alright. ima shave the head myself a little, and see how it goes. worse comes to worse, i buy a new head, or send that one to ken and get it chambered
Head Mod... Few Q's
- Thread starter Quadrider10
- Start date
Higher octane fuel withstands compression better because it takes more heat to ignite it. When fuel (any gas) is compressed it causes heat. Reducing the combustion chamber size (shaving the head) changes the compression ratio. Say your engine is 200cc and your compression chamber is 20cc, that's a 10 to 1 compression ratio (you're compressing 200cc of volume into a 20cc chamber). Think about a diesel engine, they run off detonation. Diesels don't use spark plugs but rather "glow plugs" that induce a little extra heat into the chamber so that the fuel explodes shortly before TDC. With rechambering a head it changes the way the combustion mix is moved, evens out heat inside and keeps hot spots from devolving. Rechambering is less about increasing compression and more about increasing burn efficiency. It works so well on a Blaster engine due to how badly it was designed.
ahh i get ya! i still have it chanbered by ken, but for the time being, and havig nothing to do till parts get in and cylinder get honed, ima do this. and thank guys! ill let u know how it goes!
Be sure to have a way of measuring it before you start. Once you start sanding, you can take more than you realize. If you are using something like 40 or 80 grit, aluminum cuts quick.
almost finished. just waiting on my 180 grit to get here, so i can take smooth it out a lot more, and polish the dome on the inside a little. i dident go all the way to the lip, but i took off a bit the gap from the lip to the top of the gasket surface is about half now. maybe a little less
Having a depth mic is the best way but assuming since you don't have calipers you also don't have a set of mic's. The best way I can think of with just stuff laying around would be a long bolt and nut. Lay the head down on your whatever you're using as your surface plate. Run the bolt through the plug hole til it touches the surface plate. Tighten the nut down til it touches the plug seat (it should be reasonably flat). Mark a line on the nut and bolt so you can see how much you turn it. Knowing the thread pitch you will be able to calculate how much of a turn is the amount you want to take off the head. When you set the nut to how much you want to take off and you get that much taken off the head the the bolt will touch the surface plate.
i just printed out a milimeter scale off google and made sure it was to scaleI:I
That's a better, simpler way and it never crossed my mind, lol.
lol i thought about it after i went through my entire tool box looking for somehting to measure it with hahah
I'm not being funny here...
But... have you thought of using a belt sander then finishing up with your other method?
A flat bastard file would also do the trick,Just file a little bit then rotate the head,then file,then rotate the head,so on ,and so forth.....then finish sanding the head like you planned.
But... have you thought of using a belt sander then finishing up with your other method?
A flat bastard file would also do the trick,Just file a little bit then rotate the head,then file,then rotate the head,so on ,and so forth.....then finish sanding the head like you planned.
Gotta give it to you young fella, not for choosing to shave your head, but for having the intestional fortitude to try it!
Cleaning up the surface with a bit of wet and dry abrasive paper, on a sheet of plate glass is one thing.
But taking off a mm or so, should not be attempted without a lathe or milling machine.
Now you have done it, you need to see if it is perfectly flat, otherwise it will leak.
Smear a film of dark coloured low, viscosity oil on the "machined" surface, and place on a sheet of plate glass, you will be able to see if it is flat by looking at the spread of oil accross the surface.
Well guys, I took over a mm (0.040") off Triplecrown's head in stages with nothing but an 8" Hand Bastard file (that is the real name!). Once along the way Neils had a leak between 2 head studs and I believe he glass sanded it to clean it up. I have a hard time believing there was a problem with my filing, but hey?
I am confident enough of my skills that I just rely on cross filing, which is filing lightly one direction, then going at it from 90 degrees to note your high and low spots. It takes some experience to get here so I'd recommend getting here with a thick sheet of glass to check your work.
So, you can put a sheet of sandpaper on the glass, probably no finer than 150 grit, I'd recommend 100. Finer finish is not always better. Also the wet&dry paper holds up better and can be used with a lube (water, oil, spray oil, kerosene, varsol) to keep it clean and cutting. You can fold the paper over the edges of a small glass plate, tape the edges, hold the edges with your fingers, or glue it on with thinned or spray on contact cement. Or you can use the glass with no sandpaper at all just to see the polished rub mark where the high points are. So you rub the head in a figure "8" pattern and then look to see where the high (polished) and low (untouched) areas are. You can cut the highs with a file or just keep going with the sandpaper.
