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Ate 2 cams on break in. Need advice.

12K views 39 replies 14 participants last post by  BOSS 429 
#1 · (Edited)
Hello. Have been around the forum but rarely post however I have a pretty bad situation and need advice. My buddy and I are building a 521 pump gas engine and we've ruined two cams on break in and Geezuz it sucks. I did do some research on here and we covered the usual culprits like wrong cam pin, cam bolt bottomed out etc and we even replaced the new timing gear with another one because we thought it looked maybe suspect. Second time we even went with a different cam manufacturer. Followed the prescribed break in procedure 2500rpms for 1/2 hour, used break in addative from the cam manufacturer. The only thing we didn't do either time was remove the inner valve springs during break in (everyone we know says it's not needed nobody does it) so I wonder if that is maybe the cause of our problem. Also double checked with both cam manufactures in regards to proper valve springs, push rods, lifters and spring pressure etc. First time around with the comp cams xe274 the engine lasted about 75mi then sheared the cam pin and ground up the cam bearings also messed the cam up on one lobe but not terrible. lifters were ok. Second time went with Lunati 10340703LK (227/233 at .050), puchased the lifter kit so we got everything correct for the this cam. Got harder cam bearings this time. Broke in the engine it ran great, for about 4mi. Haven't had it totally apart yet (my buddy who is the mechanic is understandably a bit burned out as am I) but the cam is chewed up on 2 or 3 lobes and a couple lifters were hard to get out. Also we noticed even though the cams came from different companies they're both sourced from the same blank supplier in I assume China somewhere and even from the same lot number or whatever ya call it so maybe the Chinese sent the U.S a bad batch of metal? who knows but we'll be talking to Lunati tomorrow. At this point any help would be appreciated. Thanks. (BTW I'm not very experience if you haven't guessed but I'll do the best I can to supply correct info etc).

What I got:
block D1ve-a2b
heads (72 police) D2oe-ab
probe stroker kit
compression is 9.75 to 1
comp cams roller rockers.
Hydrollic flat tappit cam.
 
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#2 ·
Which spring package do you have on your cylinder heads?

You say you didn't remove the inner spring. Are you referring to the flat wound damper spring or another spring inside the outer/damper or outer???

Spring installed height?

Seat and open spring pressure(s)???

Almost every flat tappet cam you'll find is ground on a CWC blank which is cast in Mexico. Only solid roller billets are made in the USA. :frown:


Oil type?



S
 
#3 · (Edited)
Until I get a hold of my buddy(he may also post under my name but he's not very familiar with online forums) who is the one who knows what he's talking about I can type in what's on my recipe(sp?) from comp cams, I hope it is what you need if not just let me know. The engine was originally going to be roller but we decided against that however both comp and lunati said the springs would work for my flat tappet.

I made a note while on the phone to comp cams: 112@1900 installed at the seat open 355 @ 1.200

924-16
valve springs, for 920-974
741-16
steel retainers, 1.550"
611-16
super valve locks, 11/32"
503-16
valve seals, 11/32" ptfe

Forgot about the spring removal question, i'm not sure, i'll have to ask.

Also we used castrol 10-30 the first time and 10-40 the second.

thanks.
 
#5 · (Edited)
my 521 ate 2 lunati cams on an engine stand. the first one ran thru 5 gallons of 110 octane before going flat. i thought it was probably something that i did. researched a429 heads about valve clipping, checked timing chain runout and clearanced the cam retainer plate, took the brand new heads back to the machine shop and had him check the heads for spring pressures and coil bind. 125/325 spring pressures and was assured were okay and no valve kssing was evident. he told me that i did not need to remove the inner springs. he said in his experience with spring pressures that low it was not necessary to remove the inner springs. i put the motor together did it again paying special attention to drag on the lifter bores. flat again after a half an hour or so. by now i am depressed and beginning to doubt my skills. took the engine back apart to the shortblock again on the engine stand , ordered a cam research cam broken in on the fixture, took the heads back to the machine shop and had him look at them again and told him to remove the inner springs. greased the cam up again with the correct cam lube being even more careful than before. I followed the cam company's recomendation for using VR1 oil and breakin lube additive and it solved the problem. it is a PIA to reinstall the springs but I am glad I removed them. i don't know if i could have got away with breakin with the inner springs in utilizing the cam broke in on the machine or not but i wasn't going to take the chance again. i ran the cam in on the run stand for several hours felt confident the engine was good , reinstalled the inner springs, ran in the motor again for 30 minutes or so and reinstalled in the 65 f100 sb. i have several hundred miles on it now. no leaks no noises and runs like a booh. I would never install a flat tappet cam again without putting light break in springs on the heads or removal of the inner springs even on a break-in stand and i could not imagine the work to install a motor into a vehicle multiple times to change a cam out.



