This is topic Break in period for 331 stroker in forum Tech Talk at Northern California Ford Owners  .


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Posted by twstd50 (Member # 1981) on :
 
My 331 stroker should be done in about 4 days...

I know the break in period is approx. 1000 miles. Would it be safe to put it on the dyno before it's fully broken in. I have an appt at the Mustang Ranch and it will prolly only have 200 miles on it.

Thanks.Tony
 
Posted by ray95 (Member # 752) on :
 
i'd reschedule and get at least 1000 correct break in miles on the motor. but hey....that's just me.
 
Posted by JohnB (Member # 969) on :
 
The break-in period is only for the rings. Depending on the type of ring you're running, you may not need a break in of more than 100 miles. [Smile]
 
Posted by Blue Oval (Member # 2548) on :
 
what kind of rings are the ones u only have to break in for a 100 miles?i want some! [Big Grin]
 
Posted by JohnB (Member # 969) on :
 
Straight from the University of Washington's Engineering website...
During the break-in period of a piston ring, the piston ring and cylinder bore wear at an accelerated rate and conform to a mutual shape and size. The break-in period is the period of operation time required for the running surfaces of piston rings and the surface of the cylinder bore to conform to one another after initial startup. In the past, the engine break-in period was very important to the overall life and durability of the engine. The break-in period required has changed over the years with improved piston ring materials and designs. The break-in period now is short in comparison with that of engines of the past. Aluminum cylinder bore engine piston rings break-in faster than those used on cast iron cylinder bores.

During the break-in period, the piston rings and cylinder bore wear rapidly to remove any rough edges on the piston ring running surface and cylinder wall. In general, there is no special engine operation procedure required during the break-in period. Break-in is accomplished by any speed above idle and may occur faster if the engine is operated at varying loads and speeds. However, break-in occurs at an acceptable rate if the engine is operated at slightly less than top no-load speed with or without a moderate load. Combustion pressures at this speed are sufficiently high to cause piston rings to conform to the cylinder wall. It is recommended that an engine not be operated continuously at full load during the initial hours of operation. This can lead to permanent deformation of the cylinder bore.

Enjoy! [Big Grin]
 
Posted by twstd50 (Member # 1981) on :
 
The rings on there are Mahle File Fit. The builder said it should be ok. He just warned me of not cruising at a steady speed for long distances, like on the freeway or the rings could get glazed.
 
Posted by CobramanPhil (Member # 2170) on :
 
Just my opinion, but to be safe go at least 500 miles of varied driving (different rpms), change the oil, check the coolant for oil (hopefully you won't see any) and then dyno it...no reason to hurt your new motor just to get a number at the dyno...
 
Posted by twstd50 (Member # 1981) on :
 
I'll make to have at least 500 miles on it before putting it on the dyno. I'll also change oil too.

I'm not too concerned about getting the hp numbers rather than making sure it's tuned right. There's a autologic chip in there already but it was last tuned for my 302 with at least one dead cylinder. I'm hoping it'll drive ok until I get it retuned.

Thanks for the advice.
 
Posted by PurpleNotch (Member # 2902) on :
 
with my 331 i ran it easy and in the low rpm range untill 500 miles than changed the oil to get all the assembly particles out and then drove another 500 miles changed the oil again and then went to the dyno. than after the dyno i changed the oil one more time ya i know a lot of oil changing but i wanted to make sure that everything was looking right and besides while your down there double check your bolts they'll all come loss after some mileage. good luck [patriot]
 
Posted by twstd50 (Member # 1981) on :
 
Thanks...I can't wait to get it back. I'm hoping it'll be done on Monday.
 
Posted by big matt (Member # 1124) on :
 
breaking in is for pussies
go race somebody, then its broke in
 
Posted by twstd50 (Member # 1981) on :
 
yeah fuck that shit...
 
Posted by Camara90 (Member # 134) on :
 
shit you talk to guys who are good engine builders they tel you to take that biatch up to redline. Most places break motors in on the dyno, you need to seat those valves, and rings. You should get the motor running, and once it is running good take it out and put a load on it. DO some 3rd and 4th gear full throttle stabs up to about 5,000 and continue to do so.
 
Posted by kwikrob (Member # 835) on :
 
First off, change your oil after your cam break in, not 500 miles! Most shit comes off right away(assembly lube, bronze gear wear, etc.) Put a couple hundred miles to be safe. But honestly, if the rings do not seat in the first 15 minutes, they never will!
 
Posted by twstd50 (Member # 1981) on :
 
I still haven't got the car back yet(Hope fully Thursday [Roll Eyes] ).

I'll prolly change the oil after I put about 40 miles on it.
 
Posted by twstd50 (Member # 1981) on :
 
Well I just got it back... It runs good but could a good tuning.

So far I've been driving at varying speeds on freeway and getting off and on every 5 miles or so. I've taken it up to 4500-5000 three or four times so far. Right now it has 17 miles on it.
 
Posted by 347 Stroker (Member # 4039) on :
 
Just keep doing the same thing. rev it up under varying loads. I just finished breaking in my 347 a month ago. changed oil after the first 25 miles, then started reving it up in 1st, 2nd to 5k,loading 3rd at half pedal up to 4k. After 100 miles I started letting 1st gear rip to 6200, 2nd to 5800, then back off..changed oil again at 125 miles & checked plugs.

She runs strong as hell, no probs at all. just need my chip re-tuned is all

Scott
 
Posted by twstd50 (Member # 1981) on :
 
When is your chip gonna be re-tuned?

I have an appt. next Saturday at The Mustang Ranch.

I should have about 500 miles on it by then.
 
Posted by 347 Stroker (Member # 4039) on :
 
real soon now, Look at the post called (dyno in Sac) Just located a dyno very very close to me. I'm putting in a booster pump tommorrow, then gonna make an apt for a few base pulls to see where my AF ratio is and try and get it as close as possible for the drive down, then i'll be making plans to head down to mustang ranch or apex to have Byron Renolds re-tune my chip NA & with the N20 flowin. I'm hoping to get down to so cal within the month.

Take Care,
Scott
 




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