It is my experience that 100 grit sandpaper is a lot of work (about an hour) to remove 0.010" or about 1/4 mm (0.25mm), whereas I can remove that much in 10 minutes with an 8" Hand Bastard file. A finer or shorter file takes longer and leaves a smoother finish. The smoothness grades of files are very smooth, smooth, second cut, bastard, and coarse (or rough) and very with the length of the file too. "Hand" means a rectangular shaped file with one toothless "safe" edge and a special very slightly raised secret cutting section at the 1/4 length.
As for the stock head, from what I saw of Triplecrown's, I wouldn't take any more than 1/2 mm or about 0020" off the stock head unless you open up the chamber. You could open up the chamber with a burr or cutter or 80 grit paper glued to a ball or block of wood in the drill press. I have not done it but I know it can be done that way. Still doesn't fix the quench angle and will take a lot of work to get results but you can do it. Better to pay the $60 in my opinion, but if you want to experiment...
As for measuring, BUY A VERNIER! How can you do good work without one?
I like the dial type because my eyes are not so great anymore. Some like the digital ones, I cannot stand them.
With my $40 vernier I can measure pistons and bores and head shaves down t 0.001".
I am confident enough of my skills that I just rely on cross filing, which is filing lightly one direction, then going at it from 90 degrees to note your high and low spots. It takes some experience to get here so I'd recommend getting here with a thick sheet of glass to check your work.
So, you can put a sheet of sandpaper on the glass, probably no finer than 150 grit, I'd recommend 100. Finer finish is not always better. Also the wet&dry paper holds up better and can be used with a lube (water, oil, spray oil, kerosene, varsol) to keep it clean and cutting. You can fold the paper over the edges of a small glass plate, tape the edges, hold the edges with your fingers, or glue it on with thinned or spray on contact cement. Or you can use the glass with no sandpaper at all just to see the polished rub mark where the high points are. So you rub the head in a figure "8" pattern and then look to see where the high (polished) and low (untouched) areas are. You can cut the highs with a file or just keep going with the sandpaper.
It is my experience that 100 grit sandpaper is a lot of work (about an hour) to remove 0.010" or about 1/4 mm (0.25mm), whereas I can remove that much in 10 minutes with an 8" Hand Bastard file. A finer or shorter file takes longer and leaves a smoother finish. The smoothness grades of files are very smooth, smooth, second cut, bastard, and coarse (or rough) and very with the length of the file too. "Hand" means a rectangular shaped file with one toothless "safe" edge and a special very slightly raised secret cutting section at the 1/4 length.
As for the stock head, from what I saw of Triplecrown's, I wouldn't take any more than 1/2 mm or about 0020" off the stock head unless you open up the chamber. You could open up the chamber with a burr or cutter or 80 grit paper glued to a ball or block of wood in the drill press. I have not done it but I know it can be done that way. Still doesn't fix the quench angle and will take a lot of work to get results but you can do it. Better to pay the $60 in my opinion, but if you want to experiment...
As for measuring, BUY A VERNIER! How can you do good work without one?
I like the dial type because my eyes are not so great anymore. Some like the digital ones, I cannot stand them.
With my $40 vernier I can measure pistons and bores and head shaves down t 0.001".
Just have to clear up the diesel referral glow plugs are used on some diesels and only to help heat the cylinders until they are above say 180 degrees then engine on its own for heat which it obtains from compression and ignition other diesels use block heaters that heat the water around the cylinders or fuel heaters which also prevent jelling or intake heaters that heat the oxygen going into the cylinders some inject ether or fuel into the intake before cylinder. i am interested in learning more about rechambering have no clue what it is lol.
oooohhhhk. its redesigning the sahpe of the dome on the head for a more efficent burn. more efficent burn = more power + the added compression that can also come with a head mod if u choose, all = ! bad ass macchine! and a shiz ton more power.
Yup, Check out www.kenoconnorracing.com
He does them for as cheap as my local machine shop can do them, and he probably knows more about what he is doing.
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