Spacer headgasket for the 2zz?

[gte]

Does anyone make a thicker headgasket for the 2zz to lower compression?

[Smaay]

No and you dont need to lower compression.

[gte]

And why do you say that I don't need to lower my compression?

I'll call cometic today




No and you dont need to lower compression.

[Smaay]

what are you trying to acomplish? what reason do you have to lower the compression?

[gte]

Turbocharging the car, and I want to lower the static, and therefore dynamic compression of the engine ... and don't want to build the motor


what are you trying to acomplish? what reason do you have to lower the compression?

[wts]

Wont a thicker HG increase the chance of abnormal combustion?

[SuperDave]

Piper cams will also drop your dynamic compression ratio too, but these methods aren't exactly the best way to go about it.

Would the thicker head gasket create a potential failure point under boost?

[monkeywrench]

Dropping the compression that way may buy you a small amount of safety from detonation but bottom line you still have weak cast pistons in there so a little detonation or too much pressure will still snap your ring lands like twigs.

[bt216]

I'll call cometic today
they will tell you they do NOT make anything fo the 2ZZ. I've already tried getting a custom one made as well, but they wont do it.

[gte]

The reason that is not the way to go about it, is because it's only lowering dynamic compression because of overlap, but not at all addressing static compression

For my purposes, there is no potential increase in failure



Piper cams will also drop your dynamic compression ratio too, but these methods aren't exactly the best way to go about it.

Would the thicker head gasket create a potential failure point under boost?

[gte]

I understand the weakness of the cast pistons, but my turbocharger is going to be a gt28, 35lbs of flow.

I am looking for a cushion for the most part. In your experience, can the stockers support 300whp, with the lower static compression taken into account?


Dropping the compression that way may buy you a small amount of safety from detonation but bottom line you still have weak cast pistons in there so a little detonation or too much pressure will still snap your ring lands like twigs.

[youngxlos]

^^ no
do it right, or don't do it at all.

[Gtsjeg04]

^^ no
do it right, or don't do it at all.

**** that, stack two head gaskets on top of each other and put a GT35 on that thang and call it a day.


Disclaimer: I am in no way liable for the **** that I type on this forum. If you take my bull**** advice and your **** blows up, dont come crying to me.

[gte]

Don't worry, I would never take your advice, nor come crying to you


**** that, stack two head gaskets on top of each other and put a GT35 on that thang and call it a day.


Disclaimer: I am in no way liable for the **** that I type on this forum. If you take my bull**** advice and your **** blows up, dont come crying to me.

[MyRomeo]

stock pistons start to struggle at about 260whp IIRC so regardles of your compression at this power level they will still be the weak point. if your going the FI route then at the very least change the pistons. you shouldnt need to lower the CR for typical boosted applications on the 2zz, you can make mean power with about 7psi and the 12.5:1 CR :)

[SuperDave]

stock pistons 12.5:1 CR :)

I'm sure you meant 11.5:1 ;)

[zzz]

I'm sure you meant 11.5:1 ;)

I'm sure he meant 12.5:1 ;)

[MyRomeo]

aye.. 11.5:1... stock, lol. too early here!

[zzz]

I could've sworn stock compression was 12.5:1

[Klint]

stock internals can handle 7 psi .. maybe 10 .. either way you need a good tune. Higher than that you need engine upgrades

[Smaay]

do this. put 3 head gaskets on top of each other and make sure you re-use the stock head bolts! then when you blow your engine and come crying here wondering why your ring lands are all busted, we will all point and laugh at you for not listening to us.


i do believe its been said here all ready.
do it right, or dont do it at all!

[Shizuma]

Won't a thicker head gasket mess with the lift mechanism too? I could be wrong but I think I read something along those lines a long time ago...I could also be retarded...but at least I didn't start this thread...

[deercelica]

So with Piper Stage 2s I can push a PSI or two more safely?

[Shizuma]

So with Piper Stage 2s I can push a PSI or two more safely?

