This man is telling FACTS. No speculation BS here. I have been a gearhead, go fast mechanic for almost 40 years and it’s not often that I get to learn anything anymore, but I learned two things watching this video, thank you! You have *earned* my sub
This man is pure and really knows his stuff. One thing I have seen over my career is worn or scored lifter bores not looked after during rebuilds that stop the lifter from rotating. I suspect that is responsible for atleast some failures as well.
Yep the occurrence of ovality in lifter bores of older high milage engines is more prevalent than most realise and this is not so much just the impact on lifter rotation but also misalignment at contact face and lifter chatter, in some cases enough ovality to cause low oil pressure issues too, lifter bore bushing may be cost prohibited but the difference in lobe contact patterns is huge, I have many times reamed to ford or chrysler sizes in chevy blocks but the hazard of clipping the lobe next door increases substantially without accurate cam endfloat control
I have a home based automotive machine shop. In 30 plus years I had never had one single instance of a cam going flat. Start my own shop build a few engines and I had one go flat year before last. It literally rubbed a hole through the bottom of the lifter. Of course I’ll state that I check and double check my valve spring rates and coil bind. Seal to retainer clearance. It is a must in the custom engine line of work. This is one major aspect that separates my work from the reman industry. That one particular engine had also mysteriously wiped out the cam bearings. Front three cam bearings lessening to no wear on the back cam bearing. It nearly wore entirely through the front cam bearing. This was a major problem. I couldn’t afford to fix too many of these problems else I’d be shut down. I had to try and figure it out. The cam mains never appeared to have seized the cam bearing material appeared to have been mashed flat and kept running. It was a FE engine with the groove in two cam mains. The bearings had formed into that groove. After many hours of scrutiny and scratching my head I finally gave up and began to reassemble the engine with a new hydraulic roller set up I paid for. When I picked up the front cover I found out immediately what had caused the issue. The customer had installed the fuel pump on the front cover and had used a bolt that was too long. That bolt busted off the back side of the bolt hole. A piece or pieces of cast aluminum about the diameter of quarter and about .080” thick had broken off the front cover. The oil slinger on the snout of the crank shaft left absolutely nowhere for those pieces to go other than on top of the crankshaft timing gear. That piece got wedged between the timing chain and gear and shrapnel was scattered. I found pieces of cast aluminum shrapnel imbedded all over the inside of the front cover. It was evidently violent. I didn’t find any debris in the oil pan initially. Just dark powdered material from the cam lobes and lifters. The oil pump and pick up screen appeared to be clear upon first glance with the old oil still in and on those parts. After I cleaned those parts off I found that more cast aluminum was inside the pickup tube and I can not figure out how pieces the size I pulled out of the pick up tube got passed the screen. The gears of the oil pump and housing appeared clear with no gouges or foreign material but after cleaning thoroughly it was very clear that cast aluminum particles were smeared all over the inside of the oil pump as well. It was very difficult to see these issues when the parts were cleaned off. No way to have seen them with the oil on them. I thought I’d share these details for others in this line of work to learn from. A fuel pump install is pretty basic but it can bring devastating consequences if someone of it paying attention. My confidence in cam and lifter cores was of course diminished after this. In spite of knowing the cause. This demonstration helps me out a great deal. I’m trying to abstain from flat tappet cams right now. However if your company is rebuilding them I’ll certainly be willing to send some work that way. Thank you for your time and information.
I have seen a bunch of 305 engines that ate the lifters and lobes at the front of the cam. The front four lifters will have a concave surface on the face and the lobes are almost gone. It was the last bunch of flat tappet cars that ended up getting low zddp oil because thats what is on the shelf in cars that idled a bunch. It did happen years ago.
I learn something every time I watch one of your videos! I had never heard lifter crown and cam lobe taper described so clearly and in just a realitively few words! Great Video!l Thanks !
I don't want to wear anyone out on comments but, I started mechancing when I was 17 because I wouldn't go to school. Worked in a shop as full line mechanic. Now am 63. I owned a small engine shop, I was amazed how many so called mechanics couldn't work on small engines even diesel mechanics. 1 cylinder engines have to be basicly all correct to run right and hold up. Example on a v8 maybe 6 cylinders are correct and 2 not, and nobody knows. At 63 I still do small engine work also atv's , utv's. I've seen so much stuff that mechanics have distroyed. Assume-ing will bite you in the ass every time! I can not express how much I appreciate you taking the time to do videos passing in your knowlege and experience. Everyone learns something from it.
