: BOTTOMLESS!!!
Big James 4XL Feb 23rd, 04, 8:20 PM Not the kind of pictures I like to take but, :mad:
Bottomless lifter 1 (http://www.chevelles.com/showroom/bottomless1temp.JPG)
Bottomless lifter 2 (http://www.chevelles.com/showroom/bottomless2temp.JPG)
And yes, you're right, a complete engine teardown is needed and is presently underway. That's presently, not pleasantly! graemlins/clonk.gif
travis g Feb 23rd, 04, 8:31 PM Man, I feel your pain. My less than 200 mile 388 is in pieces outside. It started smoking badly and was getting worse every day...found every 2nd ring butted and the bores had all kinds of taper in them. Bummer.
BB_Mike Feb 23rd, 04, 9:20 PM It's like the sesame street song.... "One of these lifters is not like the others. One of these lifters does not belong."
:(
I hope you find all of the little pieces. graemlins/sad.gif
SSuper Dave Feb 23rd, 04, 9:22 PM Mike, you been gettin' your drank on again :D
ddeennis Feb 23rd, 04, 10:20 PM wondering how someone can let a lifter go on that long with out knowing something is wrong........ did the ticking noise/clacking of the rocker arm not give away any hint that a lifter was in trouble.......i dont know about the rest of you but i kinda think someone was ignoring a problem..........and kept running the motor.................did i hit a nerve yet..............
baddbob71 Feb 23rd, 04, 10:53 PM ouch, I hope you get the problem figured out.
427L88 Feb 23rd, 04, 11:00 PM Holy Cow! That's nasty. :eek: I like the other kind of bottomless better. tongue.gif
This rat isn't making it easy on you but third times a charm.
Big James 4XL Feb 23rd, 04, 11:13 PM Originally posted by ddeennis:
wondering how someone can let a lifter go on that long with out knowing something is wrong........ did the ticking noise/clacking of the rocker arm not give away any hint that a lifter was in trouble.......i dont know about the rest of you but i kinda think someone was ignoring a problem..........and kept running the motor.................did i hit a nerve yet.............. NEWS FLASH!!!
After a 20 min cam break in, about 20 miles interstate driving and a few hard pulls to see that everything was in order(Best the car has run to date BTW), a lifter adjustment for good measure(with no irregularities noted), drove to work, 6 miles round trip, on the way home the clacking/miss started!!!
So I'm not going to let that ride!!! I monitor my engine as much as anybody if not more!!!!
This aint my first rodeo pal!!!
Yes, I'm having problems, but it's not from being inattentive!!! A bad decision on valve springs maybe, but not disregard for the signs of imminent danger!!!
My reason for showing the pictures is so others can share my grief/frustration/amazement that such a failure happened at all, not to mention how quickly the lobe/lifter went away.
I have never seen the bottom of a lifter gone even on cars with a flat cam at high milage, have you? Don't you think this is a bit out of the ordinary?
There's 15 other lifters that came out of the engine without a scratch, can you explain that?
I'm listening! Solve the problem for me! Be helpful! Or keep your wise remarks to yourself!!!
ddeennis Feb 23rd, 04, 11:50 PM gee i must of hit a nerve........lol....must of drove that sucker for miles to wear it off that fast. going down the road listening to the clacking noise.........that is alot of material just to wear off in a few miles........just think how long it would take you to gring that sucker down on your bench grinder.........to get it that way.........well i guess we all can agree that sucker wasnt spinning in its hole.............and if you pay attention to that detail this might not have happen...........i dont know how many times i can say this...... once the cam is broken in why not look to make sure push rods and lifters are rotating in the motor while it is running........and you can see what lifters seem to run slower or not at all..........every motor i rebuild and run i check to make sure lifters rotate about the same speed as the next. and if i have a slow turning lifter out it comes. i have even pulled lifters that wasnt even turning and put a new one in to save the cam(this was before i was checking the convexed bottoms).........it is easy as that............if the parts dont rotate how can you expect them to live.
make sure none of the lifters have pits or any other odd look on the base of them(if they do dont use them..........butt the bottoms together and check to make sure they are convexed.............damn i have ran across some that was damn near flat........do you think they will spin.
