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Safe rpm range for revving newly rebuilt engine?

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97eclipsegst4g63

Proven Member
36
0
Sep 1, 2015
Livingston, Louisiana
Ok so i have a newly rebuilt engine with only 25 miles on it an heard thats it is not to safe to rev the engine over 3500 rpm with in the first 1000 miles. Is this true?? I think im having a low oil pressure problem but need to rev higher then 3500 rpms to make sure my oil pressure goes up like it should. So let me know what you guys think about that. An if you dont think its true then please state your opinion thanks in advise!!
 
I have just recently rebuilt my engine as well, but i had a new clutch in with it as well so i broke that in (driving a little bit conservatively, but still using all the RPM ranges and loads following whats in that link jakk220 posted above) for 500 miles. Then i went to a lapping day with it the next day after and i recently did a compression test and it seems perfect!
 
Ive read the motomans break in secrets a couple of times but never recall seeing a safe rpm range. An is it normal for the 1g oil pump to whine an get loader with the rpms??
 
I would not sit there and free rev the engine all day. but reving it up and holding the rpms at 3000 to check the oil pressure should be fine. Do you have proper oil pressure at idle? How are you checking the oil pressure?
 
I would not sit there and free rev the engine all day. but reving it up and holding the rpms at 3000 to check the oil pressure should be fine. Do you have proper oil pressure at idle? How are you checking the oil pressure?
Yes i have good oil pressure at idle. Cold idle=50 psi, warm idle is between 15psi an 20psi. Around 25 psi at 2000rpms, 30psi at 3000rpms, but at 4000 rpms it only went up to 37psi which seems a really low to me an i dont think i should drive it what do you think?? An im checking the oil pressure with a 0-100psi mechanical gauge so my number arent exact just rough geussing because it goes in increments of 25psi an have lines have way inbetween witch would be 12.5 plus the number before it self
 
i would call English racing when they rebuilt my motor i know they said they broke it in for me (and there was defiantly not 1000 miles added) and they said i was free to bring it to any rpm i like, i recall them telling me its good to down shift and let the rpms come up something about the vacuum im sure they could help, they were really informative with me
 
i would call English racing when they rebuilt my motor i know they said they broke it in for me (and there was defiantly not 1000 miles added) and they said i was free to bring it to any rpm i like, i recall them telling me its good to down shift and let the rpms come up something about the vacuum im sure they could help, they were really informative with me
Okay thank you for the advice!
 
You don't have to downshift. Vacuum does help seat the rings. What I've done is take it up to 5-6,000 and let off the gas. Let it coast in gear down to idle, and repeat. Do this several times. If it's an auto, you can wire up the solenoids and make it stay in one gear so it decels/engine brakes properly.
 
I know some cam manufacturers recommend breaking in their cams if they are new to pattern the lifters and cam lobes for a few minutes at a specific rpm(v8 stuff). Then after i do that if i have good oil pressure and coolant temps and no weird noises or leaks i usually take the car out for a drive and do some steady pulls through the rpms and let off the gas and decelerate in gear(coast) to help seat the rings at different rpms. Park the car and let it fully cool and repeat a few cycles like this to seat rings and wear in parts. Go back and retorque bolts after a few heat cycles as well like your exhaust manifold etc because they can loosen up a bit. i read a great article about something similiar to this. ill post it if i find it
After that hammer down and let her eat! If you built something wrong, babying it wont make it last any longer
 
Parts DO need to wear in to each other and establish wear patterns with mating parts, take it easy on it for 1000 miles (stay under 3500 or so) and then go back and retorque everything and change the oil and filter. pay zero attention to any "motoman" BS, the person that wrote that nonsense has zero technical knowlege of engines and has been discredited numerous times.
 
Parts DO need to wear in to each other and establish wear patterns with mating parts, take it easy on it for 1000 miles (stay under 3500 or so) and then go back and retorque everything and change the oil and filter. pay zero attention to any "motoman" BS, the person that wrote that nonsense has zero technical knowlege of engines and has been discredited numerous times.

http://www.dsmtuners.com/threads/motoman-break-in-havent-seen-this-discussed.458306/
http://www.dsmtuners.com/threads/break-in-with-new-turbo-setup-suggestions.424744/

1) Drive the car like you plan to drive it for its whole life. Meaning, if you want the absolute best power output from her, go motoman all out. If you want longevity then be easier on it. (THIS DOES NOT MEAN KEEP THE RPMs BELOW 3500) Rings need to seat, and theres a reason you want to take the engine through its whole rev range under load and vacuum and not putt-putt it around at idle (this is why you avoid traffic and sustained rpms/speed on a new engine).

2) Oil pressure... if you are worried about it you should definitely get a better gauge. Do you still have balance shafts? Regardless, most people only worry about high oil pressure from removing balance shafts and oil squirters for turbo reasons. Don't be scared if you have lower numbers than others especially if you didnt do a bse.
 
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I break in all my engine at full power and full rev range on the dyno. First startup I run cheap 40 weight oil, Get the engine running and up to operating temp. Verify there are no leaks and make sure everything is good to go. After verifying everything is good to go I switch to the intended oil that plans to be ran on a daily basis and then it goes to the dyno for tuning.
 
start engine
Get it up to operating temp
Check oil pressure
Shut off engine and change oil
Go straight to dyno or highway
Do pulls until smoke goes away and you feel power level off
Go home and change oil
Drive easy until next oil change(optional)
Set records
 
The manufacturers make the break in procedures so a granny can hop in the car at the dealership, drive it to church on sunday, and have it last 100k+ miles.

I am not arguing that a motor might last longer after an easy break in, however none of us give a crap if we get 200k miles out of our built motor. We want power and it is a FACT that the better the rings seal the more power potential the motor has. It is also a fact that higher cylinder pressures will push the ring against the freshly honed cylinder walls harder which will create a more complete and ultimately superior seal between the two surfaces.

We do the motoman style to seat the rings then the following period of easy driving is to let all of the other components "break in".

None of the top teir racing engines in any sport are broken in easily. Do the top fuel dragsters break their 10,000hp motors in nice and easily? Not even the crappiest break in procedure in the world will cause a motor to fail, at the worst it will only shorten it's life span. If it fails during break in it was built wrong, simple as that.
 
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OP, after re-reading your original post it seems that you might have an oil pressure problem or at least you think you do, you need to find out if there is a problem with that before going further really. Running your engine over 3500 rpm is a bad idea during break in especially if you have an underlying oil pressure issue, you dont want to have to run it there just to maintain oil pressure. You should use a gauge to confirm your pressure and then if its normal you can run it at the lower rpm range during break in. Are you by chance using the forward facing housing? I have used them and had the pressure lower on the factory gauge myself.
 
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