SR20 Head Gasket Selection

[CamryOnBronze]

So I have been reading threads and other resources all over the web for a couple of weeks about head gasket installation on the SR20DET, and I think I am finally ready to give it a shot. The engine is on the stand and I will be removing the head this weekend.

I need to order a head gasket and studs, but I am sort of lost with all of the choices out there. I have heard good things about the Apexi head gasket, as well as Cometic- which makes me a little nervous just because of the price difference. I am not sure which brand and specs to choose for my application. Some of this info might not be relevant, but this is what my setup will be when everything is reassembled:

1993 S13 SR20DET Blacktop
Stock bottom end
__________ head gasket
ARP head studs
Stock valve train (If anything, Tomei Poncams with stock cam gears)
Tomei rocker arm stoppers
GT28R (s15) BB turbo
Dif turbo lines
HKS actuator
Tomei turbo manifold
GReddy suction kit
Z32 MAF
Deatschwerks 650cc injectors
Z32 fuel filter
GReddy intake manifold
Walbro 255 fuel pump
Apexi Power FC

I don't know how much of that info is relevant, but I thought I would post it just in case. I am planning to run a pretty mild/safe/streetable setup, and am not looking for crazy high power/boost numbers. I have purchased an oem oil pump/front cover, s14 oil strainer/pickup, and a GReddy oil pan- so I thought that while the motor is pretty much completely torn apart, I would replace the head gasket and studs. It sounds like this needs to be done if the oil pump is replaced to prevent breaking the front seal on the head gasket. I plan to replace the timing belt setup as well during this process.

Cliff Notes:

1. I'm looking for advice on which head gasket/specs to choose for my setup.

2. Can the head be decked while it is assembled? (with the cams removed)

I want to remove/ take apart as little as possible- get in there, replace the timing chain/head gasket/studs, and get out. I have never touched the inside of a motor before, so the less I have to mess with/potentially screw up- the better.

Thanks for any input/advice you guys may have!

Damon

[rc1honda]

Go with apex-i it worth every penny. Cometic seem to be hit or miss. Some peoples leak and others don't. Also Cosworth and Tomei both make good headgaskets.

If your trying to save a buck then I would go Cosworth. But if you don;t mind paying a little extra i would get apex-i. I have a Apex-i and it never let me down and it has a lot of R&D behind it. I have heard some people talk about how good the fire rings on the apexi are and how you can reuse it 2 or 3 times.

Also only deck the head with internals removed. You don't wanna lose a rocker guide or valve shim at the machine shop and have that be the only reason you can't put the head back on.

Also a head gasket change it pretty st8 forward but it is labor intensive. It's not a quick job will definitley take about 3-5 hours to get the head off. If you have power tools then it's faster. But you have the valve cover, head internals, both manifolds. Also you will have to remove some ancilarry stuff like IC piping, upper collant hose, drain the radiator, and the oil.

Some of the head bolts (not studs) are a PITA to get at. The ones behind the mtor are going to drive you crazy. Also be sure to have a 10mm alan wrench or socket for the head studs. And make sure you have a good torque wrench.

I didnt change my timing chain so im not sure what you have to do. I would get a new tensioner too if you going to change the chain. Do not cheap out on the tensioner, get OEM.

[CamryOnBronze]

Thanks for the input. I should add a few more details:

The motor is out of the car and on a stand. The intake manifold and exhaust manifold/turbo are removed from the motor, as well as the trans/clutch/flywheel (obviously). So it is pretty much ready to have this work done at this point. The bay/car are going to be painted during this process and all of the wiring is going to be sorted out/cleaned up, so I have plenty of time for the install.

I guess I will have to learn more about completely disassembling the head/ valve train. I want to keep things as simple as I can without cheaping out. Obviously I want to replace everything that should be with the right parts, I am just concerned about not having experience with the inside of a motor. I would hate to spend all of this money and time only to have it blow up because of a stupid mistake made on my part. I am, however, very open to learning.

The timing belt components will all be OEM from NissanParts.cc, so no worries on that end. I will do the tensioner and the guides along with the chain.

[jspaeth]

Apex'i +1


Only way to go.

PM me or post up if you have any problems, as I have recently done this and may be able to give you some tips/pointers.

[Jaketenpointo]

Cosworth +1

A bunch of locales run them with good success. The only thing I recommend against is cometic (but everyone has already said that).

[jspaeth]

Cosworth +1

A bunch of locales run them with good success. The only thing I recommend against is cometic (but everyone has already said that).

Cosworth also has had nothing but good reviews on this forum....generally people say stay away from Cometic.


You will get people that say "there's nothing wrong with Cometic, you just have to prepare the head PERFECTLY"...

Based on my readings, you are taken a risk with Cometic.....someone posted up X-ray images that show that the design of Apex'i and Cometic are superior....much stronger/thicker/denser metal rings around the cylinders, whereas Cometic appears to have almost nothing there.

