First owner

Would any of you that knows or has experience cooling problems with a BB please give me the benefit of what you found to remedy problem. Particulars: 454 060 over, bottom end is LS6 or better but CR was held to 9.5:1 GM alu 14011077 heads, crane Hi Int came, lifters, Crane SS roller rockers. GM 3 x 2 carbs, timing at 6 BTDC full in 34 deg, New 4 core rad, Stewart componets stage IV water pump, all hoses new, lower has coil spring, rad is new and was flush checked. High flow thermostat and was out of engine tested for 160 deg and is OK. Engine heats up over time even on temperate days. Removed wtr pump and check flow through block and heads and was OK. Finally removed heads, drilled additional 5/8" hole through deck into water galley as done on HD truck blocks. Replaced heads and did static and dynamic pressure test of cooling no increase or bubbles.
Went to 7 blade fan and disabled fan clutch. Went to billet pulley drive system to overdrive wtr pump. Pump has two drive belts. STILL HEATS UP. Can slow down heating by running heater at full blast but this only works on temp days. On a warm day 80 or above it will still go to boiling point. Rad shop suggested I recore rad w/special waffle style core that has more cooling area. I would like to keep it stock looking as much as possible. I currently have a heater core hanging in the front of the grill with heater hoses to it to test for effect of added cooling. It helps but does not cure issue. Estimate system runs at about 210 on a 75 degree day. Tried messing with advance and fuel mixtures. (What a B---- to do with 3 X 2 carburetion) No help. Checked the heads when I had them off and could not see any casting abnormalities. This all started when I remove the original engine and put it away for posterity and built up a driver engine. At freeway speeds it will hold at slightly elevated temp, maybe 200 or so, but will still heat on freeway if I lean into the throttle heavily a couple of times. Lastly, car has original GM side pipes and I ceramic coated the headers.
Any and I mean any ideas would be appreciated.
My E mail address if you would contact me directly is DHargrave@MSN.com

[Modified by First owner, 9:36 PM 2/27/2003]


[Modified by First owner, 9:38 PM 2/27/2003]

Bluestripe67

Welcome to the forum First owner. Lots of info and experience here. For starters, may I suggest searching the archives. I know many posts on this subject popped up last summer. Read the ones about ignition timing and advance set up. If this doesn work BB forum member are sure to respond. :cheers:


[Modified by Bluestripe67, 11:30 PM 2/27/2003]

SWCDuke

What are your vacuum advance specs and do you have full manifold vacuum to the can?

What is your total idle timing?

What is your idle speed and manifold vacuum?

Describe your radiator in more detail: "four row" doesn't mean much. It is a proper big block brass radiator with big block frontal area. Does it have a big block radiator support and fan shroud. The model year would also help.


Duke




[Modified by SWCDuke, 3:35 PM 2/27/2003]

greg454

It looks like you have most everything covered. You didn't mention your fan shroud, and do you have all of the shroud seals in place?

Viet Nam Vett

Welcome "First Owner"

The most important post answer to your question would be From "SWC DUKE"

Post the info that he has requested.... This topic has been covered quite abit here on the forum. Like they say you can search the archives and get some answers.

But The Duke and others here will stear you to an Ice Cold BB..

And again Welcome to the Forum....... :cheers:

Stinger66

I can certainly feel for your problem, I have had my 66' for 18 yrs and have never been able to drive it on warms summer days without having to do a dash into a service station to run clod water over the radiator and bring it down. I once again told myself last month when i had this motor build that it wont see the road unless it will remain drivable..Well I once again replaced the radiator... bought a 65' 396 support to allow me a larger core opening, purchased a ron davis aluminum radiator, it is a two row with 1 1/4 inch rows,
and it is a dual pass style radiator...originally designed and was built for hendrick motor sports for use in some #24 Winston Cup car.. I had an aluminum shroud specially built for this radiator and am running a 2700 cfm electric puller fan.. also mounted a high flo aluminum water pump.. I have tried different t-stats and am currently using a GM 190 degree...Anyway,, to make a short story long, the engine is running soooo nice.. BUT, after running for near 40 to 50 miles it will have creeped up to the caution zone of around 220 plus degrees.. I check it with my digital temp guage and the radiator inlet is at 220 with the return to the motor at 160,, Is this system doing all it can considering its components?... Or is there something I can do to help it more?... I will be watching your posts to see if any of it I can steal for my use as well... Good Luck :banghead: :banghead: :banghead:

ghostrider20

Quote
[I had an aluminum shroud specially built for this radiator and am running a 2700 cfm electric puller fan. also mounted a high flow aluminum water pump.]

