Sr20 head gasket advice

[Farmerbuiltsr]

Hey there I'm new to the group and I have a question for yas. I have a black top sr that I have put the greddy intake, 600 injectors, gt2860rs turbo, top mount exhaust manifold, and I'm hoping to put stage 1 or 2 cams in. Now I'm wondering what kind/ thickness of head gasket I should get for it? The motor is going into my eunos roadster, thanks very much for the help



Sent from my iPhone using Tapatalk

[KAT-PWR]

Oem
That's all

[jedi03]

That's usually easiest...calculating compression ratio is a bit much for just doing a fun driver with a mild build

[brndck]

there are plenty of good calculators online, I personally only use APEXi head gaskets, but plenty of other people use Cosworth or other brands with no issue. If you aren't changing pistons or stroke length, I don't really see any reason to change head gasket thickness though.

[Jorgs_7]

Don't know why anyone would put an OEM head gasket back In there. For OEM power, sure.

MLS without a doubt. (reputable brand)

[S14kouki805]

Metal, I had already installed an OEM on my build and said fuck it tore the head off again and went with an APEX unit I copped on here.

Do it once, do it right.

[Kingtal0n]

If you have a stock piston, you run an OEM head gasket.

cheap insurance to fragmenting them like miniature glass figurines.

[jedi03]

I guess we will see how well mine holds up...I don't see why you would other than to change the hight between the motor and the head, if I had milled anything, run bigger valves or had higher pistons...otherwise I have seen with a proper tune, a stock bottom end with cams and gears as the only internal change run 600 whp for 4 years before drifting finally took its toll on the engine...torque it correctly and tune it right and it will hold up

[brndck]

If you have a stock piston, you run an OEM head gasket.

cheap insurance to fragmenting them like miniature glass figurines.

you're saying better to pop a head gasket than melt a piston? I'm not sure I follow the reasoning here, plz explain in further detail.

[Kingtal0n]

you're saying better to pop a head gasket than melt a piston? I'm not sure I follow the reasoning here, plz explain in further detail.

Well, you see, cast aluminum pistons are a lot like the dimer crystals of acetone peroxide, easy to upset. And using a beefy headgasket is like having the crystals form on the threads, of the lid, of a glass mason jar.



quite undesirable should the unthinkable happen

[KAT-PWR]

MWF Kingtalons example is just pure lunacy
http://blacksportsonline.com/home/wp-content/uploads/2015/06/nick-young-confused-face.jpg

[cotbu]

[emoji38] !

[Kingtal0n]

?? The "question" does not actually call for a response?

ceiling cat approves this message

[Croustibat]

you're saying better to pop a head gasket than melt a piston? I'm not sure I follow the reasoning here, plz explain in further detail.

That is the whole point of a paperlike headgasket.

Anyway the stock pistons won't like what the op has in store for them and will blow their ringlands, no matter the headgasket used

[brndck]

My personal experience is 12 years on the same SR, much of that time was with a t28, Greddy intake manifold and tubular exhaust manifold, the last 4 years have been:
-Apexi head gasket with arp head studs, built head with Brian Crower valvetrain and tomei poncams, hks gt2540 turbo, 550 injectors and running 1 bar. Never melted or grenaded a piston, never blew or seized. Engine still runs fine the oil pressure is getting low when the oil is hot so I'm retiring it while I'm building a gnarly engine to replace it. I've put well over 100k on it.

[pacotaco345]

That is the whole point of a paperlike headgasket.

Anyway the stock pistons won't like what the op has in store for them and will blow their ringlands, no matter the headgasket used

Truu, I blew the ringlands off of the number 1 piston in my last SR when (i assume that) I overboosted an s14 t28. Like really? An s14 t28 shouldn't blow up a motor at any boost level. The motor had a VERY conservative enthalpy tune on it too.

[mewantkouki]

Apexi

Melted two holes in the piston of cylinder 2 and had detonation damage to the point where it pitted the quench pads on the head and melted the aluminum around the sleeve in the block. Head gasket did not blow... Removed, cleaned with brake parts cleaner, and re-used on a different long block that made 350whp. For the record neither engine had deck work done to the head or block. Surfaces were scraped with a carbide scraper and non abrasive scotch brite pads, checked with a straight edge & copper spray applied to head gasket.