I'm fairly certain the duration on those would not help your cause. If you're that hard-up for an extra 1-2 psi I'd look into a better tune or perhaps a methanol system.

[Jesse IL]

Thick head gaskets are an incredibly bad idea because remove the quench area in the combustion chamber, making the engine more knock prone. So you lowered your compression ratio but made the engine more likely to knock. Sounds like a winner to me...

[gte]

I would like to increase headgasket thickness by 1.557 millimeters.

Smaay, I wouldn't come crying here, because I would know if my engine was damaged, why it was damaged.

Spacer head gaskets do work, but they have their place. For what I'm thinking of doing with it, it can work. Is it as good of a solution, as me calling Ross and asking them to build pistons to my specifications, dish design and ring spacing? No it is not, but will it suffice for my goals? Maybe ...

I came here to ask if anyone had done it, if a company made the product and for personal experiences, not for theoretical discouragement from people who are lemmings. If the "respected members" of this community just huddle together and never consider alternatives or think outside of the box/way that everyone else is doing things, I'm sad for you all.

Intelligent theorizing is fun, and can lead to motivation to try something new, or demotivation to avoid a probable failure. Lemmings can't theorize, so if that's you, no need to post in my thread.

do this. put 3 head gaskets on top of each other and make sure you re-use the stock head bolts! then when you blow your engine and come crying here wondering why your ring lands are all busted, we will all point and laugh at you for not listening to us.


i do believe its been said here all ready.


Jesse,

The 2zz does not have much, if at all, a quench area ;) . But it is nice to see comments like this, it helps me weed out when people have first hand experience, vs people who regurgitate other peoples misinformation. I haven't popped my head off, but based on drawings and toyota diagrams, yamaha built the 2zz head to homogenize it's combustion using a swirling process, and not a quenching process. There, now you can regurgitate some correct information.




Thick head gaskets are an incredibly bad idea because remove the quench area in the combustion chamber, making the engine more knock prone. So you lowered your compression ratio but made the engine more likely to knock. Sounds like a winner to me...

[youngxlos]

edit
do it right, or don't do it at all.
i dont wanna start drama over the internet.
have fun building your cheap a$$ home made turbo kit

[youngxlos]

...

[gte]

Don't try and act like an elitist, I'm not building anything ... I bought a turbo kit and I inquired about whether spacer head gaskets were made for the 2zz or not



edit
do it right, or don't do it at all.
i dont wanna start drama over the internet.
have fun building your cheap a$$ home made turbo kit

[youngxlos]

the answer is no, now move on plz
someone :closed:

[Jesse IL]

The 2zz does not have much, if at all, a quench area . But it is nice to see comments like this, it helps me weed out when people have first hand experience, vs people who regurgitate other peoples misinformation. I haven't popped my head off, but based on drawings and toyota diagrams, yamaha built the 2zz head to homogenize it's combustion using a swirling process, and not a quenching process.
Well you may have a point, but the design looks pretty standard to me.

Here are the stock pistons, which have a pretty traditional design with what appear to be quench areas between the valves.

http://users.ameritech.net/trdcelica/cylinders-1.jpg

Here is the combustion chamber on the head.

http://users.ameritech.net/trdcelica/combustionchamber-2.jpg

That looks to me like a pretty traditional pent-roof combustion chamber with quench areas on the periphery, very similar to a B16/18 head.

Here is a block with 10:1 Wisecos in it. You can see where the center of the pistons are dished, but you can also see where they have attepted to keep the tolerance at the edge of the piston intact.

http://users.ameritech.net/trdcelica/engine-1.jpg

You're welcome to install a Cometic gasket if you're able to find one, but just know that the stock cast pistons are known to be very susceptible to cracking in the ring land area under detonation and very few of them live long unless they have impeccable tuning beyond 300 whp.

If it were me and I was going through the trouble of pulling a motor and tearing it apart, I'd use a different method of trying to achieve lower compression.