it all about taking the time to inspect your parts make sure they spin freely in the lifter bores and make sure they spin while the engine is running...............
there is no reason for cam failures i have yet to have one in the last 13 years and you can figure i broke in about 52 cams in this time since i build about 4 engines a year for myself and racing buddy's and there friends..........and yes some of them had triple spring set ups and dual springs. but all is the same......
and if you have checked everything just after break in and all looks good and everything is spinning about the same speeds for lifters and about the same speed for push rods(they spin slower then the lifter) then you know your good to go. if cam fails from here on out then i would be almost positive it is oil related problem..............
my guess is this lifter was a slow mover to start with. it might have been almost flat on the bottom to start with. it may have spun alittle during your break in and driving and then it finally stopped because it picked up a little burr from its lack of spinning fast enough to the relation of the cam. and here came the fast wear.........and you had nothing but spring pressure pushing that sucker right into a lobe............like meat thru a meat grinder.............
BillsCamino Feb 24th, 04, 12:16 AM Whatever...you're preachin' to the choir, dude. The man knows what he's doing. :rolleyes:
James,
OUCH!! :mad:
No sense testing that one. Guaranteed it got hot enough to anneal the heat treat.
Tom Mobley Feb 24th, 04, 1:55 AM James,
WOW!
that looks like a bum lifter to me. The foot of the lifter is harder than the body, as I understand it many lifters the foot is a separate piece pressed on. looks to me like it fell apart or off. the bad lifter is shorter, isn't it? When you tear it down keep a sharp eye out for the pieces of it.
Even if it was bad you still need to solve the springs deal, 145 is too much.
Tom Mobley Feb 24th, 04, 2:12 AM ddeennis,
>> "there is no reason for cam failures...."
Sure there is, defective and poor quality parts among other things.
Are you always this jerky or are you making a special effort today? Frankly, you're coming across as a mouthy know-it-all smarta$$.
James, sorry you have to put up with this crap from him, but as you know it's it's a big internet out there and anybody can wander in here and spew. I hope you know you have the respect and sympathy of most all of us on here.
I have a set of Sealed Power lifters I bought several years and never used. the were made years before the current quality problems with lifters started occurring. If you need them let me know, they're yours.
Tom email me at tmoble at cox daught net
ZZ69chevelle Feb 24th, 04, 2:51 AM I said it before, I'll say it again. Roller cam. ;) Screw worrying if it's spinning fast enough. tongue.gif :D That really does suck. I hope you aren't down too long.
ovelle Feb 24th, 04, 3:24 AM looks like a ddeefective lifter to me!!!!
dont think it's your fault at all.
did you call manufacturer and raise hell????
shane
pdq67 Feb 24th, 04, 7:16 AM Imho, it WAS SPINNING!!!
Look at it real close AND you can see that the metal is rolled over its edge uniformly everywhere which tells me it was rotating!!!
I bet the sucker was soft, period!!!
Now these two lifters are candidates for the lifter hardness test we are trying to get going! So look into and send both of them to the guy's that are doing it!!
pdq67
Eric68 Feb 24th, 04, 8:46 AM Sorry about the luck James -- I had one fail a year ago that was not spinning and it carved down like a wedge VERY quickly the lobe was nearly perfectly rounded. Your lifter looks different, out of curiosity what did the lobe look like?
PS.
I find it funny that the "expert" rubbing it in seems proud of a Big Block Camaro running low 14's . . . tongue.gif
baddbob71 Feb 24th, 04, 9:06 AM Yup the lifters definately need to rotate. Have the lifter bores been honed on this? Maybe this bore was honed too far? Have the last two cam failures been with the same cylinder? A good friend of mine has never had a cam breakin failure--he polishes the lifters with 1000 grit sandpaper before installation. I did the polish trick on my last engine and had no problems so I think I'll continue to do so. Some of the lifters being produced today sure seam to have a coarse texture on the face-doesn't make sense to me. It sure seems like you had a soft lifter but with two prior failures I'd have to say something else is wrong-maybe spring pressure like you say. Are you running a windage tray or crank scraper? How is the side clearance on the rods? Any chance the cam isn't recieving enough splash? Hope you figure this out, keep us posted.
