You're only talking .01 thousands of an inch.

You should be fine.

When you assembl the head to engine.

Get a piece of clay (play-doh) place it on top of the piston,
assemble the engine.

torques the head down (use old gasket)

rotate the engine.

let the valves push into the clay.

remove the head, measure the remaining depth of the clay.

that is your valve to piston clearance.

I believe you should be fine.

Stock Head gaskets are usually WAY thicker than need be .

 

Hey AZ Warrior, the general info. from surfing the internet is like 0.015"-0.030" max. material removal, I think it's OK too but want to know for sure.

I like what you said about the clay, the other consideration is compression, i.e. too high, pings, retarded ignition, poor efficiency...

I'll check the head gaskets I have a home, I have 1 OEM gasket and 2 aftermarket gaskets and see how thick they are, that's a good point. It may not be a big deal...

Anyone out there have the exact spec.?

Chipsndukes

 

The difference between the two is .01 inches, not .01 thousandths.

0.010 = 10 thousandths.

I have no idea of thats too much or not. But the difference is 10 thousandths, not .01 thousandths.

Not being a smart a$$ AZW just pointing out the math. :waytogo:

 

The difference between the two is .01 inches, not .01 thousandths.

0.010 = 10 thousandths.

I have no idea of thats too much or not. But the difference is 10 thousandths, not .01 thousandths.

Not being a smart a$$ AZW just pointing out the math. :waytogo:

Yes, you are right.

I saw that afterwards. :selfbonk:

.0100 is 100 thousands
not .001 thousands :brickknoc

my bad.


@Stacky

the general info. from surfing the internet is like 0.015"-0.030" max. material removal

that's within your spec.s then.



I was just putting out that if your clay ends up measuring .030 thousands
and your head gasket measures the same, you have .060 of valve to piston clearance.
(as an example)

and machining should not pose any problems.
Slight warpage is normal.

This is why we use plasti-guage right? :runaway:

 

I think Luis from ParadiseRacing has some thicker head gaskets if the material removal makes an issue. But with 10 thousandths of an inch I would doubt it would affect your compression ratio by more than a tenth.

 

Good tip, JDM thanks for the link, checked it out, there is hope!

Hope someone answers this soon, didn't mean for the thread to drag on...

Peace, thanks y'all.
Chipsndukes

 

Chip I am in the same process of getting my head machined. Your best bet would be to contact Luis at Paradise Racing and ask him....as he go thru engines like nobody's business....:lol:
This might help:
http://www.paradiseracing.com/gaskets-toyota.htm

 

Chip I am in the same process of getting my head machined. Your best bet would be to contact Luis at Paradise Racing and ask him....as he go thru engines like nobody's business....:lol:
This might help:
http://www.paradiseracing.com/gaskets-toyota.htmhttp://www.paradiseracing.com/gaskets-toyota.htm

OK, thanks JDM, PM'd him, hopefully he'll come around.

Peaces,
Chipsndukes

 

You said the shop dosent know how much material to take off, but some how they know that removing 10 thousands will guarantee a good suface? Why don't they just take the head back into the inspection room (if they have one) and sweep a dial test indicatior accross the serface? Then they would be able to tell you exactly the minimum amout of material that must me removed for the head to be flat within half a thousandth.

 

Hey McKeever, that actually is the minimum they need to be removed that they determined, here's the deal.

The head factory dimension (they have that, according to them) is 5.316".
Mine measured 5.308"-5.312" after they passed the indicator over, they threw in another 0.002" I guess for finishing the surface, heck, I don't know. I told 'em it needed to be smooth for the aluminum head, they have to slide on the gasket, not stick.

Anyways, the final number they came up with was 5.306" is what the head would measure when they were done, hope that helps explain the situation a little better.

Chipsndukes

 

Hey, I'm going to hijack my own thread:

How do you all feel about using Permatex ultra copper spray on the head gasket?

I surfed and searched around last night and here's what I found:

1. DON'T do it because with an aluminum head it needs to slide on the graphite due to diff. thermal exp. with the cast iron block, besides it wrecks the sealer that's already on the head gasket

2. Put sealer around just the coolant and oil passages.

3. Go ahead and do it, it improves the sealing, does not have any negative side effects.

Sorry to throw another topic in there, searched all the threads here (I think) and didn't find anything definitive w/regards to the head gasket and usage of sealer.

Thanks,
Chipsndukes

 

hey guy's .010 removing that little you won't even notice it .010 thou is the thichness of a peice of fax paper however if you are looking some beter performance from your none boosted engine you could shave the head some more .

 

Ok guys, .010" is nothing to shave and is still with in stock tolerances.

Compression will not be affected at all. Not to the point where you will notice it at least.

The stock head gasket is .040"

We make gaskets in .051", .060", .074", .095" and .120"

I have had to shave a few of my heads down after torching them (thanks alot Alex!!! ) and we have used .074" gaskets with no problem.

As for coating the gasket. Only if its a metal multi layer. We use copper permatex spray on ours and it is the bomb!!!

Or you can get the Catepilar Deisel engine head gasket glue!!! You will have to tie the car down to the ground and then use a crane to lift the head off. Or I have seen 4 guys with crow bars lift it off as well!!!:looney:

Hope this helps.

Luis

 

Fantastic, that was exactly the answer(s) I was looking for, thanks to GenPac for recommending Luis, Luis, thanks for stopping buy and helping out a regular guy with a daily driver question.:waytogo:

You guys are the best, thread over, have a great day!
Chipsndukes

 

I thought I would update my thread with the reflection of over four years.

Truck ran fine with 5.306" i.e. the lower limit of specification. Absolutely no detriment to performance or reliability noticed, on the contrary.

Did recently blow a head gasket, which gave me the opportunity to look at this again:

New person who machined my head this time reported the original 5.306" and said he had to go down another 0.004", effectively past the original lower limit.

He also added two pieces of info:
-his computer showed an "updated lower limit" of 5.312-5.315", no clue as to why it was changed
-he said he regularly goes below the lower limit (up to .010") without any detriment or having every received any complaints back.

Will update how my truck runs with the "underspec" head as time progresses.

chipsndukes

 

What’ caused your blown head gasket? Over heat or are you boosted?