Excellent presentation here.........The problem is the EPA...In 2008 they took all the phosphorous and zinc out of all automotive on-road oil to "save the planet"...Roller cams were in almost everything by then (New vehicles) and they told the rest of us to flip off....I had an automotive machine shop at the time and lost several engines in two weeks and ZERO losses for the 350 or so engines we had built before that time....I am retired now and still get involved with builds for my buddies and we only use roller cams now....We still use zinc and high dollar break- in oil....Even with a perfect break-in being done, A high-lift, High spring rate flat tappet engine is still vulnerable to ONE bad oil change....A retro-roller kit is way less expensive than a re-rebuild because of metal chunks everywhere and the crank may need replaced if it won't turn again.. Then its back to the balance shop for new crank to be match balanced to the other parts...Good luck and good OIL to you all...
Thank You, the last cam and "kit" that I bought and installed was a Crane in 1979 and had no problems at all. I just bought a Melling for my RV and then started seeing all of the info about "failing parts". I also found it difficult to even get the "kit" I decided that I wanted, all I heard was that suppliers couldnt get them. Anyway Im going to install this one the same way that I did the one when I was much younger, sure hope this works! Thanks
This information needs to be socialized better! One thing that people should be made aware of is the only new Hydraulic Flat Tappet lifters made in the USA come from 1 place and that's Topline Hylift in the same city as CWC. Speedpro/Federal Mogul are coming out of Mexico. Comp is in the middle or just finished moving all their equipment from TN to MS, I'd like someone to do a little more investigation into why there's cams leaving their "State of the Art Facility" with a lack of taper! I get the offshore lifters not having a crown, but COMP should have a higher standard.
@@powellmachineinc Where ever Comp is getting their lifters, their failures have cost our shop a lot of money. One project was returned with badly worn camshaft & lifters. (new Pontiac 400, hydraulic flat tappet application) We suggested upgrading to a hydraulic roller set up. Engine ran great, but was returned again with less than 1000 miles with a broken roller wheel on one lifter. Comp Cams is not offering any solutions or answers.
@@MrZdvy Comp Cams are going through the same tough times as many other businesses, I get that, but their manner of dealing with the concerns of clients who have dealt with them for years could be a lot better. More than 50% of our cam and valve train related purchases are from Comp, and to hear them say they don't know how to help you, is quite depressing.
EXCELLENT VIDEO! First time viewer, thank you for making this! Plenty of theories on flat tappet failures but you show the science and testing to rule out cam hardness. Perfect, I'm a fan, subscribing now!
I was just talking about your video with a friend of mine who grinds cams. He said that back in the day they did the same thing where they checked the hardness of everything and their results were the same as yours. One thing he did say was that for some reason when lifters are manufactured by some suppliers the end is machined first and then the body is centerless ground which seems backwards but certainly lends credence to your idea about the end of the lifter being either machined off center or off kilter from the body of the lifter. It would only take one or two to mess up the whole thing. Good video.
Buick: '50's 60's Nailheads had ZERO lifter rotation by design. '67 and up 400/430/455 DID have "normal" rotation. Possibly the cam grinder forgot to put the taper in for a later Buick big block.
Great Video! So for the most part its a "machinist problem" from the factory I'd say..?? I have seen two hydraulic flat tappet cams from two separate SBC builds chewed up in just the last two months. These were "cam kits" so the cam and lifters were sold by the same camshaft company. Several of my friends have decided to go with a hydraulic roller setup due to not wanting the worry of having a fresh build eat a cam/liter and corrupt the rest of their build. I even paid the extra money and went with a hydraulic roller in my street BBC. Again, informative video!
