I have a half filled 428 block. I asked for a "half fill", but I think it's a bit more than that. When I have the water pump off it looks to be almost to the water pump holes. My machinist was telling me to fill up to the water pump holes, but I was too chicken. Maybe he did it anyway?
I have a big oil cooler under the fender and a replacement factory big block 3 core radiator and it does pretty good. With a 180 degree thermostat it runs 180-185 if the outside temp is 80 degrees or less. When the temp outside is 90-100 it runs a little hotter, maybe up to 195 degrees. At 100 plus going down the freeway with 4.11 gears, or in traffic, I've seen it get up to 205 degrees. It will then cool down at less than freeway speeds or once I get out of traffic. I've driven as far as 40 miles in 100+ degrees with no trouble. I'm not sure I'd go cross country in the heat though.
one thing worth mentioning on a filled block, is that the oil temps will increase... and typically, the water will run cool. Reason being that there is less water (capacity) to cool in the system. An oil cooler would be a good addition, and an oil temp gauge to monitor the oil temperature. The bottom of the block isn't being cooled by water now, so the oil in the crankcase will get hotter and hotter with extended use.
A short fill or half fill as some call it, would be OK in a street car, but not a full fill. The cylinders are about 6" tall. The bottom of the water pump holes where a lot of people do fill up to, is about 3 1/4 inches or so. You can't get much higher, maybe another 1/2 inch with tape over the hole while filling, then before it sets totally, use your finger to slope it down to the hole entry. A short fill would be about half-way up into the freeze plugs, maybe about 1 3/4 or 2 inches. This stabilizes the bottom of the cylinders and the block itself, and is worth doing on a street and strip type car that will see high RPM and race abuse.
On 427 blocks, the parting line on the cylinder core molds are at the bottom, around an inch+ or so. On 390-428 blocks, the parting line is reversed... at the top. This is where core shift can be the worst. Also filled blocks control harmonics better.
The good block fillers will expand and contract nearly the same as cast iron... but not quite. You will need more skirt clearance as well as larger ring gaps because of the REDUCED clearance, once hot. So basically the filled block (cylinders) will not expand as much as a non filled block.
These are my opinions and may not be 100%, use at your own risk. I didn't stay at a Holiday Inn last night...
68 Cougar XR7 street and strip car, 428 4-speed, 3560# of fun, best firstname.lastname@example.org email@example.com 1.43 60 ft
I'm with these guy's .... mines 1/2 fill , runs a little hot with the 5K stall auto , 205 and higher , with the 4 speed and Mezerie pump the hottest this summer was 198 on short 20 mile one way trips with out oil cooler , I'm going to follow Paulie's lead and mount a oil cooler in the left fender under my ram-air clearence panel and keep it away from the radiator , I think the oil cooler will be the final answer ... I did added a surge tank to get a quart or so of extra coolant , my total capacity is now 1.5 gallons .... thought of installing the heater core for extra cooling capacity but I think the oil cooler is the real answer
XR7 - those are not opinions - they can be consired as facts
August 18 2012, 4:21 AM
I completely agree with everything you said. We've done several 427s with about 2" of fill because of the thin spot in the bores was just off the floor. And as far as I know they all worked pretty well.
Surprising no one mentioned reduced piston cooling from filling a block
August 18 2012, 7:12 AM
The #1 way a piston disapates heat by transfering it to the cylinder walls. It's wll known hyper pistons have poor conductivity in the alum so their domes run hotter. The one main thing that's going to run hotter in a filled block is the piston, everything else is just from water temp to oil temp is just like a tip of the iceberg, only symptoms thay poorly indicates the heat the pistons are dealing with. Ironically the area of the cyl where the vast majority of heat is most removed from a piston is lower in the bore conversely the top of the bore is subjected to the most heat due to compression and the power stroke. Kind of interesting that the last thing a filled blocks owner can monitor is the pistons temp. I have to wonder IF filled blocks pistons are not running hot as hell and the owners don't know. Someone mentioned filling a marine block, I can only cringe. Marine motors are virtually the opposite of a drag motor that sees full power and bursts of rpm through the powerband - not at all like a marine motor that is pinned wide open and fully loaded for sustained periods which generates enormous heat. Anyone that watches NASCAR has seen motors overheated to hell blowing steam being run until they melt. But then again THEY DO manage to go for several laps while doing so. Obviously Syn Oil plays a part. I take this as an indicator of how hot pistons can be run.
