I know about breaking in a new engine with a flat tappet cam but what is the procedure for a roller cam? My engine is ready to be picked up from the machine shop and I decided to get a roller retrofit kit.

 

The 20 minute, 2500 rpm routine is not required with a roller cam. I used a Howards retrofit roller in my last build, and that advice came directly from Howards. They said, and I quote: "No break-in required. Best part of a roller. Fire it up & have fun."

Using break in oil and keeping the rpm down for the first 500 or 1000 miles is still advised. There will be lots of opinions on exactly what the limitations should be and for how long, but basically take it easy for a while. I also change the oil after the first 500 miles.

 

I'm of the opposite opinion: You still need to "seat" the rings as quickly as possible after firing the engine up. Once the oil temperature is up to spec, this is done by doing several "power pulls" on the engine to create high cylinder pressures, which will seat the rings into the cylinder walls. I normally do this on an engine dyno by doing several back-to-back dyno pulls below red-line rpm. If the engine is in the car, run several pulls at wide open throttle through 1st & 2nd gear while limiting rpm below 5000. This will seat the rings and assure that you won't have ring oil consumption due to the cylinder walls "glazing over" from *****-footing the engine after initial start-up. Bottom line - after warm-up, take it out and nail it. We do full-up dyno pulls to redline rpm on brand new engines after warming them up and doing a few "soft-pulls" below redline. Check valve lash, check the oil, and check for leaks. If all is good, run the engine to maximum power and tune it!

Lars

 

 

x2 on asking your machinist. He said nothing?

Once the rings have been loaded up good (let the engine slow the car back down), change it out around 50 mi then give it hell. Babying new engines is not what you want to do, the 70s are over.
No reason to wait for hundreds or thousands of miles to do so, with todays rings and finer cyl finishes.

 

Those asking these questions don't have dynos. GET YOUR TIMING CORRECT FIRST! Don't think "It'll only be a few minutes and sounds ok now." Too much advance at full throttle and your new pistons are toast.

 

Yep, what he said. While you don't have to mess with the cam/lifters break-in, you do want to hammer it pretty hard early on. Get the timing set right, then give 'er hell.
If that scares you, maybe you should check your parts list and remove the stuff that you're scared of beating the hell out of.

 

This^^^^^^^^^ is almost exactly what my builder told me about my engine. He did all the machine work and assembled the bottom end. He delivered the short block to my house and I completed the assembly with the Howards roller cam, AFR heads, measured the pushrods and everything else (the roller cam thrust button and pushrod measuring techniques still cracks me up to this day about the complete nonsense that surrounds it). He was very clear and direct:

YOU MUST BREAKIN YOUR HOWARDS ROLLER CAM MOTOR just like any other new rebuilt motor. There is no ambiguity here guys! I wish folks would stop saying roller cam motors do not require breakin...they do! The component failure risks are MUCH less with a roller but not eliminated and roller lifters can and do suffer from particle contamination during breakin, if proper procedures are not followed, not to mention the ring issue LARS referenced as well.

My builder came to my house for the startup upon my request. I used 5 qts of Driven breakin oil. He primed the motor for several minutes using a drill in the distributor opening. Gas primed the carb and it fired with 1 turn of the engine. He manually revved it between 1,800-2,500 RPM for 30 minutes. I then drove the car on the road and did WOT in second gear between 2,000-4,500 RPM for about 10 runs. Went home and changed the oil and filter. Put in conventional Driven 15W-50 for the first 500 miles driving it moderately with occasional blasts to 4,500 RPM and later 5000 RPM eventually all the way to 6,000 RPM. Changed the oil at 500 miles to Mobil 1 0W-40 European Formula which is what the engine has used for the last 5 years...Zero oil consumption! The engine has been a gem 355 making big torque/hp and running flawlessly.......

 

Yes, absolutely. Use the time you have waiting for oil temperature to stabilize to correctly set the timing, check for leaks, and complete basic carb idle mixture screws adjustments. Then give it a few hard runs to get the rings seated.

Lars

 

 

That is correct...rollers need breakin! and I have said it many times, correct. You do not agree which is perfectly fine.

I am not the engineer but my builder who IS an engineer, insists that you should since as I said above that is documented in the literature (you can do a search if interested) that there is less risk of roller failure BUT there is risk. I stated above the risk is particle contamination to the roller lifter.

