FE Power Forums
		FE Power Forums => FE Technical Forum => Topic started by: fairlaniac on June 03, 2024, 06:42:05 PM
		
			
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				Coming home from the Ford Nationals at Carlisle I began to hear a faint, unidentifiable noise which quickly turned into sounding like a broken rocker dancing around under the valve cover. That happened last year so I know the sound. I ran the car longer than I should have but oh well... Today I start looking. No broken rockers but #8 intake rocker has a little extra clearance. I pull the Harland Sharp equipped rocker shaft assembly. Nothing on the wheel. So I drop my lighted bore scope in the push rod hole but the light is too bright to make out anything.
So I pull the oil filter, cut it open for inspection. My magnet is clean as shown. Then I swipe it through a couple of pleats and you can see the collection of ferrous bits. Not good, I then pull the oil drain plug and it has a stalactite on it of metallic mud.
That's all the further I feel like going today. I guess the Fairlane is done for most of the summer  :(
I'm wondering if I lost a roller lifter? It sounded like the valve train as in lighter parts. No serious hammering. Regardless, it's damage. As a mechanical engineer I can't help but go through scenarios and figure out what happened. I'm wondering if putting the Tremec TKX in and driving the highway at 2200 RPM if I'm not slinging enough oil up to the solid rollers lifters? It's a '66 solid lifter 427 block. I'm picturing a frozen up roller wheel ground flat and my Bullet cam ground down. Oh well, after June is over I'll have time to rebuild. Ugh!
http://www.fairlanet.com/images/shavings2.jpg (http://www.fairlanet.com/images/shavings2.jpg)
http://www.fairlanet.com/images/shavings1.jpg (http://www.fairlanet.com/images/shavings1.jpg)
http://www.fairlanet.com/images/shavings3.jpg (http://www.fairlanet.com/images/shavings3.jpg)
http://www.fairlanet.com/images/shavings4.jpg (http://www.fairlanet.com/images/shavings4.jpg)
			 
			
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				Well that sucks
When I first was looking at buying engine parts I found a guy that had a 427 short block forsale he was drag racing it in an early mustang he was running a roller cam in it and he had some thing done to spray or get more oil down there I can't remember what it was but i think he had pipes running in the valley that put extra oil on the lifters. I didn't end up buying the bottom end it was 14-1 comp radical thing it did have a ton of very early go fast parts on it.
I may still have the photos I will look and see it I can find them.
			 
			
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				Unless it's something like a Victor intake, you can usually fish the lifter pair out through various orifices in the intake manifold.  Easy to inspect that way.  I'd pull the lifter pair on the rocker that you thought was loose and check it out.  
Normally, you don't see many non-pressure-fed solid roller lifters going longer than several thousand miles, so it's possible, but you could easily rule it out.
			 
			
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Unless it's something like a Victor intake, you can usually fish the lifter pair out through various orifices in the intake manifold.  Easy to inspect that way.  I'd pull the lifter pair on the rocker that you thought was loose and check it out.  
Normally, you don't see many non-pressure-fed solid roller lifters going longer than several thousand miles, so it's possible, but you could easily rule it out.
I have an Edelbrock RPM intake. I'll give it a shot on trying to fish out. The smallest opening is between the #7 & #8 push rod holes. I'll have to think out this approach. Any special picks, magnets, tools to help remove the lifter pair?
Thanks!
			 
			
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				Sorry Fairlaniac dose not seem like I have the photos anymore
that guy also had oil lines that went into the centre of the cross bolts   
			 
			
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Unless it's something like a Victor intake, you can usually fish the lifter pair out through various orifices in the intake manifold.  Easy to inspect that way.  I'd pull the lifter pair on the rocker that you thought was loose and check it out.  
Normally, you don't see many non-pressure-fed solid roller lifters going longer than several thousand miles, so it's possible, but you could easily rule it out.
I have an Edelbrock RPM intake. I'll give it a shot on trying to fish out. The smallest opening is between the #7 & #8 push rod holes. I'll have to think out this approach. Any special picks, magnets, tools to help remove the lifter pair?
Thanks!
I've done it on a Performer RPM.  A telescoping magnet will get it done.  You can also pull the distributor and pass the lifter pair down the lifter valley with a magnet and pull it out the distributor hole.  Many ways to do it.  
Putting it back in is a little tougher, but a pair of magnets will get it.  
			 
