Hey guys hoping to fire up my new motor tomorow and given I can and she sounds good and no leaks I just wanted some imput on safe afr levels for the 20+ min high idle breakin. Dont want any issues and hopefully wont be none. I should be able to have my widebands hooked up if needed but have jet dst with ecmpro scan for my logging and tuning. Have a baseline tune from solomon for the new configuration. I just know there are people who know way more than me whats acceptable and what isnt. It would be nice to have it in the sweet spot but if it isnt what points should I shut her down and retune. I know the pcm learns but know it also has limits and not sure how quick it compensates so any advice would be great. Most of the guys around here that can tune are into imports. Also any recomendations as to when it would be acceptable to do some full throttle runs? I know there is alot of differing opinions there and the engine builder Kinda refrained from giving me an answer to that. Personally I feel a slow ramp up to full throttle runs and wait 4-500 miles before a several gear full throttle run. Ive heard others say drive it like you will drive it right out of the start. I believe a few heat cycles and a little build up to detect any issues and any retorquing is best but again im here to learn. Thanks in advance.

 

20 minute high idle break-in? What's that about?

Go out for a drive. Do several 3/4 throttle pulls in a row, park car, allow to cool. Repeat 2 or 3 times. Change oil and go beat the hell out of it. Break-in complete. You need to get the rings seated - babying the car won't do that.

Accept no other substitutions.

 

Agreed^^ high idle break in went the way of the dodo with the use of roller lifters

 

High idle breakin was specifically for flat tappets. Did you put flat tappets in your motor?

 

No she is a roller. Its just what the builder requested and he is definately old school. Noticed the same thing on golens site as I used their pics to help on clearancing my valve covers. Whats unacceptable on the afr on the high and low end part throttle and cruising?

 

cruise the pcm once in closed loop will try and keep it at 14.7 that is what the O2s are for.

I wouldn't go believing something is good because Golen says it, you know how many of their mediocre performing strokers have to be rebuilt by 7-8K miles. Generally a stock shortblock is more powerful and reliable than his stuff. Hell one of their failures was rebuilt by another builder who found a crossthreaded rodbolt, strongly suggesting they put it together with airtools.

Golen wants a high idle breakin so that when an engine is put together especially badly it is just damaged rather than scattered.

 

Not to mention I was told by CHAD GOLEN himself that Eagle cast crank failures are "very common and happen all the time," yet he continues to offer them in his "performance 383."

 

Lol your last comment got me. I obviously dont trust too many or wouldnt be asking questions. I figure the more input I get either the more confused or the more confident I will become. If I get confused then that means I have to learn it myself and I prefer not the hard way. Ive seen alot of negative feedback on golens stuff trying to find the pictures of the valve cover clearancing because it was the best one I had found to reference from. I got enough time and money into this motor and car I want it done right so I did more than I expected and so far with good results. Ive had to backtrack a few times making newbie mistakes but I do know my car alot better. I went for an all arounder, something to drive most of the time and that will handle the road racing or drag stip decent. I truly do appreciate the help and things ive learned from this site and hopefully she will be runnin again tomorow after two years down savin for the new longblock.

 

I had the advantage of running the engine on an engine dyno for break-in. Moderate varying RPM/moderate load for one hour. Drain oil, pull filter and open it to inspect it, refill, new filter, check bolt torques. Done. From that point on, it underwent maybe 30 engine dyno pulls for optimizing NA tune, 1-stage N2O and 2-stage N2O (275-shot at that point), with a 7,200 RPM redline, 7,000 RPM nitrous cutoff. Engine still runs like a charm 12 years later, although I doubt it has more than 25,000 miles on it and hasn't been out of the garage for the last 3 years.