Can you tell by the looks of the impeller?
I had this on and had no cooling problems, but the bearing went bad. I bought a Bosch pump from Pepboys and now my fans won't turn off. They come on and turn off at 180 in about 45 seconds. Now it stays at 190* untill I start driving.
http://www.camaros.net/forums/showthread.php?p=1043104#post1043104

Please look at this post too.

http://www.camaros.net/forums/showthread.php?p=1043103#post1043103

You get what you pay for,no thats the cheap replcement pump with the stamped steel impeller that doesnt pump worth a crap unless the backplate to impeller is set perfectly which isnt the case most of the time.

The better more expensive hi flowpumps have either a plate pop riveted to the back of the impeller to enclose the rear of it to help eliminate cavitation or a cast iron impeller thats doesnt have an open back like the cheap stamped steel unit has.

Get a Milodon hi flow cast iron pump with car iron impeller for approx $100 from summit/jegs,you must also run a hi flow stat with a hi flowpump .That's because the std stat wont allow the additional flow from the hi flow pump so use a 180 deg Robert shaw hi flow stat thet already has the 3 holes drilled in it to pass the air out of the system,it's also avail from summit/jegs. But test it 1st in boiling water to ensure it opens at 180-185 deg max due to mult decfetive stats seen here lately in t/chevelle.

Some people are going to chime in here to say the stmaped steel ones are fine well in some cases they are not fine as you found out so do it right and get a hi flow pump and hi flow 180 deg stat with the air bypass holes already drilled in it.

Scott

I ordered this pump http://store.summitracing.com/partdetail.asp?part=MIL-16301 and this pulley http://store.summitracing.com/partdetail.asp?part=SUM-G3959 . My pulley is 7" and this one is 5 5/8". With 30% more flow and the smaller pulley I hope it's not too much.

Good punmpbut why did you decide to not use the stock 7" pulley and went for the 5.5" pulley tha willspin the pump faster?

Spinning the water pump too fast could cause issues too,i would try it with the stock pulley 1st,if temp is good with stock poulley return the smaller one. But if temp is still not great try out the smaller pulley as you have nothing to loose at that point but the cost of the pulley.

But i bet the new pump will do the trick and you didnt mention getting the hi flow stat with the 3 holes drilled in it to let air escapse. So get that too if you dont already have one as its a must for a hi flow pump to work properly.

Get back to us with the results after you install the new hi flow pump & hi flow 180 deg stat with the 3 air bleed holes in it.

Scott

Good punmpbut why did you decide to not use the stock 7" pulley and went for the 5.5" pulley tha willspin the pump faster?

Spinning the water pump too fast could cause issues too,i would try it with the stock pulley 1st,if temp is good with stock poulley return the smaller one. But if temp is still not great try out the smaller pulley as you have nothing to loose at that point but the cost of the pulley.

But i bet the new pump will do the trick and you didnt mention getting the hi flow stat with the 3 holes drilled in it to let air escapse. So get that too if you dont already have one as its a must for a hi flow pump to work properly.

Get back to us with the results after you install the new hi flow pump & hi flow 180 deg stat with the 3 air bleed holes in it.

Scott

Thanks. The reason I went with a new pulley was mine was bent. When I spin it it looks warped. I'm wondering if thats the 2500 rpm light vibration I feel and even if that caused the bearings to go bad on the old pump.

I was wondering about the smaller pulley also. We'll see what happens

I have the MrGasket High flow 180 stat in there right now. I'm not sure about the 3 small holes though. Maybe I'll take it out and look. http://store.summitracing.com/partdetail.asp?part=MRG%2D4364&autoview=sku I looked today, it doesn't. I ended up ordering this one.
http://store.summitracing.com/partdetail.asp?part=EMP%2D301&autoview=sku

Ypu,thats the correct stat.