My FoMoCo Industrial friend told me it was a given that many marine motor warranty claims were determined to have failed by build-up of mud,silt,sand in the water jackets. You guys know my filter knowledge so I can say a stream of fast moving water carrying mud,silt,sand that flows into a cavern or still water chamber such as the water jackets around the cyls will precipatate that mud, silt, sand very well to the bottom of the jacket in effect like hard block. Interestingly FoMoCo stated overheating in the mains from the water jackets bottoms being an area failure.
In the least it's wise to keep in mind that hard-block will will compromise the cooling, your running blind d to piston temp and endurance engines are unlike drag race engines when it comes to cooling.
It is astounding how much filling effects the oil temp and bores
August 18 2012, 7:57 AM
A torque plate hone is mandatory, and preferably after being heated in an oven as close to running conditions as possible after a fill has set. Even filing the rings needs to wait until after the hone.
To me any type fill on the block makes an oil cooler mandatory. The temperature gradient between the top and bottom of the block from the oil being so hot and the top running so cool is a recipe for disaster. Even a street fill, I would double up in filters to get them away and put a cooler in the return feed to the block.
You only need one night with two rounds back to back to see how hot that oil gets on a full fill, and one 60 mile trip on the street fill with a gauge. I still have the cooler I ran on my truck, it just was to the bottom of the freeze plugs. 3.70's and turning a hair over 3000 on a highway run would tell you the story.
Re:"astounding how much filling effects the oil temp and bores " LOL then Insult-to-Injury
August 18 2012, 1:31 PM
the average racer will install a crank scaper, windage tray and change the lifter galley drains to limit oil splash in the crankcase....Not only that in FEs they likely will restrict the oil to the rocker shafts and plug up the lifter oil galleries for a solid cam. Except that oil splash is all that's left to cool the hot pistons!
It sure would be interesting to know how hot pistons get when run with a filled block but I guess that would tske major telemetry that no FEs ever going to see
rates? Which grows faster, the block or the grout?
I know this is done in street diesels engines without issues. Although diesels run much cooler than a IC engine around town. Under load I've seen the cast iron exhaust manifolds glow red of a diesel engine!
How much more strength would filling the block add to an already stout block, and if not what area would it prevent cracking/failure in the block.
Wonder if it's worthwhile in my marine application.....
Increasing water cooling can't hurt but it's the oild that fries. Nothing to cool the bottem end so it gets HOT and stays hot for a long time after. Serious amount of heat soak goes on there and nothing to remove it. I'd run a big oil cooler on any filled street engine and not worry about the water overheating since that's not the problem.
Substantial Piston heat is tranferred through the rings to the cylinder walls.
The balance of the heat runs into the pin, into the con rod, and then to the crank, main bearings and block, where it is captured by the water jackets.
Oil splash/throwoff from the crank, onto the rods and pistons, also cools the whole rotating assembly, plenty.
The heat load captured by the oil, is also transferred back to the water jackets, via the internal crankcase surface area, or removed by an external oil cooler. Water cooling is pretty important, overall.
A half fill, will still allow quite a bit of piston heat to flow into the water jacket from the rings.
Oil throwoff/splash from the crank, keeps working the same, cooling the pistons, pins, rods, and crank and bearings; but the heat captured in the oil cannot be relieved as well via the crankcase cooling effect, due to the lower fill, insulating the block from the water, and heat transferred from the oil splash; and an oil cooler works well to help out.
A windage tray on a non filled block, will interfere drastically with the above, cooling process. It is FAR worse with a filled block.
With a windage tray, the oil is scraped off the throws, and down into the pan, making the rotating assembly automatically run somewhat hotter, due to decreased oil splash.
This heat still goes from the pisons,pins, rods, crank, main bearings into the block anyway, it just not captured by the oil splash as much. Water/radiator has to pickup the same amt of overall heat.
Oil should run cooler with a tray, but will actually run hotter, because it retains the heat it used to dump into the block by splash. Tray needs a cooler or bigger pan,or both.
Now with a fill and a tray, the need for a cooler goes up exponentially.
Fills are generally for drag racing.
On the street with a fill, the heat problems must be dealt with, via an oil cooler and maybe, a bigger radiator. Bill Ballinger tells it right.
Fills were not factory technology, but trays were.