Rebuilt Engine Break-In Time?
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Staging Lane
Joined: Apr 2012
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Rebuilt Engine Break-In Time? Hey guys, I've just recently had my engine rebuilt with ALL new internals and I am running the same bolt-ons as well. I was wondering what the average break-in time is for a rebuilt LS1. The only aftermarket parts that I have are an MS3 cam w/dual valve spring kit and TSP hardened pushrods, i believe everthing else is stock. These were the only parts that i had purchased myself so I am at least 100% certain of those. Any ways, i was told that I had to break in my cam for at least 500 miles but, I am unsure as to how many miles I should break in the engine its self. Any advice is appreciated. If you need any other information just ask and I'll do my best to asnwer as well as I can. Thanks again guys
Last edited by arock24; Sep 27, 2012 at 09:28 PM.
Thread Starter
Staging Lane
Joined: Apr 2012
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fixed.
You're not really breaking in the cam as much as you are breaking in the springs. Run them through a few heat cycles (some people say 300-500mi) and you'll be set. As far as the engine break in goes, basically you could throw in some conventional oil (thicker grade), change it @ 500 and 1000mi, then switch back to synthetic and drive it like you stole it
edit: some may not agree with running the conventional oil or think it's necessary but I don't see why it could hurt with all brand new internals. I personally would sleep a little better running thicker oil in there for the first 500-1000mi
You're not really breaking in the cam as much as you are breaking in the springs. Run them through a few heat cycles (some people say 300-500mi) and you'll be set. As far as the engine break in goes, basically you could throw in some conventional oil (thicker grade), change it @ 500 and 1000mi, then switch back to synthetic and drive it like you stole it
edit: some may not agree with running the conventional oil or think it's necessary but I don't see why it could hurt with all brand new internals. I personally would sleep a little better running thicker oil in there for the first 500-1000mi
Last edited by arock24; Sep 27, 2012 at 09:41 PM.
Teching In
Joined: Aug 2010
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I just got my motor rebuilt as well from Phoenix Performance, they recommended 5 to 6 heat cycles with Castrol 10w 30 and then change the oil. Put new Castrol 10w 30 in for the first event I do then switch it over to Mobil 1 15w 50 after that. But after the 5 to 6 heat cycles we ran it all out on the Dyno. As long as the build was solid and clearances were correct there should be no problems. This is a topic that there will be a lot of opinions on. Hope this helps. Also you could use your own personal oil combinations.
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TECH Fanatic
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From: Auckland, Nth Is, New Zealand.
A few heat cycles on the dyno when tuning, this will add a few miles, by the time tune is done you will be safe as to go WOT on the street.
Use a mineral oil only for 5000mls + if you have new bores & rings. only change to Syn when you are passed this point. glaze your bores and you will be stripping it again.
Use a mineral oil only for 5000mls + if you have new bores & rings. only change to Syn when you are passed this point. glaze your bores and you will be stripping it again.
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Staging Lane
Joined: Apr 2012
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Alright everyon, thanks for the info. As far as new bores and rings go, Everything inside the engine is brand new so ill be sure to use the mineral oil. Any more info from ya'll is more than welcomed. It's been almost a solid 8 months that ive driven my baby and i wanna make sure i do everything right so i dont run in to the same problems again lol. The machine shop is done with the engine and now i just gotta get put back in the car alond with my freshly rebuilt trany 
Last edited by Chevyboi09; Oct 7, 2012 at 02:36 PM.
Far as breakin the kicker is while a few heat cycles is good for springs before they are pushed hard the bores can seal better if pushed hard right away so there are valid arguments for a slow and gentle breaking and a drive it like you stole it breakin.
Ideally I think you would worry about the bores first because springs are a whole lot cheaper and easier to replace than it is to tear it down deglaze the bores and start over.
Ideally I think you would worry about the bores first because springs are a whole lot cheaper and easier to replace than it is to tear it down deglaze the bores and start over.
Thread Starter
Staging Lane
Joined: Apr 2012
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Alright so HEAT CYCLES... I'm new to all of this. Do i have to park the car in-between the 300-500 mile break-in period? I assume this is a "heat cycle"? As in I shoiuldnt drive it for that many miles straight? Say the 2 hour drive from my house to where i get my car tuned? And over how long of a period of time should i drive 500 miles at the earliest? Should it take at least 5 day or something or what? I'm not that knoledgeable in this subject obviously lol. just wanna make sure i dont mess anything up
Thread Starter
Staging Lane
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Well, I have the MS3 cam and as far as THAT cam goes, TSP said to break it in, on the initial start after install, sun it between 2-3K RPMs for 30 minutes. I'm sure this process applies to most cams.
"cam breakin" is for flat tappets.
IMO the only reason it is still recommended with roller cams is because if something is wrong with the assembly 2-3000rpm at no load is a lot less likely to destroy things than if you were seating the rings at 6000rpm on the road.
IMO the only reason it is still recommended with roller cams is because if something is wrong with the assembly 2-3000rpm at no load is a lot less likely to destroy things than if you were seating the rings at 6000rpm on the road.
Alright so HEAT CYCLES... I'm new to all of this. Do i have to park the car in-between the 300-500 mile break-in period? I assume this is a "heat cycle"? As in I shoiuldnt drive it for that many miles straight? Say the 2 hour drive from my house to where i get my car tuned? And over how long of a period of time should i drive 500 miles at the earliest? Should it take at least 5 day or something or what? I'm not that knoledgeable in this subject obviously lol. just wanna make sure i dont mess anything up
