All,
A couple of you have asked about how to break in rebuilt and/or remanufactured engines. Here is my opinion and I'll back it with the fact that I've had only one failure among 40 or 50 fresh rebuilds. Of course it was my own engine and my own fault for for not checking the machine shops work after having them install pressed in cam bearings correctly. This V8 a 7.8lt spun a cam bearing about two minutes into startup.
- Moral of the story: Always check other peoples work!
First a couple of pointers about what I do for preparation before assembly of parts which are known to have the correct clearances. If you want to skip straight to break in, its down below.
I'm sure I've left things out and will add them as time permits, this it just my opinion and what I do which has severed me well. Others will offer their opinion too so post the good and the bad.
1) Cleaning:
Clean all sealing surfaces for gaskets removing old materials, wash all parts in solvent. Heads, block, crank, and rod if not assembled to pistons. Edit(2010-08-04) I would like to point out that even the toyota service manual calls for using a gasket scraper on both the cast iron block and the aluminum head. I suggest buying a 1" wide wood chisel which you keep in your tool box. A nice wide blade which is kept sharp works well for removing old gasket material. I've always used them on aluminum and never torn, gouged, or destroyed critical sealing surfaces. Take your time and use the proper angle to cut away gaskets without harming the surface. Repeat until cleaning area shows no particles or machining residue in clean solvent.
If oil galley plugs are installed, remove them and make certain all oil passages are clean of free of debris! IMO, machine shops do NOT do this well enough. Use the right tool for the job and clean those galleys! Debris left in the oil feeds tear up new bearings and shorten their life. Purchase a galley brush cleaning set. Although, gun cleaning kits offer a variety of sizes which work well too!
2) Wash them!
Using detergent and boiling water, wash all of the above parts in boiling water. Do this long enough to raise the temperature of the metal to dry itself by means of evaporation. I suggest having an air compressor to blow out water and debris. Small parts that fit in 5 gallon buckets are easy. Dip repeatedly and agitate to free up debris. Flip heads over and do both ends if too long to fit in the bucket. Replace that boiling hot water often as pulling the hot head out will speed the drying process. With iron parts, pooled water equals rust. Here the compressed air is used help to Blow them off.
Apply ATF to iron parts to keep critical areas from rusting. Once dry and if still hot, apply your favorite rattle can color (if iron to prevent rust). Clear high temp paint is an option too! Now bag your clean parts to keep them clean! Bead blasted aluminum looks fresh after cleaning. Clear coat these with high temp clear rattle can.
Note: Just because your machine shop assembled the heads, doesn't mean they are clean and free of machining particles even if they said they're ready for assembly! YOU can always get them cleaner! There is ALWAYS crap left behind that will shorten the life of your new seals, bearings, rings, oil pump, ect. I've been to plenty of places and hot tanking does not remove everything!
*** YES, You Must Take Them Apart! *** which means you'll need a valve spring compressor. If you intend to do this extra step, tell the machine shop to leave the valve stem seals off so you don't damage them taking them off. Also grab a seal saver. It fits over the valve stem keeper grooves to protect the seal while the valve is inserted through the seal.
3) Engine Blocks:
Engine Blocks follow the same process as above but are much harder to dip. Use that same boiling water technique with a scrub brush and dump lots of water on it to raise the temp and speed evaporation of the water. Oil where needed to prevent rust. If painting, I spray gasket surfaces to seal iron pores. Not required on aluminum. . . Bag the block to keep it clean.
If the hot water option isn't working so well, the local car wash may have high pressure hot water. If you do this, warm the block/parts with a space heater as hot as you can get it, haul them over to the car wash, clean them, bag them, get them home, blow em dry as soon as you get there and place them next to heat to dry.
4) Lube & Assembly:
Most parts except reciprocating parts (crank mains, rod bearings) can be assembled with straight weight motor oil. 20 or 30 weight is good. The only advice I have here is that new ring and piston materials may have recommendations for assembly lube and break in. Take their advice! Beyond that, saturate all moving parts with engine oil. Soak chains, lube valves and put seals of any kind together packing the inner lip with white grease. The tip here is NEVER put them together dry! Use assembly lube, motor oil or white lithium grease.