Piston for reference & head gasket in question (post removal)
http://i35.photobucket.com/albums/d200/ooberplex/Black%20Car/piston.jpg (http://s35.photobucket.com/user/ooberplex/media/Black%20Car/piston.jpg.html)
http://i35.photobucket.com/albums/d200/ooberplex/IMG_7511.jpg (http://s35.photobucket.com/user/ooberplex/media/IMG_7511.jpg.html)

I've heard good things about cosworth but I can personally vouch for apexi. I have also seen one withstand a 40psi boost spike from a gt3071r

[Croustibat]

The problem is quite never the HG, it is the people who install one without conforming to the instruction. Heard tons of horror stories about cometic HG, but i have never seen one blow when the head & block were decked with the prescribed finish for example ...

My personal experience is 12 years on the same SR, much of that time was with a t28, Greddy intake manifold and tubular exhaust manifold, the last 4 years have been:
-Apexi head gasket with arp head studs, built head with Brian Crower valvetrain and tomei poncams, hks gt2540 turbo, 550 injectors and running 1 bar. Never melted or grenaded a piston, never blew or seized. Engine still runs fine the oil pressure is getting low when the oil is hot so I'm retiring it while I'm building a gnarly engine to replace it. I've put well over 100k on it.

We got SRs in every stock S14 here, and a lot of S13 get swapped with one too. blown ringlands with 1 bar boost ? This happens quite often, you just need a poor gas batch and some hard use. It dets easily and the ringlands are too thin.

The most probable reason you didn't blew it is the head work, removing the squish zone is a good way to prevent them. The cams could be of help too. Or it could be you are not pushing it much :D I used to have no cooling nor braking problems. Then i installed good tires, and problems rose.

TBH i would never bother with headwork or cams on an SR. Either stay stock or get a built bottom end with the turbo of your choice. Once forged the bottom end can take nearly anything you can throw at it. I'd personnally start doing headwork when pushing at least 1.6bar, the $$$/hp ratio is just not worth it before that. But at that point you can kiss your transmission goodbye, so i'd rather spend the money on a Z33 box than on the head. And then if i'd want more power, i'd go VE head. i really can't see the point in building a DET head, esp to push 1bar boost.

[Dboyizmlg]

MWF Kingtalons example is just pure lunacy
http://blacksportsonline.com/home/wp-content/uploads/2015/06/nick-young-confused-face.jpg

LMAO.

Im running a stock head gasket, with stock head bolts. Never removed the head.
368whp at 17psi, on E85 fuel, dynapack dyno.
I have been this way for about 9 months.

I get up to 55 on knock though, but its from valve springs, or some thing in the block.
I know I need to check that out soon.

[Kingtal0n]

Apexi

Melted two holes in the piston of cylinder 2 and had detonation damage to the point where it pitted the quench pads on the head and melted the aluminum around the sleeve in the block. Head gasket did not blow...

This is exactly what I am talking about. If you had an OEM HG you might have popped it before doing any internals damage. It is a safety net with a nice fat margin for error. Installing a serious HG is removing that margin of error. I've tuned 10 or 20 sr20det engines with 400 horses on OEM internals and OEM head gaskets. There is nothing about an OEM piston engine that requires a serious HG. If you want 450+RWHP you need forgies before the head gasket, at which point I am recommending an LSx engine over a forged internals sr20det, because a typical OEM LSx engine +turbo will hold 500~rwhp in a daily driver application without even opening the engine ($800 longblock).

The sr aint the option it used to be for 500whp daily drivers

[mewantkouki]

Engine let go at 7600rpm in 5th gear in 90 degree weather. (Witness exists to prove this.) Yes, it was a stupid thing to do. There is no amount of tuning that could have prevented that. Me trying to be Smokey Nagata exceeded what factory hardware was capable of. OEM head gasket or not the engine was doomed either way. Plain and simple.

