My 340 is running hot I think.. I need a sanity check.

-
AlV said:
Greetings,
I've finally got to the point where I have my GTS on the road and now working out the bugs.
One of the more persistent issues is temperature with the 340. I thought I had it licked but It's still acting funny. When I go for a ride the Stewart Warner temp gauge says 185 and the factory temp gauge points straight up and reads 1/3 of the sweet spot, the gauges read normal but the engine seems hot and I hear the coolant burping around. I have no over flow bottle so the tube goes from the neck to under the car. Today I was leaving a trail of coolant drops as I was coming up the driveway.

I can't barley touch the rad even after it's sat for a while.
Top radiator hose has pressure lower isn't collapsed (at least when I look at it)
When its cold it starts right up. after a drive and the temp heats up it doesn't want to start.

Rebuilt engine 69 340 (It's a mild stock build)
Reconditioned crank and rods, .40 over, stock 340 "X" heads, Comp XE275 cam, Performer RPM 340/360 (non-EGR), Holley Avenger 670 w/ e-choke carb, Stock HP manifolds, stock valve train, MSD Billet Distributor w/6A
Compression: 10.5:1
Timing: initial 20 with 35 total
Plugs: are Gapped at.040
Idle: cold 800 rpm warm 500 rpm
T stat: 160 with 1/8th drill
Fan: factory 7 blade with viscous clutch.
Coolant: 50/50 mixture Tap water/coolant

What am I missing?
Click to expand...

I am probably the least qualified here to give a solution but have you tried a different radiator cap?
 
jimjimjimmy said:
185 is not even close to being hot running any cooler than that can cause premature engine ware among other things
Click to expand...
seabee said:
I am probably the least qualified here to give a solution but have you tried a different radiator cap?
Click to expand...

Right, I'm okay with the gauge reading 185-190 but I need to make sure the reading is good. I am borrowing a gun to check and confirm. It's the symptoms that are causing concern.

Yes, it has a new cap.
 
DARTH V8R said:
Unless you have an e-pump helping, nope nope nopity nope. Put the filter AFTER the mech pump.
Click to expand...

I don't have an issue with fuel pressure it's constant 5-7.. My logic for placing the filter there was cooling
.
Can you elaborate on why You recommend not to have it before the pump?
 
AlV said:
I don't have an issue with fuel pressure it's constant 5-7.. My logic for placing the filter there was cooling
.
Can you elaborate on why You recommend not to have it before the pump?
Click to expand...
Cause mech pumps aren't designed to pull fuel through a filter, only push. You'll get high speed lean out. Also, put the biggest seats you can in that holly and limit the fuel pressure to 5.5lbs.
 
AlV said:
Yes, it has a new cap.
Click to expand...
Sorry, I meant a different cap. I had a new cap that came with the new radiator that was giving me similar symptoms. It would randomly open under different temps and cause weird noise and puke out the overflow tube sometimes. It drove me nuts trying to figure it out.
 
seabee said:
Sorry, I meant a different cap. I had a new cap that came with the new radiator that was giving me similar symptoms. It would randomly open under different temps and cause weird noise and puke out the overflow tube sometimes. It drove me nuts trying to figure it out.
Click to expand...
Got ya. yes meant to say I bought a new one to replace the old one :)
 
Just wanted to take a minute to circle back on this. I have not had a chance to check with an IR but I still plan on doing it. In the meantime I found that my Rad is starting to give. I found it weeping along a 1 inch section of the seam where the tank mates to the core.


I'm pulling the rad back out and going to have it restored and re-cored adding as many rows and fins as I can. I'm also going to install a small reservoir then get back to testing and trying to follow AJ's post :thankyou:
 
seabee said:
Sorry, I meant a different cap. I had a new cap that came with the new radiator that was giving me similar symptoms. It would randomly open under different temps and cause weird noise and puke out the overflow tube sometimes. It drove me nuts trying to figure it out.
Click to expand...

I also have had a brand new cap do this.
 
You must log in or register to reply here.
-

Back
Top