over heating issues during break in

[luvbowties]

I noticed you said you are using a clutch fan, and it was been mentioned again that you use a clutch fan. I think that poster really meant to try a clutchless fan.

On a new engine, I think it is wise to use a NON-CLUTCH FAN (6-7-blade would be nice) just to eliminate the chance of a bad clutch not spinning the fan properly. The t'stat and engine dynamics should keep your engine HOT enough; the radiator, fan(s) and shroud should keep it cool enough.

My 2 cents.
Sam

[j.rigby15r]

That's my biggest worry. I've already had to shut it down a couple times and I don't want to risk flattening my cam. Tomorrow is supposed to be a high of 36. I'm thinking of trying again tomorrow to finish the break in period. I'm thinking of putting a fan against the grill and some cardboard around the sides since I don't have a shroud yet. I'm hoping that should cover my bases plenty. But I'm nervous to try, this build has been a painful one.

[brokenspoke]

Originally Posted by j.rigby15r

Why do you say that. The distributor was dropped in at aprox 12 before tdc and my chain is lined up.

Have you checked with a timing light??? The engine is dieseling after its turned off is a clue....

[j.rigby15r]

Originally Posted by brokenspoke

Have you checked with a timing light??? The engine is dieseling after its turned off is a clue....

I haven't. We got it to run good by adjusting the distributor by ear. Once I the cam was done I planned on setting the initial timing. It only dieseled the second time. Correct me if I'm wrong but if it's dieseling wouldn't that be because it's hot enough that it's detonating on its own, or its to rich? And if it's too rich then it wouldn't be too hot because gas acts like a coolant. I might be of on my thinking, that's just my train of thought.

[PGSigns]

If it is running right up to 240 there is a problem. With a 180 thermostat or even a 192 it should never get that hot if it is opening up correctly and there is enough water in the radiator. I would pull the thermostat and drop it in a cup of boiling water and see if it opens completely up. I have seen more bad ones in the last several years than we ever used to see. Please post up a pic of your setup.
Jimmy

[j.rigby15r]

Sure will. What all do you want to see?

[awbrown]

I have had that happen a few times , it is normally a combination of things a marginal radiator , fan too far away from the radiator , I now watch the temp and simply spray the rad down with a garden hose to keep it at 200 or less .. The radiator and the fan position may be fine when you drive it normal as long as you don't get stuck in traffic .. I used a fan off a citation (try to find one , I know ) but it covered a good portion of the radiator , and it draws less than the aftermarket ones.. and with a good rad it will only cycle when you sit in traffic...

[PGSigns]

Fan setup, where the temp gauge is. just to help get you good feed back.
Jimmy

[j.rigby15r]

Originally Posted by PGSigns

Fan setup, where the temp gauge is. just to help get you good feed back.
Jimmy

I will get you some posted as soon as I get off work. In a couple hours. I was wanting to try and start it today, but a combination of only a couple hours of sleep this week and a snow storm rolling in I don't think I will. Also the bottom of my fan blades sits about four inches below my radiator is there a way to center it and our need to?

[siggyfreud]

Like I mentioned before, even with everything that could be wrong fixed, there is still a good chance you're going to overheat during breakin. Cars/trucks weren't designed to see 2000+ RPM while standing still for prolonged periods. Some people may have a cooling setup that can handle it, but many won't. Space fans forcing air through the radiator will help.

Before I went with a Mark VIII electric fan my truck never overheated, but certainly would during the break-in process of a cam.

[j.rigby15r]

I understand that. I'm more worried about flattening out my cam.

[TJ's Chevy]

I'd give it a shot again....if you can try an set your timing then it'll help with the heating as well....2000 rpm it plenty fast for that fan to pull air, I'd try a shroud if you don't have one...and like one guy said maybe even try hosing the radiator down while the engine is running. But I would add some shop fans none the less to aid in cooling. Also like said, double check your thermostat and see if its opening...or...while the engine is running, squeeze the rad hose and see if its soft or hard as a rock...soft means water is flowing, hard means the water is building up tons of pressure somewhere....and probably will mean the thermostat. But after break in I would seriously consider changing to an electric fan or dual fan system...My 496 in my 77 will run at 180 on a 95 degree day with dual electric fans and a diesel radiator, but start pulling a hill with a load and things climb up. lol We've had that engine up to 220 before....Also...I believe you bored yer engine .060 over? That will make it run hotter then factory temps as well.

[j.rigby15r]

Ok, so you mentioned setting the timing before running it up to 2k rpm. How do you set timing if you are supposed to run it up asap? Not trying to be a noob just want to be sure I don't screw stuff up.

