SDPC Tech Tips: Engine Break-In
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- Опубліковано 15 лип 2024
- Pick up a new crate engine or finish a build and getting mixed feedback from your friends, the machine shop, or the directions from the manufacturer on how to fire up and do the break in procedure?
Nick goes over some do's and don'ts as well as what tends to be recommended from our suppliers like Chevrolet Performance for that shiny new crate engine.
#SDPC #SDPCRaceshop #BreakIn #HeresJohnny #ChevroletPerformance - Авто та транспорт
I'm going to take a chance and share a little aircraft piston engine break-in information on a car channel but I think it's good relatable information. Running in the crank and rods probably goes back to the the babbit bearing engines like the Chevy 216 but no longer necessary with bearing inserts and better machining tolerances. So the primary focus is seating the piston rings to the cylinder wall to establish a good gas tight seal. One recommended procedure for in airframe break-in that I have used successfully for many years is takeoff and initial climb at full power and then 65%-75% power for 1 hour. The idea is you want the rings to rupture the oil film and create a certain amount of metal to metal contact between the rings and the cylinder wall to rub off the peaks on the rings and cylinders to create a better gas tight seal. Once this process has completed there is very little metal to metal contact that occurs during normal engine operation between the rings and cylinders. Some of the compression and combustion pressure ends up behind the ring by design and this pressure helps to push the ring towards the cylinder wall and helps to rupture the oil film during break-in which is why a higher power setting is required. Normal engine automotive or aviation oils contain additives that help with oil film strength making it harder for the rings to rupture the oil film for the desired metal to metal contact during break-in. The desired metal to metal contact that occurs during break-in also creates friction and higher than normal cylinder wall temperatures that can cause additives in non-break-in oil to glaze in the honing grooves of the cylinder wall which inhibits proper ring seating and high oil consumption. Once this glazing has occurred during the break-n process on a piston aircraft engine the only remedy is to re-hone the cylinder to remove the glaze. A loaded break-in procedure was also recommended by tractor manufactures like David Brown, International, Case etc. for the same reasons as stated above.
I didn’t realize the “glaze” was oil additives. I thought it was the metal “glazing” and turning to a mirror finish.
At initial start up idle it up around 2500 rpm for 20 minutes checking for leaks and keeping a close eye on water temp & oil psi. Around 15 minutes into the first 20 minutes you want to rev it a few times to 4 to 5k nothing crazy just quick revs. Pay close attention to oil psi when you Rev it. Above 80 lbs once hot, can damage coated bearings. Ideally you want 40 to 60 lbs hot psi at higher rpm. Idle will probably be around 25.
Once all that is checking out the builder will start doing dyno pulls progressively getting more aggressive. By the time the engine has an hour of run time it's already been broken in ready for the track unless more tuning is required.
Another great SDPC video !
Useful! 😅
Any special considerations for Alusil engines?
What about boosted motors? Stay out of boost presumably for the first 1000 miles?
I was told by a summit rep that I could use 5w20 in my LQ4 not 5w30
I got a new motor, and couldn't find break-in oil or conventional motor oil. I had to use a regular synthetic blend.
First oil change at 100 miles, second oil change at 800 miles, and a third oil change at 3k miles. Which 3k is when I swapped to fully synthetic. I drove it conservatively for that first 100 miles, more aggressively from 100 to 500 miles, and then drove it the way I normally would after 500 miles. Which is a mix of conservative and aggressive driving.
That may not be how it's supposed to be done, but everything seems okay. Not burning any oil or making any strange noises. I have about 8k miles on it now.
There’s additives including zinc you pour into your conventional oil.
BREAK IT IN ON THE DYNOOOOOO
How many miles to break my Gen 4 Coyote?
I keep hearing "High Performance" engines, what is considered as high performance?
A V-6 VVT?
A Dodge SCAT PACK?
A Corvette LS7?
The last two should be, but the first one?
What about new car engines?....
Every engine needs break in and heat cycles IMO! Flat tappet cams its non negotiable!!
The idea with not using synthetic oil for break-in (even if it's a synthetic break-in oil) is that the uniform molecules provide too much friction and actually prevent the rings from sealing correctly. The same reason as to why you should use conventional on the first few oil changes, as I've been told it's essentially until you are happy with the amount of oil the engine is burning. Very good sealing should me no oil being burned. Now from research I've done GM and some very high-up shops (perhaps you guys too) have special honing techniques that allow for the use of synthetic oils immediately and shorter break-in periods. The more inconsistent the honing the the longer the engine should be run on break-in oil, before switching to conventional then synthetic. Generally what I've found researching this is to run it very similar to what the aviation guys would do.
First - Heat cycle it, and check for leaks as you said, the engine has a lot of friction from the rings wearing let it run for about 10 - 20 minutes. Vary the rpm and don't apply any load. Let it cool off, perhaps change oil and filter and check for any debris
Then take it out, on a road racing track just send it, street driving as you said vary rpm, no lugging, but also no hard engine braking (lugging i think slapps the skirt a bit, engine braking pulls oil past the rings and can glaze the cylinders). Full throttle is good, Load is good, just try to not over do it, vary the rpm and let it cool a little after larger load and WOT
The aviation guys are pretty much doing a run up then a test flight then send it on it's way. Run up is leak test, 1500rpm for a couple minutes. Test flight is full power to reduced for climb.
Saying different break-in styles all "appear" to work is sorta misleading because you can break an engine in okay, and it will run 200k miles, but it will always burn more oil, and coat the top of the piston with blowby compared to one that's broken in correctly. There is a website where they went through exactly whats going on.
GM can't drive new vettes or Camaros...........so how do they break in every LS or LT engine before it goes to the dealerships?