[kashira kureijii]

Well, you see, cast aluminum pistons are a lot like the dimer crystals of acetone peroxide, easy to upset. And using a beefy headgasket is like having the crystals form on the threads, of the lid, of a glass mason jar.quite undesirable should the unthinkable happen

does the dimer version make a chair structure? it has 6 positions.....haha freaking chair structures man

MWF Kingtalons example is just pure lunacy


It's not lunacy man, he is obviously all about that organic chemistry life, and on closer inspection a badass. look at the other names according to wikipedia

"Other names
Triacetone Triperoxide
Peroxyacetone
Mother of Satan"

Mother of Satan haha. damn son. he must have a lot of fun working with that stuff

Anyway a lot of this whole bottom end destroying business in SR has a lot to do with the way people drive em, in my opinion. If you watch your oil pressure gauge, there is a lot of difference in pressure between rpms. between idle and 3k, there is a 40psi difference. at high rpms this is likely even more exaggerated. SR's also drop rpm's very quickly. Yet people still blip the throttle, redline the engine and then immediately let off, instead of letting it work down. the drop in rpms and oil pressure is pretty dramatic, and one can imagine how it stresses the engine. I feel like by keeping it on gas and letting it work down it is easier on the bearings. Thats how I drive anyway.

[S14kouki805]

This is exactly what I am talking about. If you had an OEM HG you might have popped it before doing any internals damage. It is a safety net with a nice fat margin for error. Installing a serious HG is removing that margin of error. I've tuned 10 or 20 sr20det engines with 400 horses on OEM internals and OEM head gaskets. There is nothing about an OEM piston engine that requires a serious HG. If you want 450+RWHP you need forgies before the head gasket, at which point I am recommending an LSx engine over a forged internals sr20det, because a typical OEM LSx engine +turbo will hold 500~rwhp in a daily driver application without even opening the engine ($800 longblock).

The sr aint the option it used to be for 500whp daily drivers

Mmmm I actually blew my engine a similar way with an OEM gasket. So the head gasket was not a fail safe in that situation.

[Kingtal0n]

Engine let go at 7600rpm in 5th gear in 90 degree weather. (Witness exists to prove this.) Yes, it was a stupid thing to do. There is no amount of tuning that could have prevented that. Me trying to be Smokey Nagata exceeded what factory hardware was capable of. OEM head gasket or not the engine was doomed either way. Plain and simple.

Well, rpm/oiling does not cause piston damage like that. I would rule out RPM as a feature of the disintegration. That leaves heat and pressure. Pressure should push out an OEM head gasket easier than it does a metal one. High temperatures by themselves can deform metal of course, and it is a combination of heat and pressure which appears to have pushed itself past the piston in the example you posted. High temperature is associated with the speeding of reactions like combustion, (that is why we like water injection), and so higher temps by themselves tend to increase pressure, in a way heat IS pressure, and those are the only two things that the headgasket really has to deal with (there is very little wear/tear otherwise, on an HG)


Mmmm I actually blew my engine a similar way with an OEM gasket. So the head gasket was not a fail safe in that situation.

This is a testament to the capability of the OEM HG: Even it is strong enough to allow us to ruin the engine, as they aren't exactly super easy to blow open, I've never even experienced a HG failure on any sr20det. It is just an extra protection, an extra point of failsafe in a system which can fail due to heat and/or pressure. It seems silly to "weld" the head to block when I can have this extra level of protection between them. If you are paying attention to the air fuel ratio and EGT, you are controlling temperature (they cannot "escape" notice) which leaves cylinder pressure as a function of (besides temp which we are watching) timing and engine VE, engine VE is hopefully as high as possible and I decide the timing based on expected VE and by knowing the octane, and finally intended use of the vehicle (how much will it weigh, how will it be used) after thorough inspection for supporting hardware.

Like a condom, it doesn't always help, but it might.

[derass]

I've tuned 10 or 20 sr20det engines with 400 horses on OEM internals and OEM head gaskets.

Were these unopened engines? I've seen people recommend the use of an OEM head gasket and ARP studs as a slight upgrade.

My tuner stopped at 15psi / 320 whp saying that was a safe limit for my track-only use and stock h/g. I'd like to make the push for ~20 psi / 400 whp but I'm unsure of what to do about the h/g.