- Rod and main bearings should get assembly grease although I use a mix of grease and oil myself for these bearings.
- piston rings, before fitting the piston and ring assembly to the block, dip the whole piston top in oil and don't forget to lube the wrist pin allowing sufficient time for the oil to penetrate into the assembly. You loose most of this oil in your ring compressor so don't worry too much about having Too Much Oil!
- Camshafts, once you know the cam bearing clearances are correct and the valve lash is correct (done with feeler gauges ect), apply liberal amounts of engine assembly lube to the cam lobes to ensure the cam has lubrication during engine start up. During start up the cams and valve train are almost always the last to receive oil from the pump.
6) Torque:
Clean all bolts and holes to ensure bolts have the proper torque applied. I can not stress enough that bolts that bind in the threads will give false readings and incorrect torque readings!!! Clean and oil all threads for correct torque readings. Follow manufactures sequence for applicable patterns, counts, degrees of rotation, ect when doing cylinder heads and use new bolts where applicable being sure to apply a light amount of grease to the bolt heads washer and lightly oil the threads. Here the lightest oil is best so you don't hydra-lock the bolt with oil in a blind hole. I recommend you take a head bolt, main bearing bolt, rod bolt, (any critical bolt) and thread it to depth by hand or with a speed handle to make certain the bolts thread freely to or just beyond the depth required. If the threads bind, correct them!
** Use a known GOOD TORQUE WRENCH, that hasn't been used a breaker bar! ** Use a torque that is within the range needed.
7) Gaskets:
Paper, cork, and dry type gaskets should be coated with sealant to prevent them from weeping oil and antifreeze months down the road. I use Spray on Copper Coat and spray both sides and all edges of the gaskets.
I pulled an engine I built which had been in use for 18 years and had some 250,000 miles on it since I rebuilt it. It was clean in every direction with no leaks from anywhere! Copper Coat works! Use it!
Silicone, be careful with the application of this stuff as it can break free and plug oil pick-up screens, oil galleys, returns passages, and other small ports and kill your engine. Areas like the oil pan has lots high velocity splash that will knock excess silicone free and cause problems. Silicone in quantity will likely displace cork pan rail and even paper gaskets. Its slippery on things it can not bind to. Silicone should only be applied to cork where sharp angles meet that the cork/paper material can not seal on its own!
When parts fit and align correctly, there is usually only a very small gap if any between the parts. A 1/4" wide bead of silicone on a 3/4" wide pan rail is more than enough to seal a form in place pan gasket (FIPG). If in doubt about how much to apply, pick a couple spots, apply your silicone and fit the parts. Push them firmly into place and pull them apart. you'll get a pretty good idea of where the sealant went and how much is needed to fill most gaps. Apply less towards the inner pan rails, valve cover gasket rails and more towards the outer edge of the sealing surfacel. Circle all bolt holes but not in excess.
Before final application of any sealants, wipe the surface with a clean lint free cloth soaked in lacquer thinner. For a leak free bond there most not be oil present! Wipe surfaces until there is no evidence of oil and then apply sealant to those surfaces. Follow working times and cure times stated by the manufacture!
>> Excerpt from Toyota Service Manual, edit 2010-07-29
FIPG PRECAUTIONS:
When working with FIPG material, you must observe the following.
• Using a razor blade and gasket scraper, remove all the old FIPG material from the gasket surfaces.
• Thoroughly clean all components to remove all the loose material.
• Clean both sealing surfaces with a non–residue solvent.
• Apply the FIPG in approx.1 mm (0.04 in.) wide bead along the sealing surface.
• Parts must be assembled within 10 minutes of application. Otherwise, the FIPG material must be removed and reapplied. If the vehicle is equipped with a mobile communication system, refer to the precaution in the IN
section.
