Well my new 280/288 was doing great UNTIL coming home from work today.

I started feeling a slight miss and the tale-tale lifter clacking, you're right, WIPED A LOBE AGAIN!!! graemlins/clonk.gif

NOW COMES THE GOOD PART!!!!

When inspecting the damage the lobe didn't seem to be in as bad a shape as the last failure, BUT, when I raised the lifter(CRANE antipump)to see if it would come out(it was stuck of course)I saw something on the bottom of the lifter!!! :eek: IT WAS THE SPRING OF THE LIFTER STICKING OUT THE BOTTOM OF IT!!!

BUT THAT'S NOT THE END OF THE STORY!!!

STUPID ME keeps fiddling with the lifter till the SPRING FEEL OUT AND DOWN INTO THE ENGINE!!!

And no, it was not the same lobe that wiped the last time!!! I don't fault the cam!!! I'm thinkin that's got to be a lifter issue!!!

A new Lunati 280/288 AND Lunati lifters have been ordered but it may be a while before I feel like even looking under the hood again. :rolleyes:

That sucks. Sorry to hear about it. I wiped a lobe of my last cam, started missing nasty.

if you keep wiping lobes, then there is obviously a problem, ethier in the initial fire up (Some call it a break-in)...or there is a problem with garbage in an oil gallery.

Problems happen becuase of something! they dont, just happen.

Well James, I've never had the mis-pleasure, but my good buddy who had the L88 before me did. Time to take it all down for a cleaning. Gun barrel brushes in the oil gallies type of cleaning. Deep cleaning. After hearing about the severity of the first one, and the motor wasn't torn down and cleaned, I figured you're luckier than my bud'. He lived through it,you will too! It sucked, but the motor ran for a HARD 35K afterwards. Until I redid it last year after I cracked a head the year before, a few weeks before CB02. Friggin' heads were R&R'd three times!

I feel for ya brother.

OK guys I've settled down a bit and need to review my valve spring choice to make sure I have springs that are correct for the 280/288. I thought they would be perfect for a wide range of cams when I had the heads built but now I'm doubting everything I do. My confidence is shot.

I am using Howards double springs pn 98443, 145# @ 1.88 seat, 325# @ 1.25 open coil bind @ 1.150. I am using Howards retainers and locks designated for those springs. Provided the machine shop set the height correctly would these be acceptable for the 280/288 or have I made an error? They work fine with the 276/286 but it only has a .515 lift.

Just in case I don't have to tear the engine down can the installed height be checked on the car? I know I can use air to hold the springs up to change them out but I'm going back to zero and rethink/check everything before I try this one more time.

This is killin me!

It ran so great with this cam till today!!!


EDIT!

You guys are right, I'll tear it down and do what has to be done>

Oh James! graemlins/sad.gif
I'm very sorry to hear about this.
What is it with these cam/lifters lately???
I just had a friend lose a lobe in his 355 SBC and the motor had over 12K miles on it. :rolleyes:
If you could foretell the future, looking back, a hyd. roller setup is a hellava lot cheaper than a teardown/rebuild. I've gone thru two cam failures over the years myself. Rollers from now on.
I think Rapid Robert has recently gone thru the same thing with his son's SB.
Those flat lifter things scare me...

why so much seat pressure? that might be a place to start. Your not breaking the cam in with both valve springs are you???? If so i bet theres your problem.

James, I have the same cam but am not running dual springs. Harold said 125-140 and 325-350.
Running Crane springs but I don't recall the P/N. Maybe Mr 4 sped has it. I got the info from him.

My son pulled his apart tonight,lobe was well worn,lifter concave big time. Does the lifter go bad and wear the cam or vice versa? seems to me that the lifter would go bad first,then the sharp edges from being wollered out would dig into the cam lobe????? All other lifters and lobes look fine. It was oiling fine when we pulled the valve cover off while it was still running. The end of the valve stems wear marks appear to be wearing dead center of the stem, as far as geometry goes. It makes a person almost afraid to put the motor back together after two times already. I didn't mean to steal your post James,just thought I contribute with what we found in my sons 355.

