Starting an engine with oil but no water

Got my sbc in the car and to the point where it could be started. My partner in crime is encouraging me to start it for the first time dry, i.e. without the cooling system hooked up. Says he starts all his engines that way the first time. He's a professional diesel mechanic. Run it for less than a minute, just to make sure it will start easily when it's time to break in the cam. He says that way, you only have to look for oil leaks, and if there is a problem, there's not so much in the way to take apart to fix it. Anyone have any personal experience doing this?

 

You could do it. I wouldn't run it for long, probably 30 seconds, but it could be done.

If the only logic though is to "only have to look for oil leaks" I don't exactly get that point. Oil looks like oil, coolant looks like coolant.

 

We used to do it all the time at the junkyard with used engines, 30 years ago. We'd run them till the heads got warm, maybe 5 minutes? Didn't seem to hurt anything, all the engines were guaranteed. We wanted to get them warm for the compression test, also to see if they smoked.

I never do that with a new engine though.

 

start it up if you want and shut it off before it gets warm, no harm done

 

No. Cam break in is so essential no with our crappy oil. Hook everything up right and follow your cam mfg instructions to the t. You don't want to have to build that motor again. Many mfgs state you shouldn't let your engineget below 1500rpms at all for break in because of oil flow characteristics. I wouldn't chance it.

 

Dragsters don't run cooling systems and they run for more than a couple minutes at a time and at full bore for a bit of it. I can't see how a couple of minutes of idling could hurt much if the oil pressure is good. Still, I wouldn't do it any longer than really needed before the cam break in though just to be sure. The water probably helps distribute the heat around the block and heads more evenly I would imagine to help reduce the hot spots.

 

Did it once and ruined my water pump. The engine had sat for a while but everything was fine before i pulled it out of the first car. Now i always have a water hose flowing to the lower hose just so the pump does not turn dry.

 

I run stuff all the time without the cooling system operational. Water doesnt flow until the thermostat opens anyway...so the motor has to be fairly warm to the touch before the thermostat would have opened. I do this on "barn find" type of stuff...or better said "backyard find"...just to see if the engine is any good before going further with the project...I would never do it on a new engine...

You say that you want to start your motor dry THEN change the cam? Or is the cam in this engine new? If you are breaking in a cam, you want to have your cooling system working because you need to run it for more than a few minutes to break it in...the new engines I have started were run for a 1/2 hour or more to break everything in....you dont want to run a new cam for a few minutes then shut it off to start it again without breaking it in properly...

 

i think your water pump failure was a coincidence.

to the OP. why not just have some patience. wait to run the engine with the cooling system hooked up, then you will have nothing to worry about.

 

New cam and all new parts. Engine has not been started since it's been rebuilt. I'm thinking the potential problems outweigh the potential advantage.

 

I also think that was a coincidence...the bearings in a waterpump are sealed against water...I dont think that water in the pump or not makes a difference if the unit is going to fail....

"New cam and all new parts. Engine has not been started since it's been rebuilt. I'm thinking the potential problems outweigh the potential advantage"

Dont do it then...you want to be able to run the motor without interruption for a good half hour or more to break in the cam and rings..starting the motor for a minute to make sure it will start easily to break in the cam is a sure fire way to flatten your new cam...

 

Since you need to break-in the engine/cam, you'll be safer by hooking up the cooling system and doing a proper break-in. You can dial in the carb/timing once it's running.

If it was already a complete running engine, or a junkyard motor or something, sure, you could run it with no water for about 5-10 minutes before the temps start to go up. I've done it a lot when swapping engines in with the front sheetmetal off and radiator not installed.

 

Maybe it's just me, but I see a BIG difference in running an engine with no coolant and one with coolant, for anything more than, at most, a minute. Regardless of the thermostat opening point, the coolant acts as a heat sink and absorbs and evens out the temps of components. The heads would, I think, get hot faster than the block, but it wouldn't be too far behind. I think the concentration of heat without coolant is risky on ANY engine, beyond a minute, maybe two at most. And most especially for a new engine with new cam/lifters.

Ray

 

Unbelievable! ... And your going to listen to this moron??? Hook up a radiator and fill it! Then start it... If your breaking in a new cam, it's gotta run for at least 20 minutes at around 2000 rpm non stop..

 

By dragsters, do you mean Top Fuel? The same dragsters that have teams of people to tear down the engine between EACH run? Good example!

I wouldn't run an engine without coolant unless I wanted to blow it up! Seems like the fastest way to warp the cylinders to me.

 

I've run used ones in the 'yard as well, just enough to check for smoke and knocks before I laid down my cash. At home, I've run a garden hose in them if I wanted to run one for a short while, but certainly not in a critical situation where a cam should be broken in carefully.