Scott

Can you tell by the looks of the impeller?
I had this on and had no cooling problems, but the bearing went bad. I bought a Bosch pump from Pepboys and now my fans won't turn off. They come on and turn off at 180 in about 45 seconds. Now it stays at 190* untill I start driving.
http://www.camaros.net/forums/showthread.php?p=1043104#post1043104

Please look at this post too.

http://www.camaros.net/forums/showthread.php?p=1043103#post1043103

Scott, this pump is the one he said did a good job. I don't think we got a picture of the Pep Boys Pump. It would be nice to compare them. Squido

Scott, this pump is the one he said did a good job. I don't think we got a picture of the Pep Boys Pump. It would be nice to compare them. Squido

Yea this is the original pump. I didn't take a picture of the Pepboys one. There was a good 1/8" space between the impeller and housing on the Pepboys one and little to nothing on this one. They both looked EXACTLY the same though except for the clearance.

http://www.camaros.net/forums/showthread.php?p=1043103#post1043103

Well ,the pump and pulley is in. It's not what I expected though. The temps come up slower before though. The fan comes on at 190* and drops it to around 188* and pretty much stays there untill I start moving. Before it would drop to my fan shut off point of 183* in about 45 seconds then come back on a couple min later. It never goes over 190* so I guess thats good. Just thought it would cool it better than the other pump.

It would be interesting to see what the system would do with a 7" pulley. Are you planning on trying one?
Squido

It would be interesting to see what the system would do with a 7" pulley. Are you planning on trying one?
Squido

You thinking it would slow the flow? Cooling it better? My 7" pulley is a little bent and didn't want to put it on the new pump. I have a feeling thats what mnssed up the bearings on the old one.

Never goes over 190 deg,thats just fine IMHO.

Dan,your very welcome.

Scott

Scott,

I'm hijacking the thread. As you found out yesterday, I have some cooling issues. I replaced the pump today with an Eddy to match my intake. A couple of local Chevelle owners have them and they are not having cooling issues.

The problem is that on a hot day, (95-98 degrees, 70-80% humidity) I cannot run the AC in the car when I am on the highway. If I drive at 65+ with the AC on the engine temps will climb to 210-215+ degrees. If I turn it off, it will run 190-200. If I let it idle with the AC on, it will run at 190. I have dual 12" electric fans controlled by a temp sensor. My dash gauge has the sensor in the intake near the thermostat. The fans move 4600 CFM at full load. On the highway, I should have 8000+ CFM through the fan openings at 65 mph.

What I have done so far:
Installed Alumitech radiator
Installed dual 12" electric fans (4600 CFM)
I flushed my system
Added Water Wetter
Tried a 160 & 180 thermostat
Installed high flow 160 degree Stuart thermostat
Installed Edelbrock high flow aluminum water pump

At 65 with 3.42s, I am turning 2800+ RPM. I have driven the car a few times on the access roads at 50-55, which is about 2200 RPM. At that RPM and speed, the temps will stay around 200 degrees. My plan is to get a 4L60E in the spring which should drop RPM by 23%. 65 MPH should be 2200 RPM with that tranny.

I am going to check all the engine temps with an IR gun in the next week or so. Transmission fluid runs through the radiator.

Engine idles at 950, I have initial timing at 17 degrees and with vacuum I have 28 degrees at idle. 38 degrees total by 2800 RPM. I rechecked timing, idle bleeds, & idle RPM today after replacing the pump. Also, bypass hose is blocked.

Anyway, I think I have a 5.5" pulley. Do you think I am moving fluid too fast through the system and should step up to a 7"

Thanks,
E.

It's ok, you can hijack it. You really did it all, huh! I would check with your IR gun. Sounds weird even with the vac connected to manifold it's still a little hot. I connected to manifold vac yesterday and also had to change my vac advance canister because of low vac. Temps go to 190* and go down slowly now. That helped.

