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As so as I get the cam gear and intake back on, Im finally done. Getting ready to put the rebuit motor back in this weekend. What is the best way to brake her in? I was thinking about taking a nice 100 mile trip to our farm. Staying at about 50-55 mph, and changing oil when I get there. Is this a good way to "seat" everything, or is stop and go better? Dennis
 

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I was told to run the engine @ 2,000 rpm for 20 minutes at start up to seat the cam. then go easy on it with small load-no load driving. (curvy country road) then change oil @ 500 miles, and drive it like you would any other engine. Just my $.02 Good luck w/ the new powerplant!;)
 

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From what I have read and heard and what I also did on mine this summer is the first time you start it up and get the timing set, rev it up to differnt RPMs holding it there for 5 or so mins each. Like start at 3500 and then back it down to 1500 then back up to 3000 or so, there are a couple of sites that explane it. After doing that for 30 or so mins and if nothing goes wrong, drain the oil and look for green stuff and metal shaving, easy way is to strain threw a cheese cloth or somthing. Filler back up and like you said just drive and keep it under 55 or so for a little bit, I think the drive to the farm would be a good one, and change the oil when you get there.
I have also heard that you should start right of drivnig it like you plan to but I dont know how true that is.
Hope that helps a little.
Justin<><
 

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Thanks, I sure am looking forward to it. I tore it down and did everything except valve seats, cam bearings, and of course the machine work. I have been putting her back together this week. The anticipation of firing it up is killing me!!!!! Dennis
 

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I've rebuilt a few motors and helped rebuild a few more.

The highest RPM that I bring the engine up to before that first oil change is half the redline speed. Meaning if you're never going to spin it over 6000 rpm, then take it really really slow up to 3k, work down real slow, work back up real slow, holding it at various different speeds along the way for a few minutes each.

I spend about 30 minutes doing this. I also never put a load on the engine before the first oil change, meaning I don't drive it or put it in gear. (Just my own superstition)

Change the oil, look for bits like he said, check the coolant for oil contamination. I usually take it easy for the first 1000-ish miles, no more than 2/3 of redline, change the oil again, then beat the hell out of it.

Oh yeah, check and double check your timing and tuning frequently during break in. You'd hate to blow a brand-new motor by leaning it out or having your timing go haywire..

-tom
 

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The biggest reason that people say to rev and engine to 2 k and hold it there for 20 minutes is because when you have lifters running on a cam surface they need to spin in their bores to get a non directional wear pattern on their faces. Another reason is so that everything will sling the assembly lube off during inital startup so that the oil can coat everything. Roller lift cams dont necessarily need to be run like a flat tappet cam because there arent as many wear surfaces to be run in. Another reaon to run an engine up in rpms is to make sure that the oil gets hot and flows everywhere it needs to be and flushes the little metal particles away from the freshly machined metal surfaces, i.e the rings seating in the cylinder bores. This is all based on what I have gathered form being around people that build engines, anyhoo enough of me rambling good luck with your new powerplant.

l8r

-j-rOd:D
 

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Do the 20 min cam break in period, change the oil. After that just enjoy driving it. I was actually too damm easy on my motor after the rebuild, and never managed to get the rings to seat. Annoying as hell!

Acouple of my buddys that build race motor, actually break in the motor on the engine dyno! They do the cam break in for about 10-15 mins, set the valves, and then do acouple of dyno runs. Most all of their motors last all season, the ones that don't are usally purchased buy the guys with rich parents! You would think that after multiple holes in blocks due to over revs, these kids would start to learn.:rolleyes:
 

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sunshineoffroad said:
I was told to run the engine @ 2,000 rpm for 20 minutes at start up to seat the cam. then go easy on it with small load-no load driving. (curvy country road) then change oil @ 500 miles, and drive it like you would any other engine. Just my $.02 Good luck w/ the new powerplant!;)
exactly what I did with my motor and it turned out great!
 

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onetoncv said:
If your running a larger cam - the racers go to a 1.3 ratio for break in - Jesse :D

And if they dont use a 1.3 ratio rocker sometimes they will leave a valve spring out (of a double or triple spring set) during break in and then put the spring back in once its run in.....
 

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Some good points brought up here, but I would like to toss in a plug about oil. Make sure you do not use synthetic oil for at least the first 10K miles. Synthetic oil works too well and instead of wearing in, surfaces will gall instead.
 

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Busto said:
Some good points brought up here, but I would like to toss in a plug about oil. Make sure you do not use synthetic oil for at least the first 10K miles. Synthetic oil works too well and instead of wearing in, surfaces will gall instead.
Had an engine guy tell me this also.... this post has turned out some pretty decent tech this evening gents.
 

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What, exactly, is seating the rings, and seating the cam? Where do they seat to?

I understand the seating of bearings and I think I understand the seating of valves, but rings and cam? :confused:

-t
 

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Seating is more or less the actual contact surfaces of the metal parts that touch gaining a similar texture and finish through the process of rubbing together..... kinda like brake pads and rotors....
or like a pair of shoes ends up conforming to your foot after a while of wearing them.

When an engine is first put together the surfaces are sharp and unfinished and when they get broken in they conform to each other and seal after the friction of the running engine polishes them together. Very similar to bearings.
 

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I have always changed oil in the engines right after running it around 2 grand to break in the cam and lifters. Used a synthetic?sp oil in a buddies motor because that is what I'm gonna run in it,lost that engine to a bad cam? I think it was the oil my self. Most of the stuff that I build for myself and my friends the cam gets broken in and then run like you were gonna run it. The engine in my dually was broken in oil changed hauled racecar to rogersville 2 hr ride and back home when we finished racing. Put right at 200 thousand on it before a headgasket popped. I think the cam break-in is the second biggest thing to checking cleanances and making sure every thing is clean before putting it together.
 

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DO NOT USE SYNTHETIC OIL for the first 500+ miles...it will seep past gaskets and leak from day one...guarenteed!

As for break in, run the car up to 10mph, then use compression breaking, then 20mph, then 30mph....or as fast as u can take it.
 

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NON-DETERGENT 30W. Use it for first fire up, drain and replace filer. NON-DETERGENT for at least 500 miles.... usually I go with 20-50 Castrol (older engines) after that, or Synthetic.

GM additive. Anyone have the part number of the additive... only used once for NEW ENGINE break in period... then change at 1000 miles.

Interesting tidbit from Porsche: They "dry run" (oil is added, no water, nor fuel) by hooking it up to a giant motor and running the sucker at redline for 30 minutes! Reason for no water nor fuel is to reduce hazardous spills. Obviously they have oil in the engine. Just that way when someone buys a new one, and hits the Autobahn... engine is fully ready to go! They also measure the power of the polyphase motor to calculate engine performance on a cylinder by cylinder basis to catch any potentional problem. I don't have the rereference, but it was a SAE tech article a few years back.

tradin1... no problem on sepage with a NEW motor, but had a few with rings that never seated. Someone else did the motor, ran synthetic oil, and always smoked. Pulled pistons, berryball honed it, new rings... ran fine after that. Cylinders were glazed.

LandCroozer... every notice how hot the engine runs after a rebuilt. Lots of friction between cylinder walls and the rings. That is what needs to "seat in". Basically any metal to metal area is peaks and valleys... so you start with the Rocky Mountains.... then get Texas Hill country landscape! :)

Tom :usa:
 
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