Rebuilt motor break in?

[Sloan]

I am about to receive my FJ60 back with her fresh 2F motor and am completely ignorant of the best procedure to use for breaking it in. I'd like to get another 260,000 out of her so any info you guys could provide would be great. Would it be worth going to a synthetic oil in a low tech engine like the 2F? Thanks in advance. :roost:

 

[Gurkha]

Warm up is important.......using thin break in oil is also another aspect. Don't over rev but to let the pistons settle in and scuff them properly, it is recommended that once the engine is fully warmed up slowly bring the engine up to redline couple of times a week. This helps settle the rings settle in their landings. Never over rev or idle excessively with a/c on. Watch the temps........thats your lifeline. Change the oil at 1000 miles.

 

[R_Lefebvre]

This is a VERY contentious issue. Ask 3 experts and you'll get 4 opinions.

You've got the people who believe you should baby the engine, and that used to be the consensus for older engine, and this is an older engine design.

Lately many of the experts recommend you drive it like you stole it right from day one. In fact, when I worked in Ford Powertrain, I knew a number of engine engineers who did just that with their personal engines, including taking them to the racetrack the first night they had the car.

Most late model owners manuals do not state to do either of these. They merely recommend to not let the car idle for too long, and not to cruise at one RPM for too long. Make sure to keep varying the engine speed. This is the approach I use. Twice I've had to pick up a new car and drive it 500 miles home, which is the worst thing you could do. In this case I never used the cruise control, and tried to constantly change my speed, including using lower gears. I'm sure I was annoying all around me, and it wasn't a relaxing drive, but it's the best thing to do in my opinion.

You just don't want anything to wear in with a specific wear pattern that is set at one RPM.

Also, some people recommend NOT to use synthetic oil because they suggest it's "too slippery" and doesn't let the parts wear in. I think this is garbage. Viscosity is viscosity, and synthetic or dyno oils of the same viscosity index have the same thickness, relatively speaking. Also, some of the most high performance engines in the world ship with Mobil 1 synthetic right from the factory.

 

[ntsqd]

3 people, 4 opinions. That's just about right!

I have seen a couple cases where the rings would not seat or were very slow to seat when a good synthetic was used as the break-in oil. I suspect this is because of the oil's superior metal bonding (EP amino acid) additives. The engine shop that I do occasional fab work for suggests dino oil for break-in, then switch to your favorite brand when the engine is put into service. Partly in case this non/slow seating should occur and partly because the break-in oil isn't going to be in the engine for very long, spending a large amount of $$ on an oil whose major benefit is long service life doesn't make good sense.

Their break-in method for cam in block engines is to very lightly load them on the dyno and change the rpm every couple of minutes. Most cam in block engines do not have dedicated oiling for the cam lobes. The only way they get oil is from splash. The chaos inside a crankcase means that some rpm's may be better at splashing oil on the cam than others are. Since those poorer oiling rpm's are unpredictable you want to move the engine speed around just in case.
OHC engines usually have some form of cam lobe dedicated oiling method. Coupled with their considerably lower cam lobe to lifter/follower pressures, their break-in needs are significantly less.

 

[R_Lefebvre]

Right, so more reinforcement for the idea that the only WRONG thing to do, is to hold engines at any one rpm for too long. Which is EXACTLY what is happening if you are the type who "babies" and engine during break in, especially in an automatic transmission where the action of the torque converter and shift schedule will keep the rpm between 1000-2000 the entire time.

So, drive it normally, or drive it like you stole it and choose your oil depending on your particular religion. This issue is like so many non-clinical trialed medical remedies... the results are too vague to measure. Your engine went 260k miles last time, so you must have done good. Maybe it would have done 150, or 350 if you'd done something different, who's to say? You "feel better" with your ionic bracelet, but who's to say you wouldn't feel even better without it?

 

[AndrewP]

The 2F cam IS pressure oiled at the bearings but the lobes are splash oiled.

The cam is your biggest concern at first start up. Go over to I8MUD and search out the posts on this by Mark Whatley. The bottom line is that you want to work harden the cam lobe/lifter interface. As I remember, the proceedure is to set the valves cold, then start the motor and take it to about 2000 rpm and hold it there for 30 minutes or so with no load. Then shut down and reset the valves hot. Then break in as normal. I'd change oil after 500 miles or so. He also recommended an oil with high zinc antiwear levels like a 15w-40 mixed fleet oil (like Delo, or Rotella).

You're going to have to set the valves frequently at first. Start, after first run, after 100 miles, after 500 miles, something like that.