EDIT: Upon further review,I just went and checked the bottoms of all the lifters with a straight edge and half appear to be flat or showing wear,and the other half seem to be a little convex(rounded on the bottom) now what would cause the lifters to go bad on one side of the engine when they appear to be oiling fine? Last go around it was two lobes on the drivers side,this time it is one lobe on the drivers side,but a totally different lobe from the last time. Dang I'm :confused:

Maybe it's time for a roller cam, it'll be cheaper in the longrun. ;)

James,
Have you varified the installed height & spring pressures for yourself?
You need to check this & be sure it is where you think it is.
Also, when you remove the lifters that are a problem if they don't come out easy don't force them, rather take them out from the bottom so you do not damage the lifter bore.
It sure sounds like you have more spring pressure than you think, possibly to the point of coil bind.
After more than one cam in a short period of time I would recheck everything for yourself.
You can measure the installed height fairly easily.
I would suggest having the spring pressures varified by an independent shop if possible,, just to be sure.
145 on the seat is a little on the high side for a street hyd cam as it never gets a chance to get a "wedge" of oil like a solid but I don't feel it is a big concern as long as the spring rate is low enough that you don't get over 350 open.
I would prefer about 15-20 lbs less though.

Too bad you are so damn far away, I would be glad to check your spring set up for you for free but it would cost you a bit in fuel to get here :D

I feel you are right about it not being a cam problem. The cams have not changed but the lifters have.
Everyone is scrambling for lifters since the two major suppliers are gone & the only one left on shore I know of is Stanadyne. Far as I know everything else is coming from "other sources"
Hopefully someone will step in as this is an industry wide problem right now.
I also agree that you should pull the engine & clean everything including all oil gallerys & everywhere crap can accumulate, heads, valley, drain holes etc.
Lot of work but you have had a lot of crap go through the engine that need to be cleaned out :rolleyes:

..I guess those 2 sets of lifters that are 5 years old that I still have are gold right now :D

James,sorry to hear about this :(
Best of luck sorting it out

Originally posted by Wolfplace:
James,
Have you varified the installed height & spring pressures for yourself?
You need to check this & be sure it is where you think it is.
Also, when you remove the lifters that are a problem if they don't come out easy don't force them, rather take them out from the bottom so you do not damage the lifter bore.
It sure sounds like you have more spring pressure than you think, possibly to the point of coil bind.
After more than one cam in a short period of time I would recheck everything for yourself.
You can measure the installed height fairly easily.
I would suggest having the spring pressures varified by an independent shop if possible,, just to be sure.
Yep, I've been ignoring the spring pressure/installed height issue assuming the machine shop did there job but with the continuing problem I will start from scratch and call Lunati Monday and have springs and retainers sent along with the cam and lifters.

The thing that gets me though is the 276/286 ran for 5000mi trouble free, I changed to the 272/282 and wiped a lobe immediately. Put the 276/286 right back in and went about another 400mi till the 280/288 came and then after about 200mi it goes flat. I guess that the threshold for the problem is in the greater lift of the later cams.
Anyway, I will leave nothing to chance this time. And yes, I will drop the lifter out from the bottom! I'll be posting a picture of the bottomless lifter as soon as I get the engine torn down, hopefully early next week.

Originally posted by Big James 4XL:
145# @ 1.88 seat,

HOly Spring pressure batman!!

That sure sounds like a lift issue either coil bind, retainer to guide / seal clearance, rocker slot (stock type rockers) etc. as the pressure should not change that much between the two cams unless you are running out of room.
I know this is redundant but when you get the new parts make sure the installed height is what it is supposed to be for the spring & check everything listed ;)

And again, 145 is a bit high for a hyd on the street but not terrible as long as the rate doesn't get the nose pressure to high.

