how hot is too hot

ive got this big ass truck bumper covering my grill and am wondering if its keeping air from getting to the radiator.what is the optimum operaring temp on one of these old straight sixes

sonny,
I have a 250 in my 66 and it cools just find and stays between 180-220. Cooling has always been an issue with all these old vans so I would say "Blocking" air flow of any kind is not a good idea. It may not be hurting but sure isn't helping.

i had it out for awhile and it was running at 240 according to the aftermarket gauge in it.ill try a new thermostat and some fresh liquid and see if that helps.if not the bumpers gota go.i kinda like it-its fabbed from a peterbilt bumper

Yeah, I saw your pic's, that's one cool bumper! I would try alternatives first. I would flush the system, check the water pump and Rad. first. From the pic's I don't see that bumper causing the issue. Like I said. Check the Rad and w/pump and thermostat first. If that doesn't work then remove the bumper and take it for a ride and see.

I'd say the bumper looks cool but has to go. It's obstructing the air intake through the grill. Also it doesn't look like you have a belly pan.
They need the belly pan to draw air to the radiator.
240 is too high, 230 is critical in my book.

Is there a doghouse in the pick ups?

yeah,same doghouse as the vans and no there is no belly pan.no where i can get one?

I bet they removed the belly pan when the bumper was installed.When you replace the belly pan I would think the bumper would then have to go.To keep the bumper you may have to modify it or the belly pan to get more air flow. Only one way to find out,Good Luck.

By the way nice truck

mike

if i flush the system and put in a 160 or 180 thermostat,can i use extended life antifreeze,ive got a couple gallons laying around the garage.also,how would check the waterpump and check it for what.its not leaking-i know that.the air that flows thru the belly pan(if i had one),does it come thru the grill or from under the truck?thanx guys

If the bearings in the waterpump are gone, there will be evidence of leaking out the weep hole. the belly pan attaches under the frame rails and behind the grille.

I would ditch the bumper ASAP. and install a belly pan.Also a good electric fan will help. Get one between 2800 and 3200cfm

Here's a good one and it will fit perfect in your truck.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=HFM-ZFBC16S&N=700+115&autoview=sku

I agree,the bumper obstructs the air flow and that's critical on any early model. If you need a belly pan I have several along with just about anything else you might need. I could save you shipping by bringing it to the Bakers in Milford,Mi. meet if you are attending that this year. Whatever you may need,I can probably hook you up.

After market water pumps are inferior to the original types. Instead of a cast impeller,they use a stamped or punched sheet metal type impeller. It doesnt move the same volume of water as the cast one does. Also any of the impellers can be corroded badly and the impeller itself can be much smaller in size than it was originally, thereby being less efficient. 240 degrees is way too high for comfort. Imagine what it woud get to on a really hot day in traffic.

Mike, do you own that fan?
The specs are pretty good and only 10 amps.
3000 cfm is more for a bent 8, 2000 would be enough for a six.
Don't like the chrome though.
It would fit as a pusher but a puller is much more efficient plus blasting air over the engine is also better. My pusher ran 220 ° on hot days with belly pan and a 3 core 1965 mustang rad freshly boiled out.

I did the pusher to puller conversion today and it was not easy.
I had 1/2 inch space between water pump pulley and radiator.
The rad had to come 3 inches forward using 5 inch bolts and tubing.
We fabbed a fan mount welded to the rods 'cause I didn't like the fan hanging on the fins by those plastic rods (causes leaking).
Had to install longer transmission oil lines and change the kickdown rod.
The rad is now very close to the front of the doghouse which I'm going to open up as well as the floor in front to get more air through with a fabbed intake.
I'll upload pics soon.

Cheers

I used one( not chrome) on another van with a V8 and it kept it at around 180-190 even when it was 115 here. I used it as a pusher. I plan on getting one for my 65 but again no chrome. The one Summit has is just like the one I used, same size and everything just chrome. I don't like chrome because it does not disipate heat.

ok,it wasnt the thermostat,there wasnt even one in there.when i start the truck(warm or cold)it makes a very loud sreeching sound for about a minute then goes away.at first i thought it was the fan belt but now i wonder could it be the waterpump.it doesnt leak at all,does this make any sense?the radiator doesnt appear to be in the greatest shape either but its not leaking either.its about 200 miles to bakers-i gotta get this thing cobbled together quick

On our wheel loaders the pulley grooves end up wearing round and cause the belt to squeal alittle at start ups, A new belt in a worn groove, the belt is trying to just ride on the bottom edges of the V, whether this would be a cooling issue I dont know, it'd have to be slipping pretty severly. Usually it is the crank pulley in our case because that never gets changed, Just an idea to check

Like I said,the water pump may appear perfect,may even have good bearings and not leak. But the impeller could be severely corroded and now be much smaller than when new,thereby being less efficient,moving less water volume. ALso I would install a thermostat. It cant hurt to have the radiator hot tanked and checked either and flush the engine while its out. Dont forget to flush the heater core too. It could be clogged also.

Also a fan shround and belly pan would help too. It all kinda works together as a package. If the engine and radiator were brand new the belly pan wouldnt be as big of a factor but on used stuff which has years of internal buildup,making water passages smaller,it helps a lot. It helps maximize the airflow forced thru the radiator and prevents it from escaping below it.

Now that's a "COOL" idea Don. I had wondered if something like that would work and had tried to figure a way to have it hooked to another thermo-Switch to kick it on only when needed.

Yeah, I noticed right after moving down to Fernandina Beach that mine is starting to run a little warm. So put in a 190 degree Thermostat, Coolant Temp and Oil Pressure Gauges today. Going to make a run up to Mom’s on Tues to help her pack up the house for the move to AR. Figure that will be a good test. Heading to check out the JY’s in Jacksonville next weekend and thinking a belly pan fan may need to be on the list as well.

Finally found a good use for that "Ash Tray".....

i had the same thing. trying to keep the motor running cool.so heres what i came up with. I run a 302 roller block mustang rig with a c4 tranny.1st off if you have an automatic,get a cooler,Transmission fluid runs way hotter than coolent so running it thru your rad is not good.Flex fans did not work cause they flatten out at speed, so back to the fixed pitch total pulling fan , but for low speeds or idling,a pusher electric fan on the front of the rad works pretty fine with auto or manual switch. 160 thermostat sos to not let the temp get to high before opening.and last I cut into the heater hose to divert the flow to a 2nd rad in the space between the side doors and frame. since the heater is always open, aportion of your coolent will always go thru the other rad doing a real good job plus youve added agallon extra to the system. all good. I ran to the PA nats this year and even during the hot days ,the van never went got past 170ish. Oh yeah,the 2nd rad is made out of baseboard heater core, so it can be made any size.