Engine break in procedure tips?

VtheGNMan

Well-Known Member
Joined
May 19, 2014
I am getting close to reinstalling the engine after a light rebuild and had some questions for the break in procedure.
Here is what I have done so everyone knows as what's in my signature will change quite a bit. Pistons have new rings, new crank and piston bearings, new flat tappet cam, new lifters, new valve springs and pushrods. Obviously all new gaskets too. I will only be running distilled water and RMI. Converting to E85 too so new chip, 80# injectors, fuel pump and supply and return fuel lines. Will be running ZDDP too.

Question is on the procedure and timing of things for break in. Let me know if I have this right.
1) Upon initial start up of engine. Run it for 30 mins, varying rpms between 1500-2000. Watching for leaks and making sure oil pressure is fine. Shut down after 30 mins. Let cool.
Being it has now been heat cycled, re-torque heads.
2) Take for drive. 50-100 miles or so? Obviously if anything is not right cut short.
3) Change oil? Now or later in the process? Re-torque heads again?
4) Drive again to seat rings. When and how high of boost do I push it to seat the rings? And I understand to start with a little boost and add a little more and a little more till you get to the target lbs. Like a roll of the throttle on up to 2 #s. Then another roll on up to 5#s. etc.
5) After seated rings drive, drive sedated for 500 miles to fully break in cam and lifters?

Any corrections or tips to this process as I understand it? Thanks guys for any insight you can give!
 
New engine break-in procedures and methods can vary, and the sequence of items you have listed will do just fine. :)
 
Yep, will do. Thanks Nick and Rick.
I wasn't sure how often you re-torqued the heads, changed the oil and how high of boost to bring it to to seat the rings.
 
If you used head bolts, don't re-torque the heads, you will break the thread sealer. Studs are OK to re-torque.
 
If you used head bolts, don't re-torque the heads, you will break the thread sealer. Studs are OK to re-torque.

I agree with not loosening the head bolt or the stud nut, but a re-torque in necessary for both in my opinion.

Usually I re-torque a new build 2 or 3 times after a heat cycle, and if my first torque is at 70ft-lbs, the subsequent ones are pulled 1 or 2 ft-lbs more w/o loosening, so when I am finished the final torque is ~75ft-lbs.

This is just one of those methods that cannot be proven best, or right or wrong, but one I have used for years and am happy with it! :)
 
Nick, when using bolts what sealer do you use. You have a ton of experience, I only have my one bad experience, so I would defer to you. I had two head bolts leak on me, that I attributed to re-torqueing, it may have been the Teflon sealer I used. I also use the seal tabs now, I did not use them the time I had the leak. Just looking to spare the OP any pain.
 
I have used RTV in a tube, Right Stuff in an aerosol can, Permatex No. 2 non-hardening and Teflon sealer.

The one I like the least is Teflon sealer.

Right Stuff is 3 times as expensive than RTV in a tube and works just as well, so that is my present choice.
 
The cam should come with break in instructions not are all 1500-2000. I change my oil right afterward the 30 minutes. Use regular any brand 10/30 with a bottle of ZDDP for the break in. Make sure you primer the pump and verified the cam sensor is set.


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My break in procedure is as follows:
Start on 10/30 Dino oil (quality, of your choice)
Warm up at 1800rpm for 20-25 minutes. Pay no attention to the headers melting off the car. (They will be fine)
Make sure there is no leaks/knocks/rattles, ect.
Shut engine off.
Let it cool, and drain oil and remove filter and cut it apart, and check for major debris. (Don't freak if you see some debris.......they always make some.
Add new oil/filter.
Start and let it get to operating temp.
Put car in gear.
Slowly bring rpm up against the converter with foot on the brake pedal.
Once you build around 1-2 psi, then hammer the throttle and let the tires spin.
Take it out and drive it.
Head to the track and race it that afternoon.
I have done this for 25+ years w/o failure.
Properly machined all that is needed is to slam the rings against the cylinder wall.
Improperly machined/assembled you ARE going to be tearing it back down, soon.
Top Fuel engines make 10,000hp 90 seconds of run time after build. Think about it..........
 
My break in procedure is as follows:
Start on 10/30 Dino oil (quality, of your choice)
Warm up at 1800rpm for 20-25 minutes. Pay no attention to the headers melting off the car. (They will be fine)
Make sure there is no leaks/knocks/rattles, ect.
Shut engine off.
Let it cool, and drain oil and remove filter and cut it apart, and check for major debris. (Don't freak if you see some debris.......they always make some.
Add new oil/filter.
Start and let it get to operating temp.
Put car in gear.
Slowly bring rpm up against the converter with foot on the brake pedal.
Once you build around 1-2 psi, then hammer the throttle and let the tires spin.
Take it out and drive it.
Head to the track and race it that afternoon.
I have done this for 25+ years w/o failure.
Properly machined all that is needed is to slam the rings against the cylinder wall.
Improperly machined/assembled you ARE going to be tearing it back down, soon.
Top Fuel engines make 10,000hp 90 seconds of run time after build. Think about it..........
Couple questions for clarification Turbo Fabricator.
1st off, thanks for your input. 25+ years experience is worth a ton! These are sincere questions, I am definitely not questioning your process.
When are you re-torqueing heads in your process? or do you?
When you are on the footbrake to seat the rings. Are you holding it at boost for a length of time or doing a burn out of a certain length? I know you're not burning thru the treads before you let off but is there something you are looking for or something that tells you they are seated?
And by your comment of take it to the track and race it that afternoon, you are saying the break in period after seating the rings is not necessary?
So after the initial boost up to seat the rings just go and get on it as much as you want?
Does this process take into account I stayed using a flat tappet cam?

Top Fuel guys also tear their engines down after each run. That is a site to see if one ever has a chance to stand in the garage/pits and watch!
 
The only issue I see is that you installed new rings on old pistons/cylinder walls. How many miles are on the motor and is the cross hatch still present on the cylinder walls? The cross hatch helps seat the rings. If the cylinder walls are smooth, the rings might not seat correctly. You will glaze the rings.

With you having a flat tappet cam, you need to break the cam in according to the manufacturer. Most require a 1500-2000 rpm for 20 minutes. Just watch the coolant temp when breaking in the cam. IMHO: you should've went with a roller and not be bothered with flat tappet cam BS.

Once you get the cam broken, boost away. The boost exerts outward pressure on the rings (forces them against the cylinder walls) to break them in. A couple of high boost blasts and the rings are seated if the cylinder walls have the correct cross hatch.

I don't believe in the drive it for 500mi. If it's going to break, it's going to break.

Billy T.
gnxtc2@aol.com
 
After the flat tappet cam is broke in correctly, I do an engine oil/filter change. I take it straight to the track and put the boost to it.
 
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