[Klint]

and there you have it .

[Celicasaur]

I'm not building anything ... I bought a turbo kit and I inquired about whether spacer head gaskets were made for the 2zz or not

Yeah c'mon guys, the point has been made and I'm fairly sure this guy understands the limitations of a thicker head gasket. He wants it as added security - not a springboard to increase the power further on his set up.

[smart_rocket]

what about timing chain? Wouldn't it get also an issue?

[deercelica]

Quick question..

Say I get 265WHP from a turbo kit. But then I do bolt ons like crank pulley, intake mani gasket, bored throttle body, piper stage 2 cams, you get the idea.

Should I be worried about the 300WHP mark as I would be if it was stock motor no bolts ons, boost 300WHP? Since i'm not really messing with more boost at that point just making it run more effeciently.

[gte]

And that was much more of the type of answer I was looking for. If the ring landings are too close to the top of the piston and susceptible to high cylinder pressures that cause them to fail above the approximate PMEP at 300rwhp (or the average torque equivalent), then better designed/stronger pistons is the only alternative.

Thanks for being cordial with this response. :)





You're welcome to install a Cometic gasket if you're able to find one, but just know that the stock cast pistons are known to be very susceptible to cracking in the ring land area under detonation and very few of them live long unless they have impeccable tuning beyond 300 whp.

If it were me and I was going through the trouble of pulling a motor and tearing it apart, I'd use a different method of trying to achieve lower compression.

[gte]

Based on what I'm seeing/reading about piston failures, it's because of cylinder pressure and piston design. If this is indeed correct, then if you make more torque, yes you should be concerned because an increase in torque means an increase in PMEP and BMEP cylinder pressures.

I'm guessing that with a stand alone, you could probably go a little higher in power and be safe, if you tuned it to run a little fat, and you backed off the timing a little, but with a piggy back and stock ecu, it's much more of a gamble. Since you didn't list it, I'm guessing you are still on the stock ecu?




Quick question..

Say I get 265WHP from a turbo kit. But then I do bolt ons like crank pulley, intake mani gasket, bored throttle body, piper stage 2 cams, you get the idea.

Should I be worried about the 300WHP mark as I would be if it was stock motor no bolts ons, boost 300WHP? Since i'm not really messing with more boost at that point just making it run more effeciently.

[vamis]

Only thing I am not getting. To replace the gasket You have to remove head. But if the head is removed, to replace the pistons only what You have is to remove oil pan additionally.

If You sum amount af money You will spend on lets say 3 head gaskets and compare it to the price of forged lowcomp pistons, difference will be some hundreds of $ + worry free drive later

[gte]

I would not do an inframe on my engine if I replaced the pistons. Cost has nothing to do with it, I would buy an extra short block and build that outside of the car if I were going to do a rebuild, as this is my daily.



Only thing I am not getting. To replace the gasket You have to remove head. But if the head is removed, to replace the pistons only what You have is to remove oil pan additionally.

If You sum amount af money You will spend on lets say 3 head gaskets and compare it to the price of forged lowcomp pistons, difference will be some hundreds of $ + worry free drive later

[vamis]

I would not do an inframe on my engine if I replaced the pistons. Cost has nothing to do with it, I would buy an extra short block and build that outside of the car if I were going to do a rebuild, as this is my daily.

If You have removed head, replacement of pistons will take max 1h, including removal of old oil pan sealant, what is most time consuming in current situation

[Shizuma]

If You have removed head, replacement of pistons will take max 1h, including removal of old oil pan sealant, what is most time consuming in current situation

Uh, no not really. If he's able to use Mahle pistons (ie: his cylinder tolerances are within the specs given by Mahle), he'd still have to gap and install the rings, rods and bearings. If he's NOT able to use Mahle pistons, then he'd have to sleeve the block and go with Wiseco's....I don't care how good of a machinist you think you are, you cannot bore, hone, and sleeve a block while it's in the engine cradle.

