Highest compression festiva award

[bhearts]

Zephthechef and I just split a purchase on a nice face mill. Technically I haven't paid him, in case he's reading this, but I will this weekend. Im going to shave some face, either the head and or the block for some better squish. Here in Wichita ks we have 4 gas stations with e85, and methanol is just a two hour drive to Oklahoma city. So I'm contemplating e85 with water methanol injection to control the knock, so let's not worry about tuning or fuel. So what if I have to bring 10 gallons of e85 with me on road trips, right? That added squish should net a couple extra mpg points over factory compression numbers. Lots of articles say there is no magic CR number limit, because all combustion chambers have different designs. How extreme should I take it. I'm thinking .010 from the block, and 30 from the head. Anybody have any smart comments to add. I'm willing to Pioneer this with my build, no expenses spared. Except I'm running factory pistons. Lol. Sorry to hurt your feelings.

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[FestYboy]

Well for fitment, with the numbers you're talking, dry fit the engine WITHOUT the head gasket. Use putty and cycle the crank. That will give you an idea of what clearance you'll have after the milling.

[skeeters_keeper]

B3? Factory HG?
Adjustable cam sprocket to help fix valve timing?

[bhearts]

B3? Factory HG?
Adjustable cam sprocket to help fix valve timing?

B6d, turbo. No idea which head gasket yet

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[shorestiva]

zm engines use a mls head gasket and are thinner than the b series gasket

[sc72]

Does anyone know what the valve to piston clearance is for a stock b3, right now I do not have any spare b3's laying around or I would do the test myself, my question is, how much can we shave off the head and still have non interference if the timing belt breaks.

[Greywolf]

How high RPM do you plan to run, and with what springs?

Another way to go about it is measure the valve movement, and duplicate it with the head off to see exactly where the valves are in relation to the deck surface of the cylinder head.

You can then use a straightedge with a piston at TDC to see what kind of clearance you have.

The springs will determine how much valve travel you may have at high RPM, but I'm not sure where to look for that info. The stiffer the valve springs are, the less "BOING" over the rocker or cam follower travel you'll have. But what the gap is, plus a safety margin, I don't have the info right now.

CAM lobe shape can also have an impact (no pun intended). The steeper the ramp on the leading edge, the greater the "BOING" factor.



Myagi say: "NO break timing belt. (Oy...)"

[bhearts]

factory springs, factory cams, factory rpm, 6-7k.

[blowby]

So can water injection control any and all detonation ?

[Advancedynamix]

You won't be able to assemble a b6d without the head gasket and crank it. The head gasket is what gives you your squish clearance. This being said, be cautious of decking the block too far with stock pistons unless you also shave the pistons. One other problem with this expirament is that when you move the valve guides closer to the pistons you've now changed the geometry of the valve opening compared to the piston. Your valve pockets will not only have to be deeper, but also placed out further on the pistons (remember that valves don't come straight down, and your altering the start point of their travel.)
This is why custom pistons are used in engines that are built like your trying to build yours. Drastically altering the dimension of any component will result in the need for drastically altering the dimensions on another component.
Furthermore, you would be much better off with lower compression numbers (say 10:1) and more boost pressure. CCV is an advantage under boost because it (combined with the added air pressure) is what works to effectively raise the dynamic displacement of your engine. In short; bigger hole to fill=more air charge to burn.

[bhearts]

So can water injection control any and all detonation ?

Yes, but water droplet sizing and puddling is a seriously big concern. For low rpm water injection, a really fine misting nozzle is ideal, and as close to the valve as possible. If the water puddles and makes it into the engine as drops of water instead of a mist, you'll have problems. I would never use pure water spray, because methanol and water at 50/50 has proven to be the best at suppression of knock.

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