			
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 I'm wondering if putting the Tremec TKX in and driving the highway at 2200 RPM if I'm not slinging enough oil up to the solid rollers lifters? It's a '66 solid lifter 427 block. I'm picturing a frozen up roller wheel ground flat and my Bullet cam ground down. 
As one who is currently in the middle of my tkx swap... I certainly hope this is not the case. Good luck with what you find out!
			 
			
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				War story, back in the early 2000s, I had a group of Rat Chevy customers and they were eating non-oiled pin rollers at 2-3000 street miles.  I called Comp and they said every 75 passes they should be rebuilt (75 x 1/4 mile)  :o
Now, a BBC offset loads the lifter, a BBC is not an FE, but I would not be surprised if a non-oiled pin failed.
Hopefully you didn't hurt too much, but if you can't get oil to them with your block, I'd likely pull the intake and swap/rebuild all 8 pairs.
If you did lose one and took out the cam, I'd likely do a solid flat with tool steel lifters.  long run I'd call it safer for a long hauler
			 
			
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				Think I'd still pull the entire engine down. Too much debris for my liking. 
			
 
			
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				Small flashlight(s) with flexible stalks are a necessity.
You can usually bring the roller pair up using some welding wire with a "hook" bent into the end to snag the tie bar.
Once out of the bore, use a couple magnets to walk the pair forward to the distributor hole.
If it crushed out the needles, the debris you're seeing could be the sides of the lifter body alongside the axle.
If that's the case, the lifter will be nearly impossible to remove as the sides spread - and the cam will be toast.
Let's hope that is not the case....
			 
			
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				I don’t think the low rpm on the hwy did it in. Even at 2200 rpm oil is really blowing around inside the motor. Hate to hear this with the solid rollers. I only have 3000 miles on my car in 8 years 2700 were with a flat tapped solid. How many miles are on the lifters? 
			
 
			
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				This is why I wish I had gone with one of jays intake adaptors and tunnelwedge type top would not be a big deal to pop the top off lift the valley cover have a check and away you go
			
 
			
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I don’t think the low rpm on the hwy did it in. Even at 2200 rpm oil is really blowing around inside the motor. Hate to hear this with the solid rollers. I only have 3000 miles on my car in 8 years 2700 were with a flat tapped solid. How many miles are on the lifters?
Joe, I have about 500 miles on the roller lifters, Lunati 72903. I'm a believer in operator error over mechanical failure much of the time. Not sure what I did but I put it on myself.
			 
			
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				I have had solid rollers last for many years on the street.
My opinion FWIW is that the "killer" of roller lifters in inadequate valvetrain control and excessive lash.
			 
			
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I have had solid rollers last for many years on the street.
My opinion FWIW is that the "killer" of roller lifters in inadequate valvetrain control and excessive lash.
Barry, on a .026 hot lash, is there a cold equivalent? I ran mine a .022 cold.
			 
			
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				I have always run solid roller cams with a much tighter lash.
Instead of 0.026" I would run 0.016" 
Tighter doesn't hurt anything - it is easier on parts.
Solid roller lasted over 20 years - street driven, occasional blast to 6500+
			 
			
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I have had solid rollers last for many years on the street.
My opinion FWIW is that the "killer" of roller lifters in inadequate valvetrain control and excessive lash.
Barry, on a .026 hot lash, is there a cold equivalent? I ran mine a .022 cold.
Obviously not Barry, but usually on an iron block/aluminum head combo, the cold lash is about .006" tighter than hot.  On all-aluminum stuff, it's usually .014-.015" tighter on cold setting.
			 
			
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				Although I agree that excessive lash kills, flat or roller, and especially quickly on a roller, life of a solid flat done right is measured in decades, not years.
I know I sound like the geek in the room LOL not the first time...and I know it's not the failure discussion, but unless you have a ramp requirement that exceeds the capability of solid flat, I am hard pressed to ever push a non-oiled roller.  
That being said, tight lash and a good wall of oil is better, I lash everything tight only bad thing that can happen if too tight is the valve doesn't close all the way.  FWIW, my own solid flat is at .016 cold
			 
