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Author Topic:   Cam Break in
Winland Racing
Member
posted February 05, 2004 11:08 PM
I just purcahsed a new hydraulic cam. At the suggestion of the Cam manufacturer I also had my heads reworked with 350# springs. I get my heads back from the shop the same day my cam arrives. It states the following on the cam card "ALWAYS BREAK IN CAM WITH OUTER SPRINGS ONLY OR USE WEAKER SPRINGS ON SINGLE SPRING APPLICATIONS WHEN PRESSURES EXCEED 280#"
I have never ran 350# springs before. I am trying to get an idea of what everyone else does. The cam guy says to put weaker springs in for break in, the head shop says is should be ok????
Sounds easy, but I dont have the tools to switch the springs and money is tight due to the $750 spent for the cam kit and head work(more than just springs)
what advice do you have?????
Thanks,
WR#66


77k
Member
posted February 06, 2004 01:29 AM
You can make tools to change springs on car.#1 Brake old spark plug off,clean out center and tap for air hose,with rockers off ,screw in head and hook up air[holds valves up],[air may turn engine over a little.] #2 Take a flat, 2 inch pry bar and fork end to fit on valve spring with room in center to remove retainers.Drill hole in bar so bar will fit over rocker stud.Put nut on stud and pry up.Some times you need to tap on spring with hammer to loosen it up.You should be able to remove retainers and springs.If need be, rebend bar to get more room.Poor boys got poor ways,but it works.


Gene
Member
posted February 06, 2004 02:54 AM
I would do what the cam people say, that is a lot of spring pressure.


Raz_900
Member
posted February 06, 2004 07:32 AM
Up to 350 shouldn't be a problem if you lube everything up really well. Over 350 and you definitely need to drop pressure down.

If you plan on using 1.6 rockers... don't use them on break in. That makes the effective pressure on the lifter even higher. Use 1.5's or try and find a set of 'breakin' 1.4 rockers. I know they're available, just not sure where to get them.


dirtbuster
Member
posted February 06, 2004 08:20 AM
We have never had trouble breaking them in and we havent changed out springs before. Just make sure everything is ready to go and lubed well and dont spend a lot of time cranking it to fire it and then once it fires get it up to 2000 or better pretty quick. Also you might look into running EDM lifters. they have a little hole in the face to put more oil on the cam. They will defintely help extend cam life if you are worried about it.

Also do they mean 280# springs at closed or open. That could make a difference as well. Your 350# open springs may only be 150# closed.

Winland Racing
Member
posted February 06, 2004 08:41 AM
Thanks for the replys.
I am installing 1.6 rockers, I didnt even think about using the 1.5. Where do you get the 1.4 break in rockers?

The cam valve lift is .491, spring pressure 130 seat, 325 open. It is a 350 motor, 194 heads.

The tool fabrication seems pretty simple.

Great sight! I posted this before going to bed, come to work and already 4 replys. keep em coming.

WR#66

chomme
Member
posted February 06, 2004 09:38 AM
I would swap rockers before i started changing springs. A lot less hassle and time. But I honestly dont think you would have problems. We broke in our .580 lift cam with 1.5's and dual springs and never had a problem. That cam/lifter set is going on over 4 years now.


Okie11m
Member
posted February 06, 2004 09:18 PM
As long as it is a good cam & you use alot of lube you should be fine with the 1.5s. I bought a cheap cam & lifters last year(not to mention names MW, oops!!} & it went flat in the the first heat. I called them & they said they have had problems with the new lifters being untrue. I told them that was never mentioned in the sales pitch!!! Anyway, Ive never had any prob with name brand stuff in the .560 lift & 350# range.


dirtracer7
Member
posted February 06, 2004 10:26 PM
Been running isky cam and edm lifters.Broke in on 120 closed 394 open springs and 1.6 rockers.Like dirtbuster said have it ready to fire and run it above 2000 rpms for about 20 minutes.At 2000 rpms it insures oil is getting slung around and getting on the cam and lifters good.The edm lifters are worth the extra bucks.Changed cams this year every thing was good on the old one which was 3 years old.Broke this one in the same way this one has .584 lift.


sixwillwin
Member
posted February 07, 2004 09:49 AM
Speedway in Lincoln NE sells 1.3 ratio rockers for breakin.........