Bob

 

great thought!
it can be done. but why?

 

I've done it hundreds of times. Never had a problem.

 

Ahh let's see. NO! Ahh wait. NO No no.

 

The water pump failure was certainly not a coincidence. The seal face needs coolant, not the bearings. Runnig it without coolant, even for a short time can damage the seal gace. Bearing failure is secondary, after coolant leaks past the seal face into the bearing and washes out the grease.

The second possible failure is the valve bridge (between valves). That is a failure point on alot of engines. Many head cracks are actuall secondary failures caused by head gasket or other coolant system failures.

 

If its a new engine, new cam..I wouldnt do it..get it hooked up right and set up right and run in the cam right

already run engine that was just transplanted, and had some previous use and miles on..go for it, do it all the time, i put enough coolant in em to fill the block

 

Starting a brand new engine and letting it run for a little bit is not following the standard break in procedure. That should be the end of the discussion.

Doing that without coolant is kind of silly , but if you're hell bent on doing it anyway - its your money.

 

We run our old Dragmaster with a 354 hemi with only passive cooling and have for years. In fact this is an survivor that started life on the strip in 1962 and the only modification is we added a starter and battery. We fire it up at cackle fests and track runs for no more than 2 minutes at a time. It is good and warm then. I said we run a "passive cooling system" and on this Hemi we still have caps on the front of the heads and put coolant in the block as it still does have a heat exchange/ sink value. The engine has no water pump so once the coolant has given it's all it could get very near critical mass. Other diggers we run have utilized pour stone and this process is termed "concreting the block". It is a dedicated motor once you do that and can probably never be used in a street application but that's a whole other story. To get to the point you bring up here, you aren't typically going to hurt a motor with a couple of un cooled minutes on the block. At least not from overheat damage. Of course how radical the motor is and how much heat a very radical build will generate will weigh in on this time coefficient but you have to be very close to John Force radical to really worry about that. If you want to get a quick set on the timing, carb adjust and check for oild drips you'll be fine. KEEP IN MIND, you said you are breaking in a cam and for this reason alone you do not want to let a moment of near warm engine temp be achieved and then shut down as that can have adverse effects on your cam unless your running a roller cam. So have your timing, carb adjust and drip check thought out in near pit stop accuracy so you can achieve your objective and get the piece of mind you are after before you add coolant. I say you shouldn't let it heat and then cool without a complete break in but try to avoid interupting the block temp once break in begins until done. Honestl it wouldn't be the first cam break in that had to be interupted for what ever reason to avoid other serious damages and the next start up and break in will probably go just fine. I'm sure if you are using a standard hydraulic lifter cam that you are using a good high zinc oil and zinc additive for break in at the very least. Good luck and have fun.

 

If it wasn't for the fact it's a freshly rebuilt engine I'd definitely agree. But since it needs to seat rings, and breakin the cam I'd say no to starting it dry.
I've started and ran lots of used engines after a swap, but they're already running engines and everything is broke in and seated. Since you need 20 min. of breakin at around 2500 rpm's for the cam, I'd sure wait until it's got cooling to complete the breakin.

 

Dont forget to have a fire extingusher ready and at hand near where you can get it if necessary ..pin pulled armed and ready

 

There is a lot of difference in starting a used engine that has been sitting and a new one in my opinion....and that would be $$$.
Totally agree on the thermostat statements, as well as it isn't going to really hurt anything if it does not get hot.
However, why take a chance on your hard earned money, as well as labor (If you built it yourself) for the extra time to hook up, or install the radiator....
No decision here for me...DON'T DO IT...

 

I'd have to agree with those who say that if it was a used engine there wouldn't be problem or an issue except maybe taking the fan belts of so the water pump and power steering pump don't turn dry. I've even posted a video of me firing up a 500 Cad sitting on a tire on here to show that you don't need a lot connected to a used motor to test fire it.

A completely new engine with a new cam is a different story and even though it is a big temptation to bust it off and let it build up oil pressure and then shut it off I'd rather see it all hooked up with coolant in it so it could run long enough to break in the cam.

 

And, if it has an auto trans, be sure to have fluid in the trans/convertor.

 

Don't do it... Not worth the risk. Well unless you want to do it all over again.

I don't start old "barn find" type engines without changing oil/filter and coolant. I will turn them enough to make sure they are not frozen, if I'm serious I'll change everything prime the oil pump before trying to start it. Either that or it's just a core in which case I could care less that it starts.

Bingo.

wrong...

again see above.

Bingo.

Logic... ^^^ listen.