			
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				FWIW - and since we are sharing opinions - I have never bought into the lack of oiling as a reason for roller lifter failure - or the EDM hole in solid flat tappets for that point either.
If you ever run an engine at anything beyond idle with an opening in the intake (like the one in the rear of many FE intakes) you'll quickly discover that there is a literal maelstrom of oil flying off on the crankshaft.  I've had oil hit the ceiling of my dyno room.  Watch a crank spinning on a balancer at 750 RPM and it' apparent that this stuff is moving really, really fast.  The open bottom cam tunnel in an FE means that a huge percentage of oil being flung off that rotating assembly is being directed right at the cam/lifter interface.  OEM Ford stuff lasted forever with no direct oiling at all.  The EDM hole in lifters was a strategy employed by NASCAR teams when they were rules mandated to flat tappets, and were using enclosed cam tunnels and vacuum to limit oil movement throughout the engine.  Along with welded stellite faced cams and DLC coated steel lifters.  This stuff simply does not apply to a normal street oriented package.  Oil volume is not the problem.  Sure feels good though... 'cuz we can see it and buy stuff that looks like an intuitive "fix"...
Solid roller lifters live forever in many heavy duty diesel applications, which run at low RPM and light valve spring pressures.I believe the reason they work so well there is more related to valvetrain control than anything else.  Consider the most roller bearing applications - that also last a very long time - run at zero clearance or even in preloaded conditions.  Examples include rear end parts, wheel bearings, internal transmission bearings and rocker fulcrums.  Each roller concentrates load on a line contact and thus transmits every "hit" onto a very small area of the race.  Hit a pothole and the wheel bearing will brinnell the race and the assembly will fail prematurely.  But under normal conditions that wheel bearing will carry 1/4 the weight of a 10,000 pound (or more) truck for decades.  Rollers are not the problem.  Sends us back to the impact/lash and valvetrain control direction. Hydraulic rollers last forever because there in no lash - no impact damage - until the valvetrain loses it's proverbial shit at high RPM.
Unfortunately for us normal folks, valvetrain control is not a simple thing to quantify - other than looking at worn and broken parts and knowing that something ain't right.  Things can be perfectly fine at 7000 RPM and be completely lost at 3000 RPM.  Every darn part in the valvetrain is a spring - the pushrods, rockers, even the cam itself.  If there frequencies all happen to line up the result can cause things to go crazy even at low RPM.  By making these parts stiffer we can get most of the system "out of the way" and focus on controlling things with the spring itself.  Thats the reason for big diameter cam cores, thicker and stiffer pushrods, and steel rockers.  OEM and professional race teams can use computers, labs, and Spintron testing to sort this out, and some serious race engines run with amazingly low spring pressures.  We don't have the luxury.
That is a long way of saying that I really like hydraulic rollers.  
I have run custom made ones with only .015" travel and treated them as solids with the lash "in the oil" at 7000 RPM+.
Set them almost bottomed out cold and let them grow when hot but remain in the travel range - no lash. 
Probably not real easy for a guy in his garage on a Friday night...
Get them a teensy bit too tight and the damn engine won't start (experience).
And bushings remove all the roller issues if you can afford to make that step.
			 
			
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				There is no way that I can say I have had the race solid roller experience you have, not that I have had none, but nowhere near as you and others.
Needless to say there has to be a ton of oil at the cam surface or every flat tappet would fail, but I do not think that equates to the cushioning of a pressure lubed pin, although we certainly could say the cushioning would happen on the OD of the roller too so I can't really say.  My disagreement, if you call it that, small rollers in a reciprocating shock environment, without pressure oiling (or maybe even with) are never the right piece. I do think the rollers are asking for trouble in the long term for the exact reason you stated, packaging in a small lifter bore, it forces the pressure on a couple needles, each of which has less oil film due to its small size. I have no proof, but I think a bushed lifter would be better based on Kentucky-windage engineering, regardless of price.
That being said, I do have way too much time pulling 3/4 and 1 inch torque wrenches on big diesels.  The diesel argument needs to be taken with a grain of salt.  Many Cummins and Detroit use and have used hydraulic lash adjusters, many Cat diesels use hydraulic rollers now, and even my beloved baby Cummins solid flat 24V pickup, changed to hydraulic rollers starting in 2019 (mine is a 2013 and I tight lash the intake greatly, but leave the exhaust to factory specs for more seat time for cooling on boost/high EGT).  
On top of that, solid rollers in big trucks DO fail, in fact, most are replaceable in big diesels.  In a big diesel they are called cam followers, and they have room for a big wheel, bushing and pin, and those followers (not the entire lifter) can and are easily replaced, often only making noise or lash when they fail.   You are spot on that the valve action and matters greatly, a silly slow ramp, low lift and often as little as a 2000-2500 operating window really make it a completely different environment.  Some Cummins run as tight as .008 cold intake, and even though they are .020+ exhaust, the exhaust valves run hot with a turbo and I assume grow a ton and the seat opens somewhat when really pulling on boost.   Lube options range on manufacturer, but I have seen oiled bushings or splash oiled bushing on most big diesel.  I have never taken a follower wheel apart to see if they were ever roller bearing though, but also never found any with a magnet or in a pan
In the end though, we agree lash can hurt, valve action matters, and uncontrolled valve train hurts even more.  I am also a hyd roller fan, relatively aggressive ramp capable, after some learning over the years readily will RPM.  My last 410C happily hit 7100 over and over again with nothing that fancy, beehives with steel retainers and standard travel Morels at .045-ish preload.  Not solid roller levels, but more than we did in the past.
In the end, we don't disagree, and I hope I am not stepping on your toes.  I'd be hard pressed to change a cam if it wasn't damaged in the original discussion (although on EDIT, I would be hard pressed to change only 1-2 lfters without thorough inspection) . I just think a solid roller is a benefit when it's ability to follow a ramp others cannot is needed, before that not so much.
			 
