318 la help

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Jeremy West

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Apr 17, 2019
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Location
Fred texas
I did a complete rebuild on my 318 with a upgraded camshaft and lifter and I’m having problems with camshaft loads going flat and valvetrain noise after break in
 
Not sure what your asking? If you had a lobe go flat, all you can do is start over. Tear it down, clean everything. install a new cam and lifter. Make sure you coat the lobes and lifter bottoms with a good assembly lube. make sure it fires off as soon as possible and break the cam in at 2-2500 RPM for about 20 minutes. Occasionally hit the throttle during break in. Use a high zinc oil or additive in the oil.
 
Well your doing something wrong. Your going to have to give more details on how your breaking it in, oil type, zinc additive?
 
Yes there the ones for the camshaft I have but I was reading on didn’t forums saying you need a lower spring rate during break in the springs I have are 387lbs
 
Open rate? What is the seat pressure? If it is a dual spring, they always suggest removing the inner spring for break in.
 
DEBBACF2-8E3D-4C03-ABFE-3A840D16A213.png
318 la
Spring rate 387lbs
New rockers(stock style)
New rocker shafts
New pushrods (7.500 length)
New comp cam
New comp cam lifters
 
I have lost two cams in different engines. (I'm a slow learner) #1-use the proper oil. #2-break-in time- a full 20 minutes at 2500-3000 RPM. Good luck.
 
Single Outer Valve Springs
  • Rate: 387 lbs
  • 1.080'' ID, 1.494'' OD
  • Seat Load: 104 lbs at 1.650''
  • Open Load: 259 lbs at 1.250''
  • Coil Bind Height: 1.100''
 
The info you provided is the "manufactures info", what is the actual specs' as installed on your heads?
 
Well if they were to long and the plunger in the lifter couldn't compensate, they would hold the valve open and you would have no compression. to short and the engine would be noisy as soon as it started.
 
Man getting info out of you is like pulling teeth! What kind of break in oil did you use? Zinc additive? Assembly lube on the cam and lifters?
 
have to check everything
retainers/ keepers hitting the valve stem seals
worse case a valve could be tagging a piston

when you roll it over does the motion of the rockers look symetrical tilt up vs tilt down as you go around
i.e a line through the center of the shaft to the valve tip/ rocker = a right angle- 90 degrees you can eyeball with a machinist scale or eyeball both sides of the retainer over to the shaft- does that eyeline hit the middle of the shaft?
 
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