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Author Topic:   cam wear
joetaylor
Member
posted March 03, 2004 07:05 PM
last year I had a cam that wore out in two races now itdid get extreamly hot the lash wasset to spec. the lobes were rounded and the lifters were convexed I have never had any outher problems like this I am debating running a hyd. or roller I cant see throwing money away on anouther solid cam

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Okie11m
Member
posted March 03, 2004 07:46 PM
What was the brand of the cam & lifters?


joetaylor
Member
posted March 04, 2004 05:25 PM
speed way #8 with lifters


BrianW
Member
posted March 05, 2004 10:42 AM
The problems that you're describing usually occur from 2 things:

1) Improper cam install or break-in.
2) a cam that had not been hardened properly.

This has very little to do with hydraulic vs solid lifter so don't condem the solid lifter as being the problem.

A couple of questions:
- What valve springs were you using (seat pressure, installed height and coil bind measurement)
- What ratio rocker arms are you using?
- Did you verify the lifters are free to turn in the bores?
- What was the oil pressure during break-in? How did you run the engine during break-in?
- Did you use enough cam lube on install (on the cam lobes and lifter faces)

A lot more, but with modern cams and modern QC controls I'd hazzard to guess that most immediate failures like you've seen are installation issues and less are defective product...

dirtbuster
Member
posted March 05, 2004 11:02 AM
I would agree with BrianW. not to point blame at anyone but I would say more often than not cam failure is due to improper installation, breakin, etc. I would check all the things he mentioned before trying another cam. Chances are a hydraulic would have done the same thing. A roller might not have but you are also talking quite a bit more money. A lot of times you get what you pay for. A store brand cam that sells for half what a name brand does may be ground by the same company but might not quite pass their specs and therefore gets sold off as a generic brand. Sometimes you might get one that works fine, other times you might not. We have run the same Isky cam for 4+ years and never had problems, but I know other guys will have to change a cam after 15 nights or so.

[This message has been edited by dirtbuster (edited March 05, 2004).]

joetaylor
Member
posted March 05, 2004 06:20 PM
the springs wrer off a blower moter with a roller cam no problems I then used the same heads valves springs ect. on a figure 8 engine with a hyd. cam again no problems.

I ran the engine @ 3000 rpm for 20 min with 100 psi of oil pressure

if I missed something please let me know this was the first solid cam that I have used

If I did go with a hyd cam how much hp would I loose

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Sidebite252
Member
posted March 05, 2004 06:47 PM
Joe,

I've knocked down lobes before but it was probably due to either (1) improper brake in (I didn't remove the inner springs during the brake in period) and/or a less quality cam (in this instance it was an Elgin). I wound up with a couple of lobe knocked down and convex lifters on those lobes. Now I'm not saying that's your problem but just sharing information. You say your using springs that came off of a blower motor with a roller cam. I've never ran a roller cam but I think most springs for roller application have a much higher pressure over the nose than what most solid or hydraulic cams recommend. I do run a speedway cam in one of my engines and I used proper break in and I believe the seat pressure is set around 120# to 125# with an over the nose pressure of around 325# or 350#. The speedway cam is still good after about 12 runs on the motor. It might be worth checking your seat pressure and max lift pressure if you know someone that has a spring checker (like a machine shop or an engine builder.) Someone told me recently that Crane grinds all of the speedway cams but I don't know if its true or if they in fact do if they use the same harding process for the speedway cams as they do their own name brand cams. Good luck sourcing your problem. We all run across these type of problems but finding out why it happened will help you prevent a re-occurance.

BrianW
Member
posted March 05, 2004 06:51 PM
quote:
Originally posted by joetaylor:
the springs wrer off a blower moter with a roller cam no problems

That may be your problem - roller cams are much more agressive and typically require a much stiffer spring - see crane's page for generic spring recomendations here: http://www.cranecams.com/?show=howToSelect

You may be lucky with the hydraulic cam with those valvesprings.

I'd say use the proper springs and it'll live a much longer life...

FWIW - I've run a cheap $40 stock replacement cam for nearly 80k miles before on a 302 - and from what I know the guy that bought the car ran it for a whole lot more.... I've also run a solid MWMS cam in a 355 for 4.5 full seasons turning 6-6200 and never had to adjust valve lash so it can't be deteriorating, I'll let you know what it looks like when I freshen the engine this summer...
So cost isn't necessarily the only indicator of longevity....


joetaylor
Member
posted March 05, 2004 06:53 PM
hey sidebite from what I am gathering is I messed up on instalition what I don't understand whydidn't tear up the hyd. cam I guess I will try it again my only worrie is it puts alot of metal shaving right in to the oil

I really appreate all the help and ideas please keep tham comming

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U LIFT U LOOSE


Sidebite252
Member
posted March 05, 2004 07:04 PM
Hey, No way I can say you did anything on break in. These are just possibilities. Just from the information you've provided I would only consider the part about break in. some of these guys on here swear you don't have to go through all the break in process like we do but we still do - different strokes for different folks. I know when I knocked down the lobes in my case it was on break in. I'd be really interested in the springs like Brian is saying. These roller springs could be a bit agressive for any solid or hydraulic cam. To be honest - I've never ran a hydraulic cam but we have 4 in our inventory and plan to try one soon. We have built about 6 motors with solid cams but we check our seat pressure and height as well as what our spring pressure will be for the open lift on the cam. I'm just lucky enough to have access to a spring load checker. Info on the springs would be where I personnaly would be looking in your case joe.