[vamis]

Uh, no not really. If he's able to use Mahle pistons (ie: his cylinder tolerances are within the specs given by Mahle), he'd still have to gap and install the rings, rods and bearings. If he's NOT able to use Mahle pistons, then he'd have to sleeve the block and go with Wiseco's....I don't care how good of a machinist you think you are, you cannot bore, hone, and sleeve a block while it's in the engine cradle.

I meaned just to replace pistons. Leave same bearings and rods. And assuming he can use mahle pistons.

But that would not be wise. as bearings use to fail on 2ZZ if they still are stock. For safety its better replace them at the same time

[Boosted2.0]

Very vew people have run aftermarket HGs on the 2ZZ due to the extremely high quality of the stock one.

If you want to drop the compression just get low compression pistons. The stock pistons have weak ring lands. Slightly lowering the compression will buy you almost no margin of safety, even assuming that your new HG doesn't increase the knock tendancies. Again - the weakness of the stock pistons is one of ring and ring land strength, not that they are too high in compresison.

If this is a daily and you want a REAL margin of safety build the motor right or run VERY low boost and get an EMS with knock protection.

[gte]

Thanks for the response ... I'll see how a stock compression turbo kit runs, and I'll just turn down the boost a pound or two if I see any knock


Very vew people have run aftermarket HGs on the 2ZZ due to the extremely high quality of the stock one.

If you want to drop the compression just get low compression pistons. The stock pistons have weak ring lands. Slightly lowering the compression will buy you almost no margin of safety, even assuming that your new HG doesn't increase the knock tendancies. Again - the weakness of the stock pistons is one of ring and ring land strength, not that they are too high in compresison.

If this is a daily and you want a REAL margin of safety build the motor right or run VERY low boost and get an EMS with knock protection.

[evilthorne]

Or you can properly research this and find out that with the stock compression you can run 8-9psi without too many issues. I love it when the FI newbs come on and want to buy a turbo kit and run it at 3 psi because they think anything more will detonate.

awesome, oh well I'll keep running around at 10psi loving the car.

[gte]

FI newbs?

You psuedo-elitist jackass, I have more "FI" knowledge in my pinky, then you have in your whole body


Tell me this, (this is a rhetorical question, but not something you could easily google) how would you change the stock 2zz piston and oiling design, to better work with turbocharging?





Or you can properly research this and find out that with the stock compression you can run 8-9psi without too many issues. I love it when the FI newbs come on and want to buy a turbo kit and run it at 3 psi because they think anything more will detonate.

awesome, oh well I'll keep running around at 10psi loving the car.

[Jesse IL]

And that was much more of the type of answer I was looking for. If the ring landings are too close to the top of the piston and susceptible to high cylinder pressures that cause them to fail above the approximate PMEP at 300rwhp (or the average torque equivalent), then better designed/stronger pistons is the only alternative.

Thanks for being cordial with this response. :)
No problem. If there were more threads like this, I'd post more often. having been around here for a long time and having seen engines built a number of different ways, the current thinking for the "best" F/I engine build is a stock block with Mahle pistons.

Pistons such as the Wisecos I have in my motor are not compatible with the factory MMC cylinders and need to be run in sleeved motors. What Boosted2.0 found in recent flowbench research is that the valve cutouts you see in the top of the cylinders in the above pictures deshroud the valves significantly and have a significant impact on flow. That's why people are trying to go back to stock blocks with the Mahle pistons, since they have a special coating that allows them to run in the MMC cylinders.

The issue most people have is that on a used block, there is too much wear in the cylinders and the piston to wall tolerance is too high. So the current "recommended" solution is to buy a brand new shortblock from Toyota and replace the pistons and rod bearings. The cost of this is surprisingly comparable to sleeving the block and the comparison gets even better when you figure that you can make some money back selling the used shortblock.