In summary, roller risk is less but still can happen AND my engineer builder who has written for multiple hot rod publications and is a GM expert, advised me on the roller breakin. You can argue with him, if you like, if you cannot accept, what I have stated,

 

Roller Cams do not need break-in........there is nothing to break-in.........just get some heat in it and run the pie out of it........the load from hard acceleration runs will push gases to the backside of the rings which pushes them against the cylinder walls and "scrubs" them into the bore.......once they seat, that's it.
But it is important to get the rings seated right away as the constant rubbing of rings without load gases pushing against them will knock the peaks off the hone and it will take FOREVER to seat them afterward.
Years ago when we would finish a build (top shelf roller build), it would go straight to the Superflow where it was primed, fired, timed and a "sweep" performed on it with varying amounts of water load applied.....then the final pulls for power were made.
It almost always took five or six good pulls to seat the rings......8 to 10 seconds at a time. How did we know they were seated? It quit making more power!

Jebby

 

Last call for me on this issue:

From Summit Racing On their website:


Break-In Procedure for Roller Cams
Breaking in a roller camshaft and lifters is a little different than breaking in a flat tappet cam. Because roller lifters have less friction with the cam lobe, the concerns are different. Metal particles created during engine break-in are the biggest issue to the bearings in the roller lifter.

I will send Summit a note that they need to remove the roller cam breakin wording from their website since it is wrong............^^^^^^^^

 

 

It's not about arguing. It's about asking why.

When someone tells me something to which the reason is not immediately apparent I ask why. Is that not reasonable?

If the person who told me that can't come up with a reasonable answer or a plausible and /or believable explanation then it is likely that they do not know why either and are passing on information to which they do not understand the reason behind.
Given that is the case then that may make them an unreliable source for said information.

If your GM expert, engineer, engine builder cannot or will not explain the reason to your satisfaction then it is likely he does not understand it. Asking why is not disrespectful, It's just asking for more information.

An engineering degree does not necessarily make one an engineer, nor is it synonymous with genius. If he understands what he preaches then he should be fine with answering the question.

 

"Everything you read on the internet is true." Abraham Lincoln.

 

 

Chevrolet Performance instructions & Break-In Procedure for SP350/357 pn 19367080
this motor is a crate sbc 350 with Vortec heads & Roller Cam

https://www.chevrolet.com/content/da...e-19367080.pdf

Start-up and Break-in Procedures 1. After installing the engine, ensure the crankcase has been filled with 10w30 motor oil (non-synthetic) to the recommended oil fill level on the dipstick. Also check and fill as required any other necessary fluids such as coolant, power steering fluid, etc. 2. The engine should be primed with oil prior to starting. Follow the instructions enclosed with the tool. To prime the engine, first rotate the engine to TDC and remove the distributor to allow access to the oil pump drive shaft. Install the oil priming tool, 141-955 from our licensed partner www.factoryperformanceparts.com. Using a 1/2" dill motor, rotate the engine oil priming tool clockwise for three minutes. While you are priming the engine, have someone else rotate the crankshaft clockwise to supply oil throughout the engine and to all the bearing surfaces before the engine is initially started. This is the sure way to get oil to the bearings before you start the engine for the first time. Also, prime the engine if it sits for extended periods of time. Install Distributor as follows: (1) Locate cylinder #1 top dead center (TDC). (2) Rotate engine to 12 degrees before top dead center (BTDC). (3) Align Rotor with the cylinder #1 terminal on the Distributor. After the engine has been installed in the vehicle, recheck the oil level and add oil as required. It is also good practice to always recheck the ignition timing after removal and reinstallation of the distributor. See step 4 or engine specifications for the proper timing information. 3. Safety first. If the vehicle is on the ground, be sure the emergency brake is set, the wheels are chocked and the car cannot fall into gear. Verify everything is installed properly and nothing was missed. 4. Start the engine and adjust the initial timing. Set spark timing at 32 degrees before top dead center (BTDC) at 4,000 RPM with the vacuum advance line to the distributor disconnected and plugged. The HEI vacuum advance canister should remain disconnected. This engine is designed to operate using only the internal centrifugal advance to achieve the correct timing curve. Rotate the distributor counterclockwise to advance the timing. Rotate the distributor clockwise to retard the timing. 5. When possible, you should always allow the engine to warm up prior to driving. It is a good practice to allow the oil sump and water temperature to reach 180°F before towing heavy loads or performing hard acceleration runs. 6. Once the engine is warm, double check that the total advance timing to 32° at 4000 RPM. 7. The engine should be driven at varying loads and conditions for the first 30 miles or one hour without wide open throttle (WOT) or sustained high RPM accelerations. 8. Run five or six medium throttle (50%) accelerations to about 4000 RPM and back to idle (0% throttle) in gear. 9. Run two or three hard throttle (WOT 100%) accelerations to about 4000 RPM and back to idle (0% throttle) in gear. 10. Change the oil and filter. Replace with 10w30 motor oil (non synthetic) and a PF454 AC Delco oil filter. Inspect the oil and the oil filter for any foreign particles to ensure that the engine is functioning properly. 11. Drive the next 500 miles under normal conditions or 12 to 15 engine hours. Do not run the engine at its maximum rated engine speed. Also, do not expose the engine to extended periods of high load. 12. Change the oil and filter. Again, inspect the oil and oil filter for any foreign particles to ensure that the engine is functioning properly. 13. Do not use synthetic oil for break-in. It would be suitable to use synthetic motor oil after the second recommended oil change and mileage accumulation. In colder regions, a lower viscosity oil may be required for better flow characteristics. 14. Mobil 1 5w30 was used for dyno and durability testing.

