Breaking in motor

[Morris R.]

I just rebuilt my 66 corvette 327/350 hp motor the mechanic put in breaking oil for the first 500 miles. What oil should be used after the breaking period? The motor was rebuilt stock. Would 50 be alright?

[William C.]

Re: Breaking in motor

10w-30 or 20W-40 would be a LOT better.

[Morris R.]

Re: Breaking in motor

Thank you bill

[Clem Z.]

Re: Breaking in motor

I just rebuilt my 66 corvette 327/350 hp motor the mechanic put in breaking oil for the first 500 miles. What oil should be used after the breaking period? The motor was rebuilt stock. Would 50 be alright?

do not "baby" the engine as you have to have pressure behind the rings to get them to seat. short full throttle blast should be done.

[Michael G.]

Re: Breaking in motor

I just rebuilt my 66 corvette 327/350 hp motor the mechanic put in breaking oil for the first 500 miles. What oil should be used after the breaking period? The motor was rebuilt stock. Would 50 be alright?

Morris,

You'll need to know if your mechanic used a flat tappet cam which requires oil with an ZDDP additive . 10W-30 or 40 would be good.

[Morris R.]

Re: Breaking in motor

i just rebuilt my 66 corvette 327/350 hp motor the mechanic put in breaking oil for the first 500 miles. What oil should be used after the breaking period? The motor was rebuilt stock. Would 50 be alright?

thank you maury

[Dick W.]

Re: Breaking in motor

thank you maury

Break in oil is an old wives tale! I worked very close with piston ring manufacturers several years ago and they ALL told me to use the same oil for break in as you planned to use daily.

I am old 'nuff to remember mechanics swearing you had to break engines in with non-detergent oil. They swore if you used HD oil, the engine would use oil.

Just put a good quality oil in it, warm it up, and run the pee outta it. Never had problems breaking an engine in that way. Had all kinds of oil consumption problems when I tried to take it easy at break in. Used to be standard operating procedure for me on a new car before it had 100 miles on it I would know how fast it would run.

[Philip P.]

Re: Breaking in motor

This is exactly what the shop that just rebuilt my 283 said about the breakin, also they put in high quallity oil that has ZDDP in it and I will change the oil at 500 miles if we ever get any weather (fair weather car). It is a flat tappet type cam.
Phil

[John H.]

Re: Breaking in motor

Morris -

If your engine guy used moly-faced compression rings, they'll seat in less than 5 minutes after you fire it up for the first time. What's REALLY important is breaking in the cam and lifters - the rings will take care of themselves.

[Duke W.]

Re: Breaking in motor

I think you mean "break-in" oil, but what the hell is it... brand name, viscosity, API service category?

You should have used any 15W-40 CJ-4.

I see you are a new member, so you are probably not "oil-educated".

Download and read the following pdf. Print out a copy for your mechanic so he can get educated, too.

http://stlouisncrs.org/news_files/St_Louis_NCRS_Chapter_July_2011.pdf

Duke

[Domenic T.]

Re: Breaking in motor

I Think the oil you put in the engine for it's break in is the most important choice your going to make.

I hope it was just a figure of speach and that it was the oil that was put in during break in and had all the additives needed for a fresh engine.

It gets real hot here with no winter to speak of so I use 20/50.

When I uncrated a engine at the dealership back in the early 70's they all had a can of VI (viscosity improver) in the crate, GM engine oil suppliment.

It is common to the other VI's on the market.

DOM

[Patrick B.]

Re: Breaking in motor

Does anyone think the precaution of removing the inner valve springs is necessary to break in an L-71 with stock cam and springs assuming the use of either CJ-4 or 10-30 Joe Gibbs break-in oil?

[Dick W.]

Re: Breaking in motor

Morris -

If your engine guy used moly-faced compression rings, they'll seat in less than 5 minutes after you fire it up for the first time. What's REALLY important is breaking in the cam and lifters - the rings will take care of themselves.

When we were running the old 426 hemi engines, at break in the engine was never allowed to idle under 2,500 rpm's during the first 15 to 20 minutes. The rings took care of themselves, this was to break in the cam and lifters.

[Dick W.]

Re: Breaking in motor

Does anyone think the precaution of removing the inner valve springs is necessary to break in an L-71 with stock cam and springs assuming the use of either CJ-4 or 10-30 Joe Gibbs break-in oil?

Unless you have gorilla springs it is unnecessary Pat.