so the day has finally come, i will atempt to fire up my rebuilt 302 tomarrow, i have a few questions tho, my haynes manual says to keep the the engine at around 1200 rpm upon starting it to break it in but for how long do i keep it at this rpm? i did a serch and one guy said 15min then i herd from another guy that said 30min how long is long enough? and second to find TDC can i go by the rotor pointing to the number 1 on my distributor cap i did that on my i6 once and it worked.
What kind of cam do you have? and what type of pistons rings are you using? You cant go by the rotor since you have to find TDC first before dropping in the distributor.
Here's a good video to help you find TDC, its on a SBC but it should be the same except that #1 on a SBF is the front passenger side cylinder. follow the second technique:
i made a topic on engine break in before and like everything, theres tons of ways to do it, or not do it, with my cam/motor set-up the cam called for 2000+rpm for 20 minutes; while doing this i was bringing it up/down in between like 2000-2400ish. i just felt better about it rather leaving it at one set rpm..and the whole motor..i babied it for about 3 days listening to the theory of olerodder. and knock on wood..it ran good for me this year and ill tear it apart as i have a leak at the oil pan/timing cover..and a cam change to something larger..and i will do the same 2000-2400 20 minutes maybe longer.. if some say 15, some say 30..why not just do 30..its only an extra 10 bucks in gas to be safe. heres the link to the thread im talking about..might be some info in it you may want. http://www.maverick.to/mmb/showthread.php?t=83467&highlight=break+engine
^^^^^^^^Agreed^^^^^^ Assuming it's not roller, you really should have a oil with approx 1200 ppm ZDDP(zinc) for break in... Easiest to find would be something like Rotella 15W-40, or use a break in additive with additional zinc...... BTW none of the above really applies to a roller cammed engine, the run in is to break in the std cam... Also stockish cams with light springs really don't need a long run in, but it can't hurt... Generally back when, new engines were never fired till the vehicle was leaving the assembly line...
i did that as well...was a ton of help keeping it cool if you plan on running it for a bit, i used comp cams break in oil..has the zinc additive.
i put zinc additive in it yesterday. the guy put an RV cam in and i would assume there are stock piston rings in it also. when i had it bulit i told the guy to just do a stock rebuild and put a cam in it the puts out more lowend tourque that what the motor cam with from the factory.
lol can i do this without that little pointer on the side of the block? my engine didnt come with one. think the guy that had it before me may have taken it off
You can, take the valve cover off, pull number 1 plug out, turn the engine by hand until you start to see the intake valve close, find a screwdriver to put down the plug hole (make sure the handle is big enough to where it doesn't fall in) continue turning the engine by hand until the screwdriver comes to the highest point. That's TDC. Also you're gonna need a pointer to set the timing after its running, unless you're like me and just drive it turn it a little at a time until it pings then back it off some.
You need a timing pointer to setup your timing, the pointer has to match your balancer. Don't take short cuts unless you wanna ruin your engine.
different pistons rings require different break ins to seat the rings correctly, they make RV cams for rollers and flat tappet. roller cams don't need a break in while flat tappet ones do.
that makes my job even harder because i dont remember if its roller cam or tappet could i just break it in as if its flat tappet and cast piston rings just to be on the safe side?