Jesse66Original Feb 24th, 04, 9:53 AM James my friend, please consider the source, who is this dude anyway, sure has a way with words and makes premature assumptions. I am so very sorry for you guy, I can feel your pain and I mean that, if there anything I can do for you from over here just let me know ok. Man this is a tough one after the other deal.
Jesse
mr 4 speed Feb 24th, 04, 10:01 AM James,good luck with everything..thats got to be the sorriest lifter failure I've ever seen :( :eek:
Hope 'Ole Paint is back on the road burning rubber soon graemlins/thumbsup.gif
427L88 Feb 24th, 04, 10:11 AM I would never have thought about a bum lifter. Now, before I say anything about cheap ass foreign sub par metallurgy, which I know will get the other Camaro guy on my tail, I would send two lifters down to Bill Burke for hardness testing James. Just to see what all is up here.
Oh and btw, while Dennis was a bit harsh, he does have another Camaro Eric, runs better than 14!
And he may be eating his words if the Rockwell is way off on "the holy one".
And I apologize James, here I thought it was becuase you didnt use outer springs, or an old set of outers to break it in. I don't think anything would have helped you here. I showed that pic to a buddy, and he said impossible, until the bum metalurgy issue came up.
Send a few to Bill.
headerfire Feb 24th, 04, 10:15 AM Ouch! graemlins/clonk.gif
I used to keep a lifter in my tool box to show customers what happens when a cam goes bad.
Never seen one like that though!
Nate Feb 24th, 04, 10:17 AM James,
I read about this on GMMOC board also and am I correct in the fact this is the second cam that you have had problems with? You must have really pissed off the cam gods. I hope you have Ol'paint up and running better than ever in no time and that the third time is the charm.
Also on a side note, I finally found the cam specs on the Fire Ball cam that is in my 71. If you are interested I will send you the specs.
New68SS Feb 24th, 04, 11:49 AM Hey ddennis,
you going to chevellabration 04?
I'm sure that James would love to hear all about your thoughts in person. :D graemlins/waving.gif
ooops, did I hit a nerve? :rolleyes: sorry
Dwayne
Motor Martyr Feb 24th, 04, 12:26 PM James,
It must be tough having this problem come back.
Dont get scared away from flat tappet cams though.
Just make sure that you go through the block and that the galleries are all clean...and make sure that when you assemble the heads, you check the spring height with a valve spring mic, and check the actual spring tension at the actual spring height to know exactly where you are.
Valve spring heights will vary, and spring tension will vary slightly. Put the heavier springs into the taller spring heights, and vise versa.
Ddennis might be harse on the point he makes, but it would be wise to fallow his advice and make sure everything is working correctly this time around.
I dont know what happened last time, i wasnt there...but i do wish you luck with the next try.
cjlandry Feb 24th, 04, 2:35 PM That's the worst I've ever seen!
I'll tell you this much, as many here know, I've had a sudden cam and lifter failure after thousands of miles. I don't even have a radio in my car, so all I hear is the engine.
Driving home from work, 120 miles one way. Less than ten miles from home, sitting at a traffic light, all sounds good and suddenly "tick-tick-tick-tick", there went the lobe and lifter.
So these things do happen suddenly, and without warning. If it was an oiling problem, why did only one lobe/lifter get wiped? Maybe trash from somewhere got wedged between the lifter and it's bore. ??? Who knows.
These things have been happening to people lately no matter how perfectly everything is checked and assembled. It just makes you that much more careful next time around. And that much more paranoid about it as well.
And ddeennis, the 2.41 gear probably ain't helping those ET's with the 14 sec ride. ;)
I do wish people would find other ways to communicate rather than trying to "strike a nerve". It's certainly not necessary to come across that way.
Wolfplace Feb 24th, 04, 2:59 PM I posted this in the engine section but thought I'd add it here also as it seems appropriate ;)
====
Johnson & HyLift or whatever it was called are both gone which as far as I know leaves one US company which is Stanadyne.
There are other hyd lifters under different names depending on where you buy them that come from Mexico among other places but the information I was given is that after being tested by a well known company is the only ones that consistantly met the GM specs for finish & hardness were the AC Delco/GM ones refered to by Carl above. (Carl's post is in the engine section)
This is second hand information but comes from pretty reliable people so I cannot say I know all this for fact but the problems people are experiencing seem to back it up.
