may read that they allow more oil to flow to the top end than what is needed. So it can be recommended to tap the lifter oil feed holes and use the oil restrictors. It may have worked back in the day, but with today's oil, which has gotten a little better for us older car owners, the restricted oil flow to the lifters and lack of zinc may have been responsible for taking out the lifters/cams. I believe you can get too crazy with oil control and lose the needed lubrication for the cam/lifters by using the valve lifter restrictor and even an overly designed windage tray and/or crank scraper. I WANT some oil mist/oil slinging around the interior of my engine to aide in lubing the cam/lifters. I am willing to give up some HP due in part to slinging oil as I will be running more under 3,000 RPM's than I will be screaming it to 6,000 RPM's in a race where tenths of a second count.

Crower offers a solid lifter that has the oil feed to the pushrod restricted to keep the oil down. I feel this is a better choice over galley restrictors. Another option is a pushrod with a reduced hole to restrict oil flow which are available. Have read that restricting oil flow to the top end doesn't provide enough oil to flow over the valve springs to help draw off the heat and keep them cool. But, which brand of engine/heads, street/strip/road race or Nacar, RPM range, HP level, etc. are they referencing?

Pontiac has oil drippers both in the earlier 400CI bolt-on style or the valve cover designed drippers. My opinion, use some form of oil drippers on the top end. Buying aftermarket valve covers might look good, but you may be giving up something the Pontiac engineers put into place for a reason. And again, how hard am I going to work my street/strip engine where I have to be concerned about my valve springs getting that hot that oil is needed not only as a lubricant, but as a coolant? Maybe I need an oil cooler too for the street.

Windage tray, does it help or hurt. Pontiac thought they were good, but eventually went with a shorter version and baffle in the pan. Milt Shornack used to add an additional drain hole in his windage trays and open them up to 1" so they drain better. Better might be to get a deeper oil pan/pick-up and fill with your usual 5 quarts to keep the oil level lower and below the crank so it does not whip up the oil from out of the pan. The Mopar engineers when giving pointers to engine performance building stated that the oil level should have a distance of 6" between the crank and oil level in the pan to prevent crank windage from whipping up the oil. Don't know what the distance is in a Pontiac, but I am going to measure when I get ready to assemble my engine - just so I know out of curiosity. I don't plan on using a windage tray, but an using a crank scraper along with deeper pan/oil pick-up. My opinion, I want some oil whipping around to lube the cam/lifters, but yet still have some control so it is not excessive.

Long and winded, I know. My opinion as well. If you use a good cam lube that is more of a paste that sticks when you first fire up the engine, I feel this may be a better choice. I wonder how many guys use a thinner cam lube that is more like molasses, assemble the engine, then wait 3 months or more to fire it up? Wonder how much is still on the cam and how much had slowly dripped off leaving minimal protection upon fire-up? My feeling is that if you are not going to fire-up the engine anytime soon, leave the intake off, and just before getting ready to fire, then lather those lifters, cam lobes, & oil up the pushrods,and rocker arm balls/cups, and valve stems up. Pre-oil the engine, then follow the break-in procedure.

IF you put a little thought into your engine build and throw in some assembly procedures to protect the cam/valve train, then I see no reason not to use a hydraulic flat tappet, or in this case, a solid flat tappet. And, the solid cam does have that "cool" factor and you will see that when someone who knows engines hears that you are running a solid cam.

So I say go with the solid cam and hang on.