>> End excerpt.
8) Seals:
For an Seal to be effective, its outer perimeter must be sealed to the surface, the rotating assembly must be free of nicks, burs, varnish, rust, excessive movement, and the sealing surface itself needs to be pliable, true, and elastic yet have retention. Not too much or the seal burns or too little the seal floats allowing oil to escape.
- When installing seals always grease the inner lips so it has some residual lubrication to keep the sealing edges from burning and getting hardened during initial startup.
- Pack the spring retainer area full of grease, grease the shaft, and most important grease the inner lip area where the seal contacts the rotating assembly. Failure to do so will result in failure of that seal.
Next is the installation, I try to fit seal to the landing before i pound them into place to make sure I have the right one. Example is sliding the seal onto the crankshaft before I install the crank into the block. Its better to know now than to pound it on and find the outside is the correct diameter but the inside is not.
During installation avoid using small hammers and drivers that can ding the surface. If you distort the shell, it often distorts the inner seal and soon you have a leak. Replace seals which get damaged during installation. Make sure the seal is flush and square to the surface, and fully seated but not drivin in too far if there is no positive stop. I use sockets, inner, outer bearing races, items that fit snug onto the seals outer shell and drive them with a large hammer and intent. By intent I mean, if it lines up nice, drive it home but don't damage it. Hint: save old bearings, races, sockets, pipes that can be cut off ect. They make good drivers for installing seals.
9) Final Assembly:
When assembling the Crank and rod/piston assembly to the block, turn the crankshaft the minimum amount of rotations to complete the whole assembly process. The more you turn the reciprocating parts, the more your assembly oil and grease is displaced away from the bearings, cam lobes, rings, ect. . . . In the case of engines with the oil pump driven directly by the crankshaft, there is little to no ability to prime the engine oil feeds and the assembly lube is vital to preventing friction and wear of new parts. No oil means, increased friction. Increased friction equals heat and damage to new parts! So be careful while putting the timing belt on and avoid excessive rotations of the crankshaft.
Note: When things fit right most reciprocating parts move by hand. Look through manuals and shop books and often times they'll tell how much torque is required to turn the crank shaft while in new bearings with and without new seals. They also go on and tell you how much drag is created by insertion of one piston and ring assembly (torque required to rotate the crankshaft). Remember; rotational friction from start-up is much greater than friction in motion. Example - it will take higher torque to get movement than it will to maintain movement.
10) New engine start up and break in:
In short, once your engine is in and everything is connected and double triple-checked its time to add fluids. If i ever feel there is a possibility of a anti-freeze leak I use water and seal conditioner for the first run as it makes a great flush to get the cooling system clean and it will be dumped in the next 50 to 100 miles. When there is no doubt that things will OK - I go straight for antifreeze and water mix.
If you have a distributor, set the engine to TDC with all valves of the #1 cylinder closed and align the distributor so the rotor is pointed to the #1 cylinder on the distributor cap. With this complete, the igniter pickup should be aligned to the counter wheel. I may be mistaken, but I think most of the p/u triggers create a pulse to the electronics upon passing the highest bump, thus the trigger is sent upon the falling edge of the counter ring. Rotate the distributor to at least begin with a zero degree advance but follow specifics to that engine for setting the initial timing advance.
As for the oil, I use what I intend to run daily with a variation that synthetics may not be a good choice for break in as they can extend the time it takes to properly seat the rings and yield proper ring to cylinder clearance. Having said that, its almost always safer to use petroleum products than synthetics. Again, consult the piston/piston ring manufacture and machine shop for the best recommendation.
Me, I'll use dino oil and plan on changing it at the 500 mile mark. On engines with flat tappets cam break in is required although I suspect few of these will get new cams so this is a bit of a grey area for break in. Follow the new cam break in procedures if you use one. Otherwise apply these simple rules.
