1/2 fill vs tall fill

[Nightingale]

Okay so I have been in the process of rebuilding my lz9 thats going into my beretta. So far I have custom wiseco pistons(thermal coated tops), narrowed carillo h-beams, crank is being offset ground to fit rods(sbc big journal 2.100"), radiator fan is going to be upgraded to high flow type,arp head studs, main studs,and a double roller timing chain from TCE along with cam sleeves for gen 3 cam just to name a few mods to the engine. I am concerned with the power levels I am eventually going to push that the blocks integrity could be compromised. If this was just a v8 build I would get another block, but kinda stuck if I want to stay with the v6 platform. So I am going to be filling the block. First problem is there aren't any freeze plugs other than whats in the heads so I was planning to fill to the bottom of the block heater plug that is found on this block. This would amount to about 1.75" and the water jackets are just a tick over 5 inches. Now the other option is to fill to the bottom of the water pump holes on the block. This would be about 3.5" or so roughly, and leave 1.5" at the top of the cylinder walls to be cooled. Reason I am even considering filling that high is that this engine has piston squirters that will provide lots of oil cooling capability on the cylinder walls. I already have purchased a rather large 6 pass perma cool oil cooler(might need a t-stat so it can warm up), and will be adding a remote mount filter setup with dual wix 51522 filters. Along with running a full synthetic oil this should allow for good cooling overall.

Okay so now that I have given a brief overview(LOL), I would appreciate any constructive criticism. I've already talked to the machinest, and he doesn't think a short fill would be a concern other than checking coolant to make sure the filler isn't gunking up the water pump(leading to its death). Then I also checked around the net, and found various threads about guys having success with both short and tall fills on the street as long as cooling systems areup to snuff. I should also mention this will be mainly track use, and only short drives on the street on the weekends that may add up to less the 2000-3000 miles a year.

[bszopi]

Not sure why you are concerned with block integrity. I have never heard of any block issues on any of these engines, and many of them are pushing high HP numbers. The driveline components with fail way before the block will.

[geoffinbc]

I would agree. I would be more inclined to use a bottom end stud girdle instead of block filler. Keeping a consistent temp in the block and heads will help keep thermal expansion even and keep the bores round.

[Nightingale]

Just being over cautious I guess. I have a good chunk of cash invested in this motor so far, and I don't want to cut corners at the same time don't want to spend too much more(block filler being a cheap fix). I am already aware of the driveline problems, and I am already planning in the future to swap to a rwd setup( either backhalf the beretta or pickup an f-body) if/when the f40 transmission fails or I break too many axles(pretty much guaranteed).

[geoffinbc]

Well I guess it comes down to your concerns. Block rigidity or cooling. I myself would be concerned with even cooling.

It is the same debate as siamesed cylinders. On one hand you get a big bore and in turn more power. But the other half of the story is cylinder wall distortion. A lot of the distortion problems are over come by hot honing with a torque plate. Maybe you could take a similar route with your block filler

[Nightingale]

so essentially just warming the block up,filling, and keeping the block warm whilst curing? I've already torqued down one cylinder head, and the main caps.

[geoffinbc]

No the process involves honing the block with a torque plate while hot water (90*C to 100*C) is pumped through the cooling passages in the block. Not sure if you will find a shop to do this on our blocks since I bet no one has a torque plate for it. This process hones the cylinder walls round while all the stresses are applied to the block. So in theory when the engine is operating at temperature the bores will be perfectly round.

Maybe your right about the piston squirter's. Perhaps they will provide the necessary cooling for the cylinder area that is not surrounded by coolant. But your getting into experimental areas with the power you want to make along with the block filler. So anything you plan to do is speculation and is only going to work if you made the right call.

I know you want to keep this on a budget. So hot honing at this point may be out of the question. I would be inclined to leave the block like brad said originally. Until someone finds the next weak point in these engines there is no telling what kind of power it will take. I have been on this board quite a while and so far there are no horror stories with any engine that was built properly. There were certainly no broken cranks or blocks in any of the builds I can think of. The only stories I recall are burnt pistons, smashed valves and broken cams. So I say leave well enough alone.

[34blazer]

how much power are you trying to extract from your build? if its anything below 600hp at the crank i highly doubt you will split open a cylinder wall. i wouldnt compromise the cooling system either by filling unless you only plan to run it at the strip. $0.02

[Nightingale]

Exactly, this while engine build is really just an experiment considering I am only one of 4 who is working with these engines (CNC, Joseph,and mrtohil). I don't see the harm in the short fill so I think I will go that route just to ease my mind. If it causes problems....well then we know not to fill these blocks. I guess someone has to try it...eh?(hopefully not famous last words). Worst outcome I can see is overheating issues, which could probably be overcome by switching to a cooler burning fuel like e85. I was planning to fiddle with e85 anyhow since this will be a turbocharged engine, but then again it isn't readily availible around my area.

Planned power levels....Well I can have a clutch built to handle 550hp(guaranteed) after that I am running that on borrowed time. The F40 is an unknown, but I've heard rumors of a saab making 700hp+ on an F40(might have been modified). Axles another problem to overcome. I think for the time being I will probably have to limit myself between 500-600hp, but eventually I want to make a stab at taking down Tim King's 3800, which made somewhere north of 800hp.

[Nightingale]

Well the deed is done. The block has been filled with the heads and mains torqued down. Vibrating everything smooth, now just to wait. This is going to be quite the experiment, and hopefully betterthanyou won't have to pull out the good ole "I told you so". This is the oil cooler I am going to be running on the engine http://store.summitracing.com/partde...5&autoview=sku along with a dual remote oil filter setup. Should have about 7qt oil capacity.

[montess408]

so did you go half or all the way ??

[Nightingale]

Tall fill, slightly below water pump holes, which leaves close to 2" of cylinder wall exposed to coolant where most of the heat is anyhow. This is all experimental on this engine so I have no idea if it will be streetable at all, which isn't a big deal since its basically just going to be a race car anyhow. I plan to keep a close eye on all temperates especially oil temperature once I get this engine finished and running. Thinking june or july for engine installation into the car.

[34blazer]

in for pics of the procedure

[MidnightriderZ24]

filling a block partially will not help. ive asked many drag racers that work on top ihra drag cars. full or nothing from wat im told.

[Nightingale]

The overall process wasn't hard, but getting the mix the right consistency was. Too thin and you will lose strength, too thick and it won't work through the passages. I used a long stick to help even it out, and remove air pockets. Then, followed up with some sharp blows with a mallet, Lastly, used an orbital sander as a vibrator to get out the tiny air bubbles in the mix. I will try and snap some pics when I do the other side today. This should leave a couple weeks for cure time, and hopefully the rest of the machine work can be done by spring break (March 22nd-29th). Then I can finish assembling the block.


I have heard partial fill will dampen some engine harmonics, and give a slight strength increase to bottom end, but ya for cylinder support its all or nothing for the most part.