Griding Heads Question....

IBoughtASupra

IBoughtASupra

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Hey guys, I plan on reseating my heads. When I am going to use the grinding paste and the hand tool to grind to head, I know I will have to check the clearances.

My question is that would I have to add shims to replace to material removed becasuse a mechanic told me that I don't have to. Just check the shim at the top and the lifters adjust themselves.

Thoughts? Thanks, Andy.
 
CyFi6

CyFi6

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I am assuming you are talking about valves, not "heads", but with hand lapping you shouldn't need any change in your lash adjustment if they are already in spec, though you will want to check it. The valves move up as the seat is ground away, so if anything the clearance would get tighter, and no they are not self adjusting.
 
gofastgeorge

gofastgeorge

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I think that you should re-check the valve clearances.
When seats erode, they loose material off the face.
When you lap them, you remove more material.
This will allow the valve to go deaper into the seat, and reduce clearance with the cam.
Especially the exhaust, which erodes the most.
So check your valve clearances when you put the head back together,
just to make sure they are not too tight.
 
rayall01

rayall01

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IBoughtASupra;1380131 said:
O, Ok. So, Should I Just Replace All The Shims After Seating The Valves.
Click to expand...

No, you don't just replace all the shims. You check the clearance, and replace only where necessary. It may turn out to be all of them, but you won't know until you check.
 
N

NewWestSupras

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Dude, you might want to search up all you can on these types of things before undertaking them. Knowledge is power. As far as the head goes, maybe this time get someone with experience to guide you through it. At the very least, check the head for hardness and warping, and maybe a pressure test for good measure. Hand lapping valves is fairly straitforward, but again, try to find another member on here, or someone who has intimate knowledge of 7M heads to assist you. After the first time it's not as bad. gl.

http://www.ehow.com/how_2142943_use-plastigage-measure-clearances.html
 
IBoughtASupra

IBoughtASupra

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Ok, last question on this. When grinding the valve to seat it again, it moves more up into the head. This causes the clearances to become smaller. When the clearances are checked and the ones that are out of spec will need to be replaced because they will have a too small of a space between the cam and shim.

Where would I get thinner shims to use? Thanks, Andy.
 
gaboonviper85

gaboonviper85

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Jan 13, 2008
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Dude seriously????

Damnit man you really need to read more!

This is a Toyota motor there for one would generally go to Toyota for different shims.....how's about you just let the machine shop worry about the shims as this concept is above your head.

Ps. You can also remove material from the back of the valve stem to add cleance between shim and cam....one of the most easy concepts that would take ten of googles time to teach you.
 
gaboonviper85

gaboonviper85

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There are all different size shims that Toyota has! As well as other Toyota engines use the same type shim...easy info to find on your own within the confinds of this forum! You don't have just one size shim in your head...there will be a couple all different sizes...that alone will tell you that Toyota has a selection.......when in doubt the tsrm helps!

I'm sorry if I sound like an ass but it seems as though you're asking questions before you even did a min of your own research...as well as lacking some common sense...
 
gaboonviper85

gaboonviper85

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Dude...the machine shop isn't going to install the new seals untill all machine work is done and head is cleaned....you are asking us questions that you should be asking the machine shop! Yes hot tanking a head with new seals isn't smart and I don't know of a shop that would do something so silly.

Chillax man...just go to the most respected machine shop you can find and tell them your goal and explain what headgasket you are going to use and tell them it needs to be very smooth...let them install the seals and such as it's obvious you are not so keen on this.
 
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gaboonviper85

gaboonviper85

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IBoughtASupra;1384926 said:
After seating the valves, would hot tanking the head be bad to the seats? Obviously, hot tanking the head without any valvetrain.
Click to expand...

Oh you said "seats" my bad...read that wrong.....no hot tanking will not hurt your seats or valves!
 
IBoughtASupra

IBoughtASupra

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Good, I took the head to the shop today. I am doing most of the work myself because I paid a machine shop to do my other head and they messed it up big time. The valve seals are leaking and the head is ticking and has a tight valve. Trust me, we tried everything to fix the idle jumping up and down. Smoke test, ISCV, TPS, And AFM. Nothing helped, so that is the problem. I paid $800.00 to get a "rebuilt" head with new seals, reseat the valves, and a three angle valve job.

What I got is a load of crap. Here is my build thread that has been on hold ever since we started the car and had problems and I stopped updating it until I get this new head back. That is why I am doing everything myself with my friend's assitance who knows 7M's by heart down to the bolt and colors of the wires for every plug.

http://www.supramania.com/forums/showthread.php?t=93837&page=1
 
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