A friend of mine builds my engines and I follow his start up instructions to the letter ! First he sets the timing on the engine stand , he says never make a full rotation putting in the torque converter bolts ( you don't want to wipe the cam lube off the cam rotating it before the start up ) I use a known good carb and ignition system to make sure it fires on the first hit of the starter . When it starts NEVER let it idle - keep oscillating the RPM's up and down - I immediately drive mine still not letting it idle , I bet I don't let mine idle for at least a month if not more and he says never just rev them up and hold it at a single rpm like " they " say to do . He installs pretty sizable solid lifter flat tappet cams ( Racer Brown Cams in my MOPARS because the grind cams for MOPARS not just Chevy profiles on blanks ) I haven't killed one " YET " lol knock on wood !
@@whiteboyfromernul He sets the valve lash with the intake off and keeps painting the cam with the cam lube , plus you go back and forth across the engine instead of one side at a time
Great video Sir. I've been looking thru all these videos concerning the Cam/Lifter issue as im in the process of replacing my worn cam on my 1968 Firebird 350. Is going Roller the way to go at this point not worrying too much about cost. Quite confused and frustrated how Quality Control has gone off the deep end with these Manufacturers. Good Stuff.
Excellent information! Some 20 years ago I rebuilt a 1946 Buick 320 straight eight, and a replaced a couple of lifters that looked scored, with aftermaket lifters form Bob's Automobilia which I think is a reliable source. The cam was reground and nitrided for hardness. Some years later, I discovered that those two aftermarket lifters were chewn off by the cam, while all originals were pristine. I assume EGGE is the only manufacturer of Buick STR-8 lifters. I have to assume they are soft.
A recent step I have begun to do is to pait a line on each pushrod just below the rocker.cut a window on the intake side so all push rods are visible, (v8). Upon start, verify push rods spin. As per Howards.
Hello Daniel, I just watched your cam hardness comparison video from around a year ago. Very cool piece of machinery you have there. As always I learn something from every one of your videos. I don't really understand how that machine works. I guess my question is does it leave a mark on the cam where you check it. But on another note I read through some of the comments and one guy claimed he had been a go fast gear head for 40 years and said there was nothing more he thought he could know until he watched your video. I don't know but I thought that was an arrogant statement and having said that people with that attitude are normally not the best customers to work for.love your videos and thank you so much for sharing your endless book of wisdom.
@@powellmachineinc Come to think of it concerning the Buick cam, I had one that was walking in and out of the block (this was identified by watching ignition timing) and investigation revealed it was assembled without a spring-loaded cam button under the timing cover. Lifters and lobes seem to be fine, still.
@@powellmachineinc The buicks have a cam thrust button. This engine was fresh and after installing the button, the ignition timing was rock-steady. I'm not sure about lobe taper but seems like the cam could walk if taper was insufficient or zero?
@This Is Your Captain Speaking definitely could walk if no taper was present, Where does the button go?, never seen a flat tappet cam with a thrust button.
Lifters lack the crown that is needed to keep them rotating after mating with the cam lobes. I had to replace 2 lifters that were brand new out the box and so did my dad.
just had a Jegs Cam lobe go flat on me, Proper oil and break-in procedure done, it's the second hydraulic flat tappet in 2 engines in a year that have done the same thing. I am currently installing a Howards retro fit roller, should have just spent the extra $$ in the beginning.
That Buick cam suggests to me that some people just grind cams without thinking about it. Perhaps a giant mass producer has employees who lack passion for building car parts? This would certainly explain why people would follow break in procedure, use high zinc oil, and still end up with flattened out lobes.
Yes you can clean them up with a peice of glass some 400 grit sand paper and some marvel mystery oil run the lifter across the sand paper poor a adequate amount of oil on it in figure 8 to get a cross hatch on the lifter and your good.
I am a first time viewer.....and the first vid knocked it right out the park! I am a novice engine builder and this vid had tons of info on the cam failure issue. I never knew what those casting numbers meant, now I cant wait to see what mine reveal. Can't wait to check the taper on some unused cams in the box too. I think I know where the CWC plant is in Michigan, don't remember how I found out though. I'll be watching.
thanks to this video now i know what those logo's means. my 1967-70 dodge OEM cam had theses logos and as far as i know its from st louse plant or installed at the dealership as a new car, my Chevy 1980's OEM 305/1995 350SBC have the same logo
The problem is that these cam and lifter outsourced their products and the people that they bought from to make orders didn't also outsourced their supplies from multiple areas and it all mixes together and wrecks the whole market and makes it untrustworthy! You might have a box of lifters with 15 good ones with the right lifter specs and you get 1 with out of spec and motor is junk in minutes! I will never run a flat tappet cam unless they guarantee it won't smoke my motor and they will never put their money where their mouth is!