I am not a big fan of the electric radiator fan. They draw around 25 amps and load the alternator up. This in-turn makes the engine run hotter, I think it is tit for tat. They cancel each other out. I have seen them drop the engine as much as 200 rpm when they are turned on.

The other thing, it is possible to have too much flow. The fluid needs some time in the radiator to cool.

In both of these cases posted I suspect a timing/advance issue. The only other possibility is that the block itself is blocked or caked with internal corrosion. In the latter post, a rebuild would eliminate this point.

In both posts with the heating issues, what distributors are you using? What are the details of your ignition system layout?

Mark

Stinger66

If the cooling system was performing properly, the coolant temp sensor would only run the fan in times of extra need,, i.e. heavy traffic, hills, or hauling butt, which I never do over the speed limit...(honest x)
The coolant should be in the system plenty long enuf considering it is sent thru the radiator 2 times before being released.
Ignition is a new MSD tach drive with a msd 6al box and its profile is set up at 10 degrees advance at idle of 650 rpms and 36 degrees total. Vacuum can is run to a low port on my holly 750 carb.. there are no provisions for hookup of vacuum on my manifold. If needed I could remiove it and drill and tap a port line into the manifold. Valve lash is set at .018 Int and .018 Exh.
Any more details needed to base an opinion , please ask..

GregP

If the radiator out temp is 160 and in is 220 the radiator is doing it's job. Make sure you have enough water flow through the block (try a high-flow street rod water pump not a low drag race unit) and make sure the block doesn't have crud built up in it (open the block drains and flush water through the motor while useing a coat hanger to dislodge the junk that is usually blocking the drains).

As stated before, ignition advance can have a big impact, especially too little.

-Greg

Kid_Again

welcome....

...first off, please answer duke's question as many of these overheating problems are CLEARLY related to the amount/timing of vacuum advance - he will be able to diagnose the problem pretty accurately with the information you give him....

...second, it seems to me that you have done a lot to improve the cooling capability but, in my opinion, you have made one mistake that i'd like you to consider - you have the wrong water pump...it is a wrong assumption that a "racing" or "high volume" water pump should be used on the street because you have changed an important aspect of a closed system - the residency time of your coolant in the radiator (higher volume means shorter residency time)....

..start with the timing and then consider the water pump - i should add that an aluminum pump may be better than a cast iron pump - i am talking about the efficiency of the impeller system, not the construction of the housing.....please save your flames for when i make a mistake


[Modified by Kid_Again, 9:26 AM 2/28/2003]

Mel Foye

To both BB guys. Slow flow is not the way to go. Flow needs movement to cause turbulance which reduces or eliminates the boundry layer in the tubes which reduces heat transfer. My first shot would be to bump the initial up to just before a hot start jump back. Likely need to reduce the amt. of centrif. advance. Yes on full manifold vacumn advance if you have but may need to drop back to ported but doubt it. Second. Flush radiator and heater. Drop % of anti freeze to 10 -15% and change every year. Third using an 8-1/2 by 11 sheet of paper with engine running check your air flow through and around the radiator at idle. Last could be on the lean side but would lean toward the first 3 steps helping.
Stinger 66, we run a double pass in a road course 67 Camaro with over 550 hp sb and we run right on the thermostat opening on 105 days. I would suspect air in system if 220 in and 160 out and runs hot. Mel---and it is not summer yet you two.

TheOman

Here we go AGAIN !

Opposing view supporters to your respective corners please. Racing water pump guys in this corner, standard OEM pump guys over here in this corner, direct drive fan guys in this corner, electric fan guys in this corner, ignition curve mavins in this corner, aluminum rad guys in this corner, copper rad. guys in this corner and the carb rejetting guys over here please.

Whoops too many corners required. Well I guess the squared circle has to become at least an octagon for all the possible camps to be represented.

Come out swinging, no hittin below the belt, may the lowest average temp in all driving situations win.





[Modified by TheOman, 11:07 AM 3/1/2003]

JohnZ

Having donned my Kevlar/Nomex vest :D , having been through this many times (and recognizing your frustration with your overheating issue), I'll offer my standard advice (which is worth what you paid for it, but has been proven pretty accurate over the years).

