Newly rebuilt bbc 489 stroker. Break in thoughts?

[Txaggie76]

Howdy all,

We are installing a 489 roller striker motor in my old suburban this week. Per the builder recommendation, he wants 10w-30 break in oil for the first 50 miles and wants moderate to heavy acceleration with engine braking to help seat the rings (we chose comp cams break in oil). Once 50 miles hits, he wants me to drain the oil and filter and put new 10w-30 or 20-50 in and drive the piss out of it.

I really like Mobil 1 15/50 for my climate and price (Austin Tx, hot summers). However I’m fearful of putting in synthetic too quickly. Will this stop the rings from seating with a synthetic too quickly?

Should I run vr1 10/30 or 20/50 til 1000 miles and then switch to the Mobil 1 15/50?

 

[JeffKeryk]

Beautiful engine; bet you spent some serious coin.
I would follow the builder's instructions.

 

[Furious]

Follow the builders instructions, keep evidence you are following the builders instructions just in case of a failure you have proof for warranty purposes.

 

[PontiacHO]

If it was built with modern pistons and rings, they should seat quickly. I’m old school and would run VR1 20W50 through. That’s a large displacement old school big block even with roller tappets they will be a lot of friction in the valvetrain in that engine.

 

[Txaggie76]

If it was built with modern pistons and rings, they should seat quickly. I’m old school and would run VR1 20W50 through. That’s a large displacement old school big block even with roller tappets they will be a lot of friction in the valvetrain in that engine.

All forged everything, eagle rods and crank, wiseco forged pistons. Johnson roller lifters, crane roller rockers, comp cams Hydraulic roller cam.

 

[PontiacHO]

All forged everything, eagle rods and crank, wiseco forged pistons. Johnson roller lifters, crane roller rockers, comp cams Hydraulic roller cam.

Yep. More high performance oriented. Use the appropriate oil- VR1 20w50.

 

[BigCahuna]

Did you have it dynoed and tuned somewhat?. A bunch of controlled dyno runs usually will break in the engine. After that, use whatever oil your builder has had the most luck with.,,

 

[Txaggie76]

Did you have it dynoed and tuned somewhat?. A bunch of controlled dyno runs usually will break in the engine. After that, use whatever oil your builder has had the most luck with.,,

No dyno. Virgin crank should happen tomorrow

 

[marc1]

This is what I do, no issues to date on many vintage engine rebuilds. I buy a case (12) of whatever flavour break in oil, you are using Comp Cams that is fine, I have always used BR30 Driven and I intend to use AMSOIL break in on my next engine. I run the car initially, go for a ride around the city for a bit. Not much different than your 50 mile builder recommendation. The next oil change I also use the same break in oil, hence buying a case (12). I run that for several hundred miles but no more as they are low on detergent by design. If my rings aren't seated by then they never will be. After this I will switch to whatever oil I am using regularly, which nowadays is always synthetic of some sort. One tip I always follow is I just use water in the cooling system until I know the motor is good, once I am happy with it, I drain 50% out and add pure coolant.

 

[userfriendly]

What are your crank and rod bearing clearances? The 10w30 recommended by your engine rebuilder sounds a little thin.
HDEO 15w40 has always worked for me in BBCs and SBCs.

 

[ripcord]

You are harming nothing by using a so called conventional oil in it until the rings are well seated. Why not just use VR1 10w-30 for the first several thousand miles? Also, you don't actually need 50 weight oil if it was built with factory spec bearing clearances. If you've got good oil pressure at hot idle, there's no reason you can't use 10w-30 indefinitely for street driving.

 

[Txaggie76]

What are your crank and rod bearing clearances? The 10w30 recommended by your engine rebuilder sounds a little thin.
HDEO 15w40 has always worked for me in BBCs and SBCs.

I’ll check the build sheet tomorrow for clearances. He actually likes the heavier weight for protection but said the 10/30 will work if I want to run it.

 

[userfriendly]

I’ll check the build sheet tomorrow for clearances. He actually likes the heavier weight for protection but said the 10/30 will work if I want to run it.

I suppose it depends on which 10w30. Mobil 1300 CK4/SP for example, has a HTHS of 3.6 while Walmart 10w30 is around 3.2.
I like 2.5 thou rods ‘n mains on BBCs because the un-skirted block is not as rigid as modern V8s which allows some flex that can eat into bearing clearances.
Next is controlling crank harmonics. Guys with BBCs in their boats learn the hard way. First the stock harmonic balancer goes through the hull, followed by the crankshaft.

 

[Lawnman23]

Is that a Holley Sniper 1 or 2 setup?

Any experience with it before this build?

 

[Cujet]

The idea that the engine won't break in with M1, 15W-50 is incorrect. It is neither more 'slippery' nor too thick. Even so, using a high quality (robust) 5W or 10W-30 conventional as break in oil is a time tested method that has served people well for decades. As long as you are not asking the engine to produce maximum power/RPM while it is experiencing high oil temps, the 30 viscosity oils will work just fine.

The conventional method is to load the rings via mid RPM, open throttle, for short periods of time. A form of heat cycling. Many engine builders have their own ideas, but the conventional method was 3 seconds of full throttle, 2500 RPM up to 3500. And let off, allowing the piston and ring pack to cool.

On the dyno, we'd heat cycle the engine a bit differently, often with l5 second full throttle runs. Then shut down and check things over, adjust fuel mixture if necessary etc. With as many as 10 full heat cycles. Then off to the races we'd go, with pull after pull on the dyno.

With hundreds of dyno runs, on a great many different engines, not once did we have unusual wear, damaged parts, or failure to seat rings. And many of our engines were disassembled for component testing. So the observations were timely and accurate.

 

[Cujet]

Also, I very much like the idea of a 50 mile oil change. While modern engines don't produce much in the way of break in debris, a monster old school V8 can. A fast drain n fill can be a good idea. Do not freak out if you see glitter in the sunlight. This is common.

 

[Nessism1]

I'd use VR1 20-50 conventional, until 1000 miles, then switch to M1 15W-50. I can't technically support my opinion, just saying what I would do.

 

[JHZR2]

Also, I very much like the idea of a 50 mile oil change. While modern engines don't produce much in the way of break in debris, a monster old school V8 can. A fast drain n fill can be a good idea. Do not freak out if you see glitter in the sunlight. This is common.

Agree.

OP, it’s a pretty awesome project/machine. In the big scheme of things, going a while on conventional won’t make a lick of difference.

I’d run what is recommended with confidence, and at some later point, 500, 1200, 2500, go to M1 15w-50 or whatever you choose, and use with confidence.

 

[Txaggie76]

What are your crank and rod bearing clearances? The 10w30 recommended by your engine rebuilder sounds a little thin.
HDEO 15w40 has always worked for me in BBCs and SBCs.

Our rod bearing clearance is 2.1995 and mains at 2.7488. How does this factor in for the oil weight?

 

[Hohn]

If it was built with modern pistons and rings, they should seat quickly. I’m old school and would run VR1 20W50 through. That’s a large displacement old school big block even with roller tappets they will be a lot of friction in the valvetrain in that engine.

Black bottle Vr1, not the grey bottle dino version.

Do what the builder recommends. Hope for the best.


Next time, maybe pick a builder that cares enough about the engine to actually break it in on the dyno before installation.