Marcello7x

iTrader: (10)

Figured this would due better in the conversions section since in the regular forum everyone had an fbody. I have a relatively small radiator in my hot rod. Today was the first time i really got to run my new motor. At about the 5min mark my temp was around 250* and overflow tank was full. Its not that big of a tank tho.

I don't have a true 50/50 coolant mix, and i have one 14" electric fan on my radiator.

Here you can get an idea of the size of the radiator.http://www.youtube.com/watch?v=xyabd...er_profilepage
I plan to add a pusher fan and some more undeluted coolant to bring the mix closer to 50/50.

Anyone else come across this problem with a small radiator?

bczee

iTrader: (12)

Are you running a T-Stat ?.. and is it working/opening. I would not think that just idling for 5min would cause the temp to be above 250 without some issue with your cooling system ? (even with just water as a coolant).

Can see from the vid.. can't see what Fan setup you have !? Might also check for a Lean condition, vacumn leak.

79LS1FOX

iTrader: (11)

Seems to be idling awfully fast.....

grif54

Not sure how you filled the radiator, but I always fill mine up from the top hose to get all of the air bubles out of the system. On one of my swaps I had the same problem as you and a friend of mine told me to fill it from the top hose, no problems since. I also had I t-stat stick and it caused it to get hot, it was brand new too. Good luck.

gisqc

By the way the water/coolant thing doesn't change anything... everyone (or atleast everyone should) that road race on track use water only in their cooling system since antifreeze is like oil with spilled on track.

Marcello7x

iTrader: (10)

T stat is def opening.

This is the first time the motor has been run and the ecu was adjusting along with needing to adjust the TB limiter screw. After running it and letting it cool, and starting it up a second time for 5 min, the idle dropped to around 900ish.

I originally filled it this way. Then it leaked quite a bit at the shop[forgot to tighten a ring clamp] and it was refilled, not sure from where.

Did you simply take off the hose and add more fluid, or drain and refill.



Going to research the best way to clear to system of air now.

Gray86hatch

iTrader: (83)

Do you have a loop where the heater hoses hooked up?

You are going to need a good spal fan with a schroud covering the rest of the radiator

Tim

Marcello7x

iTrader: (10)

I do have a loop on where the heater core would get connected.

I was going to get another fan and use it as a pusher till i get time to make a shroud.

Im starting to get convinced its air in the system. Im going to try and blead it tomorrow and she what happeneds. If it fixes it i'll hold off on the pusher fan.

Marcello7x

iTrader: (10)

would coolant spill over into the overflow tank if there was a bubble in the system?

Gray86hatch

iTrader: (83)

A pusher fan is not a good idea they don't work well.

www.spalusa.com pick out the biggest highest cfm fan or fans that fit your radiator. Build a schroud and pick up a spal fan controller.

You could have a air bubble I set my stuff up so the highest point in the engine is the steam crossover in the front of the motor and put hose to the radiator tank.

Tim

grif54

I drained the fluid and started over, although I don't think it would really matter. I unhooked the hose from the radiator and just filled it up. I think your radiator looks big enough, I actually put a stock Ls1 in a 31 ford and never had any cooling issues with A/C and all. Just wondering if you had the coolant crossover rerouted into the radiator or top of the water pump? Hope you get everything figured out

usmcz28

iTrader: (3)

Here's a question for you, who built the motor? If everything else checks out fine you could have a head gasket on backwards. Several on here have had ti happen to them where the rear coolant passage from the block to the head was blocked off.

Tongboy

^ best idea yet - also - is there a tune on the motor? if it's running really wacky it could be creating undue heat in the combustion process and heating the coolant up faster than it otherwise would have.

if it really was the 5 min mark or so that is FAST - like air bubble fast - because no motor is going to heat up that fast idling

Marcello7x

iTrader: (10)

Ok ill pick up a spal fan and use the one i already have as a pusher, although the spal should he enough on its own.

The builder is very reputable, but i will pull the heads if i cant find the solution.

Yes its actual at the 5min mark that my small overflow started spiting out fluid everywhere. Im going to pull the upper hose and see if i can fill it from there. If it still overheats ill drain and start over. Also i dont have the vent tube in the correct place. Its going to a t in the heater core loop. Dont know where i got that idea but it will yet fixed as well.

FastKat

iTrader: (10)

Moving that vent tube might be your ticket.

When you put your hand on the radiator core, is it hot? Is the whole thing hot, or just the top, or just the bottom?

Does the overflow bottle need to be higher than the radiator cap?

Does it overheat at idle or just when you're driving it?

I second the idea for the fan shroud... though I'm not sure that's the problem.

Marcello7x

iTrader: (10)

The core is definitely hot on top. never though to check the bottom.

I have my below the cap. If you see the video its the bottle to the left of the radiator. It was a temporary solution till i find something that fits properly or i make on.

Just during idle. My tranny is out since its jammed and i wanted to run the motor a little and sort out bugs like this while i work on getting the tranny fixed.

It will get a shroud evetually, for now i'll pick up a stronger fan[aka spal], and i'll make a shroud when i get a chance. Maybe a good winter project.

Marcello7x

iTrader: (10)

So i drained as much as i could with my rad drain plug. then i filled it from the upper hose, then once it got as far as it could, i topped off the rad.

As the temp rose i found that only the top of the radiator is getting hot.

I also notice that my heater hose tube was kinked, so i don't think it was flowing very well. Would that cause it?

Pop N Wood

iTrader: (1)

Pulling one of the steam vent plugs until water comes out will get all the air out. I find pulling the upper hose is too messy. Normally it helps to jack up the front end, but with your radiator so high it shouldn't be an issue.

Definitely need a good fan to keep the motor cool at idle. I have an adjustable fan and can pretty much put the idle temp anywhere I want it. Getting a shroud that pulls air through a larger radiator area will help.

Pure water does cool better than a 50/50 mix, but the aluminum needs antifreeze to keep it from corroding while the water pump needs the glycol for lubrication. Don't run pure water and don't run more than 50% antifreeze.

These motors do need at least a quart sized overflow. The water will expand even with an air bubble.

My guess is once you get all the air out it will stop overheating. the fact only the top of the radiator is getting hot shows the radiator is cooling. Just keep topping it off and eventually it will shed the air.

BelAir1000

iTrader: (1)

I found that my dual pass rad will allow my wagon to idle at 215 on a hot day idling a 550rpm. Just raising the rpm to 1500rpm would cool it down to 190-195. Basically the water pump doesn't put out enough pressure and flow at idle to overcome the extra restriction of the dual pass rad. Remove your cap at idle and see if you see the water actually flowing.

The other thing is my car was sucking water out of the overflow bottle even after a few warmup cooldown cycles. So warm it up to 215 or so, then let it cool and make sure your overflow tube is in adequate fluid. Repeat this a few times and see if it draws in fluid. Basically the steam will escape and then the vacuum created while cooling down wil suck the fluid back in from the overflow.

Do you have a steam vent back to the radiator? Its advised. But if you insist on not having one, at least vent the port while filling the engine or vent it while hot to vent any steam(be careful if you do it this way).

Keep us up to date.

3pedals

iTrader: (3)

the bypass between heater hose connections MUST flow properly or the thermostat WONT OPEN.
if you look at the coolant flow path, you'll see what I mean, the only hot coolant flowing past the thermostat comes from that heater hose return, so if it is kinked, I bet that is your problem.
I found it almost impossible to get all the air out upon filling the system on my engine, I ended up drilling a couple 1/8" hole in the perimeter of the thermostat, which made it easy to fill the engine/cooling system without air lock