Break in after rebuild

[nixtux]

I was wondering what break-in procedures are recommended when you rebuild the top half of a motor?

pistons, cam, LIM, UIM, valve springs, pushrods, ect ect ect.

A hair off subject but I was wondering if anyone had any suggestions where to get replacement bolts. I'd like to replace most the bolts as I dig in but I'd also like to have them somewhat handy. Many of the bolts are mildly stripped and I can only imagine trying to take them off again.

Thanks

[latemodelnewbee]

For the cam if it is a flat tappet cam put conventional diesel oil in the motor (not synthetic), diesel oil has a higher zinc content for better lubrication and breakdown resistance. Keep the motor between 2000-2500 rpms for 30 minutes (don't maintain any given rpm slightly rev it) you don't have to do the 30 minute at once but don't let it idle at all. Change the oil afterwards.
For rotating assembly if you did rings and bearing again use diesel oil. Don't maintain a consistant rpm and no more than half throtle and 3000 rpm's. It's overkill but I go for 500 miles change the oil then another 500 miles change it again, and thats when I put in synthetic oil or if synthetic is to expensive continue to use diesel oil and change the oil on a normal schedule. I have done this on every motor that I have build from a little briggs and straton lawn mower motor (execpt for the milage) to an all aluminum blown 496 big block chevy for my buddies camaro

[tractorman]

I've been building engines for 12 years... mostly diesels, with some automotive engines here and there. I'd agree with all of the above except for a couple of points.

If you're going to run synthetic, I personally wouldn't use it for at least the first couple of oil changes- to give things time to break in.

Also, my breakin procedure is a bit different: Run the PISS out of it the first day... drive normally thereafter. That's it- nothing more techincal than that. It'll help seat the rings. And if anything breaks or leaks, then it never would've held anyway.

You didn't mention exactly what engine you're talking about, but if it has roller lifters, then cam break-in is a non-issue. I've heard lots of talk over the years about magical assembly lubes, break-in-procedures, and assorted rain-dances for NON-roller cams. Personally, I just assemble them with engine oil, start the engine, and forget about the cam.

[nixtux]

I'm buying up parts for a 3.4 out of a 2004 Malibu /w 20k.

I got my engine stand, plastic laid, and the room is clean. I'm hoping to block off a weekend in the next month to rebuild the top portion for a turbo project for my Cutlass.

Basically my first attempt at this but a friend is going to assist me (hence the month time frame.) I'm just looking for suggestions and experience for break-in. I've read various "blogs" about break-in for various rebuilds. But I've only found full rebuilds so I'm not sure if there are any differences between the top and both. Also I didn't find any for a pushrod motors mainly S/D/OHC. So I wasn't sure if those are any different.

[latemodelnewbee]

I've been building engines for 12 years... mostly diesels, with some automotive engines here and there. I'd agree with all of the above except for a couple of points.

If you're going to run synthetic, I personally wouldn't use it for at least the first couple of oil changes- to give things time to break in.

Also, my breakin procedure is a bit different: Run the PISS out of it the first day... drive normally thereafter. That's it- nothing more techincal than that. It'll help seat the rings. And if anything breaks or leaks, then it never would've held anyway.

You didn't mention exactly what engine you're talking about, but if it has roller lifters, then cam break-in is a non-issue. I've heard lots of talk over the years about magical assembly lubes, break-in-procedures, and assorted rain-dances for NON-roller cams. Personally, I just assemble them with engine oil, start the engine, and forget about the cam.

I said not to use synthetic at first wait till a thousand miles. Running the piss out of your motor might be good if like rebuilding your motor every 6 months, you have to let the rings seat. If you just use engine oil on a flat tappet cam and forget it you might as well forget about the motor running until you put another new cam and break it in right.

[ForcedFirebird]

Engine braking seats the rings as well (down shifting).

[geoffinbc]

Wasn't there an article on this site about break in?

Anyways. In the first paragraph there was a mention of piston replacement. If this is the case then it is more than a top end rebuild. You basically have to follow any new engine break in. There is a break in guide on GM Performance parts website. So if it is good enough for them it will be good for you.

Flat cams do need some attention but nothing crazy. Some moly lube on the lobes and engine oil on the bearings. Run conventional oil and the cam break in concentrate that come in some packages. With the spring pressure you will be running there should be no issues with the lobes.

[tractorman]

If you just use engine oil on a flat tappet cam and forget it you might as well forget about the motor running until you put another new cam and break it in right.

I can say with certainty that you're not speaking from experience. You're parroting magazine articles.

I've built DOZENS of diesel engines with flat tappets, and a dozen or so gassers, too. I lubed them all with engine oil, gave ZERO consideration to any cam-breakin-voodoo procedures. To my knowledge, they're all still running with the valves moving happily up and down.

To be fair, some engines DO have issues with cam break-in... generally camshafts with high lift and excessive valvespring pressure. Hence the Hot Rod Magazine articles that you're repeating. It's largely irrelevent to this discussion, though.

Running the piss out of your motor might be good if like rebuilding your motor every 6 months, you have to let the rings seat.

You run the piss outta the motor precisely TO seat the rings. If you don't run the engine hard... they won't break in properly. Been there... done that.

Exactly how many engines have you broken in?

I'd estimate that I've broken in a couple hundred, easily.

[tractorman]

Flat cams do need some attention but nothing crazy. Some moly lube on the lobes and engine oil on the bearings. Run conventional oil and the cam break in concentrate that come in some packages. With the spring pressure you will be running there should be no issues with the lobes.

That's an interesting point about moly lube. I worked at a John Deere dealership for a few years. I was rebuilding an oddball french-built inline-six diesel out of an industrial loader (flat-tappet engine). The book specifically said to coat the entire camshaft with BLACK MOLY GREASE. Damnest thing I ever saw. Just for laughs, I did just as the manual said. It turned the oil black instantly upon startup, but seemed to work fine.

