[oldstreetrodder]

I am installing a ZZ4 and have some questions.
First off, the distributor out of the crate was off by 180 degrees. I set the number 1 up for top dead center and put the distributor back in to fix the problem. The instructions with the motor state to run 12 degrees initial and 34 total. The guy at the GM dealer said I need to watch total as he has seen some distributors run up to 45 degrees which melts pistons. Is there anyway I can check total advance prior to firing the engine other than putting the distributor on a machine? I do have an Accel adjustable vacuum advance. Should I intall this instead of the "factory" can?
Secondly, I had overheat issues with the old motor. I had a Be Cool 2 row vertical radiator, mechanical fan, shroud, and 2370 cfm Zirgo puller. With a 180 thermostat it would run 192 going down the road and sometimes peg the temp gage at 240 in stop and go traffic.
On the new motor, I have installed a Stewart Stage 2 pump, fan shroud, overdrive pulley, a 17" flex fan with 7 blades. I also have a Griffin cross flow radiator on the way. I have been reading the threads on thermostatic fans and electric fans. I'm taking the position that the electric fan is insurance.
The clutch fan issue is still up for grabs in my book. I'm not really concerned about noise if I can cool the thing.
The coolant will be 50/50 anti freeze/water. I won't be using the pink stuff as a friend with a similar set up had all kinds of leaks with the pink stuff and everyone he talked to told him to drain and use the green stuff. All the leaks stopped when he changed from pink to green. Straight water is not an option due to the aluminum corrosion/electrolysis issue and the need to store the car in sometimes sub zero conditions.
Any help on the timing issue or cooling one of these motors would be a big help.
Thanks
Oldstreetrodder

[Deuce]

Originally Posted by oldstreetrodder

First off, the distributor out of the crate was off by 180 degrees. I set the number 1 up for top dead center and put the distributor back in to fix the problem.

When you set the ZZ4 up for number 1 TDC ........did you just go by the mark ? or did you have the valve cover off and check ?

I always take the distributor OUT anyway to prime the oil pump and lube the engine prior the start up anyway.

Overheating is usually one of these......

1) lack of cooling capacity
2) lack of air flow
3) too lean .....carburetor
4) timing
5) no vacuum advance
6) under hood ambient temperatures......no way for the heat to escape..





I have installed quite a few Chevrolet crate engines.......for myself and others. I have the ZZ430 pictured above in a 32 Ford roadster...with no overheating issues....but I have a Z series Walker radiator (4 row ), and 7 blade 18 inch fan ( clutch type ) and a 25 Vent hood on my car. I have the Jet Hot coatings on my exhaust.......and room at the rear of the engine compartment to let the air out....



You have seen how well the hood helps the engine cooling in this photo......almost like not having a side panel on the hood.


What type of car is the ZZ4 in ?
Which carburetor are you using ?
Do you have a vacuum source.........full time?
I always use a good Robert Shaw thermostat.....not A/C Delco......or a cheapie
I always use GM pulleys....the ratio is right.....the aftermarket stuff is not always correct.....
I like a transmission cooler.........separate from the radiator.....

I NEVER use a electric fan........I believe they impede air flow......when I have a good mechanical fan...

I run just enough anti-freeze ( green ) to insure no freezing...50/50 is not the best ratio IMHO......the less you have to use.the better......has been my experience......


DEUCE.....

[Deuce]

Originally Posted by xntrik

Many good ideas in this thread.
Let's not overlook the obvious:
1) Electric fan in FRONT of the radiator is a crutch for more serious problems. If the air is not being pulled from behind, you can't push it through faster than the rear fan can pull it.
2) Make sure the thermostatic fan clutch is operating CORRECTLY. They slip more as they age. Be sure it has the little spring on the front. Also fan clutch type fans have different blade shapes, 5 or 7 blades etc. There are more efficient ones that will swap on and pull more air at lower speeds. Remember fan clutch fans "coast" above 30 mph anyway. I used to pull in after a highway run and immediately overheat in town. I thought I needed an radiator. I changed the blades and the problem disappeared. I think I found a Buick blade at the junk yard.
3) The first thing to do if you think everything checks out mechanically, is PUT IN STRAIGHT WATER FOR A TEST. If water won't cool it, you have a serious problem.
4)The water pump should be overdriven 1.25/1 for good low speed cooling. How many people put on underdrive pulleys and complain about cooling? (hey, Mustangers)
5)Many water pumps have excessive clearance between the impeller and the housing. Maximum .030. Yes use a HV pump, Stewart is THE BEST.
6)Also check % of antifreeze to water concentration. In controlled tests I did on a 100 f day, 70/30 ran 10 degress hotter than 50/50 which ran 10 degrees hotter than 30/70, then straight water was about 6 degrees cooler. Straight water is by far the best for cooling.
Skip the Water Wetter. See #3. I never saw it cure anyone's problem. They wasted their money and had to fix the actual problem anyway.
7)THINK AIR FLOW, AIR FLOW, AIR FLOW. See Docvette reply !!!!! Then think WATER FLOW, WATER FLOW. Oh ya, always run a 180 thermostat, it increases the water pressure in the heads to prevent steam pockets, especially SBC.
8)If a rear electric fan/shroud increases temp at speed but helps at low speeds, the shroud needs air relief ports to allow air through the radiator.
9) See Docvette reply !!! You must get the air OUT of the engine compartment. Think about an air dam...or some hood relief ports, etc..... Also often overlooked is an air dam for LOW speed cooling. It helps prevent the fan from sucking air under the bumper back into the front of the radiator when stopped. Think 80 Malibu, ugly but works. You can custom make one from the flexible black plastic that circle track racers use for front air dams. Make it as wide as possible and deeper than you think necessary to see if it helps, then trim its vertical height for appearance and acceptable performance.

I copied and pasted this from another thread.....about cooling.......lot of good advice here......and I am just passing it on.... Not everything applies but you get the idea.....

DEUCE

[oldstreetrodder]

The engine is in a '56 Chevy 210 two door wagon.
I did pull the valve covers and checked timing. The mark on the dampner was right on. I also pulled the distributor and pre-lubed the motor.
The carburetor is a Demon that is supposed to be calibrated for the ZZ4.
The radiator is a two row, 1 1/2 inch tube, cross flow from Griffin. The fan is a 7 blade flex fan from Perma cool.
I am using a Stewart stage 2 pump with a 180 degree Robert Shaw thermostat from Stewart. The water pump pulley is from Zoop's and is about 5 1/2 inches in diameter which is 1 inch smaller in diameter than the stock pulley.
I will be using coated Sanderson block hugger headers and 2 1/2" exhaust.
The tranny cooler is separate from the radiator but I will probably run through the remote cooler into the radiator and then back to the transmission. The remote cooler was warm to the touch with the other motor.
I haven't fired the thing yet as I am waiting for the radiator to arrive.
I noticed that you are using a water pump riser on the ZZ430.

[GoneNova/406]

at least until you get everything running right try using a 160 stat just to avoid trouble.you can change it later .i have a 2 row 1" 31x19 griffin rad. and the stage 2 stewart water pump also but mine is in a full sizes 3/4 ton van and there is no air movement unless i am moving and its hard to cool.get rid of the flex fan they are junk.i have 2 more you can have if you want them.use a good electric fan that is big enough.i make my own from fans out of junk cars and sheet metal using dual 14" fans.you have to work with the room you have.use an adjutable timing light,one that you can check your timing curve with when starting and have a friend help you but remember to pre oil.the key is good air flow,water movement and shroud placement if you have one with a manual fan.good luck.