Rebuilt Engine First Start & Cam Break-in

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JimB73

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[SIZE=12pt]Looking for some advice on first startup of a rebuilt engine. I’m to the point of getting ready to do the first start of the rebuilt engine for our Mustang (302). This is the first newly rebuilt engine cam break-in I have done. I have gone through a pre startup check list and I think I have everything setup, carb settings, basic timing and I have a temporary fuel system setup. In reading about the cam break-in process it seems to be a nerve racking process that even professional engine builders have referred to as “a crap shoot” on if the cam will live the first 20 minutes of break-in. I’m using Joe Gibbs break-in oil so should have the proper zinc needed for cam break-in. Any tips/advice that would help give me confidence in doing this procedure would be appreciated. [/SIZE]

[SIZE=12pt][/SIZE]

Thanks!

 

Don C

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I connect a mechanical oil pressure gauge in place of the oil pressure sender/switch and have it visible.  I  prime the oil pump and fill the filter by connecting a drill to the oil pump shaft, and spin it until it builds oil pressure. You can run for a while without coolant, but not without oil pressure. I also start the engine from under the hood so I can keep an eye on everything under the hood, such as watching for leaks, and a way to shut if off, if necessary. If you have a fuel gusher leak, getting from the front of the car to the ignition switch takes way too long.

Double check fluid levels, have the timing light ready. Make sure the belts are tight and no loose tools laying around in the engine bay.

Be prepared to add more coolant.

No loose sleeves or clothes that can get caught.

Have a good fire extinguisher ready, a garden hose will just spread burning fuel or oil around.

 
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c9zx

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   It is a bit late for this I suppose but, before I install the intake manifold, I index each lifter with a sharpie and turn the engine over by hand looking to see that all the lifters rotate as the engine is cycled. If the flat tappet lifters don't rotate, is almost a sure sign that there will be a problem sooner than later (not enough taper on the cam lobe or radius on the lifter face).  If I'm using double springs I'll leave the inner springs out for cam/engine break in as well.  Your temporary fuel system needs to be able supply fuel for at least 20 minutes and the cooling system needs to be good, read big fan in front of the radiator. The battery needs to be fully charged and have a functioning charging system. Once it starts, do your best to get the timing close to correct (+/-4 degrees, use total mechanical timing, vacuum advance disconnected and hoses plugged). Occasionally vary the engine speed with the throttle from 2000-4000 RPM to help seat the rings. Monitor oil pressure and coolant temperature (not the dash gauges/engine is toast lights). If the engine doesn't want to start, figure out why, don't just keep cranking it a lot, a few restarts will be fine. If everything goes reasonably well, drive it easy a bit (100-200 miles) and change the oil and filter (with oil with appropriate levels of ZDDP, not additives, about 1200-1500 PPM). After all of this, if you want to be certain all is well, or there may be a problem, use an oil filter cutter (really big tubing cutter) to remove the outer shell of the oil filter to see if there are any shiny bits inside, don't worry about a small amount of near black film that may be there.

   I know this is a lot to absorb, and I'm not trying to give you an anxiety attack, but if you do most of the above it will likely go well. It is also helpful to have someone to help in case you need to have someone shut it down in a hurry (fuel or coolant leak, over temp or low oil pressure).

   In the "for what it is worth column", I did almost none of the above on my first solo rebuild and it turned out fine. I hope this helps more than hurts. I hope all goes well. Chuck

 

mjlan

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Lots of good info above!

One thing that I did on my last one that seemed to help it start quickly is fill the float bowls of the carb with gas ahead of time so you don't have to wait on the mechanical pump. I used a nozzle from an RTV tube as a funnel.

Good luck!

 

c9zx

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I knew I left something out! Thanks for posting. Chuck

 
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And something to check is that the carb float is not stuck so you don't flood the engine, which in turn can remove the oil film from the cylinder walls. Not unheard off in a carb that has been sitting around for some time..... trust me, I know  :whistling:

 

vintageman

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+1 on Chuck's post. I just started mine for the first time a few months ago, very stressful up to the point of starting it. Make sure that you prime the oil pump, I built a stand for my radiator and connected that. I did all of what Chuck mentioned minus the varying the engine speed and driving it for the ring seat. I will do that when I get it on the road later this year. I had mine on an engine start stand with all mechanical gauges and ran it for about 25 minutes. Never had an issue with carb priming, I worked the throttle a couple times and turned the key over and it started first time, never stalled until I ran out of gas.  Just for grins, I did start it a few days later to wake neighbors up but once again, it started immediately. Good luck with your build, once you start it, it will definitely bring a smile to your face.

Tom 

 

JimB73

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Thanks for all the great input! very helpful tips!

 

JimB73

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I connect a mechanical oil pressure gauge in place of the oil pressure sender/switch and have it visible.  I  prime the oil pump and fill the filter by connecting a drill to the oil pump shaft, and spin it until it builds oil pressure. You can run for a while without coolant, but not without oil pressure. I also start the engine from under the hood so I can keep an eye on everything under the hood, such as watching for leaks, and a way to shut if off, if necessary. If you have a fuel gusher leak, getting from the front of the car to the ignition switch takes way too long.

Double check fluid levels, have the timing light ready. Make sure the belts are tight and no loose tools laying around in the engine bay.

Be prepared to add more coolant.

No loose sleeves or clothes that can get caught.