There have been a few posts on here about people not installing things right & spring pressure & lifter rotation etc. which are all valid concerns but I think by now we all know there is a problem with the quality of the parts & it is not just people not paying attention when installing the parts or improper breakin. ;)
For info,there are a couple of excellent sources for solids, (not hyd)actually only one I know of right now & he can't keep up as Ferrea has recalled all of their lifters for a "manufacturing problem" (hey, at least they didn't send them out for you to test :mad: )& I don't have a date when they will be available again but neither are exactly cheap.
Big James 4XL Feb 24th, 04, 4:08 PM Thanks for your support guys!!!
It means a lot to me!!!
This has been a trying time for me but I will go forward even if I have to take a step backward first. I'll get the heads off tonight and start investigating the installed height but right now I'm going to concede that I had too much spring seat pressure. Beyond that I'll just have to keep investigating and chalk it up as a hard earned lesson. Should have tossed those springs the first time I had trouble.
By the way, the lifter bores were honed when the engine was at the machine shop for boring.
As for the lifter, I've never seen anything like it. And I hope I never see it again! And even though some people seem to think I was riding around with the radio turned up, hootin and hollerin at the babes, and tapping my foot to the clatter of the lifters, I assure you this happened almost instantly, and that's all I'm going to say about it.
Thanks again guys!!!
ddeennis Feb 24th, 04, 4:56 PM Originally posted by Eric68:
Sorry about the luck James -- I had one fail a year ago that was not spinning and it carved down like a wedge VERY quickly the lobe was nearly perfectly rounded. Your lifter looks different, out of curiosity what did the lobe look like?
PS.
I find it funny that the "expert" rubbing it in seems proud of a Big Block Camaro running low 14's . . . tongue.gif maybe you looked over the 468 bbc there buddy in my 81 camaro.........nothing wrong with my daily driver running 14's with 2.41 gears......its a cruiser.......duh.........
gspan1830 Feb 24th, 04, 5:15 PM Originally posted by ZZ69chevelle:
I said it before, I'll say it again. Roller cam. ;) Screw worrying if it's spinning fast enough. tongue.gif :D That really does suck. I hope you aren't down too long. I agree, if it happens again are you gonna feel like tearing it down again??
Spring is right around the corner and if your car is laid up we won't be seeing any of your show pics so don't take a chance, put a roller in it.
71chevy0192 Feb 24th, 04, 5:38 PM Believe me man...I feel for you. I've been in almost exactly the same boat. I bought my 71' malibu a few years ago, drove it for about 3000miles,(fresh rebuild when bought) and then it destroyed 4 lifters and 4 cam lobes.(or was it 5?) I suppose having the loud gear drive in the car didn't help matters. (couldn't hear anything under the hood) This was all when I was in high school and I was using it as my daily driver. I ended up putting another cam in it and it just ate that one up to. Tore the whole thing down and now.....2 years and $2000 later...i'll be getting my rebuilt 327 back in a couple weeks to throw back in. That's a lot of money for me....had to clean out my bank and all the money I have for that lol....so it BETTER RUN GOOD NOW!!! :mad:
Anyway I know how you feel....and i'm sorry to hear that happened.
71chevy0192 Feb 24th, 04, 5:48 PM By the way....what type of cam was this? Both of the cams/lifters my 327 destroyed were edelbrock POS's.
I feel your pain - lost a flat tappet myself a while back - hurts just remembering it.
ddeenis - what goes around comes around - know what I mean?
MAT
hoffbug Feb 24th, 04, 6:39 PM WOW.. That is brutal...
I can tell you from recent experience, that a trip to the nearest metal treater for a Rockwell test is well worth your while.
pdq67 Feb 24th, 04, 7:35 PM Nate,
Would you please e-mail the Fire-Ball cam spec's to me for my old cam spec. collection.
BTW, I've seen lifters with circular "engine-turned" marks on them, smooth ones and ones that had a dark, kinda rough, natural heat-treat surface on them and through the years, they all worked!