[TJ's Chevy]

Originally Posted by j.rigby15r

Ok, so you mentioned setting the timing before running it up to 2k rpm. How do you set timing if you are supposed to run it up asap? Not trying to be a noob just want to be sure I don't screw stuff up.

So, I talked with professional help...lol...Don't you love Dad's? lol. So..he's done a few of these so I'll tell you what he told me....So here goes, Yer timing is waay to retarded....fire the engine up and idle it at 650 or 750 rpm..and set your timing at 6-8 degrees btdc....12 degrees is to hot right now....also another thing, take your thermostat out, and fill the engine up with coolant...if all you did was fill the radiator with coolant then you've just created a whole bunch of air pockets which could scorch a head...So pull the thermostat out, fill the engine with coolant and Leave the thermostat OUT for the rest of the break in period...Leaving the thermostat out will allow full flow of coolant....then do your normal 20 minute at 2000 rpm break in. Set your timing at idle as quickly as possible...and right when you can; turn the idle up to 2k. After the break in...shut it down....let it cool off for a night, then pull the rad hose off and put yer thermostat in...then go an set your timing again...probably 8-10 btdc at idle. And you should be ok.

[j.rigby15r]

Alright so were I already have about 15 min into the break in process. Do I just do as you suggested but hurry and set the timing then run it up to 2k for an additional 10-15 min?

[TJ's Chevy]

Originally Posted by j.rigby15r

Alright so were I already have about 15 min into the break in process. Do I just do as you suggested but hurry and set the timing then run it up to 2k for an additional 10-15 min?

I would make this a separate 20 minute break in...just to be safe. Set yer timing, then start the watch when you get it up to 2k. Seems like kinda over doing it, but better safe then sorry. Are you running good break in oil?

[j.rigby15r]

Yes lucas break in oil.

[PGSigns]

Got to be careful not running a thermostat. It will not let the engine build temperature and that is important during break in. Also some times an engine will circulate water to fast to cool the engine and it will overheat. If the truck sits outside and the engine oil is 36 degrees like the forcast you posted it is not a good day to do the break in.
Jimmy

[awbrown]

What PG said is correct , in all reality your cam is more than likely run in now .. I do 2 engines a week and tell the guys 20 minutes at 2000-2500 then shut it down and drain the oil and change the filter .... the reason for draining the oil hot is if it sits all the fine particles from breakin end up settling to the bottom of the pan .. your best bet is run it for 5 more minutes then shut it down and do as I said .. it won't hurt to run some zinc in the first oil change .. I usually mess with the timing when it first fires and just get it around 30-40 degrees at whatever rpm it is running , after break in you can idle it down and set everything as it should be ....

[j.rigby15r]

So my t Stat works, dumped it in boiling water and watched it open and close. Also I had coolant on both sides of the thermostat so most air bubbles should be gone. I'm going to put it back in before I run it again. What I'm going to do and if anyone has an objection let me know. I'm going to put a box fan on the front, start it up hurry and adjust the timing to 8 to 10 btdc. Run it up to 2000 to 2500 for about 10 min. Turn off the motor and drain the oil and filter while motor is still warm. Put new filter and more break in oil ( I have more sitting around) or cheese cloth the old oil. Start it back up and let it warm up and check the timing at idol, then run it and seat the pistons. Drive it nice for the first 500 miles. Then change the oil and filter again. From there I will put some normal good oil in and go from there. Thoughts?

[Dans66Chevy]

I think you had a air pocket in it the hole time. I have broke in many engines over the years. Never had one get that hot that fast.

[donthekawguy]

I have only seen motors get that hot that fast with air pockets.

[awbrown]

I think you will be OK with your plan , though like I said it may be broke in so I would run it til the oil gets a little heat in it and drain it ... You plan on running breakin oil so it is a nonissue ... after you change the oil I would hit the road (after double checking your timing and making sure your vacuum advance and centrifical advance are working properly) .. Normally you are looking at the total timing and it should be all in by 2500rpm.. That's why when I break a cam in my timing light is hooked to the engine and the minute it runs I set it around 30-40 degrees at 2500rpm .. You never need to idle it .. run for 20 min. drain and change filter , fill it and road test it ... Oh and make sure you have a garden hose handy...

[j.rigby15r]

One of the guys earlier mentioned it being to cold to finish the break in at 36 degrees or less outside temp (today was a high of 24). In your opinion would this be an issue?

[duallyjams]

On break in we would leave the thermostat out and have a big fan blowing into the radiator with a water hose handy, if we used a thermostat we would drill a little hole in it to prevent air pockets.