how do you "LAP" your engine surfaces?

[gizzy2014]

hey i was wondering how a person does this seems like a great idea for getting stuff to fit together alot better?

anyone that could answer would be great

also while im asking how do you clean carbon build up out of exhaust port?

 

[Awk08]

oh wait, thats a girl lapping ice cream, LOL


you need a perfectly flat surface, some use glass, some like a piece of granite, tape wet sandpaper to it (not sure what grit) wet it down with wd-40, use circular or figure 8 pattern until all edges show sanded

similar to this...........

 

[Racer51]

You take 600 fine grit sand paper and simply rub the top of the head in a circular motion till it's smouth and looks good.
There's a selection of reading materials of porting that explains how to clean and polish the exhaust port out and make it run healther, and you cant really do one without doing the other but just use 400grit -240grit and just wipe it out till it gets lighter.

 

[gizzy2014]

oh ok sweet, thats easy enough for me to do

yeah i know they dont need to be done together i just know that hole needs to be cleaned up.....bad


if i took a level to my basement floor and was very picky would that work as a good flat surface??

 

[Racer51]

shure would 1515

 

[gizzy2014]

k sweet 15151

(now i understand the 15151 thing) LOL

 

[Blaaster]

oh ok sweet, thats easy enough for me to do

yeah i know they dont need to be done together i just know that hole needs to be cleaned up.....bad


if i took a level to my basement floor and was very picky would that work as a good flat surface??

No way would a floor be true enough, you need plate glass, a surface block or a polished granite or marble block.

The fig 8 motion will ensure that you cut evenly, a circular motion tends to cut one side low.

Lubrication for aluminium is metholated spirits, WD40 is a second choice.

 

[gizzy2014]

ok, i shall figure something out

 

[joeak47]

VW BUG (the old air cooled bugs,not the stupid new ones) side windows and rear quarter windows work well too! Nice and flat

 

[89blaster89]

VW BUG (the old air cooled bugs,not the stupid new ones) side windows and rear quarter windows work well too! Nice and flat

i heard those old bugs actually float?

 

[Blaner]

be careful when lapping not to take off too much material. If doing engine cases, you can end up with a tight crank of a cylinder that doesnt fit the studs anymore!

 

[Larry's Shee]

shure would 1515

Concrete is nowhere near flat or smooth enough, use your head. It was mentioned GLASS not concrete. Come on guys think a little bit.8-|

 

[Blaaster]

i heard those old bugs actually float?

Block up the air exchanger tubes that go through to the cabin as a heater, and smear the door seals with petroluem jelly, and they float very well.

 

[gizzy2014]

i will NOT BE using concrete, i have a old mirror that we cut part off to make a laser obstacle course. that i will be using to do this

yeah i wont be doing cases right now, just parts on my head for now, and yeah i wont take very much off just to make them true again

 

[wwholden]

The purpose of lapping a sealing surface is so that its 100% flat and claen. A surface plate is where this should be properly done. Ive seen people use glass before. Im sure it would work but a surface plate would be best.

 

[gizzy2014]

yeah i suppose there is a actually tool out there that i dont have the money to buy.... right now, and im only gunna use it once....

 

[Blaaster]

If you plan to use the mirror, make sure that it is placed on the flattest surface you can find.

It should be at around waist heigh, to allow for fluid movement of your arms as you move them, by that I mean, no slowing down, speeding up or stopping .

Glass is flexible, if the mirror you use is less than 3/16 thick, open up 2 newspapers and place them under the glass for padding, it will tend to lessen the flex.