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The used renegade motor I bought from a supposedly reputable guy turns out needed to be completely disassembled and rebalanced :mad:

Its a 347, sportsman block, forged internals, vic jr. heads and holley intake. My question is, what is the proper break-in procedure? I don't want to drive it too hard too soon, considering all of the money I have in it now thanks to the unexpected rebuild.

Thanks,

Brian
 

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the proper way is to bring it up to operating temperature by normal driving and when it gets to 180-190 start running the piss out of it.
 

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Don't let it sit at the same rpm range for long periods of time. For example, don't get on the highway and run dead on 65 for 15 minutes or more. Stay away from this for about 300 miles.

Also keep the rpms fairly low for about 2-300 miles and then slowly start letting it raise as you go. After about 200 miles of true break-in, then you can stomp on it every once in a while and let it wind up a little more each time. Don't really pound on it for at least 3-500 miles.

If you drive it hard right off the bat, you will loosen it up quickly and it will seem to be fine, but you will have ruined it for the long term.

Yes, you can pound them immediately and they won't break, unless something is wrong. But, you are not giving the rings and cylinder a long enough time to wear the proper grooves and this will cost you in the long run.

If you don't care about the long term - say more than 10,000 miles - then go ahead and pound on it.
 

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nonstock said:
But, you are not giving the rings and cylinder a long enough time to wear the proper grooves and this will cost you in the long run.


If you don't care about the long term - say more than 10,000 miles - then go ahead and pound on it.

bullspit... rings and cylinder will be broke in the first 5 min or so.
 

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Mine ran for about 15 minutes on the dyno at around 2500rpms. Oil was changed and filtered for inspection, filter cut open for inspection, heads re-tourqed, and valve lash reset. New oil added, run up to temp then the first out of eleven dyno pulls were made. Runs like a top.
mike.
 

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My machine guy said break it in hard. Moslty like hotrains explanation.
 

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kinda makes sense that you want to go w.o.t. to get your reings to seal b/c cylindes pressure forces the rings against the cylinder walls....but do you really want to spin your engine up to red line right away??? that I would imagine would be bad for the other bearings in youe engine right??? since they need time to propely "break in" as well....so wouldnt the best way to break the engine in be to run it up to 3000-4000 rpm in high gear w.o.t.

this would be after the very first break in which would be at 2,000 rpm for 15min to get it up to temp and change out the oil thats in there right???
 

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blah blah blah.. bearing dont need to be broke in .... clearances should be set during assembly and rings will be seated in the first 5 minutes..

get her up to temp under normal conditions.. then RUN THE PISS OUT OF IT!
 

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Thats what I did kindof, blew a ring and blew a head gasket =)
Oh well, low compression forged pistons with arp bolts time.
 

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My old 333 combo was broken in on a dyno. Had probably 15 minutes of total run time in my garage, then had it towed to get properly tuned. Ran perfect.
 
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