jim
 
#6 ·
Thanks everyone for the replies coming in we really do need the information and hopefully will get some more things to think about.
Fomocoloco I can't say that it is good to here someone has had the same misfortune we have but it is good to hear maybe we've figured out what's going on and someone has been there before, it sounds exactly like what happened to us. Thanks. Yes my friend who's doing the work has been a really stand up guy though the whole thing. Wish I could help more but I'm really just a wrench fetcher.
 
#10 ·
You definitely need to find out what the installed height of the springs are and spring pressure as has been mentioned.

I once destroyed an Edelbrock Performer RPM cam & lifters when breaking in a new cam/engine.

On the second time around I had the inner springs off & used a bottle of comp cams break in juice. Everything went fine from then on. But I like Scotty's idea better of using break in specific oil and not just a bottle of the break in juice.

Taking off the inner springs to break in the cam is a TOTAL PAIN IN THE A** if the motor is in the car.

Putting them back on with the motor in the car is an even bigger P.I.T.A.

...but the biggest P.I.T.A. is having to buy yet another cam & going back through the motor to get all the metal out....again.


With that being said I didn't see where you mentioned disassembling the motor and cleaning everything out to get the metal out. If you didn't do this the first time and you have now destroyed two cams you could also have bearing damage from metal getting blown through your oiling system. We know you now have to do this a third time. Don't make yourself have to rebuild the motor after you get it back together again by trying without cleaning out the metal. Get the motor out, get it apart and get the block tanked to get all of the metal out of it. Inspect the bearings and all of the rest of the parts for damage and get it back together. Don't take any more short cuts or the fourth time is just around the corner. The people who told you to break in the cam with 355#'s of open spring pressure on a hydraulic flat tappet cam with all the valve springs installed were wrong.

Sorry this happened to you but i have been there myself. It just sucks.
 
#11 ·
Talked with my builder he tells me the installed spring height is 1.860 it was set at the machine shop and my builder also checked them himself. He also checked to make sure the lifters were turning properly, oil pump was oiling and circulating etc. He is also planning on complete disasembly and taking it to the shop to get it dunked because he wants all that metal out of there as you've mentioned, we didnt do that the first time because there was very little actual cam damage just the soft babbit cam bearings.
Also we'll remove the inner spring and follow the proper P.I.T.A. break in procedure along with getting good brake in fluid.

I'll call lunati and ask about the 355 open spring pressure. Don't know why they would tel us that but I'll check. Any idea what it should be?

Yeah you're right it does really suck.

Thanks Madporter and MrSharfenberger.
 
#12 ·
Lunati should have recommended spring pressures for your cam. They will also sell valve springs for that cam with recommended installed height. If your current springs aren't close and you need new valve springs you could get those. The Mad Porter may be able to fix you up with valve springs cheaper than the Lunati ones that will be of the same spec. Just do the research. You are making progress despite the frustration.
 
#13 ·
Hey since you said you were a bit of a novice with this stuff did you know you can get a new cam that is pre-broken in? In my opinion that would be the way to go here. Yes it is extra money but it saves the total P.I.T.A. work to remove inner valve springs and then putting them back on once the break in is done. Especially if the motor is in the car.

