Engine temp, fans, etc.

**WILMASBOYL78** · #1 07-19-2004, 02:01 AM

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

Belair62 · #2 07-19-2004, 03:50 AM

Is there a fan shroud on the radiator ?

**WILMASBOYL78** · #3 07-19-2004, 04:50 AM

Yes, OEM 68 BB shroud.

**Mr70** · #4 07-19-2004, 07:57 AM

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** · #5 07-19-2004, 08:02 AM

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

Chevy454 · #6 07-19-2004, 04:41 PM

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 · #7 07-19-2004, 05:52 PM

I'm 100% with Rob !!

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** · #8 07-20-2004, 07:22 AM

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

**Salvatore** · #9 07-20-2004, 07:29 AM

What, were you running alcohol? Thats not legal! No wonder your motor was cold. Besides, There are NO cool nites in Alton,Mo.

**WILMASBOYL78** · #10 07-21-2004, 05:31 AM

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

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