Filled block on the street?

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grimreaper

grimreaper

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Anybody running a filled or partially filled block on their street car? A couple of my Ford branded friends are running filled blocks and having good luck with them for street cars. One has an external oil cooler, the other doesn't. Are there any Mopar guys on here with experience with filled blocks?
 
JMO, but if you feel you need filler, you really need a better block. Unless the rules mandate what you have to use just get a better block. If you have to run it, use up to a 1/2 fill and run an engine oil temp gage and cooler.
 
I would make sure that's what you really want to do before doing it.

There was a thread on here in the past week where a guy is asking how to get that crap out of his block as he's having overheating issues...

Many cars of this vintage have overheating issues when cruising on the street over 90° F, I think that taking some of the cooling capacity out would make it worse...
 
We had a 408 that was half filled it would run hot all the time on the street. I wouldn't do it if the car is going to be more street then race. Wasn't any fun having to wait around for the car to cool down before u could drive again.
 
If you have a partially filled block and it overheats it is a COOLING SYSTEM ISSUE and NOT a block filler issue. I have run blocks on the street that were filled to the bottom of the water pump holes and they never over heat. I always run 8 quarts of oil.

Since about 2003 I stopped doing full fills on 99% of anything because during testing we found that the extra filler didn't really add any strength that WE could prove and decided the weight trade off was not worth it.

We fill EVERYTHING we can. It's 100% BULL DURHAM that even "race" blocks can't benefit from filler.
 
In discussing the filled block question with a guy I have known for years, I just discovered that he short filled his Pontiac engine several years ago. He drives in on cruises and poker runs all of the time. He drove it to Denver, a 350 mile trip, to race at Bandimere with some of his buddies and back in the middle of summer. Claims there is no issue with cooling but he does run a modern GM oil cooler. This surprised me because the first I'd heard of running fill on the street was the two Mustangs previously mentioned.
 
grimreaper said:
In discussing the filled block question with a guy I have known for years, I just discovered that he short filled his Pontiac engine several years ago. He drives in on cruises and poker runs all of the time. He drove it to Denver, a 350 mile trip, to race at Bandimere with some of his buddies and back in the middle of summer. Claims there is no issue with cooling but he does run a modern GM oil cooler. This surprised me because the first I'd heard of running fill on the street was the two Mustangs previously mentioned.
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More people than you think are still filling blocks

Rather than deal with internet bullies about it, we just fill them and don't say much.

Filling blocks is NOT rocket science. But one guy will fill and have issues totally unrelated and blame it on the filler.

For example (just to get you thinking about coolant, where the heat is in a cooling system etc) why do some circle track engines use an "open top" design? When you grasp that, it will start to make sense about where the heat is in a cylinder block.
 
Ya, I know the heat is in the top end and I'm guessing that water at the bottom of the block is pretty much not moving anyway from the amount of silty accumulation I've seen in some blocks.

Mad, what product do you fill with?
 
I just tore down a 1/2 filed hard blocked 340 with 20000. miles and a spun rod and scufed bearings, the cooling sistem was 3core radiator all the shrouds and dames in place. on the hiway the oil preshure would go just below the 10psi to 1000 rpm numbers. had stock pan. you could not cruzse above 70 mph with this car (3.23). temp was tied to the speadometer. I dont think i will do it again. if you must a large pan and oil cooler would be my choice.anyone want to buy a 30 over 340 with hard block half way up.
 
grimreaper said:
Ya, I know the heat is in the top end and I'm guessing that water at the bottom of the block is pretty much not moving anyway from the amount of silty accumulation I've seen in some blocks.

Mad, what product do you fill with?
Click to expand...

You are pretty close in your thought process. The majority of the heat in ANY cylinder is the top 2 inches or so. If you have a 1/2 inch thick deck (or .750 with an X block or 1.0 with the R blocks) the very hottest part of the cylinder is solid. That's why they made open top blocks....upper cylinder cooling in long distance engines. There is very little heat in the bottom of the cylinders, so it's really wasted space. The factory COULD fill it with cast iron, but cost and weight make the bean counters lose their minds. But...you can fill up the space.

I use Hard Block about 90% of the time. I have used Moroso the rest. Never had issues with either. I am 100% sure of this because I have cut up several blocks (of the 3 major brands) that were filled and used up and never had any seperation or any other issues.
 
cudaman51 said:
I just tore down a 1/2 filed hard blocked 340 with 20000. miles and a spun rod and scufed bearings, the cooling sistem was 3core radiator all the shrouds and dames in place. on the hiway the oil preshure would go just below the 10psi to 1000 rpm numbers. had stock pan. you could not cruzse above 70 mph with this car (3.23). temp was tied to the speadometer. I dont think i will do it again. if you must a large pan and oil cooler would be my choice.anyone want to buy a 30 over 340 with hard block half way up.
Click to expand...



OK lets look at this post. I obviously left some things out I shouldn't have, and will point out some other things.

1. NEVER EVER use a stock pan with a filled block. EVER. I always use at least 8 quarts. You can't cool an engine with 4 quarts in the pan. The oil spends too much time in the engine. Mistake number 1.