Years ago in the early to mid 80s I replaced a lot of cams in trucks that were less than 150k miles. The cam lobes would be worn down as you show. I could find no reason for it and could not look on line or RU-vid back in the dark ages of no internet. I later found what I thought to be the answer. I learned that due to the advent of Catalytic converters Zinc was removed from the oil formulations due to it clogging the cats. I have some engines, mainly 4 cylinders in small British cars that have no cats on them. I use oil formulated for off road diesel tractors that has Zinc in it. I also have learned that there is a zinc additive available for oil. I dont put a lot of miles on my toy cars but I have not encountered any issues using a zinc oil.
I have built engines for last 26yrs and I have never had a flat tappet cam fail. I have always put cheap oil in engine crank it up with no water ran to head got warm. I done this 3 times the forth time engine is full of oil and I run engine at 2000 rpm for 25 min. I change oil to good oil I cut filter apart looking for metal. With engine at 2000 rpm the oil is splashing a lot of oil on the camshaft. I check lifter turn while building the engine, imo a lot of flat tappet camshaft failure is from not the proper break in .
UTC recently did a video about this issue with a possible cause of failure not the hardness but the shape of the lifter shape not accurately machined so the lifter would not rotate.
@@tachedtc search you tube “ getting to the bottom of the great cam and lifter fiasco” uncle Tony’s garage. I would give you the link gladly if I knew how.
Keep in mind that 80's Chevy cams were known to be extremely soft. I replaced dozens of them back in the day that failed at less than 100,000 miles, as did every other shop in business at that time. It was actually a very lucrative side hustle. We used to buy GM cars with a 305 and a flat cam on Friday night, replace the cam lifters and timing chain on Saturday, and often have them sold by monday.
I used to troubleshot GM cam lobe failures. It was almost always due to induction hardening failure as the Eddy current process failed from low coil power!
Daniel, CWC is in Muskegon, Michigan. CWC stands for Campbell, Watts and Cannon. I had some kid folks that worked there in the mid sixty. Enjoy your channel. Your integrity is greatly honored.
I was not aware of a thing called cam lobe taper till now.How many have noticed that when a lifter is dropped into its bore,it does not rest center to center of the cam lobe.There is an offset where a portion of the lifter hangs beyond the lobe.I always believed that this eccentric design was what caused the lifter and pushrod to rotate.This rotation also distributes spring load continuously on a different area as the lifter rotates.This lengthens the lifter’s life by preventing heat buildup caused by the cam lobe wiping continuously on the same area of the lifter.If your pushrod does not spin,the valve lash is not set properly or there’s a cam/ lifter problem.
@@powellmachineinc In years past I have investigated a noisy hydraulic lifter or lifters on my cars.This might be due to a rocker stud or a sloppy nut.upon pulling the valve covers,I have also observed pushrods that do not spin,like the others.However,upon loosening the rocker nut slightly,they,also,begin to rotate like the others.This is just a backyard mechanic’s observations.Hydraulics are basically zero lash lifters,be a relationship between how tight the rockers are and the lifter rotation.I have,however,never owned a solid lifter powered car,so they may be different.Anyhow,the slight taper across the lobe is an interesting fact that new to me.
Great video. I hear this from customers all the time myself. I'm glad you cleared that up. Unfortunately, most people won't listen. Great shop by the way. My videos only show my assembly area and not machine equipment. At this point I am outsourcing some of my stuff because of the overhead issue. I hope you can Keep making the great educational videos. All I build is gen-1 Chevys. They are abundant with everyone going LS. Have a Great Day sir. Buddy Langford. BLR Race Engine's.
I have a new Comp Cams flat tappet cam for my Ford 351M. Just a mild low RPM torque style. I've heard and read about break in horror stories. Now I'm hesitant to install it. The OEM cam still works fine and the lifters are quiet. I think I will stay stock and not push my luck.