So I really don't know what's going on unless "three-sigma" statistical analysis QC is letting three bad lifters out of a hundred get out the door?? I personally would test 100 percent of everything, but then the costs get outta hand!!
pdq67
Ark68SS Feb 24th, 04, 8:53 PM I don't mean to sound ignorant, but how the heck do you SEE a lifter rotating in a running engine?? :confused: A bright light down the pushrod hole, dodging the oil squirting out while you look?? Some kind of a window in the intake?? The only time I see lifters is when the intake is off, what am I missing? (And I am trying to understand, not being a SA).
BL
71chevy0192 Feb 24th, 04, 9:42 PM Ark68SS - Exactly what I was wondering. lol
baddbob71 Feb 24th, 04, 10:32 PM with the valve covers off and the engine running you will see the pushrods rotating meaning the lifters are also rotating. If they aren't rotating shut her down.
baddbob71 Feb 24th, 04, 10:41 PM Interesting post by Wolfplace about the lifter manufacturers and hardness, I bought a set of solids from Competition Products a few months ago and they talked me into G.M. lifters and said they hold up better than most. Maybe they are right?
bigjimzlll Feb 24th, 04, 10:46 PM you can always go with Schubecks<sp> composite lifters..a set sold on ebay for 150.00 a couple of weeks past
Big James 4XL Feb 24th, 04, 10:52 PM Originally posted by Ark68SS:
I don't mean to sound ignorant, but how the heck do you SEE a lifter rotating in a running engine?? :confused: A bright light down the pushrod hole, dodging the oil squirting out while you look??
BL You have to have the vision to see whith your ears and fingers and toes and all that aura stuff :D
But, an upate,
I checked the installed seat height with my crude but effective telescoping gages and a cheap digital caliper and came up with around 1.76 as opposed to the 1.88 the spring is rated. there were two shims, a .30 and .15. I don't think a .012 shortage would make or break the deal.
Still finding small bits of metal but the mains survived. I found the largest bits in the pan and when I cut the oil filter open I could find smaller pieces that I could feel with my hand.
I'll start a "part 2" thread for those that are interested as things progress.
baddbob71 Feb 24th, 04, 10:57 PM If you want to inspect that oil filter the right way, cut the element out of it and wrap it in a few paper towels then squish the whole works in a vise to push the oil out of the filter paper, you'll then be able to open the filter paper like an accordian and it'll read like a book smile.gif You won't believe the amount of material that is visable this way vs. just a look. try it, I do it on every change, any copper? any aluminum? is it metalic? gold? You can really read the wear of your engine this way ;)
Big James 4XL Feb 24th, 04, 11:16 PM Originally posted by baddbob71:
If you want to inspect that oil filter the right way, cut the element out of it and wrap it in a few paper towels then squish the whole works in a vise to push the oil out of the filter paper, you'll then be able to open the filter paper like an accordian and it'll read like a book smile.gif You won't believe the amount of material that is visable this way vs. just a look. try it, I do it on every change, any copper? any aluminum? is it metalic? gold? You can really read the wear of your engine this way ;) Yep, that's what I did. Once the canister was cut away I took a utilty knife and did just what you said except I felt every pleat in the filter with my fingers. I can feel it better than I can see it. I good trick to use for sure. Got slimey and smelly but it was kinda fun.
Wolfplace Feb 24th, 04, 11:29 PM Originally posted by Big James 4XL:
But, an upate,
I checked the installed seat height with my crude but effective telescoping gages and a cheap digital caliper and came up with around 1.76 as opposed to the 1.88 the spring is rated. there were two shims, a .30 and .15. I don't think a .012 shortage would make or break the deal.
I do believe you just found your problem :eek:
I don't remember what spring you are using but that is not .012" it is .120" & that is a back breaker when you were hi to begin with.
140 @ 1.88 & assuming 350lbs/inch you just added 35lbs to your installed pressure & your open pressure. This is assuming you were not at coil bind.
JRS70LS5 Feb 25th, 04, 12:03 AM :eek: 1/8" short on spring heighth!Well at least you found the cause ! graemlins/waving.gif
gotago Feb 25th, 04, 12:19 AM James, sorry to hear about Ole Paint gettin sick the second time around. Hope all turns out well for you.