The rings will likely seat themselves, but you can help the process by opening the throttle without a lot of revs to increase cylinder pressures. For instance; in 3rd gear at 1500 rpm accellerate at 3/4 throttle to 2500 RPM and repeat in sets of 10 until you get tired of it. I've always done that with a new car or a rebuild since I had VWs in the 70s and I've never had any issues with oil consumption or ring sealing. I don't actually know if it does anything other than make me feel good.

I would keeps things otherwise fairly gentle for the first 500-1000 miles. No WOT or revs over 3000. I am not in the drive it like you stole it camp. 2F=low revs=happy. Treat it like your favorite tractor.

After a few thousand miles, I'd switch to synthetic since this is a new motor, but no reason to use early since you'll change it several times.

Good job staying with the mighty F series motor. Many go to V8s which I think is a mistake. I love my 2Fs and would not swap except for a 2F-E

Here is the real bottom line though....What did your machine shop say? They may have a valuable opinion here.

 

[ntsqd]

snip.....
Right, so more reinforcement for the idea that the only WRONG thing to do, is to hold engines at any one rpm for too long.

Concur. I would define "too long" as more than 5 minutes at any one engine speed, but that's just my own definition. Others will have theirs.

The 30 minutes thing; eh, to me the last 1/3 of that or so you're pumping oil full of small metal particles through the engine. I'd stop at ~20 mins and change the oil. Recall that no load reving isn't exactly healthy for the engine either.
Then go to the 500 miles deal, or go back to a high idle for the last 10 mins - whatever you're most comfortable with.

The thing to understand is that the goal is to burnish the lifters to the cam lobes. In a cam in block engine that is singularly the most important thing. However you decide to do the break-in should be focused on that. Everything else will follow along.

 

[Antichrist]

This is a VERY contentious issue. Ask 3 experts and you'll get 4 opinions.

That's because different engines require different procedures for break-in. For instance, my Perkins required immediate running under moderate-heavy load (not severe load) and definitely not allowing it to idle. Others need the opposite.
The best break-in is usually what the mfg says.

 

[ntsqd]

That makes the assumption that the engine was rebuilt either by the factory or exactly as the factory builds the engines in the first place. I wouldn't discount what the factory has to say, but I would consult those with experience with the engine family in question. There are too many varibles involved to strictly adhere to the mfg's guidelines without regard to who did the work. Just changing from a chrome ring to a moly ring would substantially change the best practice.

 

[DaveInDenver]

The 30 minutes thing; eh, to me the last 1/3 of that or so you're pumping oil full of small metal particles through the engine. I'd stop at ~20 mins and change the oil. Recall that no load reving isn't exactly healthy for the engine either.

That was my logic on first start. No load isn't good on the bottom end, but on the first start the combustion pressure needs to be sufficiently high right away to help the rings take the hone quick enough and harden the cam and rocker faces. One thing to remember is at idle your oil pressure is very low and that's a fast way to ruin a new engine, insufficient oiling. So keep the RPMs up a little at first.

I cranked the engine with the ignition pulled in 15 second bursts until the gauge showed pressure, then did about 20 minutes varying the RPM from about 2000 to 3000 gently with 5W30 dino oil and 100% pure distilled water in the cooling system. Drained both (you'll be surprised how much crap is flushed out of the coolant passages) and changed the oil filter after that, refilled with 10W30 and 50/50, then did a few idle to high RPM pulls to begin the next start. After that, just drive it more or less what I would call my normal hard driving. I tried not to baby it, but I couldn't bring myself to beat it up like a 16 year old again. Still, I hit the on ramps as hard as I could, pulled away from stop lights just shy of catching the eye of John Law. I never held one RPM, changed oil at 500 and 1000 miles before going to a 3000 mile routine.

Personally, I think the key points are to make sure you pre-lube the cam and prime the oiling system, keep from idling right away, don't hold one RPM for more than a minute or two in the first few hundred miles and change the oil often.

 

[blueeyeddevil]

Do whatever you like. Don't stay at a RPM too long & CHANGE THE OIL @ or before 500 miles!!!! In my opinion give it hell while the tools are still dirty. If its going to come apart, it will. If its not, it won't.

 

[Antichrist]

That makes the assumption that the engine was rebuilt either by the factory or exactly as the factory builds the engines in the first place. I wouldn't discount what the factory has to say, but I would consult those with experience with the engine family in question. There are too many varibles involved to strictly adhere to the mfg's guidelines without regard to who did the work. Just changing from a chrome ring to a moly ring would substantially change the best practice.

Yeah, I'll agree with you there. Most of the engines I've rebuilt have a very narrow range of cylinder/ring material available, and the mfg covers them all in break in procedure. When you get to engines with more aftermarket parts, it varies more in what to do.