620 break in

[Apollo77]

i know this has probably been done before but i don't have time to look threw all the posts to find the answer. i just did a rebuild on my 77 620, pistons, rings, rod bearings, etc.. after figuring out that i had my timing off... duh!!! i got it to fire and run just like before, how ever i know there has to be some kind of break in period that i should probably follow. can anyone tell me what that is? cant wait to get it back on the road!:D

thanks again

DV

[Pacific coast Datsun]

I was told years ago theres usually a 500 mile break in period. After that maybe re torque the bolts if need be & call it good.

[banzai510(hainz)]

drive it like you stole it.

 

did you make sure the oil pump was primed(filled with thick oil) before start up? Thats usaully the BIG KILLER of a newly rebuilt motor. seen/heard of it done 3/4 times already

[nukeday]

When I read your topic title, I thought someone broke into your truck...lol...

 

Here's something useful:

 

http://forum.ratsun.net/showthread.php?t=5804&highlight=engine+break+zinc

 

Do some more searching here using 'break in', 'zinc', 'rebuild', 'start up'.

 

If you spent the effort/money to have the engine rebuilt please pay attention to this advice. Don't get in a hurry now, if you try to rush this, you might be rebuilding it again in short order...

 

Good luck :)

[79D50]

Best Practice:

 

Either prime the oil pump or pre charge the entire oiling system. My local machine shop has a handy tool called a pressurized oil pump. It is a cannister filled with 10/40 or oil of your choice that is pressurized with air (behind the cannister). Take off your oil sender unit (light or gauge) and install the nozzle end of the tool in its place. Slowly turn on the valve and the air pressure in the cannister will feed the oil throughout your entire motor to include block, head, oil passages etc. This way you will no get a dry fire. Dry fire is risky because if it takes 30-45 seconds to build oil pressure (assuming you primed your oil pump properly) you can glaze your cylinder walls and your rings will never seat properly.

 

Once you are primed. Fire it up. Do not let it sit there and just idle. Once it is running, immediately take it up to 2500 then back to idle, then 4000 and back to idle, then 5000-5500 and back to idle. Try to stay away from redline. Do this 2-3 times and shut the motor down. Check for leaks, re-torque your head bolts and check your valve clearances.

 

Now drive it. Under load, slowly go through the gears all the way to redline in every gear. Do not drive at a steady RPM on the freeway. Drive around town for the first 100 miles up and down through the gears to redline. Change the oil/filter, recheck everything and drive it like normal.

 

This is how I break in motors and I have never had a problem. There are a lot of other opinions and methods out there so find out which one best suits your style.

[Apollo77]

drive it like you stole it.

 

did you make sure the oil pump was primed(filled with thick oil) before start up? Thats usaully the BIG KILLER of a newly rebuilt motor. seen/heard of it done 3/4 times already

 

well i cant guarantee that i did it all correctly, this is my first time tearing into something like this. however when rebuilding i used a LOT of assembly lube, and i have been trying to turn it over for the past 3 weekends. once i had it back together i just wanted to see what else i needed to work on and it fired. soon as it did i went into a high idle, probably because i had all the hoses and air intake unplugged and off the truck. i maybe have run for 5-10 mins as i tried to lower the idle and check timing. but i dont want to do anymore till i know i wont screw things up.

 

sorry bout the title, i kinda thought that might happen.:o

 

and i dont have a tach so should i just listen to it and see what i can get it to?

 

and thank you all very much this has been very helpful! i hope to see some of you at some datsun get together, now that i will have something to show when i get there :D

 

DV

[Skib]

when I built my turbo motor I primed the pump, oiled the cam, and then fired it up. Made sure nothing was on fire :lol: and then ran it at ~3k for 20min to set the rings, changed the oil (you want to get all the assembly lube floating around out), and then went and took a real long test drive, winding the RPMs to ~4k but nothing to hard for a while. I gave it a 1k break in to be safe (drove it to S.OR and back :D) and then changed the oil again.

[banzai510(hainz)]

long as you put some kind of oil and or lube/grease in the oil pump as the gears will only spin air in the pump. If oil is in there it seals up the gears then to create a sucking/vacuum to the sump tube to pick up the oil.

 

If you notice alot of metal shavings in the oil then you forgot to prime the pump. If there is dont tell nobody and just drive the truck untill you ready to sell it. Change oil and filter.

 

A oil pressure gauge will catch this sooner as I think the idiot lights might go out if it senses 5 pounds of pressure(not positive).

 

 

where you get all your parts for your rebuild? Pistons? Price?

Edited November 24, 2009 by banzai510(hainz)

[nismo dr]

Datzenmike found this break in link in the piston ring sticky

 

http://www.mototuneusa.com/break_in_secrets.htm

__________________

[nismo dr]

.If there is dont tell nobody and just drive the truck untill you ready to sell it.

 

 

quote]

 

:lol::lol:

[Apollo77]

long as you put some kind of oil and or lube/grease in the oil pump as the gears will only spin air in the pump. If oil is in there it seals up the gears then to create a sucking/vacuum to the sump tube to pick up the oil.

 

If you notice alot of metal shavings in the oil then you forgot to prime the pump. If there is dont tell nobody and just drive the truck untill you ready to sell it. Change oil and filter.

 

A oil pressure gauge will catch this sooner as I think the idiot lights might go out if it senses 5 pounds of pressure(not positive).

 

 

where you get all your parts for your rebuild? Pistons? Price?

 

 

well its been a while since i got them, but i got most of it all off eBay. i found pistons and rings set for about 55 shipped. from a seller "Vintage Imports Inc"

and i cant recall but i think i got my rod bearings from them as well for around 30. gaskets all came from my local shucks auto.

 

im going to hope for no shavings at all, i love this truck and want to keep it forever. first truck and i bought it for $100!!! going on 9 years and i have only heard good things of them. if i can keep it around then i would love to do so.

 

DV

[lynchfourtwenty]

if all else fails, put in a used runnin motor :)

[Apollo77]

if all else fails, put in a used runnin motor :)

 

hell if this doesn't work i think ill try and find some new rotary engine or something and surprise everyone when they see this lil datsun take off like a bat outta hell:lol:

 

always been a dream of mine... but boy do i have some ideas...:rolleyes::lol:

DV

[DatDoug]

The pre-lube is good.

 

Prime oil pump good

 

leave coil wire off & turn over for 30 sec.

 

Once u do get it started run @ no less than 1500 rpm for 20 min.

 

Stop motor & drain oil and change filter

 

Check for gas, oil, coolant leaks

 

Fill with oil and new filter

 

Drive thru the gears like was said b4

 

Constantly change speeds. accelerate hard and then back-off (helps seat rings) do this often in the first 100 miles

 

After that go in & check valve clearance and mani bolts.

 

Cant wait to race ya!:lol:

[Apollo77]

sounds good. i need to get some tie rods and swap them out before i can take the truck out. soon as i get them in i will be able to pull it out of the garage and get ready to break in. thanks for all the help everyone.

and datdoug, its gonna be ugly but funny at the same time. im sure you'll fly past me with no problem :D

DV

[Apollo77]

i know this might be a dumb question but is it better to do the first 100-200 miles all at once or taking breaks every 50 or so miles? whats the best way to do it?

DV

[77 rustrat]

you schould probably do it all at once so that it gives the rings and bearings more time to do there thing but thats my opinion