[OddRodder]

I know many drag racers that run block fill in their engines, and I know all about the added strength that comes along with it! One racer that I know has a 400 with a tall fill running alcohol with no cooling system at all! This engine has a cracked main web and has ran 8.40's (in the 1000) for two years now! He said he may change it out before this season starts (may not!) To the point, all of the performance street engines that I have built have needed all of the cooling system capacity available (and then some!). Does anyone run block fill on the streets without cooling problems?? Have you cruised around on 100 deg. afternoons in stop and go traffic and not overheated?? With a TALL fill?? HOW??This thread is in no way meant to disspell anything another member has said, it is solely for information that I or others may be able to use to our advantage!! Thanks Odd....

[lluciano77]

For all that trouble you might as well just get an aftermarket block. Why risk cooling issues with a stock casting?

[dawg]

block filling will not work on the street period!
keep im mind a drag car is only running no more that 5 mins at a time.
driving a car on the street with blocked passages will cause it to overheat and warp the heads etc.
youll probly get 3 miles before engine quits.

[OddRodder]

That was my opinion also! But, I have heard people on this site elude to the fact that they ARE running block fill in street engines. Thought someone might know something that you or I didn't!

[redsdad]

They probably aren't filling the block up past the bottom of the freeze plug holes. The idea is that most of the heat is created in the top of the cylinder. The exhaust valve opens prior to the piston reaching bdc, cooling the cylinder even more. The piston also does not go so low in the bore as to expose the bottom of the water jacket to the combustion heat (or if it does you have bigger problems to worry about). Filling just the bottom of the jacket stiffens the bottom end and effectively shortens the cylinder length, aiding in the cylinder maintaining roundness.

On the donw side, you reduce the volume of coolent in the jacket at any one time. So you must change it out more frequently, if the radiator can not release heat to the atmosphere fast enough to sufficiently cool it prior to the next change out of liquid with the block, the next cycle will be shorter still, ultimately leading to an overheated condition.

Bottom line, I think it can be done. You just have to realize that all of the cooling components must be up to the task. Little or no scale on the inside of the cylinder and head jackets, proper thermostat to allow the radiator time to release heat to the atmosphere, efficient water pump, proper capacity radiator, sufficient air flow through radiator.

[OddRodder]

Thanks, that is the kind of information that I was looking for! Up to this point, I have always been afraid of reducing the cooling system capacity on any hi-po street engine, but if others are able to run a given amount of fill , I would like to know...how much.....h.p. range......other cooling improvements...etc...etc...

[bracketeer]

Block fill is drag race only. The fill takes much longer to heat than water. It also takes longer to cool down. Most dragsters do not use a rad or water pump. The block and heads hold appx one gallon of water. As soon as the car makes its run. The water is dumped out to allow the block and fill to cool faster. When possible the block is back washed with cool water from the thermo housing down. Putting cold water in through the water pump ports would crack the cylinder skirts.

[1BAD80]

This has been discussed before.

http://hotrodders.com/t50607-15--427%20sbc--2.html

[OddRodder]

I respect your knowledge and your input 1BAD80. So how much block fill would you suggest in a street engine that was pushing the limits of the factory block?

[Rick WI]

You can short fill on the street with no problems. We have done this many times over the years.

If you always have trouble with cooling it's not the cooling design of the block it's something else, radiator, fan shroud, pump. I run 700 HP on the street with a Stewart pump, Be Cool radiator, stock 70 Camaro shroud, and a stock 7 blade clutch fan. Rock solid 180 temps under all conditions.

[Matts99Sierra]

Originally posted by 1BAD80
This has been discussed before.

http://hotrodders.com/t50607-15--427%20sbc--2.html

seems to me with all the threads that have been posted almost everything has been discussed. (no flame intended 1BAD80)

[1BAD80]

To answer OddRodder's question, it is put to the bottom of the freeze plug's.

Rick WI hit on the other spot's, especially cooling it's all been said before plus sites & Info on the subject in are in the Knowledge Base, and do a Search This Site at the bottom of the main page and it will bring up every posting, if you want to read to allot.

[TurboS10]

Another issue is oil heat. The oil is not able to reject heat through the block to the water when the block is filled. I run my S-10 on the street with a tall fill. The old radiator did let it get a little warm, but no real issues because I never went far from home. I noticed that heat seems to build and it gets hotter and hotter. I just parked it with the fans running and it would cool down in 10 minutes. I just got a new big radiator for it so I think all will be fine now. I also just installed an oil temp gauge so I can monitor that to see if it creeps up. I will know something soon. I hope to break in the cam tomorrow.

Chris

[Matts99Sierra]

isnt block filler when you fill all the water jackets with that concrete crap to add strength to the block??? or am i mistaken? and if thats true then how in gods name can you run it on the street without burning up the engine and welding the pistons to the cylinder walls??? just a question. if im wrong then by all means correct me...

[TurboS10]

Yes, it is that concrete crap for engine strength. The engine is also cooled by the oil which transfers heat to the water through the block to the water. You can curb the obvious heat problem with a good oil cooler and a dedicated fan like I mentioned earlier. That is what keeps the pistons and rotating parts cool. Combustion heat is mainly in the heads and top inch or so of the cylinders which is not filled with hard block.

Chris