2. A 3 core radiator means little. Fin count, tube diameter, multiple pass etc. all make a difference. You damn sure should have had an 8 blade water pump, preferably the Milodon part number, which has the back of the impeller closed off. You'd be surprised what closing off the back of the impeller does for water flow, and FLOW is everything.

3. Since I do this for a living I don't always give all the details I probably should. If you fill the block and don't want to run 8 quarts of oil you either MUST run 20w50 oil (or even 20w60 or better yet, Torco makes a 10w60 that would be perfect) or you MUST close up bearing clearances. A scuffed bearing or a spun bearing only happens because of lack of oil.

4. You MUST also increase piston to wall clearance. The cylinders flex less and grow less so clearance must be opened up.

If you follow simple rules you can fill a block and GAIN HP. But you can't skimp. If you do, it will cost you in spades.
 
I had a 360 filled it ran fine at 55 with 391 rear, However if you stopped at two redlights it went to 240 pretty fast from 190 and took a while to cool down. I would not do it again get another motor. However if it was race only You could get away with it. That's my two cents.
 
madscientist said:
You are pretty close in your thought process. The majority of the heat in ANY cylinder is the top 2 inches or so. If you have a 1/2 inch thick deck (or .750 with an X block or 1.0 with the R blocks) the very hottest part of the cylinder is solid. That's why they made open top blocks....upper cylinder cooling in long distance engines. There is very little heat in the bottom of the cylinders, so it's really wasted space. The factory COULD fill it with cast iron, but cost and weight make the bean counters lose their minds. But...you can fill up the space.

I use Hard Block about 90% of the time. I have used Moroso the rest. Never had issues with either. I am 100% sure of this because I have cut up several blocks (of the 3 major brands) that were filled and used up and never had any seperation or any other issues.
Click to expand...

madscientist said:
OK lets look at this post. I obviously left some things out I shouldn't have, and will point out some other things.

1. NEVER EVER use a stock pan with a filled block. EVER. I always use at least 8 quarts. You can't cool an engine with 4 quarts in the pan. The oil spends too much time in the engine. Mistake number 1.

2. A 3 core radiator means little. Fin count, tube diameter, multiple pass etc. all make a difference. You damn sure should have had an 8 blade water pump, preferably the Milodon part number, which has the back of the impeller closed off. You'd be surprised what closing off the back of the impeller does for water flow, and FLOW is everything.

3. Since I do this for a living I don't always give all the details I probably should. If you fill the block and don't want to run 8 quarts of oil you either MUST run 20w50 oil (or even 20w60 or better yet, Torco makes a 10w60 that would be perfect) or you MUST close up bearing clearances. A scuffed bearing or a spun bearing only happens because of lack of oil.

4. You MUST also increase piston to wall clearance. The cylinders flex less and grow less so clearance must be opened up.

If you follow simple rules you can fill a block and GAIN HP. But you can't skimp. If you do, it will cost you in spades.
Click to expand...


This is good stuff! Thanks MadScientist, truly living up to the name.
 
tekslk said:
I had a 360 filled it ran fine at 55 with 391 rear, However if you stopped at two redlights it went to 240 pretty fast from 190 and took a while to cool down. I would not do it again get another motor. However if it was race only You could get away with it. That's my two cents.
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I would say the fans were inadequate if it ran fine at speed.
 
EXcappa said:
I would say the fans were inadequate if it ran fine at speed.
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Agreed. Any time you run hot at slow speeds and it cools down at high speeds the problem is a lack of low speed air flow. If your running underdrive pulleys that can also contribute to the problem cause it slows down coolant flow
 
cudaman51 said:
I just tore down a 1/2 filed hard blocked 340 with 20000. miles and a spun rod and scufed bearings, the cooling sistem was 3core radiator all the shrouds and dames in place. on the hiway the oil preshure would go just below the 10psi to 1000 rpm numbers. had stock pan. you could not cruzse above 70 mph with this car (3.23). temp was tied to the speadometer. I dont think i will do it again. if you must a large pan and oil cooler would be my choice.anyone want to buy a 30 over 340 with hard block half way up.
Click to expand...

If your serious...... then yes I know someone.

I fill EVERY stock block that I build. Mild to wild. 300 to 700+hp. Just like it is mentioned above I also build small mopars and get paid for it. Never had a problem and damm sure never over heated. Common sense comes into play here if its over heating you have a cooling problem. That problem comes from two places, engine oil, and coolant. Make them bigger via more capacity and you will be fine.
 
Plenty of perfect examples of why block filling gets a bad name, when the reality is just poor cooling management..
 
fishy68 said:
Agreed. Any time you run hot at slow speeds and it cools down at high speeds the problem is a lack of low speed air flow. If your running underdrive pulleys that can also contribute to the problem cause it slows down coolant flow
Click to expand...

Part of engine cooling is to direct the air THROUGH the radiator, not AROUND IT...

Shroud is important. When set up properly, the shroud directs and helps the fan PULL the air through the radiator. You have to seal the gaps so the air does not go around the radiator, but through it.