Tom Mobley Feb 25th, 04, 1:03 AM James,
You're dropping a decimal place there. 1.880 - 1.760 = .120, not .012. .120 is almost an eighth of an inch, .012 is twelve thousandths of an inch. JRS70LS5 has sharp eyes, didn't miss that. .012 probably wouldn't break the bank unless it was really close anyway, .120 will wreck stuff. Who set up those springs for you? Not close.
live and learn, I guess.
Tom
Doug F. Feb 25th, 04, 7:40 AM Yep, you're probably up around 180 lbs seat.
427L88 Feb 25th, 04, 9:50 AM Not to mention taking .120" off the coil bind spec and also the effect on pushrod geometry when the valve is shorter. Yeah, cluster futz happening there. I stand corrected on the mettalurgy deal. James, at least you find the issue.
Can iron heads be run without a shim under the spring? ( although removing .045" isnt going to set heights correct, it'll get them to 1.810.)
Where does the other .070" come from? Not being a cast iron head guru at all...just asking.
73camaro Feb 25th, 04, 10:25 AM You can pick up .050 plus locks for the retainers or cut the valve spring seats. One of mine was .025 too short and it had me worried. Mark
Ark68SS Feb 25th, 04, 10:34 AM You should use a shim under any head, as the spring moves, it will scoot around & eat at the head. If you're using Comp Cams 10deg retainers, there is a +.050 valve lock available to gain some height. You will have to cut the srping seat to get the other .070 or use a different spring. I'd also borrow or buy a real valve height gauge. There's too much margin of error using the telescoping gauge & a mike. (Guess how I know?? :D ) At least you seem to have found the problem, but still look for anything else that could be messed up. That forest & trees syndrome can really mess you up.
graemlins/thumbsup.gif BL
69LS1 Feb 25th, 04, 11:28 AM Speaking of shims...I attended a seminar last night and there were several engine builders there.I was talking with one whom I have known for many years.We got to talking about valvtrains.
They were haveing a problem with what they thought was a spring problem.The have a dyno but not a Spintron.They cut windows in the valve covers and epoxied clear plastic so they could view the upper valve train while the engine was running.
On this praticular stout SBC they discovered that at 4000 RPM several valve springs started to rotate while viewed with a timing lite.They continued to rotate until 6800 RPM when they stopped rotating...then at 7000 they started rotating again but in the opposite direction.This continued until 7300 RPM ...witch is as high as they ever run this engine.
They checked the springs and reintalled them the exact same way with a different cam ( very simular spec but a different brand )....Not a single spring rotated...
Granted a slightly unuseual situation but does show that correct shims can be a good idea.
Motor Martyr Feb 25th, 04, 12:29 PM Installation height the spring mnufc gives you is the Recommended height.
YOu must find actual height, and find springs that will get you to the recommended seat and open pressures @ the height that you have....for the cam you have.
The cam manufacturer has no idea what your spring heights will actually be, since you may have heads that have had seats installed, many valve jobs, taller valves, retainers that seat higher, +.050" locks, ect.
BTW when finding pressure with your double springs, make sure you use the retainer on the spring and spring mic when testing pressure. otherwise you will get a false reading becuase the inner spring is retained lower then the outer.
Also rememeber to find your clearance between the coils, and your retainer to seal clearance.
Big Blocks need hardened shims under the springs to prevent the springs from chewing up the spring seats, becuase of the extreme angles that the valves are set to, this is a possiblity.
Live and learn, before you know it, you'll be the most knowledgable guy about spring heights and spring installation in the neighborhood! :D
engineguy Feb 25th, 04, 12:57 PM James,
I think the problem you encountered was a combination of things. First, your spring installed height was off substantially which would affect all of the lifters. Secondly, I think there was a metallurgy problem with the lifter body. I have never seen a lifter wear like this one, as they usually quit rotating and the lobe wears a large groove across the lifter face. Obviously the lifter was still rotating, judging by the consistant wear all around the lifter. My guess is that the corresponding lobe is probably worn, but not completely flat as is the case when a lifter stops rotating. There are a lot of questionable lifters getting into the supply chain, especially from India and China.
Don't let certain people who write negative posts get under your skin. I have noted previous posts that can be catagorized as junk and are not worth reading, much less responding to.
Good luck on the rebuild.