At the school I went to we had a machine that spun the engine to check out pressure and well mark each push rod to check for it spinning if one didn't spin something was wrong and we sorted it out before starting it.
My second commet - so when anyone gets a new cam and lifter they should get the mic's out and check each and every lobe and lifter? I can see where a roller cam and lifters could be off also, but a different design so if they have a defect it may not show up for quite some time later? Do you agree?? Thanks for your videos!
I worry constantly about flattening a lobe on hydraulic flat tappets. I use Comp break in oil and a bottle of their break in lube. I use a drill and prime engine, rotate, prime, rotate, prime until oil is dripping off rocker tips. I break in for around 20 to 25 minutes with RPM up. I've not had issues yet. I talked to a Comp Cam tech on the phone probably 12 ish years ago. He said to run stock valve springs or remove center spring for 500 miles. So a stiffer spring is not good during break in. Does this seam like a sensible cause for early cam failure. I have just been running stock valve springs on my sbc's since they're just drivers and not race cars. I usually buy the Summit line of cams with their lifters. Not sure who they're made by.
Spent 27 years at a truck dealership built and repaired too many 5.9 cummins with flat tappets always assembled them with 105 luberplate and never had a come back cam issue i wonder why
Interesting. Since you are no longer dealing with the flat tappet stuff, are there any problems with the roller lifter needle bearings? What is your opinion of the Isky rollers with bushings? Thanks.
There used to be a cam company in the '70s and '80s guaranteed whether hydraulic or flat tablet it would fail boils down to spring tension when your breaking in the cam and making sure in the engine is timed so it fires right up proper breaking lube back in the day I used to use the GM additive oil wasn't like it was nowadays. PS when you learn how to work on VW engines timing valve adjustment it teaches you how to work on any engine especially how the Germans would adjust wheel bearings that is amazing.
my dad has been building engines since he was 14(hes 60 now) and NEVER had a cam go flat. 2020 we put a mellings cam kit in a 305, and in 5 minutes, almost every lobe was flat. used proper zddp levels, proper rpm, etc. the cam was labeled american after we looked, the lifters were not. made in mexico.
I recently had a premature wear on my cam. I found out that the cam is 63 HRC and my lifters are all above it, with an hardness average of 65. Shouldn't the lifters always be a little softer than the cam?
Normally roller cams are 60-63, rarely can you get harder than that, the wheel is Normally 52100 bearing steel, with harness roughly the same "harness ", but harness isn't the entire picture, it's just a snapshot, toughness is the key, alot of times it's lobe design, valvetrain instability and not enough hardness depth that can create these issues.
Excellent video and you seemed to debunk at least one myth/urban legend about cams and lifters being soft. So, it seems bad or nonexistent lobe taper along with lifter face taper may be the culprit? If so, that's a QC issue. Could be bad manufacturing processes or faulty equipment. One side note...i have always asked machine shops to do a light hone on the lifter bores of any engine block that I have had hot tanked. Might be overkill but, I worry about egg-shaped bores and core shift in old blocks. Not sure if it was always necessary but, couldn't hurt.
Built a bunch of small blocks over the years and cam swaps. Always wondered why the lobes had that half worn profile. Now I know why and it makes perfect sense knowing the tappet has to rotate to keep from creating a indent in the wear face. Just found your channel and very happy to know you're just 3hrs up the road from my place. All the best hot rod performance machinists are from the South! ;D
I’ve always understood it was because zinc being removed from engine oil due to environmental concerns. A zinc additive is recommended for break in and would be a good idea to use for one or two oil changes.
This is a great video with hard facts. Thank you! Please show us how to measure the taper you mentioned and how you achieve the taper on the cams you grind.
It's a shame here in Australia over the past 10 years three of our best cam shops have closed, it makes it difficult to get good machining done when machinists are going out of business. I might have to go to NZ to get some lifters ground and a cam custom ground.
Great video, thank you. Is there a way, to check/ measure/ verify the taper on the cam lobes, and the crown on the lifter, before installing them in the engine? I know by holding two lifters together, some of the crown can be seen, but that’s just a guess. If you were sent a new cam and lifters, could you check it and verify? As well as checking the hardness on both? Thanks.