			
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				As long as we are sharing opinions... ;D
Way back in 1981 I ran a Crower solid roller setup in my 68 Shelby.  This was Crower's most conservative cam grind, only around .560" lift if I recall correctly, with their matching roller lifters, springs, etc.  The car was a street car, not a race car, and if I recall correctly lash was around .022".  That setup lasted exactly 770 miles in my car before the needle bearings in two lifters failed.  Back then, there were no EDM holes providing additional oiling to the needle bearings.
Fast forward to 2005, when I ran my Mach 1 at Drag Week.  We went 2500 miles that week, lots of city and highway driving, with Comp Cams roller lifters and cam.  Lash was about 0.018", again IIRC (I have since bailed on Comp Cam's roller lifters, have had much better luck recently with Crower stuff).  But the bottom line is those lifters had the pin oiling feature, and when the engine came apart a few years and 5000 miles later there were no failures.
Seems pretty black and white to me that the pin oiling feature dramatically extends the life of solid roller lifters in a street application.  So, I'm going to disagree with Barry on this one  ;)
Here's another example, although not quite the same.  The 427 SOHC features rocker arms with needle bearings on the roller wheel that contacts the cam.  This was the factory setup, and all the aftermarket SOHC rockers (except mine) are the same design.  I have been on Drag Week with my SOHC engines 4 different times, and every time I have lost at least one rocker arm; the needle bearings just give up.  In 2008 I lost 11 (!) Dove rockers, and didn't even make it to fourth track.  The failures always happen after some extended time at low engine speeds.  The most memorable example was in 2016, when I was stuck in traffic in some town for about 15 minutes.  Back on the highway you could start to hear valvetrain noise, but I was intent on making it to the hotel so kept going.  By the time I got to the track in Martin MI the next morning, I found I had blown up three T&D rockers, and wrecked both cams.  I had to change it all out at the track.
After that experience I designed my own SOHC rockers, that feature full time pressure oiling to the pin, and a bushing instead of needle bearings.  Unfortunately I haven't been back to Drag Week to give these rockers a real test yet, but I'll bet they will last a lot longer.
I think if you are running strictly at the race track, or taking the car to the occasional show, maybe that additional pin oiling isn't required.  But if you want to actually drive your car on the street with solid roller lifters, and put some miles on it, I think it is wise to get the pin oiling feature.
			 
			
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The most memorable example was in 2016, when I was stuck in traffic in some town for about 15 minutes.  Back on the highway you could start to hear valvetrain noise, but I was intent on making it to the hotel so kept going.  By the time I got to the track in Martin MI the next morning, I found I had blown up three T&D rockers, and wrecked both cams.  I had to change it all out at the track.
I remember that day and route, from Summit Motorsports Park (Norwalk), to Martin, and the area where the jam was. It was in the 90*'s that day, and also being stuck in that jam, it was the only time my car reached over 200 degrees, and it was about to hit 220. I was about to pull off and shut it down when the traffic finally moved and I was able to get on the highway, where it cooled down right away. I'm sure the oil got very thin, which probably contributed greatly to your lifter failures. I was nervous about that also, and kept tapping the gas to keep oil slinging around.
That's the main reason I run the factory oil cooler. Even if there was no air flow over it at the time, it probably helped. Not saying it would have saved your lifters, Jay, because I doubt it would have. That was just a bad spot for any performance engine, and IIRC, several other guys had issues that day.
None of this has any bearing (pun intended) on the conversation though. ;D
			 
