New head break in procedure?

[Veg_Out]

Friends,

I've gotten new heads on my burb. She needed them badly, overheating etc. All is well now. Thanks to Missy and TD for the Clearwater Cylinder head recommendation. Excellent quality, great price, even the machinist was impressed.

Should I do anything different as far as breaking in heads? She runs great, sounds good etc. No leaks either!

BTW, 30,000 veggie miles and the cylinder walls look great. 6.5's and veggie are meant to be together.

 

[bison]

nottin to break in,just give her.

 

[Missy Good Wench]

Run it like you stole it ):h

Nothing to break in really. The heads are nothing more than a chunk of cast iron with some holes to let air in and out and water to flow though.


The term "Break In" stems from a time when machine shop practices and such were not as accurate as they are today. 50's on

When the precision bearing shells came into being and such the need to run the "High spots" off easily are long dead dinasour.

As long as the clearances are within specs the engine can be placed in service and run at peak output imediately.

It never hurts though right after a rebuild to run the thing very reasonable for a couple hours to make sure there are no leaks or such.

The only real areas of concern are with a new cam (Not our diesels as they have a roller cam.)

A flat tapet cam (Hydraulic or mechanical) needs to be started and run at a high idle (1000-1500) for the first 30 minutes or so. This is to assure that plenty of oil is thrown onto the cam lobes and that the lifters seat to the cam correctly.

The higher the valve spring pressure the more attention that needs to be paid to this issue.

On High output race engines, many builders will fire them with minimal springs to break in the cam, then install the high pressure springs after the initial run up of 30-60 minutes.

Back in the old days of poured babitt bearings, the babitt bearing was poured into the block then line bored and hand scraped to get the clearance right.

Many old engines had shims on the caps to adjust the clearance.

There was always the possibility of a "High spot" and these needed the "Breakin" time to adjust and actually wear in.

The old style rings were somewhat the same.
The designs of pistons and rings today are such that as long as the clearance is right they are good to go right from the box.

The 6.5 diesels use Moly filled top rings which seat almost instantly. The pistons are a cast autothermic design that has controlled expansion and this makes worry's of "breakin" pretty much non existant.


Run the thing, have fun and enjoy.

MGW