I also think you ought to give The Mad Porter a call before you buy an "off the shelf", "one size fits all" cam. Depending on what you want to do with this vehicle he could spec out a cam for you that will give you more bang for your buck. I know I'll never buy an off the shelf cam again. The custom grind cams are the way to go. Especially if you are trying to make power and not just get from point A to B.
 
#23 ·
Nice to know




I just stumbled on this thread and decided to give it a read while I'm staying in and staying warm today. I'm considering transplanting a 460 into my '78 T-Bird in place of the 351m that is in there. The cam gear that drives the distributor wore down to the point it lets it jump time. Of course it cost me about $200-$300 to figure out what the problem was, naturally. The 351m was a pretty good engine though so I was also considering putting in a recreational cam at some point so we could put that engine and transmission into my son's '78 Diamond Jubilee. I was a bit worried about the break in but hearing you can buy a cam that's already broken in is great news.
 
#14 ·
I still have never taken the inner out,and never hurt a cam, going to test run a new engine,new cam in a week or so. You just have to check stuff, lube, good oil etc. i understand why you guys do it., i just dont,never have

feel bad for the op, sucks
 
#16 ·
924 comp springs are fine for the application even if installed at 1.860" but you have to remove the inner. This explains a lot when placed in context with std lifters and SF oil and break in additive.

Remove engine, clean, replace parts as needed and break in properly.



S
 
#17 ·
At 1.860 installed, I'm calculating 126# on the seat, and 322# over the nose. A bit on the high side for a hyd flat, but certainly livable. I'd definitely be removing the inner springs at those pressures though.

I've used a few dedicated break-in oils, and actually experienced some problems with them, so I went back to Valvoline VR-1 20w/50 and a bottle of Lunati's break-in additive (have also used Amsoil break-in additive too). Haven't ever had a single issue with that combination.
 
#19 · (Edited)
Thanks everyone for the advice it's much appreciated. Also talked with Lunati tech dept today to get their input and they reiterated a lot of what you have all said.

We're going to.
Tear the engine down, check everything and send it back to the shop for a bath.
Double checked the valve spring specs with Lunati.
Obviously now we're gonna remove the inner spring at break in.
Get 5qrts of break in oil and skip the "red glop" just to be safe and get some good break in grease.
1/2hr at 2500 rpms at break in.

Wanted to ask do you guys/gals run any additives like zinc etc after initial break in? I assume this is a long discussion for a new thread but wondered what to do after we break it in (for the 3rd time ugh). I'm a bit paranoid at this time.

It will be awhile but when done I'll post an update.

Thanks again.
 
#20 ·
Thanks everyone for the advice it's much appreciated. Talked with Lunati tech dept today and they reiterated a lot of what you have all said.

We're going to.
Tear the engine down, check everything and send it back to the shop for a bath.
Double checked the valve spring specs with Lunati.
Obviously now we're gonna remove the inner spring at break in.
Get 5qrts of break in oil and skip the "red glop" just to be safe and get some good break in grease.
1/2hr at 2500 rpms at break in.

Wanted to ask do you guys/gals run any additives like zinc etc after initial break in? I assume this is a long discussion for a new thread but wondered what to do after we break it in (for the 3rd time ugh). I'm a bit paranoid at this time.

It will be awhile but when done I'll post an update.

Thanks again.

after lubing the cam good on install,all i run is BRAD PENN oil
 
#21 ·
All flat tappet cams have to have a high ZDDP oil after break in.
We use Driven by Joe Gibbs exclusively. BR for break in and HR for regular duty as well as the assembly grease for cam lobes, lifter crown and cam / distributor gears.
Personally I switch to synthetic after a couple of oil changes.

There are many good hot rod type flat tappet cam oils to choose from
Brad Penn
Royal purple
Amsoil
Valvoline VR race oil in the grey container

There are others as well.


S
 
#22 ·
You also want to avoid excessive cranking on start up. If possible use a known good carb and make sure the bowls are full before you start cranking.
 