joetaylor
Member
posted March 05, 2004 08:46 PM
I'm not dogging any one I justdon't want to make the same mistake twice I'm just lookingfor answers that is so please no onetake offence to my comments or questions
my machinest is baffeled and currently looking foranew one my firat thought was breake in thenthe extreem heat that I experenced orboth not sure

just looking for answers thatnks gus

dirtbuster
Member
posted March 05, 2004 09:00 PM
I would defintely look into the springs. Then i would venture to say that they have to much pressure. You shouldnt have more than about 350 max on a flat tappet cam. A lot of rollers are well past that even for street use. Why it didnt cause problems with the hyd cam i dont know. Could have been borderline on tearing them up and then when this solid got hot and the oil got thinned out it couldn't support the loads and lubricate the lifter face and thats when it started and once it started there was no stopping it. Or maybe the side clearance on your rods was a little tight and didnt put enough oil on the cam.
Was the same block used for all the engines? It might be you have a couple of lifter bores that have a burr in them and wouldnt let the lifter spin.


Sidebite252
Member
posted March 06, 2004 03:19 AM
Didn't think you were doggin me joe - just didn't want you to think I was saying it was break in OR the springs for that matter. I was just throwing some ideas at ya bud. I'd rather you not have this problem again too! Lord knows I'm no expert at this stuff. Just a redneck hobbiest that has had the misfortune of several undesirable results. Hey man - good luck and I hope your able to zero in on the cause of your failure. Check those springs man!


joetaylor
Member
posted March 06, 2004 03:53 PM
does any one have the correct way to break in the cam and what exactly happens I'm not sure what is to take place when one does this

This has been a little of a sore spot for me seing that it has never happened to me before

My springs are 400# at compressed and they don't bind up at all for the cam that I use rockers are 1.5 roller tip with longated slots any help would be great

thank you for any help

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U LIFT U LOOSE


Okie11m
Member
posted March 06, 2004 07:15 PM
I had one go down last year. The story I got was the cheep lifters were not machined right & would not rotate like they are supposed to. It lasted 4 laps. Put a Howards cam & lifters in & it is still going strong. The other cam was a MWM #8. When I called them they already had the lifter story ready. It was almost like a recording!!!! Use good parts & follow the breakin procedure & you should be fine.


Sidebite252
Member
posted March 07, 2004 04:19 AM
Joe, Call Speedway motors and ask to talk to one of there techs. We called several years back and actually talked to Kevin Larkin. He was helpful and gave us recommendations on cams, seat pressures and open pressures to run on the cam as well as break-in procedures. You'll probably discover that the 400# open lift might be more than is recommended. Okie11 has another good point with the lifters not rotating. They got to be free and rotating or that will also cause pre-mature failure. Lot's of things to consider but a call to the manufacture might give you some direction. We also installed a Comp cam in a motor last year that came with a sheet that gave break in procedures, lash setting procedures, as well as other good information. Most cams come with a spec card that will give the recommendations for spring pressures, ect.

[This message has been edited by Sidebite252 (edited March 07, 2004).]

dirtbuster
Member
posted March 07, 2004 09:24 PM
In my opinion 400# is too much pressure for that cam. 350 should be about all you need. If you are running a very agressive cam and turning very high rpms then the extra pressure might be needed but I would defintely run edm lifters at that point. We run a pretty agressive Isky grind 74-7500 and have right around 350# at full open.

At installation make sure the lifter faces and cam lobes are well coated with cam lube. Not just assembly lube but something made for cams. Also make sure the lifters are free in the bores so they are able to rotate and remember only new lifters on a new cam. Only use conventional oil and when you get ready to fire it make sure everything is ready to go. Get the distributor as close as possible to correct timing and then fire it. If it doesnt fire right away dont just keep cranking on it, stop and figure out whats wrong then try again. Excess crankin will wipe the lube off and there will be nothing to protect the cam. When it does fire, get it up to around 2000rpm right away and keep it there. Dont let it idle for at least 20 minutes. If you have problems and have to shut it down make sure when you refire it you get it right back up to 2000. We usually vary rpms between 2000-2500 for 20-30 minutes adn have never had trouble. After you make the time limit then you can set your final timing and make any carb adjustments then you should be done. You can change oil and your ready to go.


[This message has been edited by dirtbuster (edited March 08, 2004).]

bigcityracer
Member
posted March 07, 2004 10:29 PM
I had this problem in 2-races. The cam spring were to strong.


Ego Racing
Member
posted March 08, 2004 01:21 PM
You lucked out with the HYD cam because you adjusted it for zero lash and when the spring pressure got to great it would just colapse the lifter a little to releave the pressure. 100 LBS of oil pressure is extremely high. It can cause problems by not allowing the oil to remove heat from the parts.


joetaylor
Member
posted March 08, 2004 04:16 PM
dirtbuster that makes total cnnts I'm going to print that thanks for the help

ego I like that theory It has beed the only one that fits the problem. the only thing that I didn't mention was that I beat the $#it out of this engine for 7 years with out touching it something to be said about hyd cams and lifters.

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