Regardless, Nixtux is talking about a roller-cam engine... this discussion is moot.

[nixtux]

I found the below link. It's for new cars and break-in I'd assume that's a fair guide short of first run and whatnot. For the initial start, by run the piss out of it what do mean?

http://wheeltalk.fancal.net/?p=449

I'm planning to use a 4T65E-HD sent to the wbodystore. I've done little research at this point. But I've heard pretty good feedback about them from various forums. I'm also looking for a place to purchase shorter axles.

http://www.wbodystore.com/grandprix/...ons-p-140.html

I'm going a bit slow on this project as I want it to be a long lasting machine. And it's only been above freezing a couple days this month. So I'm fixing a room in my house for the motor build.

There is a old shop next to me which I'm hoping my landlord will let me rent. It was used for maintenance on the Fuel trucks. So it's heated and has piping for air hoses. And just a wealth of awesome shop tools. It sounds promising...

Thanks for the wealth of advice

[95Grand-Am]

Follow your cams manufatures advice for cam beak-in. Which won't make a differance with a roller cam. But I agree with tractorman with the ring break-in. It has been proven that an engine that has the ring loaded while the hone marks are fresh will seal better, and there foremake more power. accerate then let off and the the engine slow the car do this a good number of times and the rings will seat in. Thats how I break-in my new engines.

[latemodelnewbee]

I can say with certainty that you're not speaking from experience. You're parroting magazine articles.

I've built DOZENS of diesel engines with flat tappets, and a dozen or so gassers, too. I lubed them all with engine oil, gave ZERO consideration to any cam-breakin-voodoo procedures. To my knowledge, they're all still running with the valves moving happily up and down.

To be fair, some engines DO have issues with cam break-in... generally camshafts with high lift and excessive valvespring pressure. Hence the Hot Rod Magazine articles that you're repeating. It's largely irrelevent to this discussion, though.



You run the piss outta the motor precisely TO seat the rings. If you don't run the engine hard... they won't break in properly. Been there... done that.

Exactly how many engines have you broken in?

I'd estimate that I've broken in a couple hundred, easily.

Well what kind or motor have you built and desktop dyno doesn't count. Most of the motors I build don't put around with grandma at the wheel. When you build some nitromethane motors you can talk.

[tractorman]

I found the below link. It's for new cars and break-in I'd assume that's a fair guide short of first run and whatnot. For the initial start, by run the piss out of it what do mean?

Yes, I should've been more specific than "run the piss out of it". What I mean by that is that you should run the engine HARD for the initial break-in. Ideally, I'd run it on a chassis dyno like I do with trucks at work... but I doubt you have one of those layin' around.

So, for your purposes, I generally agree with 95-Grand-am's advice. I'll also add that once you have it pulling hard in second gear, you can run it against the brakes some... just to keep the engine loaded a bit longer without going stupid-fast. This should be done in moderation, of course. Half an hour of slowing/accelerating/making an ass of yourself on a relatively clear highway should do the trick.

As you read up on engine/vehicle break-in, you'll find that there are generally two schools of thought:

Most automotive manufacturers reccomend a gentle, slow break-in. In my semi-qualified opinion (12 years as a heavy equipment mechanic, and now over half way toward my degree in mechanical engineering having returned to school as an old man), such break-in procedures were chosen by accountants rather than engineers. IMO, an easy break-in is designed to minimize warranty costs, but is not in your engine's long-term best interests.

Most heavy equipment manfacturers and most professional mechanics, for that matter (not people who jack-off to HotRod Magazine), prefer a hard break-in. It'll help seat the rings and minimize oil consumption. And the reduced blowby will keep you engine cleaner over the long-run.

[latemodelnewbee]

Ok build your motors your way and I will build them my way and when my stuff runs like a top for years and and your stuff runs great for a season then craps out maybe you will listen to someone who builds 1000 horse street motors.

[tractorman]

Ok build your motors your way and I will build them my way and when my stuff runs like a top for years and and your stuff runs great for a season then craps out maybe you will listen to someone who builds 1000 horse street motors.

Ok. Let's compare resumes. Like I said earlier, I've been a heavy equipment mechanic for 12 years. I've worked at a Cummins dealership, a Case dealership, a John Deere dealership... and right now I work at a Detroit dealership. I've worked on engines 5-6 days a week, 8-10 hours a day YEAR AFTER YEAR. I couldn't possibly tell you exactly how many engines I've diagnosed, repaired, rebuilt/overhauled, and BROKEN IN. But I'd estimate that I've rebuilt (and broken in) a couple hundred engines in total, plus lots and lots of major engine work that didn't require a complete overhaul (you know... head gaskets and such).

Since horsepower is what gives YOU a stiffy... I'm currently working on a series 60 Detroit Diesel rated at 515 horsepower and 1600 ft-lbs of torque (that isn't a typo. 1600 ft-lbs. I'm practically GOD.). Like most heavy truck rebuilds, this one will be under warranty for something in the neighborhood of 200,000- 400,000 miles, depending on which warranty the customer opts for. Now, when I get this engine back together, I'm gonna do just like I've done with hundreds of other engines. I'll chain that truck down on the dyno and RUN THE PISS OUT OF IT for an hour. That will seat the rings nicely, and if anything leaks or breaks... then it never would've held anyway.

Now- back to that warranty of 200,000- 400,000 miles. Out of all the HUNDREDS of engines I've built during my stellar career, none has failed. Not one.

So let's hear about your little Hot Rod Fantasy. Exactly how many engines have you built? How long have they lasted? What do you do for a living? Again, I can state with confidence that you're NOT a mechanic.