I run 150-170 seat on flat tappet circle track stuff all the time but keep the nose pressure down to about 375 & do not have problems but this is with solids which are a little different as they get a chance to get some oil between the cam & lifter when the valve is closed :D

James, That would be enough to make a preacher cuss. If you're using stock type rockers, be sure they're not bottoming out at max lift or at close. Some of my long slot intake rockers were bottoming out on the close side. One way to check is to stick a straightened paper clip up between the slot and stud at both max lift and at close.

Big James, Sorry to hear that :(
The hyd roller set ups are more $ no doubt, but you just start the car, let it idle while setting timing and making small adjustments and watching for leaks and the like.
Once the motor comes up to temp; shut off. Repeat once or twice more (after the motor cools to room temp) and you`re all done. smile.gif
No more hassles like that ever again.
Next go around you might want to look in to one, again ...sorry to hear about that :(

If you are going to run that high of a double sring I'd consider removing the inner as long as is still around 90 seat 250 open. After an hour breakin put the inners back in. A pain, but not as much as a flat cam.

I would run springs with less pressure. About 110-120 seat and 300 open.

I lost 1 cam once and it stinks bad. Made a real mess of the bottom end.

Originally posted by mr 4 speed:
..I guess those 2 sets of lifters that are 5 years old that I still have are gold right now :D

Man, my old used Cranes might be worth a dime if they can be reground.

No reason that a flat tappet won't work James, just needs to be in a clean, and properly spec'd environment.

James,
Email me if you're interested in participating in this "experiment"...
http://www.chevelles.com/cgi-bin/forum/ultimatebb.cgi?ubb=get_topic&f=9&t=015295#000004

Originally posted by BillsCamino:
James,
Email me if you're interested in participating in this "experiment"...
http://www.chevelles.com/cgi-bin/forum/ultimatebb.cgi?ubb=get_topic&f=9&t=015295#000004 You have mail!
I've got a bucket full of lifters to pick from!

What causes the lifter to quit spinning? Is it spring pressure? lack of oil? Anyone tried those Microlube lifters from Lunati?

I have at least 13,000 miles on my 280/288 cam. Lifters are crane fastbleed. Both wetn through a motor tear down (valve seat breach from over cutting). I use Harland roller rockers on top of it all. Not sure on spring pressures, they came recomended from the head assembly shop. They are crane springs though. One blue and one yellow I believe?

Sorry for the headaches James.

I broke a rocker stud once.
Does that count? ;)

Sorry to here of your pain.... hope you figure it out. here's one I did not see so far>>>>>

This may be a wild shot, but are you sure you don't have oil restrictors in the rear cam oil galley holes?

Well while you need to address the problem, you are going to need to pull the engine all the way down and replace all bearings at a minumum, all those finely ground metal particles did not get filtered in the filter, they are now embedded in your bearings. Keep running it and the repair will be far worse than just the bearings, Rob

IF IT IS THE SAME LOBE EVERY TIME IT COULD BE THE BLOCK.THE ANGLE OF THE LIFTER BORE CAN BE OFF,IN A STOCK MOTOR IT IS OK BECAUSE THE SPRING PRESSURE IS LOWER BUT PERFORMANCE CAMS NEED MORE PRESSURE THEN THE PROBLEM SHOWS UP.HAD THAT PROBLEM BEFORE I WORK AT A SPEED SHOP AND HAVE SEEN IT HAPPEN TWICE. graemlins/thumbsup.gif

COULD BE A BURR IN THE BORE. IF YOU PUT THE LIFERS IN THE MOTOR CRANK IT OVER WITH JUST THE LIFTERS IN (NO PUSHROD OR PRESSURE APPLIED)THE LIFTERS SHOULD GO UP AND DOWN WITH NO HELP.THE ONES THAT STAY UP NEED WORK ON THE BORE.I USE AN OLD LIFTER WITH THE FACE GRINDED TILL THE CHAMFER IS GONE (DEBURR THE SIDES)PUSH THE LIFTER THRUOGH THE BORE AND PULL IT OUT LOOK AT THE BURR YOU GOT ON THE FACE OF THE LIFTER.WIPE IT OFF AND GET THE NEXTONE THAT IS STICKING. graemlins/beers.gif