Have a good fire extinguisher ready, a garden hose will just spread burning fuel or oil around.
Don,  Thanks for the reply. Yes, I have connected a temp mechanical oil pressure gauge as you suggested and I got a priming tool to prime the oil pump. I have tested and got oil to the top end (all rockers showing oil). I'll check on getting a remoe starter button.  I also plan to have a fan setup in front of the radiator. Good info, Thanks![SIZE=12pt][/SIZE]

 

JimB73

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   It is a bit late for this I suppose but, before I install the intake manifold, I index each lifter with a sharpie and turn the engine over by hand looking to see that all the lifters rotate as the engine is cycled. If the flat tappet lifters don't rotate, is almost a sure sign that there will be a problem sooner than later (not enough taper on the cam lobe or radius on the lifter face).  If I'm using double springs I'll leave the inner springs out for cam/engine break in as well.  Your temporary fuel system needs to be able supply fuel for at least 20 minutes and the cooling system needs to be good, read big fan in front of the radiator. The battery needs to be fully charged and have a functioning charging system. Once it starts, do your best to get the timing close to correct (+/-4 degrees, use total mechanical timing, vacuum advance disconnected and hoses plugged). Occasionally vary the engine speed with the throttle from 2000-4000 RPM to help seat the rings. Monitor oil pressure and coolant temperature (not the dash gauges/engine is toast lights). If the engine doesn't want to start, figure out why, don't just keep cranking it a lot, a few restarts will be fine. If everything goes reasonably well, drive it easy a bit (100-200 miles) and change the oil and filter (with oil with appropriate levels of ZDDP, not additives, about 1200-1500 PPM). After all of this, if you want to be certain all is well, or there may be a problem, use an oil filter cutter (really big tubing cutter) to remove the outer shell of the oil filter to see if there are any shiny bits inside, don't worry about a small amount of near black film that may be there.

   I know this is a lot to absorb, and I'm not trying to give you an anxiety attack, but if you do most of the above it will likely go well. It is also helpful to have someone to help in case you need to have someone shut it down in a hurry (fuel or coolant leak, over temp or low oil pressure).

   In the "for what it is worth column", I did almost none of the above on my first solo rebuild and it turned out fine. I hope this helps more than hurts. I hope all goes well. Chuck
Chuck, Good stuff, Thanks! I'm anxious but hopeful that it goes well. I have read that you should drop the oil right after the break-in is done, you mentioned driving it for 100-200 miles. Would that be with the break-in oil? or a change before driving?

 

JimB73

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Lots of good info above!

One thing that I did on my last one that seemed to help it start quickly is fill the float bowls of the carb with gas ahead of time so you don't have to wait on the mechanical pump. I used a nozzle from an RTV tube as a funnel.

Good luck!
That's a good one, I was wondering about that also. It's running the stock carb (2100D) Is there a vent on it or another place that fuel could be added to the bowl? (I don't see one) or would I have to pull the top to put fuel in the bowl?

 

JimB73

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And something to check is that the carb float is not stuck so you don't flood the engine, which in turn can remove the oil film from the cylinder walls. Not unheard off in a carb that has been sitting around for some time..... trust me, I know  :whistling:
Thanks! Good thought. The carb has been rebuilt but as you said it has been sitting a while so that is something I'll be checking.

 

JimB73

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+1 on Chuck's post. I just started mine for the first time a few months ago, very stressful up to the point of starting it. Make sure that you prime the oil pump, I built a stand for my radiator and connected that. I did all of what Chuck mentioned minus the varying the engine speed and driving it for the ring seat. I will do that when I get it on the road later this year. I had mine on an engine start stand with all mechanical gauges and ran it for about 25 minutes. Never had an issue with carb priming, I worked the throttle a couple times and turned the key over and it started first time, never stalled until I ran out of gas.  Just for grins, I did start it a few days later to wake neighbors up but once again, it started immediately. Good luck with your build, once you start it, it will definitely bring a smile to your face.

Tom 
Tom, Yes having an engine start stand would be nice! It sounds like your startup went well. I keep going through the check list over and over....just the nerves I guess! Hope mine goes as well as yours did, I'm definitely ready to smile on this project

 

JimB73

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A follow up question(s), during break-in should the radiator cap be on tight or loose for monitor the coolant level?

Would it be okay to use distilled water in the radiator during break-in? I have a repaired rad in the car (it was done by a reputable shop and pressure tested but still....) would hate to fill the rad with $$ antifreeze only to have it puke it all out on the ground if there was a problem...My thought was to run water during break-in, if no issue then drain it out and then put in antifreeze. Bad idea? good idea?

Thanks!

 

midlife

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A follow up question(s), during break-in should the radiator cap be on tight or loose for monitor the coolant level?

Would it be okay to use distilled water in the radiator during break-in? I have a repaired rad in the car (it was done by a reputable shop and pressure tested but still....) would hate to fill the rad with $$ antifreeze only to have it puke it all out on the ground if there was a problem...My thought was to run water during break-in, if no issue then drain it out and then put in antifreeze. Bad idea? good idea?

Thanks!
Good idea.  Better yet, when you drain the water out, replace it with half antifreeze AND distilled water.

 

c9zx

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I run the break in oil for about 100 miles just to make sure everything that is going polish itself in has the extra protection while it is doing so. Just my and my machinist's opinion, others may differ. Always use distilled water, fewer, if any, trace elements in it. I run a 70%water 30% anti-freeze mix. Water carries the heat away better than ant-freeze and my old cars never see use in very cold weather. If I lived in a cold climate I'd run 50/50. Chuck

 

vintageman

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Another +1 on Chuck, I ran mine with distilled water during break in and run 50/50 after. 

 
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