Modify head gasket for use on LZ22 or LZ24 conversions

[spottedog]

I am doing cylinder head replacement on a LZ24 I built some time ago, the bitch is drilling the extra
coolant holes in a new head gasket all over again to complete the job. :devil:

I use a Felpro 9210 PT-1
"Fel-Pro performance head gaskets feature a PermaTorque/blue gasket body with a solid-steel core to minimize torque loss and gasket blowout. Fel-Pro performance head gaskets also have a wire-ring combustion seat with stainless steel "armor" for extra sealing force around combustion chambers."

I have used this type of gasket on several brands of cars, no issues.
But ANY graphite and steel gasket is hard to "modify" for use on a Datsun Frankenstein engine.

I made up this guide hoping it will be of use for anyone doing a LZ22 or LZ24 conversion.

The problem is any normal kind of fluted drill bit will NOT make a clean hole in a graphite/steel
head gasket without the bit grabbing and ripping up the sheet steel under the graphite.
THREE gaskets later and two days of futzing with it,and a mangled finger, I have learned this:

Got money? Take the damn job to a machinist!  :w00t:

Gasket punches, Greenly punches and leather punches don't work.

Exacto knives and small sharp chisels don't work.

Any normal metal cutting drill bits don't work.

"Unibits" (which have no flutes) don't work.

Whatever you use to bore the holes has to cut through the soft thin graphite layer, then through the
hardened thin stainless steel center layer, then through the graphite layer on the other side
leaving a nice clean hole through the gasket without futzing up the graphite or mangling the thin
stainless steel center.

I tried everything short of a laser, here is what worked:

Use wood cutting bits of the size you need!  (yes, wood bits, they have a sharp little center point
that goes in first and pilots the bit then two little cutter blades carve out a nice clean circle
in the graphite then the steel leaving a little disk of the steel that just pops out of the hole.
Nothing pulls up on the work piece. Read the instructions, keep the rpm low.
Dremel rotary tool required, variable speed drill required, Dremel carbide bit 26150125AC is nice
for deburring. Work on a hard wooden (expendable) surface not your coffee table.
----------------------------------------------------
Drill coolant holes in graphite/steel gasket:

GENTLY just hand push a punch into the graphite to locate the hole (don't use a hammer!)

Use a wood bit and drill until the point is just visible on the other side (check often)

Start the bit in the small hole in the other side and drill through the graphite

Drill on each side, back and forth untill you see the center steel "disc" spin then stop

With gasket on a flat surface, use your thumb to push the slight graphite burr into the hole edge
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Make oval coolant "hole" in graphite/steel gasket:

Use a felt pen to draw the oval coolant "hole" on the gasket

Drill hole in each corner of hole using procedure above

Connect the holes with small thin dremel disc corner to corner

De burr edges with dremel stone or conical steel cutter
--------------------------------------------------------
I tried this on a Fel pro copper gasket "dead soft" copper is also a BITCH to drill, this also works
great on copper.

 

[datzenmike]

Sealik did something like this. I think he clamped the gasket between wooden blocks and drilled through them.

[Sealik]

I made a jig

Now I can make an exact duplicate that matches the holes in my block,....... in about 10 mins.

 

 

 

No edges to deburr because the HG is sandwiched between some wood.

 

[dr.feltersnatch]

You should start selling modified gaskets sealik.

[uberkevin]

http://datsunpartsllc.com/cart/index.php?p=product&id=238&parent=30

 

I haven't looked at it yet but I bought this gasket for my lz2.3 build.

[datzenmike]

It's essential that the bores are 89mm and no less. If the fire ring is exposed into the cylinder it will cause pinging and erode away.

[Sealik]

A little too tight?....all stock app HGs are set back from the cylinder wall

The Felpro HG for the 2.4L/89mm is 91ish (crushed)

 

Hopefully 'composite'.

[uberkevin]

I called datsunpartsllc.com and talked to a guy named... Allen maybe? he told me he's used them on a few of his Lz2.3 builds, sounded pretty sure about it.

 

I'll also be modifying a Z24 head ggasket to see what one I like more.

[Sealik]

Do post a pic of that HG when you get it....what's the PN?

[uberkevin]

 

 

 

 

 

 

[uberkevin]

[url=http://s46.photobucket.com/user/love2scream/media/20140730_205105_zpsnsooxbbh.jpg.html[/url]

 

So I should had, Allen had said that the gasket is oval.

 

Over all I don't really like the fitment of this gasket. Getting it as straight as possible it still left an over lap in side the bore...

[Sealik]

Yup....too small

 

Felpro PN...21178 PT- L16/L18/L20B 

No good for larger 89mm bore

[uberkevin]

The datsunpartsllc site says it's an 89mm l20b head gasket, knowing I can't believe what I read online I called and asked if it was truly a 89mm gasket. I know he said he has used them, doesn't mean I wwill. Pretty shitty it's not truly 89mm or more. Thanks for those pictures sealik, what drill bit did you use?

[wayno]

So that is the gasket that you got from that link above?

[Sealik]

"Composite and 89mm" might throw some people off

Nothing fancy about that...it's just a basic L20B HG from Felpro

 

Have you done any research on DatsunpartsLLC ?

 

1/4" drill

[uberkevin]

Wayno yes.

 

 

And research... no...

[uberkevin]

No I guess this ways my research...

[wayno]

Looks like your back to making a gasket, it sucks as far as I am concerned, I have tried a lot of ways, I always ended up back with the dremel with a death grip.

[uberkevin]

You try the way sealik did it?

[wayno]

I tried drilling, I tried punches, I tried cutting with knives, I always ended up back using the dremel with a kind of grinding bit, and sometimes it bites in when it hits one of the metal threads inside the gasket, everything deformed the gasket except the dremel, but when I put my hands on the gasket to hold it still while working on it, the coating on the gasket comes off, that's the problem, if you squeeze the gasket with anything, the coating comes off, sealik made some kind of jig for making the holes, but I don't know how he protected the coating on the gasket from coming off when he squeezed the gasket in his jig.

[uberkevin]

You should start selling modified gaskets sealik.

Yeah sealik if you did happen to make some I'd buy one from you haha..

 

I can pick up a Z24 hg for about 13 buck.. or at least got my last one I bent for that much..I'm sure I'll mess up a few hgs, wish I don't but that's life.

I'll try the wood like sealik did and post some pictures of the outcome..

[EricJB]

The Victor and ROL HG's are sticky out of the package. When you have to pull the head again, the sticky coating stays on the head and block. That may be the coating Wayno is refering to. The felpro's don't do that. I stopped using the others because of the cleanup. Felpro's take the abuse the longest too.

 

I have tried everything I could think of to drill them  as well. Die grinder with a tiny pointed burr works best for me.

That sucks about that 89mm HG. I was hoping you had found something there. 

[uberkevin]

Didn't even think about what I'd use to cut the front off of the gasket... I don't really have anything. Shit!

 

All I have is a dremel and a grinder but that would seem pretty sketchy using.

 

Wish the gasket did work for my block. Wonder how Allens lz's turned out using this gasket.. that's alright I guess the l20b I have needs a gasket.

[EricJB]

Tin snips for the front. Piece of cake.

[banzai510(hainz)]

I have 87mm L20b gaskets but you guys are doing Napz blocks