I have rebuilt my 455 Buick which made about 600/600 on the dyno previously. It has a hydraulic roller and will be broken in and tested again on the dyno. Clearances are roughly .0023" rod and .0028" main. I have 6 qts of Driven BR30 (5W30) in the pan and Baldwin B9 filter. I will set the initial timing (but 4 deg low) and adjust the carb then run it at a fast idle till it warms up. I plan to use the LSJR method and load it to 15% (90 ft lb) at around 3000 rpm for 20-30 minutes. Then change the oil and filter.
Next fill it with either 6 qts of Quaker State All Mileage blend 5w30 or 3 qts Quaker State All Mileage plus 3 qts Mobil 1 Euro 0W40. Then do 2 to 3 pulls to see if the numbers stabilize and repeat. If so, then dump oil and filter.
Fill with 6 qts Mobil 1 Euro 0W40. Bump timing and start testing combinations. I have 3 carbs and 2 manifolds plus a spacer etc to experiment with so maybe 8 to 12? more pulls.
One of my concerns is changing the manifold and possibly getting water in the oil. Obviously that will require another oil change but I plan to take precautions to prevent spilling water as much as possible.
Anything I'm doing wrong or any things to improve on this? Thanks.
The break-in procedure you are describing is typical for a flat tappet cam.
It is NOT correct (IMO) for a hydraulic roller.
The static timing you set should be based on the advance ability of your ignition system (ignoring vacuum advance if present). It's probably a good idea to lock out your distributor during initial running and just set a value that you know is conservative like 20 degrees BTDC. (final timing will end up 32-40 degrees typically unless your combination is really whacked and needs more than 40 degrees). This is probably enough timing to get good cylinder pressure at peak torque without risking any knocking or such.
Use premium good fuel while testing/tuning/breaking in. (ideally, race fuel from a drum, nothing from a pump).
The reason the LSJr breakin method isn't appropriate for your engine is that you need to focus on the rings more than the cam. Hydraulic rollers have almost no break-in at all. And the prolonged 30 min of light load to give them a break in they do not need is compromising the CRITICAL break in of piston rings. You simply cannot get back that precious initial opportunity to seat those rings properly.
This is why you need a break-in more like this:
1) Use the BR30 oil.
2) Start the engine, let it idle and verify stable oil pressure and RPM.
3) Run the engine up to your estimated peak torque RPM at no load
4) Monitoring oil temps, raise engine load progressively (10% every minute) until you get oil temp over 220F.
5) Once you get oil over 220F, GO TO FULL THROTTLE. Experiment with RPM to see if you can get more torque by going higher or lower in rpm. Find the RPM that gives the highest torque reading. That is your reference RPM from now on.
6) Hold the engine at full throttle and peak torque for 5 min.
7) Remove load until the engine can pull up 5000rpm or so.
8) Hold the engine at 5k rpm and pull throttle down to zero at 5k (or whatever min throttle on that dyno will allow 5k rpm). Let the engine sit at 5000rpm no load for a minute.
9) Pull the engine back down to the 100% load peak torque RPM from step 5. Stay there 5 minutes.
10) after five min, let the engine "Rest" at 5000rpm for a minute.
11) repeat the 5+1 cycle 5 five times. You should end up with 25 min at peak torque and full throttle and 5 min total "Resting" at 5000rpm or something that's high rpm but well below your redline or rated peak HP.
After this, return the engine to low idle, let the oil temps stabilize. Shut it down, then drain the break-in oil.
It's important to "rest" the engine at
HIGH RPM, not low RPM.
High RPM assures lots of oil is flowing to key locations during the cool down cycle. This cools pistons and other things that got hot much more effectively. It also avoid the "hot soak" of going from peak torque down to low idle with very little oil, coolant, and air flow.
During a dyno break-in, the engine should spend little to no time below peak torque RPM. The only reason we're babying it a bit when first starting is because the break-in oil isn't going to be optimally protective until it's good and hot, so 220F is a MIN temp IMO.
