khaulotte

I am installing a new 94 LT-5 (crate) engine in my 91 ZR-1. I have several questions that I would appreciate some advice on.

1. Should I add oil on top of the pistons through the spark plug openings before turning the engine over?
2. If so what type of oil and how much per cylinder?
3. There is oil in the engine. Should I change the oil and filter before starting the engine?
4. What type of oil and filter would be best for the break in period?
5. What type of oil and filter would be best after the break in?
6. What are the recommendations for breaking in the engine?

Thanks for any advice you offer!

A26B

I'll offer my thoughts, realizing that there may well be subsequent posts from others with different/better responses.

Questions:
1. Should I add oil on top of the pistons through the spark plug openings before turning the engine over?
2. If so what type of oil and how much per cylinder?
3. There is oil in the engine. Should I change the oil and filter before starting the engine?
4. What type of oil and filter would be best for the break in period?
5. What type of oil and filter would be best after the break in?
6. What are the recommendations for breaking in the engine?

Answers, in order of priority:

Preface, the engine has already been run at Mercury Marine, when it was dyno tested. A typical dyno run would run the engine at low rpm until the oil temperature had stabilized, then full power runs were made.

Prep: Bleed air in coolant system from T/Body coolant hose. Insure coolant recovery tank is full to top level.

First: 3 & 4: Change the oil & filter. Use Mobil 1 5w30 synthetic oil & Mobil1 filter. Make sure you do not overfill. You know the procedure.

Second: 1 & 2: Using an oil squirt can, give each cylinder a single squirt of the same motor oil used in the first step. Leave the spark plugs out.

Third: Turn the engine over by hand, at least 2 revolutions.

Fourth: Reinstall plugs

Fifth: Key on, let fuel pump & vac pump cycle off then crank to start. Do not crank excessively to start. After start, check for proper oil pressure, then raise rpm to 1,000~1,200 for 15~20 min, checking temps & oil pressure. Coolant temp should be in the 200~215 range. If temp gets too high, shut down, allow to cool off to pull coolant from recovery tank.

Sixth: 6: Re-start & drive for break-in. Break-in procedure is 500 miles under 55mph (4th gear). Do not drive at constant speed for long periods, vary speed/rpm frequently.

Seventh: 5: Probably not necessary, but I recommend changing oil & filter after the break-in period. Same oil & filter.

LT5corsa

Have you seen our site? www.zr1netregistry.com and the forums www.zr1.net/forum

Lots of info on the site and people with similar questions.

How many miles were on your 91? Color? Upgrades?



David

glass slipper

Very good post A26B, lots of very well thought out suggestions and good recommendations.

I'd like to add my thoughts to the above:

Sixth: There is no break-in required for the engine as the rings are cast iron with a moly coating on the face of the top ring. Moly face rings have almost instant seating with a few turns on the engine stand and have certainly seated after being run at Mercruiser on the dyno after it was built. The "under 55 MPH" and "varying the speed" is for the gears in a brand new car/transmission/differential, in particular the ring and pinion gears. The 500 miles is also for the gears with 200 miles for brand new brakes. Since your brakes, transmission, and differential aren't new, no break-in period is required. After getting everything stabilized and confirming no problems, you can hammer away. If it makes you feel better to wait 500 miles, it's not needed but it won't hurt anything.

Seventh: I agree, not really needed. GM didn't recommend an oil change after 500 miles and still doesn't on new Corvettes. If that oil is bad, just think how many thousands of times it has gone through your engine in the 500 miles you ran it. Again, if it makes you feel better to change it at 500 miles, have at it...it certainly won't hurt anything.

khaulotte

It is a 91, White with gray interior 98k miles. The only mods that I am aware of is the top of the engine and valve covers have been polished and coated. Looks great... But, the timing chain skipped a tooth or something and I have been told that is not good... While traveling down the highway at 70 mph the engine made a short clatter (chain) but kept running fine. I thought that I ran over a piece of corrugated metal on the road or something. Drove a half mile and had to slow to 55. When I gave it the throttle again it seemed to flutter with no power. Pulled over and the engine idled just fine, all Heat, oil pressure all looked normal, opened the hood and had friend give it gas a couple of times and I heard a slight noise at the top of the timing chain cover so I shut it off...
Long story!

Going to be parting the engine out as soon as I get the new one in!

A26B

I agree with you on all counts. Just happened to have a 94 owners manual handy & quoted the manual for break-in. Didn't wanna get flamed for not being consistent with the manual!

My mentor on engine building (back in the day :-)) said it's impossible to get an engine perfectly clean. Granted, the pickup screen & filter should catch most everything, but it also gets contaminated from cam & bearing assembly lubes, etc. So, I have always followed that advice.

I wondered if the oil was drained and refilled with new after the dyno run, before it was crated for storage?

c ya,