Hey all, I couldn't think of a group with more guys experienced in building old flat-tappet Olds V8s, so I'm pitching this here. I hope that's OK. I've got a motor here that was rebuilt, then sat around in storage for a bit. It was described as having a new RV cam, and an overall mild stock build. I thought I should pull the intake, lube things up, check the pushrods for rotation, etc. My question mostly regards the appearance of the camshaft. It has a less polished appearance than I expected for a new one. It looks worse in pictures than it does in person. The whole thing is kinda speckled, almost like it surface rusted. But, I can't say it was actually rusty, and it has no detectable texture to it when you feel it. It was also covered in cam paste that I suspect had moly. The bare, cast iron lifter valley doesn't show signs of corrosion, so I don't know why the cam would. Is this just the "raw" appearance of a cam that isn't broken in? I've only dealt with used stuff in the past. I'm terrified of the notion of wiping a cam, so I wanted to check with the experts. Also, some of the pushrods aren't rotating when I turn the motor over by hand. Is hand rotation not fast enough? Or do I need to get the lifters pumped up first before I expect the pushrods to spin? Again, I'm fairly worried about wiping a cam. I don't have a lot of extra time and money, so I want to get this right the first time.
Looks like all new flat tappet cams I have ever seen. I believe that speckled look is Parkerizing they coat the lobes with to help in the breaking process.
My experience and knowledge of RV cams is that they are less prone to wipe out as long as they are run in directly ftom start-up. The ramps are not as severe as a comp cam. Just be sure to give the lobes a nice coat of lube.
Yes, Parkerized as @greybeard360 said, the freckles on the cam are shallow spots caused by the process and they aid in oil retention which helps in break in.
Everything looks fresh in the valley . Did you put the red lube on the lifters ? It looks fine,,,,.,but,,it should be on the face of the lifters only ,,,not the body in the lifter bore . If it has sat for some time,,,the lifters can become stuck,,,and not spin . They will still move up and down,,,,just not rotate well,,,,,and cost a lobe or two . Only use motor oil on the lifter bodies,,,,,,extra good lube on the face . And yes,,,that is Parkerizing on the cam lobes ! Tommy
Also, my engine machine shop friend recommends adding a bottle of break-in lube with the oil. There are also break in specific oils on the market, but I personally have never used it. My go to oil is conventional 15W-40 Rotella and Red Line break in additive and haven't lost a cam in any of the 4 or so engines I've built in the last few years. Lynn
Thank you all for your valuable input, it's a huge relief! I wanted to believe the cam was fine since it didn't feel rough on my fingers, in the presence of the cam paste made me really doubt the possibility of it corroding in storage. But I'm certainly no expert on new camshafts, so I'm glad to have you guys weigh in. I do have a jug of SAE 30 Lucas break-in oil that's supposed to have 4000 ppm of ZDDP. I think I'll fill the sump and prime the oil pump and see if I can get the lifters and rods spinning like they should. That's pretty much the last thing that has me concerned.
What and all you're doing is very good but don't crank over the engine any more than necessary before the run in procedure. When you're ready to go ...... start the engine as quickly as possible and bring it up to ~2000 rpm, check the oil pressure and carb settings etc, and keep an eye on the temperature as you go along. Keep this RPM up for at least 20 minutes. If you don't mind a little oily mess during this operation you can quickly remove the valve covers to observe/confirm the pushrods rotations. I generally mark/stripe the top of the pushrods with a white paint marker beforehand, that makes it much easier to check their rotation. After finishing this run in procedure drop the oil and filter and replace it with a fresh batch of the same oil and a new filter. You can cut the filter open if you wish but it IS going to have some metal residue present. You're ready to go now, replace the oil and filter again after ~200 miles ..... always use an appropriate grade and style of oil for flat tappet camshafts, preferably with at least 1500 ppm ZDDT ...... I'm not a fan of adding the zinc concentrate to a regular oil. Good luck, I hope that it all goes well for you.
Since it has set for a long time, I would consider removing each lifter and disassembling it to make sure it isn't stuck or partially stuck and reinserting it in the same hole it came from. Put the moly lube on the lifter bottom and the cam lobe as you do this. Cam break in is a perilous time in the life of an engine. It only takes one lifter to stick and cause a problem.
Some lifters actually contain debris inside them from the manufacturer, and many builders clean and verify them before installation. Also, depending on how long the lifters have set and where they sat can allow some rust to occur. Given the precision of the matched components, it doesn't take much to impede proper operation. It's basically a matter of how much effort someone is willing to go thru to insure that they won't have a problem . Most people never clean their lifters before installation and many have good results.......but all it takes is one inadvertent grit from the manufacturers grinding machine in one lifter to wipe a lobe. The inside of a lifter body is the most precise interaction of components in an engine. So how long did the rebuilt engine sit around? Also, the lifters need to rotate as the cam turns. You mention your concerns about wiping a cam. None of us can tell you that you will not have a problem.....we can only suggest ways to minimize that chance. Most times when people ask this type question, what they really want is for everyone to tell them it won't be a problem. The truth is that you need to check and verify the things that you don't really know the real details about. Good luck with your project.