Assuming your cooling system is in decent shape and everything is functioning properly, heating at highway speed is only affected by two things - radiator heat rejection capability and airflow through it (which requires that the radiator-to-radiator support gaps be sealed properly). Blown head gaskets will cause the same highway-heating symptoms, but are rare.

Heating around town involves the same two principles, and the fan/shroud/clutch combination now becomes very important, including sealing the shroud-to-radiator and radiator support-to-hood inner panel gaps to force all airflow through the radiator core. Ignition timing also becomes important under these conditions, and manifold vacuum on the vacuum advance can (not the factory ported spark arrangement) is essential to reduce idle operating temperature.

Most of the other stuff (water-wetter, "whizbang" water pumps, low anti-freeze concentrations, electric and flex-fans, etc.) are band-aids to cover up a basic deficiency in the cooling system. The car cooled fine when it was new (although it had little margin), and the stock cooling system will work fine today if all the components are operating properly and the vacuum advance is allowed to do its job. If either radiator heat rejection capability or airflow through the core are compromised, you'll have "overheating" problems. It's also a good idea to verify your temp gauge reading against an I.R. gun "shot" of the thermostat housing to make sure you're getting an accurate reading, especially if your original sending unit has been replaced.
:cheers:

Kid_Again

...Oman...i KNEW i'd get flamed...yup, here we go again........

..it is amazing to see the number of people who get "knowledge" from a jegs catalog :banghead:

..btw, first time ever, i've removed and disassembled trailing arms to the individual components...banged the spindles out with mid america's spindle knocker tool (no more difficult than a shock mount) and removed the pivot bushings by first cutting off one side of the bushing face plate and then used a pickle fork on an air hammer to pop that puppy right outta' there...i'll be darned, very easy...

...i am now TOYING with the idea of doing the trailing arm rebuilds myself but i am now VERY nervous that once i put everything together correctly according to my documentation, JohnZ will post something to make me tear the whole thing apart and start all over again....LOVE his posts but he's gotta' work on the timing :banghead:

...i may send him a case of the beverage of his choice and set up a teleconference BEFORE i do anything else :seeya


[


[Modified by Kid_Again, 11:51 AM 3/1/2003]

Viet Nam Vett

Quote*
-----------------------------------------------------------------------------------------
Here we go AGAIN !
Opposing view supporters to your respective corners please. Racing water pump guys in this corner, standard OEM pump guys over here in this corner, direct drive fan guys in this corner, electric fan guys in this corner, ignition curve mavins in this corner, aluminum rad guys in this corner, copper rad. guys in this corner and the carb rejetting guys over here please.

Whoops too many corners required. Well I guess the squared circle has to become at least an octagon for all the possible camps to be represented.

Come out swinging, no hittin below the belt, may the lowest average temp in all driving situations win.
-----------------------------------------------------------------------------------------


:lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:

TheOman

My cooling system works just great and I understand the frustrations of the guys who cannot get their systems workin. Nothin is worse than sittin in traffic thinkin.."This freakin thing is gonna cook off any time now". Bad enough your ankles are frying, watchin that guage only adds to the misery.

One of the issues with my car was the #$%^^&&**((*&^% sending unit. Whoops forgot to put a corner in my hypothetical "ring" for the temp sender replacers / proper grounders. Sorry guys no offense meant. I now have a MECHANICAL water temp guage down under the hand brake lever...sorta outta sight but visible with a little craining of the neck. It consistently reads 15 or so degrees lower than the factory guage when the engine temp is in the 160 to say 200 degree range. I sorta smile every time I compare the two numbers.

For the record I feel compelled to fuel this argu....no no make that this discussion....with the laundry list of components I am running. Griffin SB aluminum radiator, OEM 67 Vette { with OEM A/C} fan blade, direct drive hub (You go Kid!), MSD Billet distrib with Dukes favorite vac advance can, full time vac source, original NUMBERS MATCHING (whooo hooo an original part on my bucket of bolts) SBC GM OEM water pump, fan shroud from a non A/C 66 SB engine, correct seals around the radiator and the correct above the radiator seal that goes between the rad support and the hood on A/C equipped cars. No special lotions and potions like water wettter or Coors inj the Radiator just 50% anti freeze good old Fulton County Tap water and a 180 stat.

