dhirocz

iTrader: (2)

I'm getting tired of this.

Installed a new 383 a little while back. Has run hot off and on ever since I installed it. Radiator was original, so I replaced it with a champion 3 row. T56 so there is no trans cooler. I run the power steering through an auxillary cooler since I also run a hydraboost. The pump is new, hoses, radiator, everything. Fans do run when they are supposed to. The engine is a Vortec 383 with an external bypass since it's also a vortec '880' casting.

What amazes me is the air coming off the fans is COLD, not hot. This is with the temp approaching 260*. I'm starting to explore the possability that either my new thermostat is stuck or they gave me the wrong water pump. Any ideas?

91 1LE

iTrader: (1)

Is the upper radiator hose hard/under pressure while the engine is running? I would replace the thermostat first because it's cheap and then look into the possibility of an incorrect water pump. If it's an off and on problem, I would suspect the thermostat.

sofakingdom

iTrader: (1)

What water pump did you use, and what belt system do you have?

Blocks aren't "Vortec". "Vortec" is a property of the heads. That has no bearing on how the cooling system in your car is supposed to work. That same block, FYI, is what they build the ZZ4 out of these days.

dhirocz

iTrader: (2)

First water pump was a reman unit. I replaced it with a new unit when the reman unit had issues. I even pulled the.back cover of the pumps to.verify.they had the right impellers installed.
Thermostat is a 180. I have a 170 going in today I'm going to try.
I pressure checked the system; no leaks. Hose gets plenty firm while running.
I'm going to look into the possibility of the lower hose collapsing while driving. Also going to look into the possibility that my under drive pulleys may be underdriving my pump too much though it wasn't an issue with the 350.
Belt system is factory serpentine.

The car runs fine, it just continues to creep up beyond 200 until it gets to 250, regardless of highway or city driving, time of day, etc...

Vortec blocks are different than the L98 blocks in that the vortec blocks do not have an internal crossover...use of a bypass to the water pump is required or one head will run hotter than the other. This is why older blocks run fine with vortecs without the bypass without sensitivity to detonation. Other than that they are the same as the zz4/L98 block.

sofakingdom

iTrader: (1)

No SBC BLOCKS have any kind of crossover (exc maybe LT1, not too sure about the passages in those). One leg of the water pump feeds one bank.

Me sure your water pump is the right kind of rotation for your pulley system, which the pump should be "reverse rotation" (CCW) for a serpentine system. Vortec isn't a property of blocks or water pumps, except that some of the newer blocks don't have the small bypass hole on the driver's side which makes them act funny while the thermostat is closed but makes no difference once they reach operating temperature. The same WPs will work on any of them though, just like the ZZ4 that's built out of that same 880 block.

drew.davis83

iTrader: (1)

i have been having the same problem ith my 383 i just built and it ended up being the cooling fans i have did not put out the cfm my high strung 383 required to stay cool in the 110 deg weather we are having down here in texas dont know if thats your problem but i thought there was no way that is what it was since i got some brand new fans but thats what it ended up being

RS Chris

So it was the fan after all Andy?

drew.davis83

iTrader: (1)

yea it never got over 220 all the way to kemah my buddy said it would run allitle hot due to the break in and said i just needed run it on the freeway and see he said it should be fine and when i did that it ran 190 to 220 there and back

regal301

dhirocz

iTrader: (2)

Do a search on google before you let your online ego get the best of you. While you are at it, ask an engineer who was involved in the Vortec program in the mid '90's like I did before littering the online community with false information. After all, I'd be more inclined to believe someone involved with the design of the part rather than a guy who knows how to use nifty smilies.

