Block Heaters

[DirtyLittleSecret]

Looking for a really good block heater...what's the best for these trucks (w/ 350's)?  Just looking for some prevention/easier starts.

[BLUE BURBAN]

On your 78 model you can run a "tank" type heater that simply splices into the heater feed hose (the hose coming from the intake maifold and going to the heater) they make these in 2 different styles. Style one and the easiest to install is a 1000 watt horizontaly mounted heater with hose fittings at each end. Simply cut a 6-8" section out of the hose and install it. Be sure though that the heater is full of coolant before you plug it in or you will burn it out in a heartbeat.
 Style #2 is a vertically mounted unit with an outlet straight out the top(output side) and the other one coming out the side near the bottom(inlet port) of the heater. This bottom intake port is plumbed to a fitting in the lower side of the block replacing a coolant drain plug. The top outlet port feeds into a plastic "Y" fitting that is installed again into the heater inlet hose.
Both of these heaters are perculating types of heaters and work excellently.
 HOW EVER>>>>>> You DO NOTwant to use these on computer controlled vehicles because they have little "check balls" that rattle around inside of them and the knock sensor will hear them sending a signal to the computer to retard the timing because it thinks it's hearing preignition detination (engine ping) and will continue to do so until it stops hearing it thus causing rough running conditions to a no start condition.

A freeze plug style heater is only about 650 watts and replaces the center freeze plug on the drivers side of the block with the heater element in the 12 o'clock position and has no moving parts. Just knok out the old plug and replace it with the heater then refill your coolant with a 70% antifreeze/30% water to protect your system down to -50* before it starts to freeze without plugging in.

[werewolfx13]

I personally plan on installing two freeze plug heaters, one on each side of the block, of the engine I'm building for my truck. I know a few guys around here that have done this for their plow trucks and swear by it on REALLY cold (sub zero *F) days. The engine reaches a nice, easy starting warm temp in less than an hour.

[Blazin]

One block heater is plenty. Just waste of energy running two. I have mine set on a timer to come on about an hour or so before I plane to get up. That way its not running all night. Did that years ago with my first block heater. After the next electric bill I started using the timer.

[VileZambonie]

Agreed on on the one heater. 2 is pointless.

[BLUE BURBAN]

Agreed on on the one heater. 2 is pointless.

Really depends upon your locality too. Here in Anchorage, Alaska one is enough as well. Some people also have a battery blanket plugged in as well. Now as for Fairbanks,Alaska where the Temperature in the winter can drop down to -45* to -65* alot of vehicles have 2 block heaters, 1 battery blanket (2 if a diesel) as well as oil pan heaters on both the engine and the transmission.

[werewolfx13]

I'm still installing two, regardless. Should one fail, a second is already installed in the block, ready for use.The second may not be neccessary to use except if I want to warm the block in <30 min, but freeze plugs are far easier to install/remove with the engine on a stand than in the truck.

 Before I gave my '84 GMC 305 to my dad, I used a 1500w tank heater and a 400w magnetic oil pan heater on a timer to come on 2 hours before I'd leave the house...when I'd go to start it, it was already a toasty 120* regardless of what the outside temp was.

[mike357]

move to houston...it's a natural block heater. 

[werewolfx13]

But then we'd miss out on all the purdy white snow n icey roads, and layers of salty sludge..

[Blazin]

Plus up here if you get sideways and stay in the throttle performing you can blame it on the slick roads.

[sav_x69]

do the tank style heaters circulate to

[werewolfx13]

Yes, they circulate the coolant..I just put a previously mentioned style 2 in for a friend of my dads yesterday evening..Looks didn't matter and he wanted it done in an hour or less, so I installed it on the drivers side fender, the inlet connected to the drain plug on the radiator, the outlet routed along the firewall to a plastic Y fitting i installed on the inlet hose to the heater core. That doesn't really heat the block, but it heats the coolant in the radiator and heater core which still allows the truck to warm up faster. In fact, the heater will blow warm/hot air from the time you start the truck, since the coolant in the heater core is already warm.