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OVERHEATING

Posted: Wed Apr 11, 2012 8:31 pm
by dallen91yj
NEED SOME ADVISE. I HAVE A 88 YJ WITH A 305 CHEVY/TURBO 350 TRANY AND IT OVERHEATS WHILE IDLING OR TOWING. WHAT I'VE DONE SO FAR IS A NEW STOCK WATER PUMP, 195 THERMOSTAT, NEW FAN COWL WITH STOCK FAN. I'M THINKING OF TRYING AN ELECTRIC FAN WITH A HIGHER CFM. ANY ADVISE WOULD BE GRATEFUL.

THANKS

Re: OVERHEATING

Posted: Wed Apr 11, 2012 8:40 pm
by ASauer17
is the Radiator fan coming on??? Did you check your head gasket?

Re: OVERHEATING

Posted: Wed Apr 11, 2012 8:45 pm
by dallen91yj
THE FAN ALWAYS RUNS, NO HUB INVOLED AND THE HEAD GASKET SHOULD BE GOOD,BRANDD NEW REMAN LONG BLOCK

Re: OVERHEATING

Posted: Wed Apr 11, 2012 8:53 pm
by ASauer17
whats your current fan at?? 2500 CFM?

Re: OVERHEATING

Posted: Wed Apr 11, 2012 8:57 pm
by dallen91yj
SORRY I CAN'T ANSWER THAT, WHATEVER STOCK IS.

Re: OVERHEATING

Posted: Wed Apr 11, 2012 9:02 pm
by ASauer17
blah! with a turbo you should pull 3300 cfm with an adequately sized radiator and coolant flow esp for towing and with your engine swap. Look into an electric fan.

Re: OVERHEATING

Posted: Wed Apr 11, 2012 9:07 pm
by ASauer17
look into a thermal electric fan like flex-a-lite..

Re: OVERHEATING

Posted: Wed Apr 11, 2012 11:04 pm
by ZAEDOCK
asauer17 wrote:blah! with a turbo you should pull 3300 cfm with an adequately sized radiator and coolant flow esp for towing and with your engine swap. Look into an electric fan.
The turbo is the transmission, it's a Turbo Hydromatic 350, aka turbo 350.



Couple of questions:
What aspiration are you running? Carb or EFI?
What size radiator? 2 core?
How old is the clutch on the stock fan? (a stock clutch fan actually moves a lot of air).
What coolant mix? 50/50?
What kind of fan cowl?

Re: OVERHEATING

Posted: Thu Apr 12, 2012 6:52 am
by ASauer17
and this is what happens when you are up past your 8pm bedtime!

Re: OVERHEATING

Posted: Thu Apr 12, 2012 7:01 am
by scrambldcj8
Has the timing been verified? Timing and airFLOW
are often primary cause of overheats with swaps.
What other mods if any.....comp ratio...heads and etc?

***What year 305...serp belted 305/350 had reverse rotation H2O pumps...new water pump rev or standard rotation?

Edit: I am asking what accessory drive are you running (serp or v-belt) and is the H2O pump rotation a match?

Re: OVERHEATING

Posted: Fri Apr 13, 2012 1:43 pm
by dallen91yj
WOW LOT OF QUESTION. BEST I CAN ANWSER, EDELBROCK CARB AND MANIFOLD, 20X20 RADIATOR NOT MUCH ROOM FOR ANYTTHING LAGER, 50/50 PANHOL (GREEN STUFF), AND TIMMING WAS DONE BY A PRO ????. MOTOR IS STOCK GEN I MID 80'S , FAN SHROUD IS CUSTOM AND ONLY COVERS 2/3 OF THE RAD. THINKING THIS MAY BE THE ISSUE.

THANKS FOR ALL THE HELP

Re: OVERHEATING

Posted: Fri Apr 13, 2012 4:59 pm
by ZAEDOCK
dallen91yj wrote:WOW LOT OF QUESTION. BEST I CAN ANWSER, EDELBROCK CARB AND MANIFOLD, 20X20 RADIATOR NOT MUCH ROOM FOR ANYTTHING LAGER, 50/50 PANHOL (GREEN STUFF), AND TIMMING WAS DONE BY A PRO ????. MOTOR IS STOCK GEN I MID 80'S , FAN SHROUD IS CUSTOM AND ONLY COVERS 2/3 OF THE RAD. THINKING THIS MAY BE THE ISSUE.

THANKS FOR ALL THE HELP

Timing on an 80-something 305 should be about 6* BTDC @ 500-600 RPM.
It doesn't take a pro to set timing. :handgestures-thumbupright:

The fact that she overheats at idle points to the fan/radiator shroud.

Re: OVERHEATING

Posted: Fri Apr 13, 2012 9:30 pm
by dallen91yj
THANKS THATS WHERE I'LL START, EITHER A 12V OR A BETTER SHROUD.

THANKS FOR EVERYONE'S INPUT