Do you know how your running lean with your A/F? Just another thought.
Try the IR gun or even another mechanical gauge and connect it with the one you have now. I have the factory gauge connected to the drivers head and a mechanical gauge connected to the manifold. The electric fans have another sensor in the manifold that I tapped also.

Lean? I don't think so. I think it is actually running rich. I want to swap the plugs to verify that. I have been trying to find a local tuning shop with a dyno that I can run the SS and my Formula. I need to get some tuning work done on the Formula since I have rebuilt the LT1 and it has a bigger cam. If I could find a shop, they could install a bung and hook up a wide band O2 in the Velle. I'm just having no luck finding someone to do it. Everyone wants to work on LS engines, not the older LT tech.

I am planning on installing a vacuum gauge, so maybe I will get a two gauge kit and put another temp sensor in the head. The one in the intake is hooked up to an AutoMeter gauge.

I'll see what the IR gun tells me. :)

Thanks,
E.

Eric,try the lager pulley if its not a real pia to do ,it's worth a try,just maybe the hi flow pump is moving the coolent so well/fast that it doesnt get enouhg time to cool down when cruising at higher rpms.,you never know.

But i have found in the past that when there is an ac cond in front ofthe rad that always slows down the airflow thru rad no matter what you do and in some cases the elec fans cant cut it.

Your timing and general motor setup/tune seems plenty good enough to run cool and 342 gear isnt that crazy a gear to cause heating up issues.

I would love to see what a severe duty fan clutch with a 772 7 blade gm fan with stock shroud would do,i bet it would be able to handle it with ac on .

Just curious,does your engine compartment have the inner fender splash gaurds/cowel to hood seal/and the hood insulation all installed? If not its been stated that not having those items in place can also upset proper airflow for cooling but i dont know if thats really the case 1st hand,just read it here in t/chevelle a few times from people that seem to know what they were talking about.

Scott

Scott,

I just finished reading this thread (http://www.chevelles.com/forums/showthread.php?t=237329). I almost posted to it but thought differently. I have read virtually every post regarding overheating, radiators, cooling, etc over the past 6 months and the archives. There is definitely a difference of opinion regarding what temp is okay to run an engine, either SBC or BBC.

I still have some things to look at and will try with the current setup to see if I can make it work without switching back to the clutch fan and shroud. I might be wasting my time and effort not doing this right away. I went to a lot off effort, time, & money to put the electric fans in there. They are not impossible to remove, but not a picnic. They didn't come with the car, so pretty much everything had to be fabricated. I'm going to get a new temp gauge for the head and then test with an IR gun to confirm what the intake sensor is reading. It might be a few weeks before I get around to this as there are some other things needing done first.

As for your question, I have the hood insulation, gap bumpers on the edges and the rear hood seal to cowl. The hood to cowl seal could stand to be replaced, but it's not completely flat. I have a cowl induction hood, but don't use it. I guess it is possible to it might be causting turbulance problems. I can see if I can make a seal for it and try that.

I think one item that leads me to the RPM issue is that if I stay at a lower speed, same outside temp, AC on, etc... Then the temps are lower. As soon as I start getting more RPM, then it starts to warm up. It has been weeks since I have gotten it out in the middle of the day and headed out. Maybe I will do that this weekend and see how she does. Now "overheated" is not an overflowing radiator. I am talking about temps of 215-220. That's hotter than the car used to run. It's hotter than the other cars in my local car club. Many of them are running BBCs with more cam, aluminum heads, etc. Several have 4 speeds, and several have 4 speed autos. If I follow that line and go with the 4 speed auto like I want to, it will bring RPM at 65 MPH down to about 2200. That RPM allows the engine to stay cool with the AC on at steady speeds.

Another point that has been brought up is the size of the coolant passages in the head gaskets. I know I have the right gaskets for my head, but I also remember the holes in the gasket were smaller than the ones in the head.

Sorry for the long post. I appreciate you taking the time to respond, again. :hurray:

Thanks,
E.