[stevenb8]

I fired up my motor last night for about 30 seconds to get it ready for the cam to be broken in today. I started the car got the rpms to 2500 for about 7 minutes before I had to shut it off because the temp got up to 225 or so turned it off then temp rose to about 240 and then cooled back down. Drained some water out added more coolant let it cool down to about 100 degrees and ran it again at 2500 for another 7 minutes or so before the temp hit 230 again.

My question is although I didnt get to break the cam in for a full 15 minutes at 2500, I did break it in for 15 minutes but it took 2 times to do it. Will this cause my cam not to break in or go flat? I hope not, I have spent to much time and money and dont want to pull the cam out in a thousand miles.

Im sure someone out there has had to break there cam in the sane way I did, did it cause any damage or did the cam go flat on you? Should I worry about it or to be safe should I run it one more time at 2500 for about 6 minutes?

Thanks any help or ideas would be great (also I had no thermostat in it)Sounded great though and the neighbors didnt seem to mind.

 

[Wes Briscoe]

Shoulda had a thermostat in it. Thats probably why your temp rose uncontrolled.

I had a simular problem, the car caught on fire about 8-9 minutes into the break in, and the next day I ran it for another 10 or so. It didn't hurt it any.

As long as your have the RPM's up to 2000-26000 you should have been splashing enough oil up to keep the cam oiled. And as long as you got enough minutes in (total) you should be okay. I'd finish breaking it in, and see if you have any problems from there.

I would put a thermostat in it before doing it next time. If you've got a box-fan, I'd stick that in front of the car as well.


Wes

 

[Fine69]

Wes, Can I go for a ride with you? 26000 rpm! Guess you don't need any gears to get down the street in your car!

Some one was bound to give you a bad time... Merry Christmas all!!! <BLOCKQUOTE>quote:</font><HR>Originally posted by Wes Briscoe:
As long as your have the RPM's up to 2000-26000 you should have been splashing enough oil up to keep the cam oiled.
Wes<HR></BLOCKQUOTE>



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...DjD
69 Ragtop

 

[stevenb8]

Guess I made a dumb mistake I thought if I left the thermostat out that it would have constant cooling and I woulndt have to wait for the thermostat to open and add more water and coolant. Didnt think about the thermostat regulating the temp, oops just hope I didnt cause any damage.

 

[rick]

steven If you are gonna run it again in the driveway, it will pay to have a fan set up in front of the grill to blow cool air thru the radiator. The engine fan needs help at higher temps-usually your vehicle speed provides the help.
rick

 

[mr409]

I always heard that it's the first 5 minutes that makes or breaks a cam. So your probably ok.

Just for piece of mind, run it again for 5 or so minutes at 2,000 RPM's.

BTW, even if you had the thermostat in doesn't mean it wouldn't have overheated. My 409 was starting to overheat the first time at the 15 minute mark so I had to shut down. (I had a house fan in front of the radiator too) Turns out it was air pocket in the system. After the first fire up, I drained the system and filled again and no more overheating. Also, I just ran plain water in the system for break in. I was told that if you have an internal leak and antifreeze gets in the block, it could freeze up the bearings and really make a mess. You guys ever hear of that? I did it to be on the safe side.



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Bob (Pa.)

1963 Impala 283
1966 Chevelle SS 409
1969 Malibu 307
1972 Malibu 307
1969 Chevy stepside 350

Bob's 409 Chevy Page

http://members.spree.com/entertainment/mr409/bob_s_409_chevy_page_index.html

 

[stevenb8]

I fired the car up again one more time with the thermostat in for about another 5 minutes at 2200 just to be sure it was fully broken in. Motor still got hot but not to bad I shut it off at 200 degrees.

Not sure what the problem is I think It may be the fan clutch I ran one on a small block about 3 years ago and had cooling problems installed a 19 in flex fan and fixed that.

Does everyone have problems with fan clutches or just me? I am trying to go back to stock and would like to keep this setup what is the best or heavy dudty fan clutch you can buy.

thanks guys,

 

[Randy Mosier]

I ran mine without the thermostat to break in the cam. I wanted a full cooling system right from the start and I didn't want the coolant level to drop suddenly when the t-stat opened. I just had a water hose running slowly and I let it trickle down in front of the radiator. I also sprayed the fins every few minutes. It was a little messy, but it was only water. It didn't overheat and I installed the thermostat later.

 

[chev64]

Randy, Unbeknownset to you, Your engine overheated at the rear of the engine because the coolant wasn't circulating back there. The thermostat provides restriction to flow as well as temp control. The water/coolant at the rear of the engine just sat there and got hot cause it couldn't circulate

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Leo Paugh
Maryland Chevelle Club #017
Those who do the world's real work don't usually wear ties.

 

[Randy Mosier]

I've heard of that with in-line sixes, but never on V-8 engines. The coolant is moving constantly with the thermostat out. Plus, the design of the V-8 engine forces coolant in the bottom and out the top of the engine. The only potential problem you may encounter is with the hot coolant not staying in the radiator long enough to dissipate heat. But that generally happens when other cooling problems are present, like a radiator that is partially plugged. I also pull the thermostat when I want to flush the system, since I'm usually installing a new one anyway. I did this all the time when I worked in fleet maintenance. Those vehicles were typically run up to 150,000 to 180,000 miles before they were traded. I had the opportunity to build a history with each vehicle. I only lost one engine due to a heat up problem during my stint at that company, and that was because the driver wasn't paying attention to his guages when his thermostat stuck closed. He ended up boiling it dry. Otherwise, our Chevys, all small blocks, were tough as nails and ran like champs when traded. Now sixes on the other hand can be overheated as you describe. The Ford 300 is notorious for cracking the head if the thermostat sticks and it isn't caught fairly quick.
So I'm not in agreement with you about heating up the rear of the block. Not on a V-8. I agree that the thermostat is there for a reason. I also agree that the coolant at the rear is warmER, but not hot enough to cause any damage. But to run the engine without one during cam break-in doesn't do any harm to the engine. There's been many a thermostat that has stuck in the open position as well, and if it were harmful, these would crack heads as quick as when the t-stat hangs closed. Usually the only complaint you get with an open thermostat is a lack of passenger compartment heating in the winter. And the engine oil will eventually sludge up if it isn't fixed in due time. I had many a driver come in in the winter and say the heater wasn't working, and by the way, it's been running cold all summer. New thermostat, no problem. But during engine break-in, you do need to take extra precautions like placing a cooling fan in front of the radiator or running water in the front of it. I've been doing this for years. No comebacks, cracked heads or blown head gaskets. I would have seen a pattern if that were the case when I worked in fleet maintenance. And I would have been burned for the comeback when I was a flat-rate dealership mechanic years ago. Just remember, everyone has a slightly different way of doing things. It's not bad, just different. To each his own.
Now, with the 87 and later version small block, I'm told you have to be extra careful not to get it hot. Same goes for the new Chevy V-8 as well. So sometimes an old dog has to learn new tricks.