Confuzed1

iTrader: (4)

Cool air blowing from the fans after it goes through the radiator (assuming it's a "normal pull through" setup) screams to me that it's barely flowing water or not at all. I'd look into the same thing you posted....T-stat or water pump....

regal301

ego...?ok, talk all the trash you want. I AM RUNNING A VORTEC MOTOR IN MY CAR . would you like pictures ?

chevelle600

iTrader: (9)

just curious, what're you running for an intake manifold? still a stock tuned port? or have you gone aftermarket? EGR deleted?

if you still have the TPI intake, what did your engine builder use for headgaskets and intake gaskets? are all coolant passages opened up?

on my motor, i have the HSR intake, it ran hot for a while until i did the champion radiator (stock one ran free and clear). the rear coolant passage is blocked off and the intake doesnt have egr provisions. I assume those were the issues behind my higher temps/overheating.

regal301

edelbrock intake :http://www.summitracing.com/parts/EDL-3817/

stock runners, i ported the upper plenum. no egr.

intake gaskets are for any chevy fullsize pickup 96-00

other than the intake,you swap over all the stock l98 accesories.

i left the vortec plastic timing cover and balancer.it even dropped right in with the truck motor mounts.

all the water outlets are in there stock location,just on the new lower intake. i have ZERO heat issues. i put the car together myself.

regal301

http://www.sallee-chevrolet.com/Cyli...ads/Vortec.cfm

dhirocz

iTrader: (2)

Great. I'm also running one. I also had a 40 degree variance in cylinder head temp compared to without an external coolant crossover. Apparently some people have issues and some dont from what I've seen. Also some people dont have their water pump bypass drilled and some do. Most people dont have issues. There can be minor midyear differences in castings of the same part number so who knows? Years ago on occasion I'd pull 4 bolt 350 Vortec's out of 1500 GMC Sierra's and 2 bolts out of 2500 HD pickups when I tooled around at the dealership. Who the hell knows what GM was doing.

I have no reason to doubt the information I was given. Just because you choose to dispute it doesn't give you or anyone the right to raise a bs flag. There's plenty of bs on here enough as it is. Agree to disagree and call it a day.

Do I want pictures? No, I have built enough Vortec based engines to know what they look like. I have also built enough to know that this hasn't been a factor on all but two of them.

I built the engine. I welded and ported the base, pocket ported the heads with some work in the runners, runners are AS&M LT runners and I am running the EGR. Head gaskets are felpro 1094's I believe, .015" compression height if I remember right to give me a .040" quench after machining. Compression is a tad high at 10.65:1 but the engine no longer shows signs of detonation as I expected. Intake gasket is the new design felpro vortec gasket. Thermostat was just swapped from a 180 to a 170.

Apparently the pinging was the lack of a crossover spiking the temp on the passenger head. Since I added a crossover from the intake to the water pump the problem went away. I will admit I still find it odd that this has only happened on two engines I've built, both built pretty different but both vortec R code engines. As far as cooling it appears the underdrive pulleys were causing the problem. They were too far underdriven, I put the stock pulleys back on and it seems to be running ok. Engine apparently didn't like the loss of about 15% of water pump speed. It'll still climb up if you toy with it somewhat, but quickly come back down. I need to make sure I purged the air out of the coolant all the way; next up is a high volume water pump and silicone hoses to be on the safe side.

regal301

.

startat2

iTrader: (2)

I'm with the crowd that says double check your water pump rotation. While you are at it also check the cooling fan rotation. If the fan is running the wrong way, swap the wires

dhirocz

iTrader: (2)

True. I'm sure the pump is correct, I pulled the back cover off the 2 pumps I've swapped out to inspect the impellers, then I swapped pumps just in case. It was just the pump was running too slow per engine RPM.

InfernalVortex

iTrader: (4)

Where is this alleged "crossover" at that's inside old blocks? Ive never seen it.

dimented24x7

iTrader: (2)

Ive never seen any cross-overs in the blocks, either. Each bank of cylinders is seperate, with the cross-over taking place at the intake if you happen to have the rear passages open along with an intake that has a cross-over.

Ive never had any issues not having a rear cross over. Perhapse it may cause a slight imbalance of temperature, but in this case it sounds like the OP isnt getting hardly any flow at all if the fans are blowing cold air. With the engine at 250 the air coming off the rad should be hot as hell.