does anyone know if it is safe to breakin a motor open header??
here is motor setup
f20 w/h22p@p head
obx stage 2 cams
je 13.1 pistons
and some bolt ons

 

it shouldnt matter. i doubt any pro all motor cars get an exhaust system upon a rebuild or reassembly. how are you planning on breaking it in???? this is how i break mine in as per hastings ring manufacturer:

BREAK-IN PROCEDURE
1. Make a test run at 30 miles per hour and accelerate at full throttle to 50 miles per hour. Repeat the acceleration cycle from 30 to 50 miles per hour at least ten times. No further break-in is necessary. If traffic conditions will not permit this procedure, accelerate the engine rapidly several times through the intermediate gears during the check run. The object is to apply a load to the engine for short periods of time and in rapid succession soon after engine warm up. This action thrusts the piston rings against the cylinder wall with increased pressure and results in accelerated ring seating.
2. Following the breaking-in, turn the vehicle over to the owner or operator with the following suggestions:

PASSENGER CAR AND LIGHT TRUCK
Drive vehicle normally but avoid sustained high speed during the first 100 miles.

if you do not have a wideband O2 sensor or a way to tune your vehicle upon startup you should go to a dyno. if you feel that you dont want to run your motor into higher RPMs until you put more miles on it then get it tuned for narrow throttle settings and then drive within those parameters.

 

sweet man..thanx for the info

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lohatch &raquo;</TD></TR><TR><TD CLASS="quote">it shouldnt matter. i doubt any pro all motor cars get an exhaust system upon a rebuild or reassembly. how are you planning on breaking it in???? this is how i break mine in as per hastings ring manufacturer:

BREAK-IN PROCEDURE
1. Make a test run at 30 miles per hour and accelerate at full throttle to 50 miles per hour. Repeat the acceleration cycle from 30 to 50 miles per hour at least ten times. No further break-in is necessary. If traffic conditions will not permit this procedure, accelerate the engine rapidly several times through the intermediate gears during the check run. The object is to apply a load to the engine for short periods of time and in rapid succession soon after engine warm up. This action thrusts the piston rings against the cylinder wall with increased pressure and results in accelerated ring seating.
2. Following the breaking-in, turn the vehicle over to the owner or operator with the following suggestions:

PASSENGER CAR AND LIGHT TRUCK
Drive vehicle normally but avoid sustained high speed during the first 100 miles.

if you do not have a wideband O2 sensor or a way to tune your vehicle upon startup you should go to a dyno. if you feel that you dont want to run your motor into higher RPMs until you put more miles on it then get it tuned for narrow throttle settings and then drive within those parameters.
</TD></TR></TABLE>




i see so many people giving the "drive it gently for 3k miles" break in, which imo is completely wrong.

kindof interesting - the shop i had bore my block builds pro-mod drag cars (2-3000hp, mid 6's) and the guy there said "you know how we break in our motors? we put it together, start it and make sure its ok, then take it to the track."

its the high cylinder pressures that seat the rings, not babying it.

 

break it in on the dyno

 

Make you have a good A/F ratio