#24 · (Edited)
I got a custom hydraulic cam kit from Scotty, sent it and the lifters off to Cam Research and had them break it in on their machine (probably not necessary, but good insurance for $65 I thought. The lifters come back marked so you know which lobe they go to), then used the assembly lube Scott sent with the cam. Removed inner springs and ran between 2k-3.5k rpm varying for 15 minutes. Reinstalled inner springs and changed oil. Ran that oil change for 300 miles, then changed again and after that I'm on my normal schedule of 1500-2000 mile between changes I use on my hi performance stuff. I use Rotella with Lucas Zinc additive on break in and every oil change. This all seems like overkill, probably, but the alternative sucks much worse, as you've discovered.....

Lucas
 
#26 ·
I went thru a lot of the same things several years ago and the only thing I can think of that has not been mentioned is to double check your clearance between the retainer and valve seal as the guide often need trimmed for enough room with larger than stock cams. I doubt it is the problem but it sure could be..
 
#28 ·
Well it's been a while and not sure if anyone remembers my predicament but I wanted to update my post and thank everyone for helping me out! Long story short I took the advice offered, used dedicated break-in oil (not modern oil with additive) and my mechanic also removed the inner valve springs at break-in and the 521 runs great! I still have to figure out a lot of things like what gear ratio and what tires I want etc but the main thing is she's back on the road and runs great even with the stock 2.80 gears (which was one of my goals= mainly built for the highway).

Thanks again everyone.
Scott.
 
#35 ·
There is a lot of discussion about the increase in lifter failure over the past couple of decades. One of the forums had a link to an article (can't find it now, but i'll link to it if I can find it) that explained why so may cams/lifters are failing - it is because the majority of flat tappet lifters are now manufactured off-shore (i.e. China, Mexico) and they are a lower quality then what was previously available (in the 60s, 70s, and 80s) - which results in the higher number of failures. When the auto manufactures switched from flat tappet to roller and overhead cams, the US manufactures of flat tappets saw a large drop in demand for flat tappet production so most/many stopped production. The remaining demand (such as for our old engines) could not support the cost of US manufacturing plants/lines staying open. With only a few overseas producers now supplying the US market many of the suppliers have no choice but to buy these inferior lifters and providing with their cam packages.

That seems like a reasonable explanation.

One solution is to use a roller cam (either hydraulic for street or solid for racing) and not worry about the quality issues and break-in problems.
 
#37 ·
I have no idea how many flat tappet cams i have installed in the last ten years, but 5 this year( others were all roller) ,and no idea how many sense i was 14 when i did my first one, still NEVER A FAIL , I HAVE at least 4 more to do before aug.




OIL, how its broke in / installed ,and HOW the valves were set. im sure is the main problem.

I have seen a lot of solid roller cams die also.
 
#39 ·
Old thread, but would like to add some things for future readers:

Do all mock up/ geometry/ push rod length measuring with LIGHT springs as in: can collapse to coil bind with your hand.(generic hardware store springs)

Get everything correct before installing the actual break in springs(inner removed or light rate), rockers and then rotate the engine to set lash or preload.

This way, the cam only gets ONE ROTATION with any amount of spring pressure to help keep the cam lube in place. Use the firing order....90* rotation on the crank will put the cam lobes in the same/correct position for adjustment on the next cylinder in the firing order.

Also, notch the starter hole in the mid plate so more than one torque converter nut can be installed at a time, limiting more engine rotations.

As stated in previous posts, be sure your dizzy has spark and properly timed, and a known good carb is full of gas. I like an electric pump...can be sure the carb will not flood etc before firing the engine, and of course make sure the accelerator pump is working.

30 years of intermittent engine building, haven't lost a cam....more racy spring pressures in the last few years.

ARP ultra moly lube on the lobes and lifter crowns, Brad Penn green oil in the pan,(dumped after cam break in) VR1 conventional the rest of way.

454 bbc(hard on cams) with healthy springs, no issues
440 mopar with 300+ over the nose, no issues
351w twin turbo mild springs in the shop now with JG driven lube on cam and lifters and Brad Penn in the pan, no worries.

On a side note, have always been a BBF fan and only do Fords in my shop now. Done some turbo and nitrous 460's, ya just can't beat em! >:)
 
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