I have a long thread about installing rebuilt heads and cam/lifters in my 68 350. But i wanted to start this thread separately to get advice on what to do next and if my motor is done and needs full tear down to clean it out. My install went great, did everything I thought was right and broke in the cam and lifters as recommended. It wasnt running quite right after a few test runs. found one lobe was lifting less than all the others so Pulled the cam and lifters and found one lobe is definitely worn. My question is, is the whole motor done for and needs to be completely tore down and rebuilt to make sure its clean of metallic particles? Or can a new cam be installed and ran again? The car was running good prior and ready to enjoy this summer with my kid as before. I just had some heads built I wanted to install and did a cam while at it. Did my summer cruising just get real boring? Didnt expect this at all. What next? clean it and install a new cam? Or pull the motor... Matt Sent from my LG-H811 using Tapatalk
What was your break in procedure? Did you use a break in additive? Do you have double springs installed by chance?
They are TA stage 1 springs. Has an inner damper but spring pressure is something like 280# and was told its not necessary to remove. Maybe should've? I used a tube of joe gibbs assembly lube and coated the cam lobes and lifter base generously. Also used Gibbs breakin oil. BR30 I believe. Primed oil pump until flowed from rockershafts, Cranked about 3 turns and fired up, held at 2000-2200 and ran for 20min. Sent from my LG-H811 using Tapatalk
Did all the lifters spin easily in the bore?, check the one on the bad lobe, ID be willing to bet it doesn't spin as well as the others
I never did really look for ease of spin. They moved freely up and out though when removed. I have a pic of the lifter butt. Its not a smooth swirl like all the others.. Sent from my LG-H811 using Tapatalk
One thing I always do on breakins is never let it stay at one rpm, ,2k minimum, but I myself never let it stay at a given rpm for more than 1maybe 2mins, run it up to 3500 even 4k occasionally once water temp and oil temp is up, this helps to spin the lifters at different speeds, but obviously we're past that now so to answer your question, I would drain oil of course, pour some cheap thin oil down thru lifter valley, and on heads. Then reassemble, if damage was done to bearings then what do have to loose? If anything it will be a good opportunity to break in the new cam on a questionable bottom end, can't hurt it and if it does start to lose oil psi or whatever it won't be immediately. Engines are tougher than people think. I've pulled apart strong running 455s and 350s with copper showing on half the bearings and they were doing just dandy. I say put it back together and try again, I run plain ole ND 30wt with a tube of Lucas break-in additive myself, but the break-in oils certainly are nice to have. Just drain the first belly out a few mins after it reaches operating temp , then put another belly in and finish break-in, then go to either another belly of whatever oil you wanna run and drain after 50to100miles, that procedure should flush most the contamination out
Great reply thank you! Thats kinda where my mind was at, ive driven this car since 95, if this doesnt go well and things go south how bad can it really be?! It will just mean i enjoyed it for many years and time to build a new motor the way i want! When you said run it and drain after it warms up to op temp, you mean during break in? Just shut it down and drain, refill and continue? Or after break in, get it warm and change oil Sent from my LG-H811 using Tapatalk
Yea stop during break in and drain oil you want to run the oil long enough to get hot and thin so it can grab as much contamination as possible and take it to the pan, drain it while it's hot then refill and complete breakin
And to clarify I'm not saying hold rpm at 3500 or more , just pop the throttle and occasionally ease into it to 3500 or so and then back down
Ok makes sense. Thanks! Honestly i wanted to hear an answer like this. I didnt know the procedure when something like this happens and didnt want to hear the motor needs to be disassembled. I didnt want to go buy another cam only to have everyone tell me NO you WILL ruin it. At least it seams there's a chance it will be fine and I'll go for it. Keeping minimum 2k and occasionally higher blips Sent from my LG-H811 using Tapatalk
i myself wouldnt, its for sure gonna have metal in it so no need in having to visulize it and get depressed ha, just replace it each time you drain oil obviously, its either gonna eat itself or live forever
Usually when you install a new cam, you start with fresh lifters as well .. in this case he may be able to just replace that one. I'll leave the experts to comment
Just another opinion here. I have never changed the oil during a break in, or during a dyno session. In fact,I tell local customers, to run the break in oil 500 miles before changing it. This was a recommendation from Joe Gibbs racing. I have to drain the engines out to ship them, and that is a shame to waste that oil.. Because: I have had the occasion to take brand new flat tappet engines apart right after the dyno session, for one reason or another.. sometimes just to check them again, when I came across one that was sent to me with a weird bearing failure or something. Engines that make it thru the break in successfully have zero material in the oil, or in the oil pan. There will be very little in the filter. I file this under the "personal preference" tab... some folks swear by it, others have built hundreds of engines and never done this, never had an issue. Therefore it is my opinion that not changing the oil during a break in was not a factor in your failure. I know your looking for an easy answer, but this is not it. Also, I don't agree with the idea that we just plunk a new cam/lifters in