need help picking a ka24de comestic gasket - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

grnappletree14 · 05-21-2008, 11:33 PM

i want to buy a new cometic head gasket for a ka-t. this guy is selling on for a real good price but he listed it as .040" mls 90mm is that the stock size for a k24de, with out boring it or is that the one for boring it. lmk thansk

HalveBlue · 05-22-2008, 02:33 AM

I don't know the exact size of the KA's cylinders but I can almost guarantee that they're not 90mm.

EDIT: According to the FSM the inner diameter for the cylinders on a KA is 89mm.

grnappletree14 · 05-22-2008, 10:22 AM

so it wont work then

just1pepsi · 05-22-2008, 10:29 AM

There are the cometic part numbers directly from their website.
These are the only two cometic makes for the KA

91-94
90mm MLS .040" C4285-040 1 $89.96
91mm MLS .040" C4286-040 1 $89.96

95-98:
90 mm MLS .040" C4285-040 1 $89.96
91 mm MLS .040" C4286-040 1 $89.96

FRpilot · 05-22-2008, 11:12 AM

that's weird, phase2 list cometic 89mm stock bore headgaskets on their website. must be wrong?

http://phase2motorsports.stores.yahoo.net/coheka.html

just1pepsi · 05-22-2008, 12:08 PM

I guess so.. same p/n... only way to know for sure is to measure it.. or maybe call cometic directly.

orion::S14 · 05-22-2008, 08:27 PM

Why Cometic?

OEM or FelPro, IMO.

There have been too many issues with Cometic's...unless the head and block are *perfect*, it'll leak.

Are you building a motor for stupid power levels? If not, stick with the OEM type gasket.

My unsolicited advice.

...

What do you have planned for the rest of the setup?

- Brian

essforteen · 05-22-2008, 10:01 PM

Quote:

Originally Posted by orion::S14

Why Cometic?
OEM or FelPro, IMO.
There have been too many issues with Cometic's...unless the head and block are *perfect*, it'll leak.
Are you building a motor for stupid power levels? If not, stick with the OEM type gasket.
My unsolicited advice.
...
What do you have planned for the rest of the setup?

- Brian

he is going KA-T so oem wont be his best option a metal head gasket is ideal

HalveBlue · 05-22-2008, 11:14 PM

^^^ Says who?

OEM head gaskets are good up to 350 hp, maybe even more.

FWIW, when I had my block and head at the machine shop I asked the machinist whether he recommended metal gaskets over paper. He said unless you are pushing stupid amounts of power he actually prefers OEM/paper gaskets. He's reasoning was that the simpler design and OEM specs are less likely to cause problems.

sunnys14 · 05-23-2008, 12:01 AM

A lil bit of copper spray on the Cometic MLS gasket will help it seal better. I've used copper spray on my last 3 builds and they haven't leaked. Just make sure you use the correct torque specs on your head studs/bolts.

orion::S14 · 05-23-2008, 11:58 AM

Quote:

Originally Posted by essforteen

he is going KA-T so oem wont be his best option a metal head gasket is ideal

The stock headgasket is WAY tougher than the stock pistons.

So if he's doing a basic turbo setup on a mostly stock block...a metal HG is more likely to leak, more $$$, and 100% not needed.

Building a block for +500rwhp...then, consider a bad-ass gasket.

...

I don't know where it comes from, that as turbo'd car needs an upgraded headgasket?

For a turbo'd motor that was originally an N/A application - The weakest link should get upgraded first, if you're gonna bother doing anything internal work.

...and the weakest link, on a stock KA...is BY FAR the stock piston ring lands.

FWIW.

- Brian

hitman · 05-23-2008, 01:04 PM

brian, what would you recomend for me?
i just got rod knock so im putting my block back together with cp pistons, arp head/main/rod bolts, oem gasket kit, and a gt3071r.
reason why i want a cometic is because drifting at the track is really hot and id like it not to blow at the tinyest bit of detonation
reason why i want stock is because it comes with the gasket kit, i dont (and probably wouldnt either gasket) want to get my head milled (i dont know how flat it is)
and have you heard (im sure you have since youre on ka-t.org) about the 10% more torque on the head bolts with the arp bolts to help seal it better?