Winland Racing
Member
posted February 09, 2004 01:33 PM
I got a price on break in rockers. FYI, they are not cheap. about 250.00 for a set. Not in the budget!
My cam is a 491 lift with 1.6.
125 seat and 325 open pressure. My head shop stated that the seat pressure is the main issue. He is working on shimming the valves for proper pressures. He says to lube it good, run the 2000 rpm as discussed and just leave the 1.5 on it for break in and running.
Any advantage on switching to the 1.6 after break in? I assume I wont get 491 lift with 1.5 which means the cam wont run as optimal as designed?? Any Comments?
Thanks again,
WR #66


towmandan
Member
posted February 10, 2004 06:37 AM
I havent done the math but im guessing if you run the 1.5s your lift will be around the 460 range which aint much just about any 350 combo will benefit from at least 500 lift Ive used alot bigger cams with double springs and had know breakin trouble I would use the 1.5s just for peace of mind good luck....towman


Sidebite252
Member
posted February 16, 2004 05:43 PM
For what's it's worth - we've built several motors and a couple of years ago we fired up a fresh motor without removing the inner springs and I'll be darn if we didn't knock a couple of lobes down on the cam so I'm glad some of you haven't had this type of misfortune but believe me it can happen. We actually did just as 77K suggest up until this year and purchased a tool for removing the springs (did away with the por boy spring puller) but personnally I'll never break in a cam with full spring pressure again - Once bitten twice shy! Good luck. I might add by doing this method 77K wrote about (using air with an old spark plug set up - yes we still use it because it works) you'll also know real quick if your valves are leaking. Chao!

[This message has been edited by Sidebite252 (edited February 16, 2004).]

dirtbuster
Member
posted February 16, 2004 06:11 PM
I think the cam material itself has something to do with it as well. My guess is there is a better chance of losing a lobe on a 50$ cam as compared to one that runs $150-200. Not that it cant happen to both I just think there is a reason why those cams are cheaper more than just missing a brand name.


Jesterondirt
Member
posted February 17, 2004 08:11 PM
My Engine builder puts a coating on cams for about 35$ that hardens the metal to were you dont have to worry about the break in period


Sidebite252
Member
posted February 18, 2004 04:51 AM
Sounds like "Snake Oil" to me. I think he's just taking your $35 bucks.


rexalott
Member
posted February 18, 2004 05:59 AM
I've wiped out cam lobes before and it ***** ! The damage is done cranking with no oil pressure.
Put the moly lube on the lobes and lifters.
Put in an extra quart of oil during break in.(the cam is splash lubricated)Pour the last two quarts across the rocker arms, balls etc on the top end.
Make a oil pump primer out of an old distributor with the cam gear removed.Turn it with a 1/2 in drill motor.Pump until you get some pressure on the gauge at least, preferably until you see some flow at the rockers.
Set the timing.If you have a 36 degree mark, make sure #1 plug is set there.Take care that its not #6.
Fill the fuel bowls through the vents, make sure there's plenty of fuel in the tank.Add a SMALL amount to the intake.
Make sure you have power to the distributor, make sure you have the motor grounded to the chassis.(I once started an engine where the only ground was the temperature gauge.It looked like a 4 foot light bulb filament)LOL. MAKE SURE the battery is fully charged, preferably a 1000 cranking amp battery.
If you turn the motor over more than a couple of times and it doesnt fire, STOP. figure out whats wrong and fix it.Winding and winding the motor with the starter is what will mess up your new cam in a hurry.You dont want the motor to drag and struggle to start!!!!!!!!!!!!!


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