and go, assuming that all the damage has been done. Fine particulate material will pass thru the filter, and this is exactly the stuff that sticks hydraulic lifters, loose metal particles in the pan will splash up in the oil and score every round bore in the engine. It's nearly impossible to remove that stuff from the pan, without removing the pan, and washing it. My preference would be that you need to take that engine apart completely, wash and inspect it and re-assemble with a brand new cam and lifter set. At the very minimum you have to take the oil pan off and wash it out. The Lifter on the left in your picture was not spinning, I assume that came off the lobe that failed. Hugger is correct to say that the failure of the lifter to spin properly is a factor in this failure. I have seen this many times, and it's not always going to take a lobe out, but it is a factor. Dirt and/or other foreign material between the lifter body and the bore are the number one reason for the lifter not spinning, followed closely by having a peened over edge on the lifter bores, due to a clean up process using hard materials to clean the cast iron, via blasting or vibrating. To help prevent this in the future, take these steps: Dis-assemble the engine, inspect all areas for wear and damage due to the cam failure. Replace bearings/rings as required. Ground cast iron often gets in the oil and splash throws the contamination back on the cylinder walls and embeds the material in the rings. Wash, wash wash... it simply cannot be clean enough. Immerse the engine completely in a hot water rinse.. a 30 Gallon or bigger garbage can works good for this, and it helps "float out" debris. Nitride harden your new flat tappet cam.. I don't always do this on new motors, because I don't have a history of camshaft failures.. but if I did, that is exactly what I would do. This process is available thru most cam manufacturers as an extra cost option. It's just a little insurance against the unknown. Use the cam manufacturer's specified lube on the lobes, and degree the cam, on just one lobe set, before you slather up the cam lobes. Once the cam and lifters are installed, turn the engine over as little as possible. For those of you familiar with stamped steel rocker 455's, you will recall that after you bolt a rocker shaft on, as you turn the motor over the rockers will "snap" into place as they come off the lobe that they were on when you tightened the shafts. I turn that motor over so little during building, we often here that "snap" as we are spinning it on the dyno during the procedure we use to set the timing before startup. Insure all the lifters slide in the bores, and turn easily by hand. Lubricate the outside of the lifters with engine oil only. STOP SPINNING THE OIL PUMP WITH A DRILL UNTIL OIL COMES OUT THE ROCKERS!!!!!!!!!!! I understand why folks do this, but trust me, the upper end will oil, if it has the correct parts in it. Your valvetrain should be pre-lubed when assembled, and that lube will last plenty of time, certainly long enough for the engine to lube the upper end. When I start a new motor on the dyno, I do two things to every one.. Check the timing, and removed the oil cap or breather on the LH valve cover and look in the hole, to insure that I see a trail of oil going back to the head drain. Typically, you can see this in less than a minute after it starts. And the LH bank is the last to get oiled. You must pre-lube a new engine, but the only reason to do this is to insure that the oil pump will suck oil up the pickup tube, fill the filter, and pressurize the system. Once the drill slows down, count to 5 and stop. Your done. While your doing this, look for massive leaks externally.. after the drill stops, listen for air bubbles.. If you have neither, your good to go. All you accomplish by over-prelubing the engine is washing off the assembly pre-lubrication that the engine should have been built with, and if your using the correct pre-lubes, they provide much more protection than oil. Excessive pre-lubrication, excessive rotation of the engine after it was built, are factors in your failure.. I know this is not what you want to hear, but the only thing worse than having to do an engine again, is having to do it 3 times. JW
You're right, i didnt want to hear it I just spent a lot of money on a rebuilt carb and of course one of your nice converters that i wont get to use for awhile now. Dangit Thanks for the reply Jim. I was hoping it wouldnt come to this because I have zero motor tear down experience, dont have the equipment to yank the motor. And most of all pretty sure i wont have enough money for parts and machine shop work. So basically if I do it right, my car is done for the summer. Crap. Sent from my LG-H811 using Tapatalk
but this is an older maybe original shortblock correct,? thats the way i understood it, if so whats to loose? it was passing all that material around while it was running so damage is done already, cant hurt it worse imo, like i said you got a 50/50 chance of it living or dieing , ? is do want to gamble or just pull it and start over. its not a big money shortblock so who knows you may get lucky jmo tho. but obviously the "best" thing would be to tear it down and clean it but once you pull it stuff snowballs i promise you, just keep that in mind. that being said Jims suggestion is the best and technically correct approach.
Yes its the original block. I purchased it from the original owner in 95. I know tearing it down would be the right thing to do but i just dont think its practical for me, as much as I want it to be. No way I could afford it from start to finish. Only other option would be to find a cheaper used running engine and drop it in. Then take the rest of the year and next to slowly re build mine as money allows. Its a real bummer because we drive this car ever summer. Hate to see it park for so long. Sent from my LG-H811 using Tapatalk