 

350/290 HP Engine (19355658 Base) Long Block Specifications

This is a sbc 350 crate with Non-vortec heads (similar to C3 sbc heads) and Hydraulic Flat Tappet Cam (similar to C3 sbc cams)

https://www.chevrolet.com/content/da...e-19355658.pdf

Start-up and Break-in Procedures: 1. After installing the engine, ensure the crankcase has been filled with 10w30 motor oil (non-synthetic) to the recommended oil fill level on the dipstick. Also check and fill as required any other necessary fluids such as coolant, power steering fluid, etc. 2. The engine should be primed with an engine priming tool that is not included with the engine. Tool is available from a variety of sources. To prime the engine, first remove the distributor to allow access to the oil pump drive shaft. Note the position of the distributor before removal. Install the oil priming tool. Using a 1/2" dill motor, rotate the engine oil priming tool clockwise for three minutes. While you are priming the engine, have someone else rotate the crankshaft clockwise to supply oil throughout the engine and to all the bearing surfaces before the engine is initially started. This is the sure way to get oil to the bearings before you start the engine for the first time. Also, prime the engine if it sits for extended periods of time. Reinstall the distributor in the same orientation as it was removed. After the engine has been installed in the vehicle, recheck the oil level and add oil as required. It is also good practice to always recheck the ignition timing after removal and reinstallation of the distributor. See step 4 or engine specifications for the proper timing information. 3. Safety first. If the vehicle is on the ground, be sure the emergency brake is set, the wheels are chocked and the car cannot fall into gear. Verify everything is installed properly and nothing was missed. 4. Set initial spark timing at 10º before top dead center (BTDC) at 650 rpm with the vacuum advance line to the distributor disconnected and plugged. This setting will produce 32º of total advance at wide-open throttle (WOT). The HEI vacuum advance canister should remain disconnected. This engine is designed to operate using only the internal centrifugal advance to achieve the correct timing curve. Rotate the distributor counterclockwise to advance the timing. Rotate the distributor clockwise to retard the timing. 5. When possible, you should always allow the engine to warm up prior to driving. It is a good practice to allow the oil sump and water temperature to reach 180°F before towing heavy loads or performing hard acceleration runs. 6. Once the engine is warm, set the total advance timing to 32° at 3000 RPM. 7. The engine should be driven at varying loads and conditions for the first 30 miles or one hour without wide open throttle (WOT) or sustained high RPM accelerations. 8. Run five or six medium throttle (50%) accelerations to about 3000 RPM and back to idle (0% throttle) in gear. 9. Run two or three hard throttle (WOT 100%) accelerations to about 3000 RPM and back to idle (0% throttle) in gear. 10. Change the oil and filter. Replace with 10w30 motor oil (non synthetic) and a PF454 or PF1218 AC Delco oil filter. Inspect the oil and the oil filter for any foreign particles to ensure that the engine is functioning properly. 11. Drive the next 500 miles under normal conditions or 12 to 15 engine hours. Do not run the engine at its maximum rated engine speed. Also, do not expose the engine to extended periods of high load. 12. Change the oil and filter. Again, inspect the oil and oil filter for any foreign particles to ensure that the engine is functioning properly. 13. Do not use synthetic oil for break-in. It would be suitable to use synthetic motor oil after the second recommended oil change and mileage accumulation. In colder regions, a lower viscosity oil may be required for better flow characteristics.

 

It make you wonder why they are insisting on dino for break in. Since it's GM, it could just be a cost savings directive, since you change it quickly.

I am quite sure the new cars are filled with synthetic, and shipped out without any break in.