Engine temp, fans, etc.

[WILMASBOYL78]

Looking for some input on my latest creation. First the specs: 454/425 hp crate engine in my 68 Nova. TH400, 4.10, GV. No external trans cooler. Stock exhaust manifolds, duals w/flowmasters,std 163 hi-rise,780 68 Holley carb, HEI Crane in the points dist.New 4 core rad, new short water pump, 160 thermostat. Started with a period style 7 blade clutch fan, I think the clutch temp is 190. Timing is set at 10BTDC, air/fuel mixture seems good. Not sure of total advance in the dist. The car runs hot!! Switched to a 7 blade steel flex fan(small blades). Checked all systems: rad, stat, w/pump everything seems ok..Runs at 185 for a while and slowly gets to about 195-200. If I stop at a lite or idle the temp goes up quick to 220 plus, then drops down a little when I go. I am getting a large fiixed blade steel fan tomorrow to try. Any thoughts or comments would be appreciated. Tom http://www.yenko.net/ubbthreads/images/graemlins/dunno.gif

[Belair62]

Is there a fan shroud on the radiator ?

[WILMASBOYL78]

Yes, OEM 68 BB shroud. http://www.yenko.net/ubbthreads/images/graemlins/confused.gif

[Mr70]

What fuel mixture & Spark plug are you running,R43TS?
I'm running full smog,7-bladed,3-core Harrison,stock exhaust,on L78-TH400-4:10-R43T green ring & am nearly identical to your stats.I hate those red lights.She's a heat Pump,but we've come to an understanding,stay in the express lane.

[WILMASBOYL78]

Don't know what plugs are in it I will have to look. Whatever came with the crate motor is what I have. Running sunoco 93-94 for gas. My original L78 cars don't run nearly as hot. In fact when I use the "good" fuel the old motors run cooler. You are right this baby is a heat pump!!! Tom http://www.yenko.net/ubbthreads/images/graemlins/rolleyes.gif

[Chevy454]

Your fuel will definitely make a difference. With our 10.2:1 L72, I had to be mindful of the type of fuel and the temp. When we mixed too much good fuel in we would actually have a problem not getting enough heat in our engine (mainly the heads)...especially in the spring/fall months. During cool nights at the track I'd have to make sure we were burning just a premium pump mix...if there was too much of the good stuff in the tank it couldn't get any heat in the heads and it would run like a dog.

Also, you need to know where your total timing is...the wrong timing can really cause you to heat up in a hurry. Oh, and I'd stick with the clutch fan setup...

[Casey Marks]

I'm 100% with Rob !! http://www.yenko.net/ubbthreads/images/graemlins/biggthumpup.gif

My L72 in the 'Scayne has NEVER gone over 180*, and that is after a full pass, on the return road of the track. If I stage it at 140*, it seems to run the best. I have the original radiator, a replacement clutch, and stock fan. The shroud was cracked when I got the car, so I don't even have that on right now. I DEFINITELY concur that fuel-type is a big factor. I run Torco most of the time, and it really keeps the temps down.

[WILMASBOYL78]

Installed the 6 blade HD steel fan with fixed blades. It made a difference right away! Car ran tonite at 175*, never went over 185* at idle or stop lites. Will have to test during the day to see how it is in the heat, but it is looking good. Planning on checking curve in distributor and carb jetting to get it really dailed in. May even get a thinner spacer to bring the fan back 1/2" more to increase air flow. Many thanks to all who took the time to share their thoughts. I'll keep you posted. Tom http://www.yenko.net/ubbthreads/images/graemlins/rolleyes.gif

[Salvatore]

What, were you running alcohol? Thats not legal! No wonder your motor was cold. Besides, There are NO cool nites in Alton,Mo. http://www.yenko.net/ubbthreads/images/graemlins/eek.gif http://www.yenko.net/ubbthreads/images/graemlins/rolleyes.gifhttp://www.yenko.net/ubbthreads/images/graemlins/haha.gif

[WILMASBOYL78]

Well, another day another problem. Broke my a** to get home for a local cruise nite hoping to drive my "cool" running sled to the gathering. Didn't get 5 miles and it went totally bonkers. Starting missing and bucking and acted like it was starved for gas. Then it started to diesel when I came to a stop and finally I pulled over and it quit. Plenty of spark but the gas wouldn't keep pumping. If you pumped the carb manually and just hit the key it would start and then die. Thought it was vapor locked and removed the tank cap. Finally it started again and I got it back home. Ran so-so at highway speeds and then would buck and diesel at the stops. Got it to the garage and parked it. Hard time getting it started again but finally it went. Checked timing and set idle mixture and idle speed. But something just isn't right, I feel like it is fuel but I can't be sure. Well I'm running on like the motor so I'll leave it here. Any input is welcome. TW http://www.yenko.net/ubbthreads/images/graemlins/dunno.gif http://www.yenko.net/ubbthreads/images/graemlins/dunno.gif

[Pantera]

Sounds like a vent hole on the gas tank cap may be closed up. Try leaving it loose and put a shop rag between the deck lid and the actual gas cap to keep it from coming off completely. Then drive it easy for a while and see if that makes any difference.

Be sure to blow out the overflow drain line from the gas tank rubber boot that goes down to the ground just in cast any may slosh out. Unless your tank is totally full you will not even loose any as long as you don't do a hard launch.

This will point you in the right direction.

Also check out the fuel pump to see if the fuel lines or the pump it self, is too close to tube headers (if you have them).

It sounds like you are boiling your fuel. Now all you have to do is figgure out how?

Good luck.

Pantera

[WILMASBOYL78]

I think I found a major part of the problem. It appears that the heat riser is not functioning properly. When the engine warms up it doesn't open (didn't check this until yesterday).The excessive heat from the exhaust really gets the intake manifold and pass side head very hot. I wired the flapper open and tried to get the car started again, but no luck. Guessing that the heat has cooked the intake manifold gaskets and this creates a huge vacuum leak. Checked all other components carb, fuel pump, coil, distributor. It just seems like the only place left to go. http://www.yenko.net/ubbthreads/images/graemlins/confused.gif

[Pantera]

Sure hope it didn't cook the "Head Gaskets"....! You might give a look at the gaskets under your Carb then if it has been that hot.

Sounds like you are on the right track.

Good Luck

Pantera

[WILMASBOYL78]

Doing the basics before I start tearing things apart. Took a compression test tonite 175-180 in all cylinders, put in a fresh set of plugs. It fires and runs for a second while you crank it but then quits when you let off the key. Now I, m thinking that Crane electronic system might be acting up??? Next step will be to throw in a points distributor and see what happens. And the beat goes on.......TW http://www.yenko.net/ubbthreads/images/graemlins/confused.gif

[WILMASBOYL78]

FIXED!!!!!! Coil resistor wire was N/G reapired and it runs. Will now reinstall original carb, check all fluids, clean her up and load in the box for Atlanta. Hopefully this is it....... http://www.yenko.net/ubbthreads/images/graemlins/tongue.gif http://www.yenko.net/ubbthreads/images/graemlins/tongue.gif http://www.yenko.net/ubbthreads/images/graemlins/tongue.gif