Cooling System

[DailyDriverSst]

Finally got my build "done". Went for a 30 mile drive (split in half), 90-98* ambient, and water temps hovered 215-225* with the header on highest setting trying to shed heat.

Iron block, Iron head, Cometic MLS gaskets. Block is half-filled (I asked for 1/4 fill, machinist didn't listen). EFI.

It took 9 minutes for coolant to go from 90* to 212*.

After an hour of cooldown, it went from 245* (heat soak) to 185*.

It took 9 more minutes to go from 185* to 235* then came down to 228*.

It makes 6 pounds of boost at 3000 and 10 pounds at 6000.

I'm going to add a Craig Davies booster pump (9051) in the heater hose line to recirculate with engine off. But is there anything I can do with the primary system?

I'm going to fatten it up a little in the EFI tune and considering adding water-methanol off a RPM switch at 3,000 with a 2GPM nozzle at the blower and 1GPM in the hat.

It has a 180 thermostat with three 1/8" holes, and an AFCO aluminum radiator.

I'm just not sure what else I can do?

[Jeff Stout]

Richen up, add more timing above the 3k rpm. Need alot of fan to help cool. Radiator large enough?

[jmcarter]

Compression ratio? Possibly high, perhaps put thicker head gaskets on it otherwise you’re likely to have real trouble in a traffic snarl. Multiple auxiliary fans might help as well, have even seen them on transmission coolers to limit heat from the ATF.

[Keith 944]

i drive my high 10 sec street/strip car on the street. only prob i have is long trips at high rpm not sitting, idling so i know its a flow issue. anyway i have a grid system so i just back the timing down for cruising. you can also ritchen up the fuel, also a big help on my truck was an engine oil cooler!
also i would try it without the thermostat just to see if any difference

[1legjerry]

You don't need a thermostat if you are running that hot.

What engine? How much HP? What transmission and rear gear?

[DailyDriverSst]

Small block mopar, powerglide (1.80), 4.10 rear and 29.5 tires. weighs 4400 pounds. Shooting for about 700 HP.

Oil cooler has been suggested but not sure where it would physically fit. The blower, radiator, and intercooler are pretty well tetris'd in there with a 12-rib blower belt going forward, and going backwards the exhaust Y pipe goes behind the filter. I'd have to go under the engine, along the driver side header, past the flexplate, until I got to a clear spot on the driver side frame rail.

CR is about 10.0:1.

9.575 deck, 2" crank swing, 6.123 rods, 1.460 pistons, -20cc dish. Pistons are .008 out of the hole. 50 MLS gasket, 63cc chambers.

I've been suggested to drill and tap the rear manifold vents to make a cross-over and run it to the thermostat housing. May not help cooling, but could help with bleeding air out and preventing steam holes.

[1legjerry]

Originally Posted by DailyDriverSst

Small block mopar, powerglide (1.80), 4.10 rear and 29.5 tires. weighs 4400 pounds. Shooting for about 700 HP.

I've been suggested to drill and tap the rear manifold vents to make a cross-over and run it to the thermostat housing. May not help cooling, but could help with bleeding air out and preventing steam holes.

Adding the Cross over coolant in the back will help the rear cylinders to run cooler but might not help over all temps.

You do not need a thermostat.

[340Cuda]

My son runs a 418 cubic inch small block R1 Mopar with W2 heads, so all iron like yours, he also runs a 4.10 rear gear. This year will be his seventh year as a participant at Hot Rod's Drag Week, I think the second year with this exact setup. In 2018 he placed third in Street Machine Eliminator. He started with a 360 with a four barrel so the car has evolved a lot.

He does run hoses from the rear water ports on the heads to the thermostat housing. No thermostat and a Meziere 35 GPH pump. He controls the water pump and the fans with his ECU (Megasquirt). Historically he has run dual fans adapted from I think a Dodge Intrepid. This year he plans to run a new Delta Pag brushless fan.

It has a tunnel ram with EFI and probably is around 600 HP.

In the past no real cooling issues except on the interstate highways, worse behind semi's. Even in this case I can't remember a problem with it boiling over, just getting over 200.

He is hoping that the higher CFM of this fan will help.

He has an off brand aluminum radiator that does not fit flush with the radiator core that may allow air to escape over the radiator that otherwise would go through it.

He does use the ECU / CNP ignition to run a lot of advance under low load conditions.

Probably more than you or anyone else wanted to know but perhaps this will trigger some thought on your part.

Bill

[DailyDriverSst]

Originally Posted by 340Cuda

My son runs a 418 cubic inch small block R1 Mopar with W2 heads, so all iron like yours, he also runs a 4.10 rear gear. This year will be his seventh year as a participant at Hot Rod's Drag Week, I think the second year with this exact setup. In 2018 he placed third in Street Machine Eliminator. He started with a 360 with a four barrel so the car has evolved a lot.

He does run hoses from the rear water ports on the heads to the thermostat housing. No thermostat and a Meziere 35 GPH pump. He controls the water pump and the fans with his ECU (Megasquirt). Historically he has run dual fans adapted from I think a Dodge Intrepid. This year he plans to run a new Delta Pag brushless fan.

It has a tunnel ram with EFI and probably is around 600 HP.

In the past no real cooling issues except on the interstate highways, worse behind semi's. Even in this case I can't remember a problem with it boiling over, just getting over 200.

He is hoping that the higher CFM of this fan will help.

He has an off brand aluminum radiator that does not fit flush with the radiator core that may allow air to escape over the radiator that otherwise would go through it.

He does use the ECU / CNP ignition to run a lot of advance under low load conditions.

Probably more than you or anyone else wanted to know but perhaps this will trigger some thought on your part.

Bill

I think the big issue is that my block is half filled. It's a stock magnum block, not an R1 or R3. I'm asking alot out of it to hold 12psi of boost with the factory ECU and pump gas.

I'd like to see how the rear steam vents are plumbed to clear the distributor - driver side looks tight. I'm thinking 45* 1/4 NPT to 4AN, then a 90* hose end? Granted he would just have a plug in the distributor hole, so it might not matter.

Going to hit Summit tomorrow. Davies Craig 115 pump came in yesterday, I already have a good idea of where it's going. Going to get an oil cooler and remote filter kit, put the cooler under the oil pan and oil filter hanging off the passenger motor mount. Also going to de-plumb the heater core and factory bypass hose, so that the radiator is the only path for water to flow. I'm keeping the mechanical pump, but will be able to turn the EWP on as-needed.

I'm just not sure if I should run no thermostat, or de-core it to act as a 1.25" restrictor. I'm leaning towards the latter.

[Hacksaw]

My vote is try the restrictor. Need to slow the coolant flow down, give the rad time to cool it.