[Smaay]

what Jesse said is totally correct. brand new shortblocks can be purchased from Toyota for about 1500 bucks. just pull the rods, replace the pistons and rod bearings and rock and roll. i would also suggest looking into a used head somewhere and just rebuild it with new parth. then you can sell your used long block and make back a good amount of your money

[zzz]

Wait so....mahle pistons are better than wiseco pistons with darton sleeves? What power levels are we talking?

I r confused.

[youngxlos]

the sleeves will allow you to run more boost, I guess you can say for stupid crazy 2zz turbo builds go with sleeve block and wiseco, if you are just doing a slap on turbo and are going to be running 8-9psi stick with the stock short block and Mahles.

[Jesse IL]

i would also suggest looking into a used head somewhere and just rebuild it with new parth.
I believe the number of good condition, used, non-air injection heads is getting to be somewhat of an issue. I believe there are too many out there that are warped or the sealing surface is in bad enough shape that machining them flat would remove too much material.

Frankly if it were my project, I'd simply pull the head off intact and just move it right over to the new block. No worries about valve adjustments, warpage or the sealing surface getting messed up.

[gte]

Hmmm,

What type of piston to wall clearance do you all set? I usually like 3 to 3.5 thousandths but I don't want piston slap which is why I was hoping to stay with stock ... does anyone know the silicone content of the mahle pistons? What type of expansion rate they have?

I have a spare engine sitting in the garage, that I use to fabricate on, so I'm not sure if I want to go with the idea of sleeves or not. Anyone ever sleeved it and threw in factory pistons from say a 7m (it's 1mm overbore)? That may not be worth it, if piston to valve relief clearancing is required, but I really really hate piston slap, at least in a daily :D . I don't mind it in my Supras.

Since we are on the subject, what type of torque can the factory rods take?



No problem. If there were more threads like this, I'd post more often. having been around here for a long time and having seen engines built a number of different ways, the current thinking for the "best" F/I engine build is a stock block with Mahle pistons.

Pistons such as the Wisecos I have in my motor are not compatible with the factory MMC cylinders and need to be run in sleeved motors. What Boosted2.0 found in recent flowbench research is that the valve cutouts you see in the top of the cylinders in the above pictures deshroud the valves significantly and have a significant impact on flow. That's why people are trying to go back to stock blocks with the Mahle pistons, since they have a special coating that allows them to run in the MMC cylinders.

The issue most people have is that on a used block, there is too much wear in the cylinders and the piston to wall tolerance is too high. So the current "recommended" solution is to buy a brand new shortblock from Toyota and replace the pistons and rod bearings. The cost of this is surprisingly comparable to sleeving the block and the comparison gets even better when you figure that you can make some money back selling the used shortblock.

what Jesse said is totally correct. brand new shortblocks can be purchased from Toyota for about 1500 bucks. just pull the rods, replace the pistons and rod bearings and rock and roll. i would also suggest looking into a used head somewhere and just rebuild it with new parth. then you can sell your used long block and make back a good amount of your money

[gte]

I found a number for Mahle and called them.

They recommend 2 to 2.5 thousandths 13% silicone, and their coating takes up 1 thousandth of that free play, so I would imagine they are very quiet with such a low expansion rate and that makes me happy :).

I'll just have to see what type of condition the cylinder walls in my other motor are and decide from there.

[Jesse IL]

My Wisecos slap a tiny bit when cold but quiet right up. As far as the rods, nobody has yet failed the 2ZZ rods. Many people run stock rods on built engines. Most people are purchasing aftermarket rods for balance more than anything. While on this subject, the main bearings have never been known to fail on any engine but the rod bearings are known to spin. Most people run MWR upgraded rod bearings, but they don't come in a variety of sizes so you'd have to size the rod ends to really set the clearance where you want.