			
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				Well, not to muddy the waters, so to speak, but I have had an engine ruined by hydraulic roller lifters come apart and destroy the engine.  Ford 351/377 with Crane hydraulic roller camshaft.  Ford Motorsports roller lifters, dog bone/turtle, etc.  Had less than 3000 miles on the camshaft and lifters.  Ford Motorsports valve springs, retainers, keepers, Smith Brothers push rods, EFI limited to 6250rpm.  Joe-JDC
			
 
			
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				If you are running a solid roller on the street more than likely it is a big cam. By that I mean .600"+. The spring pressures for these solid roller cams are enormous compared to a regular flat solid lifter. The killer is "spring pressure" which is hard on everything including valve seats. The solid roller lifters are not designed to get thousands of miles out of. It's race stuff. Run for a short period, take apart and check everything.
I hear a lot of comments about how many years guys have had solid roller lifters in their motors with "no problems" (I believe them) but almost no mention of how many miles have been put on them in those years.  Most of these motors with these big solid roller cams sit most of the time, so yes, they will last "for years" for that reason. But if you are putting real miles on the car beware. Unless you are prepared to tear down and check everything every couple thousand miles, or sooner. 
This is just reality through my experience running a solid roller on the streets. No more solid rollers for me anyway. Anything but.  
Hope your motor has only minimum damage.
			 
			
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				I have no experience whatsoever with roller cams of any type. But I do have many years experience as a maintenance fitter on all sorts of different machinery with all sorts of different bearings, so here goes.  ;D
There is no way in hell I would want to run a needle bearing in that spot, with lash clearance, pressure fed or not. Even if you have your valvetrain fully sorted through your intended rev range who amongst us here hasn't over revved their engine a bit sometimes, on purpose or not? And who apart from semi serious racers replace their valve springs BEFORE they are showing signs of loosing control? Regardless of any life expectancy comparison, the failure mode of the needle roller is catastrophic. At least with a bush you can see/hear it coming and replace it before it shits the bed. Needle bearings in solid rollers just do not seem worth it to me.
Just the opinion of a rank amateur.
			 
			
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If you are running a solid roller on the street more than likely it is a big cam. By that I mean .600"+. 
Just as an aside, cam size really shouldn't be judged by the lift.   It's very common to see very streetable cams (hydraulic roller, solid flat tappet, solid roller, etc.) that have .600" lift or more.  It's really not the valve lift that causes the issues, it's the durations and more specifically the amount of "snap" the lobes have that require higher spring pressures to keep everything in check.   I have towing cams out there in vehicles that have tens of thousands of miles on them with ~.600" lift.   On the other side of that coin are the Cup guys who used to run .750"-.800" lift cams with just 400 lbs of spring load.  Everything has to be looked at as an individual case.  A "big cam" to me is a cam with a lot of duration, which would generate a lot of rpm. 
I totally agree with you on the other points.  I would rarely recommend a solid roller for a street vehicle, unless it's a unique case or it's for an engine with a block that doesn't oil to the lifters. With the rpms that we can get out of hydraulic rollers now, it's a much better/stable choice. 
			 
			
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				My block is a '66 Solid Lifter block. With everything reported over the recent years and the higher rate of solid lifter cams getting eaten. With the available data, it seems the roller came would be easier on the engine than a solid lifter so I went that route. It's not perfect and I'm finding that out. 
			
 
			
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My block is a '66 Solid Lifter block. With everything reported over the recent years and the higher rate of solid lifter cams getting eaten. With the available data, it seems the roller came would be easier on the engine than a solid lifter so I went that route. It's not perfect and I'm finding that out.
I'd usually rather have a solid flat tappet in that scenario.  
IMO, the cam failures generally boil down to guys running too much spring load.   Don't get me wrong, there's a statistical bell curve to every part and I'm sure there are failures, but I see so many guys buy heads off the shelf "for flat tappet cams", bolt them on, and watch the cam lobes get ground to oblivion, because they didn't know to check spring loads with their cam, or pull the inners out to break it in.
			 