Funny you mention that, in all my searching I ended up reading about EDM lifters where they burn the hole in the bottom for oil feeding, then give a quick touch-up polishing. Apparently some places do that AFTER the lifter is assembled, and it leaves junk inside! After hearing about that, I think I'll just tear everything apart and be sure it's clean. From what I can estimate, 2-4 years inside a shop in a dry climate. Yep, that's why I was concerned. I marked all my pushrods, lubed the cylinders and cam, and rotated the engine over by hand a couple times. Some of the pushrods did not move from their original position. Yes, I've seen that many times before as well. They'll argue with every piece of advice. Myself, I came here to hear from the voices of experience. I'm only interested in the best long-term results for this engine, and this engine will be worked very hard, and the stakes for it are high (to me, anyway).
Lifters are not going to spin when turning by hand. Now, stop turning it over and get some cam lube back in there. You could pull one or two lifters apart and double check the innards but if they were new they will likely be clean. Any idea as to the brand of the lifters? Since this build is only a couple years old it is possible that some offshore parts could have been used.....less than ideal. You might consider replacing the unknown lifters with Top-Line Johnson and sleep easy.
Many times when an engine is rebuilt, the skill and the quality of the build are unknown. I posted a thread on here once called "Worst Merchanic Ever" and it showed just how poorly some people do things. I'm not suggesting your engine was done poorly, but even a well intentioned builder is often limited in the tools and experience he has available. They check things that they feel are necessary but often just assemble parts and figure they will work. Any disassembly/ressembly that you perform only costs you time, but very little money. It is also a learning experience that sticks with you on future builds. The lifters in the engine should be rotatable by hand when there is no pressure on them. Many times the varnish buildup in the lifter bores will prevent one or more from rotating. That leads to bad things like a wiped cam lobe. When cranking the engine with the starter, and the intake removed, you should be able to determine if they are rotating. You need to put a lube on the cam lobes and lifter faces that is specific to cams, NOT just the normal engine assembly lube that goes on the cams bearings. They are different. Also, I would verify the amount of lift your valve springs can accomodate before they coil bind and the pressure they provide. They are probably ok, but you may want some softer springs for break in... maybe the old springs if they will accomodate the lift of the new cam. That initial break in is the most critical time in the engines life...... You can rotate the cam to max lift so it's holding the valve open and use a feeler gage between the spring coils, but best if you can actually check them. Maybe the engine came with info on what springs were purchased. Thats a great attitude. You are entitled to disagree with any advice you get, but always consider whether you have a rational explanation of why you want to do something rather than just don't want to do it. Last I heard, Johnson had quit manufacturing flat tappet lifters several years ago. They are top quality lifters if you can find any. I bought their roller lifters for my roller cam conversion in my Cad engine.
Well the story goes, the engine was rebuilt in poor fashion. Then the owner took it to a well reputed performance shop to get it redone. They found and documented several issues, including poor valve conditions and loose crank bearings. They redid the bottom end and heads, including grinding the crank .010" under, replacing all the valves, replacing the cam/bearings/lifters etc. There is documentation for all this, so I feel pretty good about the quality of the 2nd rebuild. I'm not too worried about the springs being overly aggressive, as the shop documented it as a "stock spec" build.
73RR I disagree with the lifters not spinning in bore when the engine is turned over by hand. I always check to make sure lifters are spinning only takes a few revs of engine , I mark the top of the lifter with small dot, grease pencil will work. Knock on wood never had an issue with lifters not turning. If I had one not turning I would disassemble and determine the cause, several things can cause the lifter to not spin, too tight or too loose in the bore, incorrect radius on lifter face even an incorrect grind on the cam lobe. A few turns by hand will not damage the cam or lifter if it’s lubed correctly IMO. Dan
Ok, this sounds like it was done by someone who knew what they were doing. If you notice, when I give you my opinion, I try to explain why I think what I think. Then you can weigh it's plausability. It doesn't mean that someone else may have just as plausible of an explanation, but you get to hear what different people think and then you have to sort out what you think makes the most sense. Don't want to keep pointing out negatives here, only trying to provide you with food for thought and hopefully help you learn as well. The only question I have about your statement above is the designation of a "stock spec" build. That may apply to clearances on the bearings and most moving parts. It could also mean stock type pistons and rings and rocker arms and compression ratio as well. Where I'd be a little unsure of it's meaning is the valve springs, since it has a "new RV cam". Now RV cams are usually pretty mild and the additional lift on the lobes may not be an issue. At any rate I would want to be sure they were not the stock original springs. I would want to be sure that you use some new springs and that there is sufficient travel without bottoming/binding the coils when at full lift. Sometimes they can hit the top of the valve guide or guide seal. The valves can also hit the piston if travel is too much or springs are too soft for higher (5500/6000) rpm use. Again, this is the concern I would have if it were my engine. If you have no way to check a valve spring, send me a couple of them and I will check them and let you know what you have. All of this stuff is a learning process, and you arm yourself with knowledge by checking things. It's kinda like going to the doctor and he finds nothing wrong......so you feel like you wasted your time and money. But then, that's really what you hoped would happen when you stop to think about it.