Another thing I'd almost say you need is an upgraded oil pump (MWR sells this). These won't fail typically, but if you ever over rev the motor, it's basically a ticking bomb. Another thing that happens is the stock valves mushroom above 8500 rpm. Not an issue if you stay within the stock rev range, which is really all that's usable with the stock cams and intake manifold. I'd say upgrade the valves to be safe, but there have been a number of mysterious valve failures lately and for that reason I'd stick with stock valves unless I was doing other work like stiffer springs.

[SuperDave]

As far as the rods, nobody has yet failed the 2ZZ rods.
One of the engines I have sitting here didn't like going to 8800rpm on a daily basis, http://i33.photobucket.com/albums/d65/billybob156/toyotaclub/2zz%20engine/coreys/P1040933.jpg. It wasn't a hydrolock failure either, I know as I was following it when it went bang.

[Jesse IL]

That's definitely the first I've seen that wasn't from a hydrolock.

[gte]

I'd love to put that next to a factory 2jz rod, it's hard to gauge its thickness from a picture



One of the engines I have sitting here didn't like going to 8800rpm on a daily basis, http://i33.photobucket.com/albums/d65/billybob156/toyotaclub/2zz%20engine/coreys/P1040933.jpg. It wasn't a hydrolock failure either, I know as I was following it at the time.

[SuperDave]

That's definitely the first I've seen that wasn't from a hydrolock.

I still think there was a manufacturing error in that rod, but no way to check as the rod pounded the block a number of times thus removing any evidence. Since I have no intention of using the remaining 3 rods might be interesting to see how much tension they can take. But I think we are starting to move off topic.

gte: Unfortunately I don't own any 2jz rods :gap:, could always measure it I guess.

[monkeywrench]

Wait so....mahle pistons are better than wiseco pistons with darton sleeves? What power levels are we talking?

I r confused.

We've run the Mahles without sleeves to 30+ psi many times. We've run them for miles at a time over 9000rpm. They work fine.

The stock valves do mushroom a bit but more importantly the heads break off if they're run at high rpm a lot. Major destruction.

[GSBoek]

Major destruction. :chuckles: I still have two valve heads embedded in an old head.

[zzz]

We've run the Mahles without sleeves to 30+ psi many times. We've run them for miles at a time over 9000rpm. They work fine.

The stock valves do mushroom a bit but more importantly the heads break off if they're run at high rpm a lot. Major destruction.

what rods are you guys using?

[deercelica]

running 8-9psi stick with the stock short block and Mahles


Mahles in stock short block should be able to see much more than 8-9psi. But how much PSI are we talking with low compressions?

[gte]

It depends on the turbo, because different turbos have different efficiency ranges, and how a turbo heats the compressed air and restricts the exhaust flow directly correlates to the amount of pressure that premium gas can support safely.



Mahles in stock short block should be able to see much more than 8-9psi. But how much PSI are we talking with low compressions?

[gte]

Stumbled upon this today when looking for something else, says they have them for the GT and GTS

http://www.jscspeed.com/celica/engine/headgaskets.htm

[bt216]

Stumbled upon this today when looking for something else, says they have them for the GT and GTS
thats :bs: call Cometic.

[vamis]

At details is mentioned 87mm bore. I imagine how will look like GTS block :rofl:

[sillycar09]

i had put 1.8 metal gasket to low compression..
so far dont have any problem :D...
can boost higher ....
safe money too :)

[gte]

I called them last month ... I'm guessing that someone commissioned them to make head gaskets, and gave them a few measurements, and they made the custom gaskets as a 1 time run for that company. If not, then yes it is BS.


thats :bs: call Cometic.

[gte]

Which motor, which turbo, how much boost, how much power/torque?



i had put 1.8 metal gasket to low compression..
so far dont have any problem :D...
can boost higher ....
safe money too :)

[bt216]

they make a metal gasket for the 1zz, so that would be my bet.

[sillycar09]

Mahles in stock short block should be able to see much more than 8-9psi. But how much PSI are we talking with low compressions?

We've run the Mahles without sleeves to 30+ psi many times. We've run them for miles at a time over 9000rpm. They work fine.

.