[cotbu]

The headgasket doesn't care how much boost you run! Your tuner is lying if he can tell you what's the safe boost or power for a gasket is. Even if everyone on the Interweb recommended metal headgaskets for 300hp. That will not make it law. If so, megan racing would be considered top quality. Every body loves their megan racing parts.[emoji41]

[mewantkouki]

Well, rpm/oiling does not cause piston damage like that. I would rule out RPM as a feature of the disintegration. That leaves heat and pressure. Pressure should push out an OEM head gasket easier than it does a metal one. High temperatures by themselves can deform metal of course, and it is a combination of heat and pressure which appears to have pushed itself past the piston in the example you posted. High temperature is associated with the speeding of reactions like combustion, (that is why we like water injection), and so higher temps by themselves tend to increase pressure, in a way heat IS pressure, and those are the only two things that the headgasket really has to deal with (there is very little wear/tear otherwise, on an HG)




This is a testament to the capability of the OEM HG: Even it is strong enough to allow us to ruin the engine, as they aren't exactly super easy to blow open, I've never even experienced a HG failure on any sr20det. It is just an extra protection, an extra point of failsafe in a system which can fail due to heat and/or pressure. It seems silly to "weld" the head to block when I can have this extra level of protection between them. If you are paying attention to the air fuel ratio and EGT, you are controlling temperature (they cannot "escape" notice) which leaves cylinder pressure as a function of (besides temp which we are watching) timing and engine VE, engine VE is hopefully as high as possible and I decide the timing based on expected VE and by knowing the octane, and finally intended use of the vehicle (how much will it weigh, how will it be used) after thorough inspection for supporting hardware.

Like a condom, it doesn't always help, but it might.

Heat is was did my engine in. Loading an engine up like that with ambient temperature that high would melt pretty much anything on any sort of a sustained pull. I don't think a CP or Wiseco piston would have handled that flat out pull for much longer than the stocker did.

[Kingtal0n]

Heat is was did my engine in. Loading an engine up like that with ambient temperature that high would melt pretty much anything on any sort of a sustained pull. I don't think a CP or Wiseco piston would have handled that flat out pull for much longer than the stocker did.

I've run forged pistons at lean air fuel ratios. the pistons themselves DID handle several back to back dyno runs at 16:1 air fuel, EGT went off the chart. It never detonated or pinged. the pistons came out looking perfect, the head gasket intact, everything looked normal. This was on 93 pump gas, about 23psi of boost.

What did NOT survive, were the rings. The high temperature caused the piston rings to lose tension, and after the 5th or so pass, it started burping oil (blow by). After a new set of rings was installed, everything went back to normal and the engine is still running fine to this day. This was an experiment to determine if lean air fuel ratios by themselves will cause detonation, head damage, or piston damage.

[Kingtal0n]

Were these unopened engines? I've seen people recommend the use of an OEM head gasket and ARP studs as a slight upgrade.

My tuner stopped at 15psi / 320 whp saying that was a safe limit for my track-only use and stock h/g. I'd like to make the push for ~20 psi / 400 whp but I'm unsure of what to do about the h/g.

the oem piston limit for reliable daily drivers is between 320-380rwhp (the lower the mileage engine you start with, the better your chances at higher power)

All of my customers are informed that 400+ is a bad idea on OEM pistons, but some proceeded anyways "this is not my daily driver". I've never had anyone come back, ever, and tell me their engine blew, so I am not even sure that any did. On the other hand, I have had people come back and tell me that their "temporary engine" (a stock engine temporarily installed in the car while they built one on the side) performed for years afterwards, so well that they never had a reason to install their built motor. My timing numbers are not a secret; I use 9* btdc between 15-20psi of boost on 93 octane, never had any problem, detonation or high EGT, and this fits the majority of 350-400rwhp sr20det setups. If an engine has many "top mount auto-X" type mods, such as additional cooling capacity for engine oil/water, blankets, shields, a large efficient turbo, I have used slightly more, around 10-11* btcd (depends on rpm). But no setup has ever called for 15* on 93. that is a death sentence on the majority of setups, and seems to be the cause for much heartache.

[mewantkouki]

I've run forged pistons at lean air fuel ratios. the pistons themselves DID handle several back to back dyno runs at 16:1 air fuel, EGT went off the chart. It never detonated or pinged. the pistons came out looking perfect, the head gasket intact, everything looked normal. This was on 93 pump gas, about 23psi of boost.

What did NOT survive, were the rings. The high temperature caused the piston rings to lose tension, and after the 5th or so pass, it started burping oil (blow by). After a new set of rings was installed, everything went back to normal and the engine is still running fine to this day. This was an experiment to determine if lean air fuel ratios by themselves will cause detonation, head damage, or piston damage.


There's a difference between a dyno pull and flat out on a road. I'm talking about a sustained pull held at that rpm for a length of time.