Using a micrometer, measure the lobe on each edge. Should be .002”-.003” difference. That’s your taper. Use a precision straight edge on the lifter faces to check for crown.
I always hone my lifter bores with a flex hone and engine oil just enough to clean them up then clean the lifter bore and install a lifter and feel for to tight or to loose. If they are you need to find the problem. I wonder if you could blueing up the cam ramps and then the bottom of the lifters and just put the cam timing gear on and rotate the cam while putting pressure on the lifter to see if you get a good contact before you put everything together and get a flat cam and you no the work and money down the drain. I have done this with all my cams 20 plus years ago and only found one problem was a bad lifter bore at the bottom of the lifter bore. Never had a cam go bad on me. Would checking like this before you put eveything together and the cam go be a good thing to try. I always did just to be safe as other people had cams go flat back then also? Not as bad as today though.
What you have stated reinforces what I have seen over the years. The real culprit is the " I followed the proper break-in procedure", bet he didn't. Going out on a limb and saying poorly ground cams are the oddball not the norm. Back to that break-in procedure. Did you use a BREAK-In oil like driven that has the right amount of ZDDP and no detergent or friction modifiers? Buying Rotella and pouring in some zinc does not cut it. Did you make sure you had oil coming out of all push rods before starting? Did you use a known working carb? Did you use a known working ignition? Did you get the distributer stabbed right with proper initial timing for instant fire up? Was the cooling system sorted out? Did you have an exhaust system so that you could listen to the motor and catch issues before catastrophe strikes? In the old days all oil had ZDDP so you just bought the cheap non detergent oil and you were good. Not now. Will be giving you a call before my next project.
dude, ive not followed the break in procedure before, and been fine. i broke the cam in on my 400 mopar with a lunati cam, at idle and holding 1500 every now and then to slightly splash lube, not 2k for 20 minutes. cam is great.
also, ive never used break in oil, only valvoline 10-w30 with a bottle of stp oil treatment(i use sddp additive now, because its just insurance) and would not do the first turn start stuff.
Would like to see the operation of the hardness tester(never seen or used 1). The procedure/process for testing. Would expect the hardness of some of the cams to be a little higher as you must be getting some deflection due to the way they are supported. Does the testing leave a mark that has to be dressed?.
Nice job people must listen to you as you have proof. I don’t think checking worn lobes give the correct C#’s at least CWC told me and many others in our industry. Glad to know you know! MC
Excellent video. good info and the test results make the situation much more clear. Seems the issues are not to do with cam cores or materials, likewise with the lifters, The issues fall back onto the lobe grind angle and lifter crowns.
every cam I've bought in this last year have been engle. each has pits under the black nitrate. very rough pit like a rust pit . These pit are casting flaws and on the crown
I have put over seven different camshafts in my small Journal 327 in the last 20 years just trying different types I always use Rhoads lifters I never have any trouble
Regarding high rpm break in, that makes no sense, ever. The cam turns 300 rpm at 600 rpm idle. The lobes are actually pushing the lifters ~1/3 of that, duration of ~120°. So about 100 lifts per minute or 1.7 per second. You can blink or tap your finger thrice as fast, for perspective. This is trivial and breakin grease or even oil is plenty. When you raise the rpm 4 times idle like many recommend you have increased the velocity at which the lobe approaches the lifter and the speed that the lobe wipes accross the lifter thus increasing friction dramatically. Like starting a fire by twisting a stick on a piece of wood slowly vs very fast. And pump oil pressure at lifter bore and crank slinging takes a few seconds. Someone should make a test rig of an engine with cam, only 2 lifters and 2 valves and springs. Put a motor turning 300 rpm on the cam with NO lubricant and measure the temperature rise vs time. If the surfaces are hardened properly there should be no wear. Then raise the rpm to 1200. A drill or lathe tool with no lube experiences much higher pressures and dont dull unless the rpm is very high. Best of all, get a sixties GMC V6, the cam is IN a pool of oil at all times. As far as rings seating, use a bit of thin oil and low rpm. High rpm break-in makes no sense. The opposite, low rpm does make sense. No car factory ever breaks in an engine first start, not ever, for over 120 years. Start the engine, drive it to the parking lot, turn it off. How many engines have been stored for 1, 30, 70 years but start and run fine? Abandoned in a field? No lube at all, dry.