- once the new engine is fired up immediately begin checking for leaks of oil and water. Look everywhere but the goal here is to make sure its running correctly, has all of its fluids and is not over heating. Don't forget to fill those transmissions if the ATF was dumped. There's a allot to keep an eye on so get a helper to fill the transmission.
New cams require break-in at sustained RPM to ensure lots of cooling oil is spraying everywhere. Typically above 1800 RPM will do the trick for about 20 minutes. Used cams are still fitting themselves to new hardware and I can't see how this process would hurt them so I'd apply it there too.
Once your engine is up and running and has everything dialed in, here are some driving recommendations:
* Don't Lug it this makes heat! and incredibly high cylinder pressures, piston loads, bearing loads. Let it free rev and maybe even turn the over-dive option off in town.
* Don't hold it at steady RPM's. Changing the RPM makes sure cooling oil is sprayed everywhere and everything gets lubed and cooled! This includes freeway use; Vary the RPM's ALL the time as holding steady RPM's oil tends to sling in very specific patterns this may not lubricate and cool everything.
* Do not set the cruise control. Vary the RPM's as you drive.
* During the first 30 minutes use at least 55% of its potential. Check for leaks & over heating. Allow to cool if too hot.
* After 30min of run time use at least 75% of potential output. Don't be afraid to momentarily take it to red-line by accelerating quickly. Not stab it to the floor but a brisk increase to red-line and let off slowly.
If you plan to rev it to the limit later in life; don't baby it now. That doesn't mean tach it out 6000, but exercise the range of use you intend to use it at following the rules above.
Its OK to rev it lightly just don't do no load static revs over 3500, Don't hold the gas steady, Don't pull long hills in high gear ect . . . Rev it lightly, it won't hurt it promotes cooling via good oil circulation. Don't run it lean and confirm the timing is right. Both of these make lots of heat. Avoid that!
EDIT: Since writing this I've stumbled upon a couple of articles that support "use the entire RPM band early on!" If you checked all the clearances in the engine and everything is within specification, rev it up, use it, and let it work in the upper RPM's. Your goal is to seat the rings quickly for long lasting engine that doesn't burn oil. Driving about never exceeding 3000RPM will not accomplish this! Again, follow the rules!
That's the nutshell and what I've always done for break in during the first 2000 miles or so. Break-in can vary depending on many things including the drivers habits. Hint, babying it and lugging it, build heat and wear patterns. Then, one day when you stomp on it thinking its all broken in, but it never really rev'ed over 2500 RPM and WHAM, you bust the top rings. Don't kid yourself. Mechanical parts stretch. Putting around thinking this is best is a myth. Just rev it lightly through the gears so as not over-rev and not to lug it. Because we have automatics, run the lower gears and change the speed often so that cooling oil gets everywhere.
Indicators that engine rings are not seated: aka broken-in; engine smokes, engine burns oil, compression is lower than expected, compression from cylinder to cylinder varies by more than 10PSI on new pistons, rings, valve job. ** THAT IS NOT to say, ignition, fuel and other factors could affect cylinder pressure. They can. **
Change the oil and filter in the first 500 miles dumping the oil into a clean pan so you can look for particles should something be going wrong. IF, IF you suspect anything at all, cut open the oil filter and look at the contents. There really shouldn't be any!
We'll thats about it. Listen and pay attention to all the small details.
After the first 500 miles I short cycle the oil changes to 1500 miles and look everything over pretty good until it hits the 5000 mile mark and I think everything is OK. (primarily leaks and such)
I hope this helps,
73
Edit history:
2010-08-07, Added section on
OIL SEALS.
2010-08-04,
1) Cleaning, even the toyota service manual calls for using a gasket scraper
2010-07-29, Added FIPG application direct from Toyota Manual AX1 page 2.
2010-05-10,
9) New engine start up and break in:, added comment about "use the entire RPM band early on!"
2010-04-26,
4) Lube & Assembly:, added details about Camshaft lube.
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Tags: break-in, break in, startup, start-up, start up, New, rebuilt, remanufactured, reconditioned, oil, filter. . .
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