Topic: Stacked MLS headgaskets... thoughts? (Read 25074 times)

AstroVannin · « **on:** March 11, 2009, 10:57:55 AM »

The engine in my NAVEX Corolla is the standard affair 4afe. Ive got a spare 4AGE just sitting around. Im assuming hte 4AGE would have a beefier bottom end, but higher compression.

My thought was if I could use 2 or 3 MLS 7AFE headgaskets like shims I could lower the compression, and just use the entire bottom end with a 4AFE head. I only thought of this after seeing that Mr. Gasket makes a "stackable" MLS head gasket set. I dont know what would diferentiate them from the standard type of MLS gaskets.

Anyone heard of this / tried this?

snm95ls · « **Reply #1 on:** March 11, 2009, 11:02:51 AM »

Heard of it, but never tried it.

Separate both of the gaskets into their various layers, use the inner layers form the two gaskets that you separate as the shim material, them slap a set of outer layers on.

dvst8r · « **Reply #2 on:** March 11, 2009, 11:11:07 AM »

VW guys do it all the time without issue.

AstroVannin · « **Reply #3 on:** March 11, 2009, 11:14:00 AM »

Is there a limit to how far you can go ?

dvst8r · « **Reply #4 on:** March 11, 2009, 11:22:50 AM »

Quote from: AstroVannin on March 11, 2009, 11:14:00 AM

Is there a limit to how far you can go ?

Till the motor won't run.

AstroVannin · « **Reply #5 on:** March 11, 2009, 11:29:36 AM »

Ha ha ha , awesome, good anwser.

Im going to price e thicker cometic headgasket too and see which will work out cheaper.

dvst8r · « **Reply #6 on:** March 11, 2009, 11:30:45 AM »

Quote from: AstroVannin on March 11, 2009, 11:29:36 AM

Ha ha ha , awesome, good anwser.

Im going to price e thicker cometic headgasket too and see which will work out cheaper.

I would stack MLS gaskets down to 6:1 before I would touch another Cometic. They are overpriced and under performing.

AstroVannin · « **Reply #7 on:** March 11, 2009, 11:36:43 AM »

http://cgi.ebay.com/ebaymotors/_Car-Truck-Parts-Accessories__TOYOTA-COROLLA-CELICA-7AFE-CYLINDER-HEAD-GASKET-THG7AS_W0QQitemZ140091228058QQadiZ2865QQadnZCarQ20Q26Q20TruckQ20PartsQ20Q26Q20AccessoriesQQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?_trksid=p4506.m20.l1116

3 of these = $60

Looks good to me.

92CXyD · « **Reply #8 on:** March 11, 2009, 11:57:31 AM »

Speaking of HG where can I get a 2-layer y8 HG I keep seeing in http://www.zealautowerks.com/dseries.html

snm95ls · « **Reply #9 on:** March 11, 2009, 12:00:27 PM »

Quote from: 92CXyD on March 11, 2009, 11:57:31 AM

Speaking of HG where can I get a 2-layer y8 HG I keep seeing in http://www.zealautowerks.com/dseries.html

You make one out of a stock one.

I wouldn't trust it, but yeah...

Basically take out the middle shim.

92CXyD · « **Reply #10 on:** March 11, 2009, 12:10:21 PM »

If that is the only way then hell no.

I thought maybe they were available already made.

BoostedSchemes · « **Reply #11 on:** March 11, 2009, 12:11:24 PM »

I wouldnt try to drop compression more than a point and a half with stacked HG's... it may work beyond that, between doubling the gasket size from stock dramatically changes the combustion chamber geometry.
Going to a .140 MLS from a .070 stock HG on a bmw, I had to add 15* of timing to get to the same power on a car... and those are THICK gaskets man, are you going to really sit your head a half inch above your block? :somb:

Tim · « **Reply #12 on:** March 11, 2009, 12:36:06 PM »

If the engine you are working on is overhead cam, adjusting the distance from crank pulley to cam pulley (thick head gaskets or milling and decking) will throw off mechanical timing. Most of us here don't worry about it for minor changes, but for decent amounts of adjustment or to do everything 'properly' even with a minor adjustment you should degree your cams and adjust your cam pulleys as needed.

And I don't mean your distributor timing, mechanical is the relationship to your valves opening and closing to the relation to the crank and therefor piston position.

snm95ls · « **Reply #13 on:** March 11, 2009, 12:37:30 PM »

Quote from: 92CXyD on March 11, 2009, 12:10:21 PM

If that is the only way then hell no.

I thought maybe they were available already made.

Depending on your setup, you may not want to go that thin anyway. Even with an open chamber head like the PM3 casting or the Z6 head, you will still run onto piston to head clearance issue. Again, this really depends on your setup though. The amount a block has been milled, and the compression height of the pistons you are using will determine how thin you can go. You kind of have to keep quench distance in mind when fiddling with this stuff.

As BoostedSchemes mentioned, this will have an impact on the combustion chamber geometry. Reducing quench distance is usually much more beneficial than increasing it, but you have to keep the piston form kissing the head at High RPM. The rods will stretch a little. The stock rods will stretch a little more, not necessarily a bad thing, when compared to most aftermarket rods, so that is another thing to keep in mind.

brine04 · « **Reply #14 on:** March 11, 2009, 01:18:08 PM »

I used one of the cometic .074 gaskets with my ls/vtec with itr pistons. It worked fine, just had to adjust the cam timing.

ShoofIsLudin · « **Reply #15 on:** March 11, 2009, 02:13:52 PM »

if you stack too many gaskets together, wouldn't u run the risk of having the headgasket leak? Or do they make a good seal even if they're stacked up? I haven't dealt much with multi-layered HG's (actually none at all)

AstroVannin · « **Reply #16 on:** March 11, 2009, 02:28:13 PM »

Quote from: ShoofIsLudin on March 11, 2009, 02:13:52 PM

if you stack too many gaskets together, wouldn't u run the risk of having the headgasket leak? Or do they make a good seal even if they're stacked up? I haven't dealt much with multi-layered HG's (actually none at all)

That was my question. I just wondered if they would want to leak if there was 2 or more.

Does having stacked gaskets affect the tq specs you would use, or is it same as normal.

bgdriver · « **Reply #17 on:** March 11, 2009, 04:00:50 PM »

The more area of the headgasket exposed to combustion pressure the more likely it is to break. Also in some cars, thick headgaskets affect the shape of the combustion chambers enough that it actually is more likely to detonate then with higher compresion.

98vtec · « **Reply #18 on:** March 11, 2009, 06:48:35 PM »

i had a conversation with mike belben a long time ago about thick headgaskets and he mentioned not to go too thick because you will run into hot spot issues and preignition.

any thoughts?

dr3w · « **Reply #19 on:** March 11, 2009, 06:51:52 PM »

Why not do it right the first time... stacking gaskets is just ghetto, at worst get a spacer made etc..

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Author Topic: Stacked MLS headgaskets... thoughts? (Read 25074 times)