What can be done to an 89 Chevy Silverado with a 305 with 200k to get more performance without sacrificing reliability? Refresh ? Cam? Bore? It came stripped down with only A/C. No smog pumps. It looks basic.
I guess I better knock on wood I been building engines since 1970 and haven`t lost a lobe for 20 years. I turn just the cam and lifters with light oil by hand or a slow drill and watch to see the lifters turn, they`ll turn between 1/4 and 1/2 a turn every lift cycle, it they don`t I hone the bore till they do. On my competition flat tappet stuff I break them in with low pressure springs then change them, the circle track motors run 3 yrs usually. I try to stay with Bullet, comp and Johnson Hy-Lift. CWC is Cambell foundry isnt it?
50% proper break-in procedure the other 50% is proper lash adjustment, the other 69% is just plain dumbassery from Donald Duck and Wiley Coyote who ought to be bagging groceries instead of building an engine, seems like everyone with an engine failure wants to blame it on the parts, 99.999% of the time it's the assemblers fault. Thanks for sharing Danny we appreciate ya'll 💪
O.E.s switched to Roller for Good Reasons. Improved emissions, economy,&power were obvious. Astronomical Warrenty Costs for Flat Tappet Cam failure were also yuge issue Rollers solved. Save yourself a bunch of grief and wasted cash. Switch to Roller
Good work i have done dozens in my life and had 100percent success unitil last year i wiped one .thats one to many a comp cams item i now have. Gone to billet rollers .no taper on a flat tappet ment death to my cam and lifters therefore my race season also .won t happen again..
Nice Content! Not sure how old you are, but using mid 80's GM cams/lifters as the 'standard' isn't really best. GM had major issues with cam failures back then. I had a 1986 305 that ate a lobe at around 120k miles. Was very common.
I put a amc 360 together earlier this year using a bullet racing cam with.512 lift . I used lots of cam break in lube , Rotela t4 and Lucas break in zink additive. Used oem springs. Also I used 15 nos flat tappet lifters and sealed power China lifter. Pre filled carb and got the ignition timing advanced a little. Engine fired up quickly enough and I took the rpms up to 2000 rite away . Ram for 25 minutes with about 55 psi oil pressure. After the cam break In period in pulled the intake to inspect the lifters. I put the China lifter in the no.1 exhaust position to ensure I would know where it was. The 15 nos lifters broke in perfectly but the China lifter had 12:24 circular groves worn into the face and it was almost flat . I didn’t use the China lifter because I wanted to, but because that was what I could find. I would like to send you the picture of the lifters .
The only time i have had a flat tappet failure, was when it was something i did wrong. There is an elephant in the room though. That is the oil side of things. As I'm learning over the years and keeping up with technology, I'm learning from Lake Speed that the zinc additive you can buy for cam break in could be the cause. It is better to just buy the break in oil and skip the additive, as I have done for years and been wrong! Things are going way better since changed that process.
This thread is probably too far back in the lineup to get an answer . However , here's my question . We know by now , through your testing and opinions , along with several others , that the grind pattern and taper on both lifters and cams is why many combos are failing on break in or shortly after . The obvious answer is ' the guy that grinds the cam should also be the one who grinds the lifters . Then taper is correct and each part matches the other . Now I'm seeing ads that push the DLC coating . DLC is great stuff all by itself , but it does not address the incorrect taper / grind that caused the issue to begin with . I dislike using manufacturers names usually , but Comp Cams are the ones advertising the DLC coating . Have they adopted the process of grinding both cam and lifters correctly , then DLC coated the parts , or have they simply coated batch produced parts ....leaving the original problem unaddressed . We know DLC coatings are slicker than snot , but will the DLC contact patch impart the needed friction between parts to spin the lifters / pushrods , etc . Thanks for your time and experience .
On a 2021 5.3l V-8 Chevy Silverado I had a lifter failure at 3900 miles, bent the push rods on a couple of cylinders, the dealer replaced the all lifters and bent push rods, is there a chance the cam is damaged and the dealer did not do a complete repair?
