Dumb question, cold starting...?

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MopaR&D

MopaR&D

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This might be obvious or not a big deal but I was surprised to not find anything relating to this using the search tool. I built my first "block-up" 360 with bearing clearances on the loose side and a normal-volume oil pump. Is it better if I crank it for a few seconds before pumping the gas to get it fired in order to get the oil flowing a bit, or should I just pump the gas beforehand and let it fire off with the first crank? I notice it usually takes a second or two for my oil pressure to come up after it starts and there is a bit of a lifter tick during that short time, just wondering if this is something to be concerned about at all or if it will wear the bearings more.
 
Cold starts are where the most wear comes from. In my plow truck, which has a mild low end noise when hot, I turn over to get fuel in the carb and get the oil moving before I pump the gas to fire. Turn it over about 6-8 seconds, give it a pump or two, and fire it. That way the pressure is immediate and it's quiet. Otherwise it makes a bit of noise for a few seconds.
 
I just get it to light off as fast as it can, so that the higher rpm gets that oil moving faster.

if ur lifters tick every time u fire it up....thats not a great thing.

How loose is this motor?
 
1wild&crazyguy said:
I just get it to light off as fast as it can, so that the higher rpm gets that oil moving faster......................
Click to expand...

X2 You have to remember that cylinder walls and the cam lobes are mostly lubricated by "slop" and I doubt there is much of that going on while cranking.
 
Someone makes a spring loaded canister that as soon as you turn the key on, it pumps a quart of oil into the engine bearings and lifters.
Basically it pressurizes the oiling system before the engine even starts.

Here is one kit.
http://www.autoenginelube.com/
 
It's an oil accumulator. Canton make s nice one too.
The thing is at least for me, it's the bearings that I'm concerned about. I have a mini starter and it can develop 50psi cold on it's own. For the OP, the lifters would be pressure fed too (in terms of ticking... i.e. valve train slop). I don't think it matters much either way for lifter noise. So long as it goes away quickly, no problem.
 
OK thanks guys, I'll be sure to 'dry crank' it for a few seconds from now on. I plastigauged the main and rod bearings and they came out just over .003" (as in the edges of the piece of plastic were just barely wider than the 'slot' on the gauge strip). The engine makes 55-60 psi max when hot (70-75 when cold) and after pulling off the highway (hottest time for oil) the idle pressure goes down to 15-20 psi. I'm mainly worried about the bearings too, I know the racing engines with big clearances have to get oil pressure before the engine is fired so the bearings don't get wiped.

Nice tip on the oil accumulator too, I might look into one of those later on.
 
In my experience the rings always seem to wear out before the bearings. If you crank it without allowing it to start you just wear the rings even faster, along with the starter, ring gear, battery, etc. Usually on a re-ring you would do the bearings anyway, as you don't want to run them till they fail. Oil changes are the secret to saving the bottom end. Most of my cars will start at the touch of the key, and then I just let them idle. I have repaired many engines with bearing failure. Here is what many of them did. Sub-zero outside, car starts and dies. Car starts again and dies. Car starts again and dies. At this point they will actually have oil pressure because the oil is to thick from the cold to bleed down. Then they start it again and rev it up, and sure enough a bearing will fail, taking the crank along for the ride. Just my $0.02.


Sorry for this strange reply. If this is a first start, just ignore it. I read this wrong. I think some others did also. Anyway, put it together with the proper lube, prime it and start it. Break in the cam using the manufacturers recommendations.
 
I hope you put assembly lube on the cam lobes. Pour a few drops of oil down each spark plug hole. Best to run oil thru the galleys first. Most people use a rod that spins the oil pump (~$10), but you must remove the distributor and its drive shaft. I put a T in-line w/ the oil pressure switch so I can inject oil from a small garden pump sprayer, then block off the port. At the very least, ground your coil output wire so it won't fire and turn over the engine for 20 sec. Maybe better to turn it over by hand if easy to do.
 
The cam was already broken in from another engine, I swapped the lifters and cam over together (and yes I put each lifter in its own labeled container to not mix them up). But great now we have two conflicting but equally reasonable takes on the starting issue lol...

I'm curious of something else, there seems to be a 'resonance' in the valvetrain when I'm cruising at a certain RPM, usually 2500-2700 that sounds like a lightly tapping lifter. Does this mean I have a lifter going bad? It only happens in that range, any faster or slower and it goes away. I noticed this too in my old 318 which I swapped the cam and lifters from.
 
So I am currently running Valvoline conventional 10W-40 for break-in but like I said the hot oil pressure isn't quite as high as I'd like it to be. Once the engine passes 1000 miles I'm going to change the oil, AutoZone was having a deal on Mobil 1 oil and filters so I bought five quarts of the 15W-50 formulated for "performance vehicles". Is this a good choice or will it be too thick for my street engine?
 
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