Recommended break in for rebuilt engine ?

[Ed_K]

I put 120 miles on the Healey today which brings up a
couple of questions;
1..How many miles should I go with the Castrol HD30 and filter on a rebuilt engine before changing the filter and oil to Castrol 20-50 GTX ?
2..How long should I wory about staying out of full throttle for the " break in " of a rebuilt engine ?
And a related question about oil pressure; The oil pressure seems very good using the HD30 oil. how much of a drop in oil pressure should I expect when switching from HD 30 to 20w-50 ?
Thanks !
Ed K

 

[Randy Forbes]

I usually run 1000 miles on the break in oil, though I've done less. As a reference, BMW recommends 1200 miles/oil change for the ///M engines (regular BMW engines have no recommended break in period).

I would avoid full throttle/RPM over 3500 for the same duration.

There really are two (2) schools regarding engine break in; the other is to drive it out of the barn like you stole it (look at the drag racing crowd). I prefer my method /ubbthreads/images/graemlins/wink.gif Whenever I build an engine for a customer, I always put the first 100 miles on it, and I do it may way.

 

[Keoke]

Hi ED, I would not expect any significant drop in oil pressure when going from HD 30W to 20W 50.

OH by the way I had a conversation with Valvoline Engineering. They indicated that; Their Racing oils are not affected by the current ILSAC Requirements and contain the highest level of additives and friction modifiers of the currently available oils.---Fwiw---Keoke

 

[Dave Russell]

[ QUOTE ]

And a related question about oil pressure; The oil pressure seems very good using the HD30 oil. how much of a drop in oil pressure should I expect when switching from HD 30 to 20w-50 ?
Thanks !
Ed K

[/ QUOTE ]
Hi Ed,
See attached graph --
A straight 30 oil should have a viscosity of about 480 SUS at 100 degrees F, & 62 SUS at 210 degrees F.

A SAE 20W-50 oil would have a viscosity of about 250 SUS at 100 degrees F, & 92 SUS at 210 degrees F.

The straight 30 oil might show a little more oil pressure when relatively cold, & less when hot, as compared to the 20-50. Surprisingly, the two oils don't reach equal viscosity until they are at around 200 degrees F.

It wouldn't be unusual for the oil temp to be at 210 or higher. In fact, it needs to get hot enough to boil off the water condensation/combustion by products.
D

 

[Ed_K]

Dave,
That makes sense as I was almost shocked by seeing 60 lbs of oil pressure when the engine is not warmed up all the way. After it warms up to 180 or so, the max oil pressure is somewhere over 50 perhaps as much as 55 lbs. The chart would indicate that I should expect the same oil pressure reading after the engine warms up all the way when using the 20w-50.

 

[Ed_K]

Keoke,
I have Valvoline VR-1 on my list of " good " oils for the Healey. Back when we had the thread about ZPPD content, I made a list from the three or four web articles in my Healey notebook of " good " oils.

 

[Ed_K]

Randy,
I had heard the same two schools of thought but didn't know if one or the other was a " more accepted " practice. I have combined the two schools of thought;
1.. After it is almost up to full temp, drive it like I stole it.
2.. Avoid full throttle most of the other time while driving.
3.. One or two more full throttle " episodes " during the drive.
I am probably kidding myself that any of that makes a difference but I " feel good " ,( liberal terminology), about it.
/ubbthreads/images/graemlins/devilgrin.gif

 

[Keoke]

[ QUOTE ]
Keoke,
I have Valvoline VR-1 on my list of " good " oils for the Healey. Back when we had the thread about ZPPD content, I made a list from the three or four web articles in my Healey notebook of " good " oils.

[/ QUOTE ]
/ubbthreads/images/graemlins/savewave.gif
Well ED, you better hurry up and get some because I am seeing it priced at $40.00/ Case of Six!. Also as TH pointed out ealier Castrol GTX is available with the rebate at $1.59/Bottle.--Fwiw--Keoke