Thats all folks

Ironcross

The only thing I found wrong with your discription was the thermostat. Take the 160 out and replace with a 195. You are allowing the water to circulate too fast. You must hold the water back in the engine to allow the radiator to be able to cool it. I know it sounds backwards, but that will solve it unless the head gaskets are too small for the 60 overbore which I doubt. White smoke would come out the back if a head gasket leaked and the temperature would get extremely high. Good luck, :thumbs: Did any of you experts see what thermostat he was running, a 160. I guess not. Thats an immediate overheat. Hell some of the engines don`t have an advance can. Timing, the damn thing wont start. It`s overheating and running a 160 stat. You dont have to be a rocket expert to figure that out. About California being hot, try Miami, the water temp in the Ocean is close to 90 degrees let alone the air temp. :lol:
Modified engines or not, the same cooling works. I run L88`s and LS7`s 12.5-1 the same way without fancy waterpumps, pulleys, or radiators with zero overheating problems. And anyone out there should be able to do the same. Horsepower does not creat heat problems. :cheers: :D


[Modified by Ironcross, 6:10 PM 3/1/2003]

Viet Nam Vett

ROUND TWO !!!!




[Modified by Viet Nam Vett, 3:21 PM 3/1/2003]


[Modified by Viet Nam Vett, 3:23 PM 3/1/2003]

Stinger66

I know this wasnt my thread to begin with but i share the same problem, right now the biggest problem im having is that it's hard to make a somewhat intelligent decission to a serious problem when there is soooo much diversity in the opinions of who are intelligent fellow forum members....Problem is obviously answered somewhere in this mix of reasonable corrections....

OR IS IT????

In my simpile minded opinion,, and having fought this nagging problem every summer for the past 18 yrs, I must wonder if, being how I have tried 4 different sure fix radiators, 8 different style waterpumps, (one for each new motor), every fan known to man, 3 different fan shrouds, every type and brand of coolant that set upon an auto parts shelf, (after every boil over), water wetter and even Evans "not a coolant" answer to end all overheating, and not to be left out, countless hours at the radiator tech school, I cant help but wonder if I am barking up the wrong tailpipe with my undieing love of midyear corvettes in the configuration I wish to have it..

The racers are able to keep bigblock/high hp engines cool, General Motors was able to do it, and last but not least, all these fellow corvette owners willing to share their best 2 cents in helpfull experiences with anyone who asks...You are all the best,, even if you dont allways agree....BUT, I wonder if I am not asking too much, no, should say expecting too much of opinions that are not under the same conditions as my situation,, None of the racers or possibly forum members are having to deal with the extreem. That being the unique So. California scenario of many 100 to 115 degree days of bumper to bumper, stop and go freeway traffic, or having a blast going thru the mountains that is only 15 minutes away,, or flat out running thru the Calif. desert with temps running over the formentioned on the hot highways nearing the 130 degree mark. Again only 15 minutes away, Or the So.Cal beaches that require slow cruises to prevent missing any bikini clad sweetie strolling thru the sun and sand, again only 15 minutes away...

Do any of the posting members see any credence in this?

So I guess Im saying,, as strongly as every member believes his opinion to be correct, perhaps,, just perhaps,, they are all feasable, given the conditions they were made. But just not apples for apples with my situation..


:_dupe: :_dupe: :banghead: :banghead: :steering: :steering:

Viet Nam Vett

Heh Stinger 66,

If you do a search in the archives under this overheat problem you will find that most of these problems .....(NOT ALL) .... are caused by Incorrect Advance settings do to No Vacume at Idol or damage related vacume components. Or Vacume taken from the incorrect spot on the carb.

I know of at least 3 to 4 of my friends who had this problem which caused the big :banghead: overheat prob. And since has been corrected with the propper attention mentioned above.

One of the formost poster's on this subject Is "SWC DUKE" . you might want to look at his past post's.

Now the Disclaimer
I am not saying that this is your problem.
I am not the smartest guy on the Forum
There are other highly quailfied people here who also can help.
And if you take some time to research the archives and post your experimental findings after trying one or two of the reply posted suggestions,
I am sure this forum with it's extreamly knowledgeable members will be able to help you.

This is the only place you will get the correct answers. Because these Forum Members have done it all...

Good luck in you quest..and yes...your Vette can run cool :cheers:


[Modified by Viet Nam Vett, 4:38 PM 3/1/2003]