Another part of the shroud set up is how much overlap the fan and shroud have. One design spec for engine cooling is called FOOS (Fan Out Of Shroud). If the fan is too deep or too shallow into the shroud, it looses some of it's efficiency. Start at 50% FOOS (half the depth of the fan is overlapped by the shroud) and go from there. Usually you don't want more than 20% either side of halfway in at the most (30% to 70%)...

Consider the shroud as a funnel to direct the air through the radiator and fan...
 
krazykuda said:
Part of engine cooling is to direct the air THROUGH the radiator, not AROUND IT...

Shroud is important. When set up properly, the shroud directs and helps the fan PULL the air through the radiator. You have to seal the gaps so the air does not go around the radiator, but through it.

Another part of the shroud set up is how much overlap the fan and shroud have. One design spec for engine cooling is called FOOS (Fan Out Of Shroud). If the fan is too deep or too shallow into the shroud, it looses some of it's efficiency. Start at 50% FOOS (half the depth of the fan is overlapped by the shroud) and go from there. Usually you don't want more than 20% either side of halfway in at the most (30% to 70%)...

Consider the shroud as a funnel to direct the air through the radiator and fan...
Click to expand...

This is 100% correct.

I forget to mention stuff like this because:

1. This information has been out there for DECADES and is more accessable than ever.

2. You can pick up the phone and talk with a dozen different manufacturers on the phone about YOUR specific issues. If you give them straight poop they can almost always fix an issue for you.

Thanks for postings this often forgotten info.


BTW...if you want to see what works...look at a STOCK, UNMODIFIED MoPar fan/shroud/radiator. They OEM system is bullet proof but not idiot proof. I've seen guys break a bowling ball in a sand box without tools.
 
This is a good thread. So i can use my 1/2 filled block without a problem. just buy a 8 quart pan and oil cooler. whats a good pan for an a body.
 
madscientist said:
OK lets look at this post. I obviously left some things out I shouldn't have, and will point out some other things.

1. NEVER EVER use a stock pan with a filled block. EVER. I always use at least 8 quarts. You can't cool an engine with 4 quarts in the pan. The oil spends too much time in the engine. Mistake number 1.

2. A 3 core radiator means little. Fin count, tube diameter, multiple pass etc. all make a difference. You damn sure should have had an 8 blade water pump, preferably the Milodon part number, which has the back of the impeller closed off. You'd be surprised what closing off the back of the impeller does for water flow, and FLOW is everything.

3. Since I do this for a living I don't always give all the details I probably should. If you fill the block and don't want to run 8 quarts of oil you either MUST run 20w50 oil (or even 20w60 or better yet, Torco makes a 10w60 that would be perfect) or you MUST close up bearing clearances. A scuffed bearing or a spun bearing only happens because of lack of oil.

4. You MUST also increase piston to wall clearance. The cylinders flex less and grow less so clearance must be opened up.

If you follow simple rules you can fill a block and GAIN HP. But you can't skimp. If you do, it will cost you in spades.
Click to expand...

a few months ago i detonated a piston when the water meth failed on the dyno. the bore was not hurt at all. i have since filled the block to 1" below the inlet holes with Moroso fill. i run a 8qt pan. block is +.040" and was hoping not to rebore. won't now until it goes back to machine shop and see if fill has moved anything.
you mention in ya post that filled blocks should have more piston/wall clearance. how much more are we talking. this could be beneficial to me.
this is a 410 sbm withe s475 turbo.

i also suffered low speed cooling issues. just had 16" electric fan direct onto rad, no shroud. looking at doing twin 12" fans with shroud.
any rule of thumb for shrouds and electric fans.
cheers

BTW great thread, good info
 
My .030 over 318 was filled to top of soft plugs by the previous owner and it runs hot any time I'm not moving 35+ mph. I have a 8qt pan and have tried several different water pump/fan combos, including mechanical and electric of each. No matter, it always creeps to +/- 220 in traffic, 190 moving down the road.
 
GT451 said:
My .030 over 318 was filled to top of soft plugs by the previous owner and it runs hot any time I'm not moving 35+ mph. I have a 8qt pan and have tried several different water pump/fan combos, including mechanical and electric of each. No matter, it always creeps to +/- 220 in traffic, 190 moving down the road.
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Like a few guys just said a low-speed cooling issue is due to bad airflow through the radiator and/or coolant flow. If the engine was putting out too much heat in general it would run hot no matter what. Put a nice big electric fan like one off a modern sedan mounted with a shroud and a couple inches back from the radiator with the shroud sealed all the way around the best you can. If you do pull a fan off a junkyard newer car for instance try to recreate the setup that was in that car, modern cars make TONS of heat and engineers spend lots of time and money figuring out how to squeeze air through those tight-packed engine bays.

FWIW the big factory Mopar viscous-drive fan and shroud setup is tough to beat I have a 10.5:1 360 that only gets up around 200* if I'm stuck in traffic on a sunny 100* day, and that's with a 180* thermostat which actually puts MORE strain on the cooling system.
 
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