Dan, Fair enough, we all have individual experiences. I rarely turn the rotating assembly enough after dialing in a cam to consider lifter spinning or not. Never had an issue. Gary
They should spin. I’ve done the same thing, mark the pushrod with a white marker, then rotate the engine by hand. Some spin very little, 1/16 of a full circle, others will spin close to a 1/3rd of a full circle. I’d be concerned if they didn’t at least a tiny bit.
Gentlemen what do you think is causing the cam and lifter failures we hear about lately? 30 , 40 years ago I don’t remember people having cam failures on new cams and lifters, I think everyone used the supplied cam lube, some guys did run in cams 20 - 30 minutes at 2000 rpm or a little higher, but I remember some slammed in cam, degreed, it finish assembly , and sometimes starting several times in the first half hour. What gives. Dan
I have seen the evidence and the testing of several cams and lifters both new and used. I am convinced that the single biggest reason for all the flat tappet cam failures in the not so distant past is due to horribly bad lifter face grinding (improper crown radius) or a lack of proper lobe taper or both. Improper surface finish and even the chamfers on lifters has been another issue. Even some of the top name lifters have been proven to be junk. Proper brake in procedures, good cam lube and good oil with 1200 ppm ZDDP are certainly important but it's not what has been killing all these cams. It's not a cam core, heat treat, or hardness issue either. All that was tested. It's poor grinding resulting in bad geometry between the lobes and lifters. Maybe a few could be from a poor spring choice but that's probably a very small percentage. Problem is, if you don't check these things. and there is a failure. you have no way to know what really happened and that's when all the speculation and finger pointing starts. The old days of relying on the manufactures to produce these parts properly is over. Fair warning, if your going to run a flat tappet these days, better get out the dial indicator check every lobe and every lifter.
OK, I'm going to put some info out here that I'm NOT SURE it's correct......but I'll tell you what my foggy brain keeps trying to recall. It's up to everyone to do their own factchecking here. The Topline Automotive site you provided has some excellent information and worth people taking the time to read it. When I bought my Johnson roller lifters for the Cad, I talked to someone at the manufacturer......I THINK it was the owner. He definitely told me that they had quit making flat tappet lifters. I had to wait about two months to get my lifters. I believe he said they no longer had the machinery for manufacturing the flat tappets because they had moved to a new location. I also vaguely think I remember being told that there were actually 2 companies manufacturing automotive lifters under similar names...the similarity being "Johnson" used in the company's names. I think the one that is the one respected by racers is : https://johnsonlifters.com/about-us/faq Doesn't mean that the other Johnson does/does not make quality lifters. What you are saying is exactly the same thing that the former (?) wizard at Comp Cams, Billy Godbolt stated in the book he wrote. The book is so far over my head and has such technical info that I can only figure the guy knows way more than I do about this stuff. This is a very good book and anyone purchasing it will learn a lot from it even if some of it is too in depth to wrap my 2 gray matter cells around. It will explain a lot of things that do help us. So first I will post his actual words rather than paraphrase them. This is the Book: Topline Johnson however appears to have a different opinion from Godbold about what causes cam failures. Here are a couple other pics from Godbolds book. Everyone can decide for themselves if this info is accurate or not........ So here are the things that I form my opinions from. The experts seem to have different explanations, and apparently there are 2 companies manufacturing lifters under the name of Johnson. If that isn't correct, my apologies............
^^^^^^WOW Maybe the best thing these days if you have a stock cam core that is good and stock lifters that are good is to regrind cam to a profile desired and have the lifters resurfaced Cost wise they will be the same or less than new. You will know the material is good and if using a reputable cam grinder you’ll know the geometry is correct. Problem solved? Dan
Looks and sounds like you’re good to go, get everything buttoned up and set and fire that bad boy up!!! If you haven’t noticed there are few engine and camshaft freaks on the HAMB. Lots of knowledge way beyond my level. Let everyone know how your engine turns out. Videos are great. Thanks for letting me participate. Dan
@ekimneirbo thank you for posting the additional technical resources here. Although I am certainly aware of who Billy Godbold is, I did not know about this book. Now that I do, I would like to get a copy and see what more I can learn from it. I can't say I'll be any better than you at understanding some of this stuff as it can get pretty deep. Much of what is written in pages you posted does seem to back up the independent testing I have seen. The overseas material quality issues have been a big problem in many industries for quite some time now. I saw it first hand while working for my previous employer. On a side note, there are some shops that will resurface lifters and there is probably still a demand for it but many are getting away from it. With the rise of Hydraulic Roller cams they have seen the writing on the wall and no longer want to spend the time or risk their reputations should something go wrong. Call me a Dinosaur, I don't care, I still want to run flat tappet cams and plan on doing so.
There is a fellow HAMBer who resurfaces lifters but I don’t remember who, I’ll have to look back at some of threads I’m sure I’m following him just don’t remember who I need to get a notebook and write down who does what. ekimneirbo has twice the storage space as me,maybe he knows who does lifters Dan
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