Need Tips on breaking in engine after rebuild
Thread Starter
Safety Car
Joined: Aug 2000
Posts: 3,943
Likes: 44
From: Florham Park NJ Port Credit Ontario
Need Tips on breaking in engine after rebuild
I am almost ready to fire it up but want some pointers on the break-in process. The engine was completely re-done inc. cam, pistons etc etc. I have a pre-oiler so I will use that before I do anything.
Advice appreciated.
Stew
Advice appreciated.
Stew
Le Mans Master
Joined: Jan 2000
Posts: 8,721
Likes: 108
From: Canada
Re: Need Tips on breaking in engine after rebuild (Stewart's74)
I`am just completing this process now. I made good use of Synergyn as the lubricant with Pennsoil and ran for .5 hour to seat the cam. Then changed filter only topping up oil and took her up a long hill 5 runs putting the engine under load, @ 2200 - 2500 rpm to sead the rings. Put another 500 miles on the engine another oil change adding Synergyn and I am good for the next 2500 miles or so. Just watch your temp and oil pressure.
Drifting
Joined: Mar 2001
Posts: 1,896
Likes: 0
Re: Need Tips on breaking in engine after rebuild (Stewart's74)
This is what I did.
1. Set the valve lash as best as possible.
2. Make sure EVERYTHING is torqued.
3. Re-check to see if there's oil in the pan.
4. Prime the oil system.
5. Instal dist strait up with no advance.
6. Double check everything
7. Start the car, get the timing at 0 w/out vac.avd and keep it plugged.
8. Set your carb as best as you can (do everything as quick as possible)
9. Hold the motor at a steady 3-3,5000rpm for ATLEAST 30 minutes (cam break in)
10. After the break in change the oil and then you can tune everything and go find some placed that will put a decent load on the motor (NOT the race track). That's the best way to set the pistons.
(the reason I used no advance or anything was, since I dind't really have much time to let the motor run, doing it like that will keep the ceramic coating on your headers (if you've got it) from burning off in the break in period.)
[Modified by Aaron-74, 9:56 AM 7/31/2002]
1. Set the valve lash as best as possible.
2. Make sure EVERYTHING is torqued.
3. Re-check to see if there's oil in the pan.
4. Prime the oil system.
5. Instal dist strait up with no advance.
6. Double check everything
7. Start the car, get the timing at 0 w/out vac.avd and keep it plugged.
8. Set your carb as best as you can (do everything as quick as possible)
9. Hold the motor at a steady 3-3,5000rpm for ATLEAST 30 minutes (cam break in)
10. After the break in change the oil and then you can tune everything and go find some placed that will put a decent load on the motor (NOT the race track). That's the best way to set the pistons.
(the reason I used no advance or anything was, since I dind't really have much time to let the motor run, doing it like that will keep the ceramic coating on your headers (if you've got it) from burning off in the break in period.)
[Modified by Aaron-74, 9:56 AM 7/31/2002]
Melting Slicks
Joined: Feb 1999
Posts: 3,078
Likes: 1
Re: Need Tips on breaking in engine after rebuild (Aaron-74)
Do NOT break in a new rebuild with synthetic oil! It will cause your rings not to seat. If you have a flat tappet cam, you need to run it at around 3000 rpm for 20 minutes as soon as you start it. That's very important. You should pre-oil your engine. I have also heard that you should change your filter in 50 miles, because most of the clogging occurs then.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Re: Need Tips on breaking in engine after rebuild (Stewart's74)
Do not use synthetic to break in as was said before. I ran mine for 30 minutes at 2500 rpm. Idled it down and set the idle and carb and timing. Changed the oil. Went out and ran under a load for about 50 miles. Changed oil and went out and ran it like I usually run it. If the motor is properly built you should be able to run it very hard after the cam break in. Mine did loosen up a little after 1000 miles but they were not easy miles. It runs good to this day no problems.
Safety Car
Joined: Feb 1999
Posts: 3,631
Likes: 14
From: Fountain Hills AZ
Re: Need Tips on breaking in engine after rebuild (Aaron-74)
I agree with everything Aaron said except the no advance thing. It's just as easy to set it what it needs to be as it is to set it at 0º. If your engine calls for 8º, set it at that. If you've gone to a bigger cam, you might want to add a little more. It's no more difficult to align your tdc mark with the 8º than it is to align it with the 0º mark. Starting a fresh engine can be tough enough without it's timing being way off. Besides the backfires through the carb that inadequate timing causes, the higher exhaust temps it causes won't do your exhaust valves or your headers any good either.
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Drifting
Joined: Oct 2000
Posts: 1,825
Likes: 56
From: Shawano WI
Re: Need Tips on breaking in engine after rebuild (Vetterodder)
I agree that you do not want to retard the timing that much. That would induce a lot of heat into the exhaust and could cause popping through the carb (depending on the cam specs).
I can not stress enough that you double check everything before you try to start it, so once it is started it can run for 30 minutes. Be sure the timing is on, carb full of fuel, radiator full of water, all lines tight and tied back.
99% of cam failure are caused at start-up. Cranking on the starter to get everything right is very hard on a new cam. Double check everything so the motor starts imediately! I do not like to see the motor held at one steady RPM. I preffer to vary the RPM between 2500 and 3500 for 30 minutes, changing it a couple hundred RPM every couple of minutes.
[Modified by Pete79L82, 9:26 PM 8/1/2002]
I can not stress enough that you double check everything before you try to start it, so once it is started it can run for 30 minutes. Be sure the timing is on, carb full of fuel, radiator full of water, all lines tight and tied back.
99% of cam failure are caused at start-up. Cranking on the starter to get everything right is very hard on a new cam. Double check everything so the motor starts imediately! I do not like to see the motor held at one steady RPM. I preffer to vary the RPM between 2500 and 3500 for 30 minutes, changing it a couple hundred RPM every couple of minutes.
[Modified by Pete79L82, 9:26 PM 8/1/2002]
Race Director
Joined: Aug 2000
Posts: 18,478
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From: Quincy IL
Re: Need Tips on breaking in engine after rebuild (Pete79L82)
i broke my cam in by running the rpm between 2k and 2500 rpm for about 40 minutes, let it cool down, fired it up and fine tuned the timing and carb, drove it a little bit. next day changed the oil & filter, the cam lube and assembly lube can clog up the filter, i used 10w-40 pennzoil, that's what the machine shop put in b/4 i brought the engine home. i still use 10w-40, any name brand, and change it often,98k on the car,5k on the rebuild.
