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Discussion Starter · #1 ·
I'm gettin ready to lap my head and block and im wondering, how much lapping paste do you need? Are you supposed to have the entire surface covered or just a light spread, it seems to me certain areas would get more than others and it would be uneven? I've seen tubes in 5 gram to 18 grams, is this enough or too little?

Also is it possible to get the locating dowels out of the block without heating it?
 

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Grumpy Old Man
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Amounts all depend on how smooth the surface is after the head has been milled.

I use a piece of flat 20mmx3mm aluminium on the block to protect it then use a pair of sidecutters to lever the dowels out.
 

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Discussion Starter · #3 ·
The surface is honestly not that smooth, i can feel the tiny ridges with my fingernails...im guessing 80-100ra. How much did you use?
 

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Madd Tyte JDM yo ®
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are you doing the head or the block? the head doesnt have dowels pressed into it, only the block does.

if you are dong the block and its already been machined/milled (which i highly recommend), then i would only say youll need ONE 5gram tube of diamond paste, about 320-400 grit size grains. all you have to do is apply a little bit a time, then hose down the lapping tool with WD40 or any other lightweight oil to extend the lapping paste. in raw form, its too thick to work with. work the paste and lube around till its fully dissolved and thinned out. then go to town with it.
 

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Grumpy Old Man
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I use a light weight oil called Hyspin and squeeze a small blob here and there over the Deck Lapp for awhile then repeat if needed, My machine shop returns my blocks with a very smooth finish so lapping is just the final dressing.

Lapping is NOT A SUBSTITUTE for good/correct machine work.
 

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Madd Tyte JDM yo ®
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lol... IJ... +MF1. if you DO try to substitute lapping for ANY semblance of machine work... be prepared to put in about 3-5 hours a day for at LEAST one week of back-breaking labor.

i probably wouldnt recommend any dilluting oil heavier than ATF. lightweight penetrating oil is almost too light but worked well for me. it allowed the diamond to do more cutting and the oil didnt have a tough shear-resistant film.
 

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Grumpy Old Man
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Hyspin is a bit heavier than ATF ;)

(The diamond compounds I use recommend Vegetable oil like Canola)
 

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Discussion Starter · #8 ·
The block is new from toyota, the head was surfaced by a nascar shop......nascar sucks lol. The new block is way smoother than the cut, the head was brand new but my dumbass roomate put a nick in the sealing surface near cyl. 6. So I had it surfaced down to get rid of it, but of course they didnt have the poly cutter required to get a 5-10 RA finish. I watched him do the last .001" cut to do his best to smooth it at the fastest head speed/slowest moving speed. Old machinery just doesnt cut it and i've yet to see a shop around here that will work on indpendent stuff buy new stuff. He swore up and down that its smooth enough for a cometic gasket but i'm not inclined to believe machinests or mechanics as theyre usually full of shit. I work for toyota lol. It's just not near as smooth as the new block so im tryin to get it there.

I know the head doesnt have dowels, I was speaking of the block, I figure if im doin the head I might as well do the block. So can you give me a step by step, when to apply the paste, when to apply the light oil, where......do I cover everything first or put it on the tool first and let it spread it. Any recommendations on where to order from.
 

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Grumpy Old Man
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Put a bunch of small blobs of paste here there and everywhere over the deck surface, pour some Oil onto the lapping plate turn it over and work in figure 8's making sure you're NOT leaning on the plate.

Let the weight of the plate and the paste do the work not your muscles, you're only guiding the plate not pushing down on it.

You'll feel the resistance change as the paste begins to wear out and become fine enough to cause suction, then it's time for a little more oil repeat and then wipe the surfaces down and inspect.

Repeat if needed but the least amount removed for an acceptable finish should be your goal.
 

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Madd Tyte JDM yo ®
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i did mine in a figure 8 but i was doing it from the side, so i was just waving my arms around instead of pushing and pulling towards my body. that wawy, it was virtually impossible for me to put any sort of weight on the lapping plate... especially at full arms length away from me.
 

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90T
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Snapon makes a nice dowel puller for $200.

Since I was too cheap to buy it, I tapped my pins (they are 8mm diameter if I recall correctly), and used a few washers and nut to pull the pins out.

IJ's side-cutter approach sounds faster, but the tapped approach is a little less risky IMHO.
 

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Grumpy Old Man
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Spyder: LOL yep I'm an Aussie.

Flub: Don't know how tall you are but a 7M is right at the limits of my reach. ;)

Pie: The side cutters thing is safe as if done correctly and you don't run the risks of breaking a Drill/Tap or getting swarf everywhere :)
 

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It might run right......?
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mk2spyder i am dont know where Etowah NC is but i am in greensboro and i had T.Hoff in Raliegh NC do my block and head got an RA of .14 on both its SMOOOTH i am still plan on doing as IJ and Craig(fluburedbyu) has done with the diamond compound and lap it a few times just for that extra little bit

PM if u want more detail on T.Hoff and to met up or something
 

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Discussion Starter · #15 ·
Thanks for the offer yakuza but my short block is already assembled etc...im ready to slap this bitch together. I bought an 8"x8" thatched cast iron lapping plate from mcmaster-carr and its perfect for our engines, price at $175 shipped but it was here in 1 day. I ordered some diamond lapping paste from japan of all places and it seems to be high quality, I have 12 different grades of it. I blocked off all the holes and passages in the block with an 80 pack of ear plugs, it works good but u have to watch the bigger water jacket holes as the plugs will eventually fall in.. Then you have to sit there with a LED flash light, a long pick, and turn the block upside down to get them back out. I thought I was so screwed when the first one fell in until I realized how much room there is in there hah. I've been lapping the block for prolly about an hour straight now using the same side to side figure 8 like flubyux described. Not only does it work the best but its really a good work out if ur too lazy to get to the gym lol.

One question though, since I cant see alot of results yet, when the slurry of diamond paste and oil turns like dark charcoal black thats from the block shavings right? That means im doin a good job right haha? Need a little encourgement.
 
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