			
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				Here is my cam spec. It was considered streetable upon my build. 
(http://www.fairlanet.com/images/camspecs484.jpeg)
http://www.fairlanet.com/images/camspecs484.jpeg (http://www.fairlanet.com/images/camspecs484.jpeg)
			 
			
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Here is my cam spec. It was considered streetable upon my build. 
(http://www.fairlanet.com/images/camspecs484.jpeg)
http://www.fairlanet.com/images/camspecs484.jpeg (http://www.fairlanet.com/images/camspecs484.jpeg)
Streetable is always subjective but that's a good street lobe.  
However, a non-pressure fed solid roller lifter just won't last forever.  
What does stick out to me is the required seat load.   Valve weight has a lot to do with things and 190 lbs on the seat for a middle-of-the-road solid roller camshaft just doesn't sound like enough.   I am not shy when it comes to seat pressure because that's what keeps everything happy.  
If it were me, I'd run about 50 lbs more seat load, and I'd tighten the lash up.  Those lobes are Bullet lobes and the intake lobe has a lash ramp of .012", so a 1.76 rocker would lash at ~.021" and a 1.8 rocker would lash at ~.022".  A .026" lash sounds a little loose to me and could certainly exacerbate things with low seat spring load.
			 
			
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Here is my cam spec. It was considered streetable upon my build. 
(http://www.fairlanet.com/images/camspecs484.jpeg)
http://www.fairlanet.com/images/camspecs484.jpeg (http://www.fairlanet.com/images/camspecs484.jpeg)
Like Brent said, what some call streetable, others may not. That cam appears to be very similar in lift and duration to the Oregon Cam solid flat tappet cam that I ran for years in both several 428s, and the 427 in my Fairmont. That cam ran for years , with 145 pounds of seat, and 320 open, and ran a best of 10.03 at 132 MPH in the .030 over 428, and 9.97 at 132 with the 427 with 428 crank. Both engines used stock iron Cobra Jet heads, and despite shifting those engines at 6200 RPM, I would have been pretty hard pressed to call that cam "streetable", at last MY version of streetable. To me, a streetable cam is one that can idle down well below 1000 RPM, and have enough vacuum , so that the power brakes can function normally, if so equipped. And most anybody could be able to drive the car, without needing a crash course in how to drive the car. To some, anything that can stumble down to the local burger joint car meet is streetable, but others prefer a street car to be able to go 1000s of miles per year, without needing to be checking valve lash, spring pressures , and other items more than once a year. I know that Drag Week, and similar "Drag and Drive" events are fairly popular,  and some guys think that a Pro Mod race car is a street car, if it can make the trip from one dragstrip to the next, without wipers, functional glass windows, a steel body , especially with a naturally aspirated engine. When I see a car with a turbo  or blower sticking a foot above the stock hood, or a 8" tall cowl hood, the hood and fenders held together with Dzuz fasteners, lexan windows that don`t go up and down, and the open headers sticking out of the front fenders, to me, that is not what I consider a street car. But thats just one old guys opinion. Some of those "street car" drivers, as well as most "Rat Rod" drivers, must have heart papilations if a Police car happens to pull up behind or along side them at an intersection.
			 
			
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				That is kinda frisky for a street oriented cam.  
More street racer than street driver.
Used similar cams often for that purpose.  
I would agree with Brent on the spring deal.  
I used a Manley Nextec oval track spring on stuff like that when I was running traditional four stud rocker mounting - had around 220-230 seat and still only around 600 open.
Couple with a TI or tool steel retainer, set up installed as tight to .050 from bind as you could comfortably get -  and they would do really well.
And I would look at that .012 as a cold lash target - should get you right around .020-.021 hot.
Sometimes hard to define "hot" and keep it consistent through the lash process.  But room temperature cold is easy.
			 
			
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				I only have one engine with flat hydro tappets in it, and those have been in there since around 2000. They are in the back up 302 and have been beat to death but are still happy to be here LOL.  Everything else is roller.  If I was going to run street or street/strip with the occasional Friday Night TnT passes, I'd stick with hydros - depending on the shift RPM.  Under 6500 - no problem.  I run solids in the race engines without regard to max RPM and will only use pin oil models.  The current setup is a hydro roller with solids on top running .005 lash.  I note that .005 lash is a pain in the ass to run and I may back off to .010 to get a little bit of wiggle room.  It's taken 2 races to make sure the valve train is all set for full blasts.  That's a mechanic issue, not the valve train LOL. With about 600lbs over the nose, everything has to be set really good-n-tight. 600 lbs will find your weak spots quick.