Wolfplace Feb 25th, 04, 1:09 PM Originally posted by 69LS1:
Speaking of shims...I attended a seminar last night and there were several engine builders there.I was talking with one whom I have known for many years.We got to talking about valvtrains.
They were haveing a problem with what they thought was a spring problem.The have a dyno but not a Spintron.They cut windows in the valve covers and epoxied clear plastic so they could view the upper valve train while the engine was running.
On this praticular stout SBC they discovered that at 4000 RPM several valve springs started to rotate while viewed with a timing lite.They continued to rotate until 6800 RPM when they stopped rotating...then at 7000 they started rotating again but in the opposite direction.This continued until 7300 RPM ...witch is as high as they ever run this engine.
They checked the springs and reintalled them the exact same way with a different cam ( very simular spec but a different brand )....Not a single spring rotated...
Granted a slightly unuseual situation but does show that correct shims can be a good idea. ==
Hi Al,
Not that unusual :rolleyes:
They had a deal on some spintron testing at The Superflow Advanced Engine Technology Conference a about 3 years ago & if you ever get a chance to see the video you may never want to build another engine :eek:
The damn springs went through harmonics at different RPM's where the suckers spun, surged & came clear off the heads & retainers at certain RPM's & then would settle back down at higher a RPM.
If you were running the engine at say 7800 instead of 8200 & 7800 is where the problem was you would probably make about a half a lap before really ugly things happened :D
This is one reason it is a good idea to use a spring that is known to get along with the cam & valve train you are using, especially in endurance type applications like circle track & also boat engines.
Not near as important in drag racing unless it is an application where the RPM doesn't change much. Like TF, FMD, PRO etc.
This doesn't have a lot to do with hardly any street & lower RPM type engines as we are rarley at an engine speed that will cause these kinds of problems but it can happen in almost any application under the right circumstances I guess.
If you ever take your engine apart & find the shims beat to hell & the bottoms of the retainers real shiny it is a very good indication you should be trying a different spring.
Pretty interesting stuff,,, at least to me ;)
69LS1 Feb 25th, 04, 3:09 PM Hi Mike,
Ya that whole harmonic thing is scary.The whole idea of the valve gear seperation and slamming back together...OUCH....
I would love to get a chance just to watch some serious flogging on a Spintron.I'm sure I would come away with a better understanding of things !
Big James 4XL Feb 25th, 04, 4:40 PM Thanks guys!!!
Yea, realized my mistake this morning as I mulled the whole deal over again. My crude measurement is not exact but I do have experience with precision measurement so I'm close for sure, even if my math was off. It was a long day! graemlins/sad.gif
Lots of good info coming out here guys. Thanks for the input!
I still want to check the springs actual pressure as installed. I don't have a proper gage but I'm trying to get in touch with a friend who does to see just how far off it really was.
I guess this thing bit me in the butt mostly because the first cam and lifters I ran in the engine for about 5000 miles with the same springs had no problems and I was not taking the issue seriously enough. I still feel like this last failed lifter was of substandard material though.
But I'll get Ol Paint back on the road again soon! Then I'll start posting pictures of fun things and not broken things.
Jim W Feb 25th, 04, 5:14 PM We changed cams in a 402 and the lifter lasted about 80 miles, it was a crane www.geocities.com/bad67chevelless
Eric68 Feb 25th, 04, 6:25 PM never mind . . .
427L88 Feb 26th, 04, 9:38 AM James, if you need another set of springs, let RJ BRagg know. He has a set of COMP 924s of mine that will work just fine. They're duals, so you can easily run the new cam in on outers and then swap in the inners.
Let RJ know if you need them. I got them "really cheap" from Nick Lewis, so the discount passes through....
Big James 4XL Feb 26th, 04, 6:05 PM Originally posted by 427L88:
James, if you need another set of springs, let RJ BRagg know. He has a set of COMP 924s of mine that will work just fine. They're duals, so you can easily run the new cam in on outers and then swap in the inners.
Let RJ know if you need them. I got them "really cheap" from Nick Lewis, so the discount passes through.... Thanks my friend!!!
I've already recieved a set of Crane 13308-1 springs and retainers from Jegs. If I get the cam, and lifters tomorrow I'll get this thing back together pretty quick.
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