correctly breaking in a new flat tappet cam

[grumpyvette]

Proper cam break in is really all about getting enough constant oil flow between the lifters and lobe surfaces, The cam and lifters should be coated with moly cam lube before being installed and a can of G.M. E.O.S or MOLY ADDITIVE added to the oil, Break-in sould be done by running the engine in the 2000+to 4000rpm range for about 20 min MINIMUM to get the oil to the cam and keep it there, in significant volume. This can be difficult, because you need to set the timming, etc. and keep the engine cool. Dry cranking the engine hurts it because it can wipe off the cam lube. YOU NEED THE MOLY LUBE AND ADDITIVES,YOU NEED TO KEEP THE RPMS ABOVE about 2000rpm
for a flat tappet cam to break in correctly you must keep the rpms high enought that both the spinning crank assembly is throwinhg a constant oil spray and the lifters are constantly supported on a film of oil spraying from the area around the lifter bores, plus the cam lobes contact must not drag across the lifter base for a long enought time to squeeze out that oil film between them, untill the lifter base wears to exactly mate with the cam lobe. the contact time and oil volume flowing across the contact area are both dependent on the engines rpm range. it takes a minimum of about 1500rpm before your getting into the safe oil volume and time area with new parts

read this
http://www.cranecams.com/?show=camLiftWear

http://www.cranecams.com/?show=adjustingValveTrain

http://www.mrmoly.com/break-in.html

http://www.holley.com/HiOctn/TechServ/TechInfo/IECCTech1.html

http://www.holley.com/HiOctn/TechServ/TechInfo/IECCTech2.html
http://www.holley.com/HiOctn/TechServ/TechInfo/IECCTech3.html
http://www.holley.com/HiOctn/TechServ/TechInfo/IECCTech4.html
http://www.holley.com/HiOctn/TechServ/TechInfo/IECCTech5.html

http://www.engineparts.com/Motorhead/techstuff/caminstall.html

http://www.2quicknovas.com/happycams.html

http://www.iskycams.com/techinfo_index.html

you should use mineral base oil as its cheaper,it allows the parts to mate faster and your going to throw it out in less than 3 hours with the partly clogged filter after cam break-in, you need to change the oil filter and additives to remove them and any metallic dust from the engine break-in to prevent that crud from clogging the filter, after that its your choice as to the oil used ,but I normally use mobile 1 synthetic and add a pint of marvel mystery oil for added corrosion protection

AND YES THE FILTER AND OIL YOU USE MATTERS
READ THIS

http://www.micapeak.com/info/oiled.html

http://www.aera.org/Consumer/breakin.htm

http://www.geocities.com/MotorCity/Downs/3837/oilprime.html



http://www.scuderiaciriani.com/rx7/oil_filter_study/

 

[Ken]

As usual, a well done and very thorough explanation. Thanks Grump!

Is there a difference to breaking in a roller cam vs. a flat tappet cam?

 

[grumpyvette]

yes roller cams don,t require a breakin period at significanly higher rpms, just coat the cam and rollers with the normal moly lube mixed with synthetic oil when installing them to add some extra friction protection,and prime the engine untill oil flows from the rockers before starting the engine and your good to go!
roller cams normally run higher spring pressures but the rollers on the lifters lower friction significantly
but you still need to change the oil and oil filter for best results ,(remember the rings,bearings,rockers,ETC. are also causeing metallic dust to enter the oil flow durring a new engine break -in,) yeah you can use mineral base or synthetic on roller cams but since you throw it out after the first 2-3 hours mineral oil being cheaper is the better choice, and remember that your removing the moly and E.O.S. and metalic dust , thats the reason you need to change filters at the very minimum

 

[Ken]

Thanks for the insight.

_ken

 

[sofast4u]

hey grump thanks for the great insight on the cam
how familiar are you with the comp cams extreme
i'm toying with the idea of swaping the cam on my 69 BB427 (NOM)
i was reading about the E268, any info will be greatly appreciated
jeff

 

[grumpyvette]

post the rest of your combo and the true specs on combustion chamber,size,valve size,heads and port size,displacement,carb size,compression,intake,exhaust and gearing and I can get a much better Idea of the type of cam youll need for good performance.
while the ex268 might be fine its not necessarily the correct choice