05-21-2008, 11:33 PM	#1
grnappletree14 BANNED Join Date: Aug 2006 Location: SOCAL/chino hills (909) Posts: 1,829 Trader Rating: (6) Feedback Score: 6 reviews	need help picking a ka24de comestic gasket i want to buy a new cometic head gasket for a ka-t. this guy is selling on for a real good price but he listed it as .040" mls 90mm is that the stock size for a k24de, with out boring it or is that the one for boring it. lmk thansk

05-22-2008, 02:33 AM	#2
HalveBlue Zilvia FREAK! Join Date: Mar 2004 Location: I'm somewhere where I don't know where I am! Posts: 1,549 Trader Rating: (0) Feedback Score: 0 reviews	I don't know the exact size of the KA's cylinders but I can almost guarantee that they're not 90mm. EDIT: According to the FSM the inner diameter for the cylinders on a KA is 89mm. Last edited by HalveBlue; 05-22-2008 at 03:55 AM..

05-22-2008, 08:27 PM	#7
orion::S14 Nissanaholic! Join Date: May 2003 Location: Orange Park, FL Posts: 1,666 Trader Rating: (0) Feedback Score: 0 reviews	Why Cometic? OEM or FelPro, IMO. There have been too many issues with Cometic's...unless the head and block are perfect, it'll leak. Are you building a motor for stupid power levels? If not, stick with the OEM type gasket. My unsolicited advice. ... What do you have planned for the rest of the setup? - Brian __________________ www.KA24DEvelopment.com

05-23-2008, 01:04 PM	#12
hitman Zilvia FREAK! Join Date: Mar 2006 Location: late 19th century prussia Age: 37 Posts: 1,057 Trader Rating: (3) Feedback Score: 3 reviews	brian, what would you recomend for me? i just got rod knock so im putting my block back together with cp pistons, arp head/main/rod bolts, oem gasket kit, and a gt3071r. reason why i want a cometic is because drifting at the track is really hot and id like it not to blow at the tinyest bit of detonation reason why i want stock is because it comes with the gasket kit, i dont (and probably wouldnt either gasket) want to get my head milled (i dont know how flat it is) and have you heard (im sure you have since youre on ka-t.org) about the 10% more torque on the head bolts with the arp bolts to help seal it better? __________________ driftparty.com

05-22-2008, 10:22 AM	#3
grnappletree14 BANNED Join Date: Aug 2006 Location: SOCAL/chino hills (909) Posts: 1,829 Trader Rating: (6) Feedback Score: 6 reviews	so it wont work then

05-22-2008, 10:29 AM	#4
just1pepsi Zilvia Addict Join Date: Dec 2003 Location: OKC Age: 42 Posts: 657 Trader Rating: (0) Feedback Score: 0 reviews	There are the cometic part numbers directly from their website. These are the only two cometic makes for the KA 91-94 90mm MLS .040" C4285-040 1 $89.96 91mm MLS .040" C4286-040 1 $89.96 95-98: 90 mm MLS .040" C4285-040 1 $89.96 91 mm MLS .040" C4286-040 1 $89.96

05-22-2008, 12:08 PM	#6
just1pepsi Zilvia Addict Join Date: Dec 2003 Location: OKC Age: 42 Posts: 657 Trader Rating: (0) Feedback Score: 0 reviews	I guess so.. same p/n... only way to know for sure is to measure it.. or maybe call cometic directly.

05-22-2008, 11:14 PM	#9
HalveBlue Zilvia FREAK! Join Date: Mar 2004 Location: I'm somewhere where I don't know where I am! Posts: 1,549 Trader Rating: (0) Feedback Score: 0 reviews	^^^ Says who? OEM head gaskets are good up to 350 hp, maybe even more. FWIW, when I had my block and head at the machine shop I asked the machinist whether he recommended metal gaskets over paper. He said unless you are pushing stupid amounts of power he actually prefers OEM/paper gaskets. He's reasoning was that the simpler design and OEM specs are less likely to cause problems.

05-23-2008, 12:01 AM	#10
sunnys14 Zilvia FREAK! Join Date: Mar 2006 Location: a land far far away... Posts: 1,549 Trader Rating: (19) Feedback Score: 19 reviews	A lil bit of copper spray on the Cometic MLS gasket will help it seal better. I've used copper spray on my last 3 builds and they haven't leaked. Just make sure you use the correct torque specs on your head studs/bolts.