Ryan change your oil and filter, run regular 10W-30. After the motor breaks in you might be able to run synthetic. Synthetic can be too thin for breaking. Your dad always used normal weight oil for breakin.

 

yedister. Dump the synthetic and change to dino for the break-in period. Then go back to your synthetic.

 

Yes, this is how you are suppose to break in a new motor. You have to gradually load and unload the rings. Higher rpm decel's in gear will produce big vacuum in the intake side, thus a big pressure differential between the crank case and chamber, which will force the rings outward and seal. They break in better this way.

I'd use regular oil on the break in but new cars with tight tolerances are broken in on synthetic so its possible to do so, but I still think you need to run that car somewhat hard at first to break it in. Dont baby it for 400-500 miles.

Idle til its hot and then do some mild 1/3 throttle pulls in your first or 2nd gear, from off idle to midrange rpm, decel in gear. Then do some half throttle pulls in those gears to alittle higher rpms, maybe 3/4 to redline. Decel in gear all the way down to idle. Do several pulls like that, and then move on to 3/4 throttle to full throttle runs across the rpm range hitting the peak rpms, decel in gear.

Your smoke should stop and motor should be ready to run.

 

Went out and got 1st dyno pull on a mustang dyno. Bottom line, terrible terrible numbers. Max hp, 293, max torque 290. Air fuel ratio average is 15.2, wideband put in tail pipe. So i go to get the pull done, i am behind the wheel doing the pull myself. Start at 4000rpm, the air fuel was at 16.2, and the guy says floor it, air fuel drops to 15s. Never mentioned to me the ridiculous air fuel number till after the pull and were done. Canr believe thar guy had me pull it up to 6k with it. So once i get back home, i call pcm 4 less, they say i should be at least at 380 rear, and that i shouldnt have done on mustanf dyno and i should get another pull with wideband before the cats. They also stated that thr computer was not going into right data tables for some mechanical reason, essentially were saying that their tune is good and not their fault. So i called a lt1 tuner that the corvette club knows around here, named moe bailey. Got a good vibe from him and goingnto have him redo it after my military training for a month in california. Problem is its a pretty pennny of 450 for dyno tune, unlimited runs, and time allotted though. Will upload graph if anyone wants to see.
Also. When i just had the head and cam upgrade my dad and i did, we did a mail order tune with pcm for less as well. Got a pull on that as well before i deployed was 245 on mustang dyno and was high 14s air fuel as well.

 

Yikes thats lean they should be slapped for even running it like that
Yes on the wideband on the header collector youll get a truer reading that way

Noone seems to want to listen to this.

 

Wow... I'm a fan of street tune vs dyno tune and you def need to stay out of WOT until you get a better tune. What injectors are you running?

 

define street tune

 

If the rings havent set yet, I wouldnt be jumping the tuners just yet...

Have you done a compression check?

 

Have about 1000 to 1500, if not more on the new build and running 42lb lucas injectors with walbro 255 pump

 

with your compression ratio I would be shooting for a starting point of around 12.5:1, get the fuel curve flattened out in that bad boy while running conservative timing. once fuel is straightened out and flat you can bring the whole curve up gradually keeping an eye on knock retard, once you get it around 12.8-12.9:1 without seeing any knock retard, start upping the timing a degree at a time until you start seeing the point of diminishing return on power output OR you see knock retard. Your tuner should know all of this. what year car is it? 94-96 cars are generally the most difficult to dyno tune because there is no way to upgrade the computer to realtime tuning and each change takes FOREVER to complete and runs a high risk of stalling. 92-93 ecm's are MUCH better for tuning but generally require some attention because the speed density system makes it difficult to understand airflow on a modified motor where the MAF cars can calculate airflow and given your fuel pressure is correct and your injector flow rate is set properly will fuel pretty accurately until it hits the max adjustment value to the entered map value.

anyways.. not sure why I went into that, but the short reply would be get it tuned IMMEDIATELY so you don't have to do all this again from hurting the motor.

Chris

 

Thx chris. It is a 96 and i will get ittuned as soon as i get back

 

I think it correct to say that you don't live with a female in your housing unit as you could never get away with doing engine work in the house if you did.
Story from my early Army years: I got in an accident with my 65 vert while stationed at Ft L J McNair in Washington DC (1967). The body shop let me keep the front fender bulge and I put it in my wall locker to remind me to drive safe. Had a suprise inspection one morning and when I opened the locker door the fender fell out. First Sergeant went ballistic!
Good luck with your project.

 

Miles does not equal broken in... sealing rings means they are seated properly. I would hate to see all this effort wasted....

 

I tryed in the mail tune and it was WAY off , Drove the Corvette back to the tuner that made the ( In the mail Tune ) and he gave me some kind of BS ,We retuned it on the rollers and was great.. Getting it right sometime taked time you may get a so-so tune by mail but you want it right Put it on the rollers run it up and tune it..My old LT-4 runs very good it's in the tune....Took five trys to get the air/fuel right can't do that my mail...Just saying...

 

by the time you set the lash , account for pushrod and rocker arm flex, that .610 lift camshaft is more like .550 at the valve . That big CI will eat up duration .. also head CCs means nothing as far as peak HP , its all in the MCSA at the pich .

 

Thats a No NO right there... the rings might not seat properly .

 

That is a pic of 1st assembly, Unfortunately i have reassemled the entire engine 3x times for different reason, all new rings were put in the last time it was done and the heads were reworked. Also i do have a wife, and as long as mess was cleaned up evernight i could assemble. Flywheel, harmonic balancer and timing chain cover was all that was reused

 

Based off the spring ii chose for the heads the max lift they could take was more than the max lift of the cam shaft

 

.......... Huh ? ...............

 

Whats not clear ?