farmer12

I know I should probably post this in the turbo forum but I know a lot of the guys on here are pretty knowledgeable so I thought I'd give it a shot. I'm out of ideas. Little backround...its an early 90s 5.0 standard bore, with 351 heads fully ported and polished, full roller, xe274hr comp cam, twin T3s, intercooled, with a blow thro CSU carb. Have a 2 1" core alum rad with a full shroud elec fan on it, bout 3k cfm, 180 degree thermostat. The dam thing slowly gets hot on me, just cruising down the road at 55, bout 2500 rpm. Even today with it being 60 degrees it still got hot, its not instant, its very gradual to get hot. Within 6 miles it will have gotten up to 200 and anymore it continues up to 220. Forget bout putting boost to it, it'll gain 10 degrees in one 10 second romp, that's with the fan running constantly. I've tried everything I can to make it stop but I am plum out of ideas. Anyone have any?

Chris_1

iTrader: (1)

I assume you made sure the thermostat actually opens ?

farmer12

That... and its the 2nd one I have tried.

Crownman

If the thermostat is working properly, you're getting good coolant flow, and don't have a head gasket issue then I'd say you need much better fans with a good shroud setup.

BobSchuman

Pull the plugs and see if it is running to lean. Flush and fill the cooling system. Maybe have it power flushed. It it was running good with the fan set up before, I wouldn't mess with that.

qdeezie

What head gasket are you using? Also, are you using head bolts or head studs?

farmer12

This is a brand new rebuild, it won't need flushed. These are all new parts as well. The fan and shroud completely cover the whole rad and the fan itself catches all but one or two cores of the rad. I have cometic multi layer gaskets and I'm running studs. And it's not running lean I have a FAST a/f dual sensor gauge on it. I'm at 12.5 cruising. If anything it's running rich under boost.

farmer12

I should point out this thing only has about 50 miles on it and I've had this problem since I got it running this spring.

djfllmn

iTrader: (1)

hows the coolant flow? do you have a standard 302 water pump on it or a higher volume one? maybe a good electric water pump will help

unit505

I'm just curious, 2500rpm at 55mph? That thing must have no top end. That's got to be generating allot of heat not to mention the turbos. Are you ventilating the engine bay? If you've stuffed two T3's under the hood with a V8 your going to have to add a hood scoop or remove some or all of the inner fenders. Also, are you running an intercooler and or AC? The cooler and condenser both need adequate ventilation. They will both block some air flow to the radiator to an extent as well. You've got allot of heat soak with the T3's and your going to have to remove as much of that as you can. Marine bilge blowers could be one option pointed down and towards the rear of the engine bay. Your going to have to have a good alternator to push a set of blowers and that 3k cfm fan. Also, is that fan an absolutely reputable fan? 3k cfm for sure? One other question... forgive my ignorance, is that 4 speed manual or auto? If it's auto, are you using a separate cooler? A 3k cfm fan running full time should bring your coolant down to room temperature in a couple of miles. An overheated transmission can bring that temperature back up and play hell with temperature balance with a radiator designed to cool two different fluids. I run a Hayden remote trans cooler with a 10" fan at 180* on my Silverado for pulling my travel trailer. It reduced my engine temp by a few degrees when a installed it and bypassed the radiator. You can mount a trans cooler remotely and completely take away that source of heat soak. You can also consider a remote oil cooler to help reduce some heat soak as well.