[rc1honda]

Thanks for the input. I should add a few more details:

The motor is out of the car and on a stand. The intake manifold and exhaust manifold/turbo are removed from the motor, as well as the trans/clutch/flywheel (obviously). So it is pretty much ready to have this work done at this point. The bay/car are going to be painted during this process and all of the wiring is going to be sorted out/cleaned up, so I have plenty of time for the install.

I guess I will have to learn more about completely disassembling the head/ valve train. I want to keep things as simple as I can without cheaping out. Obviously I want to replace everything that should be with the right parts, I am just concerned about not having experience with the inside of a motor. I would hate to spend all of this money and time only to have it blow up because of a stupid mistake made on my part. I am, however, very open to learning.

The timing belt components will all be OEM from NissanParts.cc, so no worries on that end. I will do the tensioner and the guides along with the chain.

Ok if you have the motor then it's pretty fast and easy. The head internals can be a little complicated but not really.

This is a good time to pick up some cams and rocker arm stoppers.

Back to the head internals you have the cams, cam caps, cam gears, oil squirters, springs, retainers, rockers, rocker guides, valve shims, valve seals and hydro lifters.

You can go ahead and leave the springs and reatiners in with the valves. You migth wanna buy some new valve seals just for comfort but you would then have to take the springs off which can be a PITA. But if all your doind is changing the gasket then you can leave the springs and retainers and seals in there they won't fall off or move.

The rockers, and guides and shims are a different story though. One thing a really want to stress to you is the inportance of reassembling everything into it's orgininal place. DO NOT REVERSE THE ROCKER GUIDES AND VAVLE SHIMS. If you do you will throw all your rockers no matter what and can kill the motor.

So take the cams off. Take the rockers, guides and shims off and label them in a bag. Guides have the little groove in them for the rocker to rest on. Take the hydo lifters off. Try not to tip them over or you may have to bleed them. All you need is some pliers and you can take the lifters out. I would b;eed them anyway just to make sure before you put them back in, you don't want lifter tap. And then send it off to the machine shop to be decked. But you might wanna clean it out real good with some brake clean and air blower just to make sure there is no metal shavings near you valves and springs.

Other then that you might wanna use a copper spray on the Head gasket. Also make sure you clean the block surface real good. You can scrub it gently and get all the old gasket off there. Just to ensure a good seal. I use it on mine and had perfect leakdown after i was done. It really isn't needed but it doesn't hurt.

[jspaeth]

As mentioned above, key point:

Label EVERY SINGLE nut, bolt, shim, guide, rocker arm, HLA, cam cap, cam bolt, EVERYTHING.

Put everything in separate plastic baggies if need be, but make sure everything goes back in the EXACT same spot you took it out from.

[CamryOnBronze]

Good info guys, I really appreciate it!

Like I said, I have experience with cars and whatnot... pretty much everything except for the inside of an engine, so taking everything apart and screwing something up really worries me. It's good to have all of this info.

Do any of the items that I need to remove the head commonly need to be replaced? Like I said, I'd like to take apart the smallest amount of things that I can, but if I have to pull something anyway and it is a good item to replace, I would be up for it. I am strongly considering doing rocker arm stoppers and Tomei Poncams if I take this all apart, but it sounds like I should be ok with stock cam gears and valve springs/retainers while using those cams, correct?

I will have a friend with a lot of engine experience helping me out, so I think it should be possible. Thanks again, this is great info!

EDIT: Also, how do I choose the correct specs for the head gasket? Is this the one I should be ordering?

http://www.frsport.com/Apexi-814-N107--87mm-x-1-5mm--Metal-Head-Gasket-SR20DET-S13-S14-S15_p_9430.html

[jspaeth]

Honestly, with the engine on a stand, I would just take the whole thing apart.

It will never be anywhere as easy to do as it is when the motor is on a stand.

I would do new springs/retainers (BC sells a kit for $200 on FRSport for springs and retainers....good enough).

Cams if you want to.
Valve stem seals wouldn't be a bad idea...costs maybe $50 for all of them.
maybe a new valve colver gasket depending on the condition of the current one.


You REALLY REALLY should find someone with the "Snap-On Valve Spring Compressor Tool".....it bolts to the head and allows you to use one hand to compress each valve spring while working the keepers with the others.


Also you are gonna want a small magnetic wand for the times when the keepers fall into the head or get stuck "halfway on" but then don't want to wiggle down into position.


Just keep asking us questions as you go.

I would go with the 1.1 mm Apex'i HG.

Stock bore is 86 mm, their HG come a little over....so you want 87 mm x 1.1 mm thick, unless you plan on decking the block....to keep stock-ish compression

[CamryOnBronze]

Alright, good to know. I wasn't planning on decking the block... unless it needed it for some reason, but it sounds like it is usually the head that needs it if anything, correct?

You guys are giving me confidence... I think I might get the HG/studs ordered and give yanking the head off a shot on Sunday. Appreciate the advice... who says you can't get any help on Zilvia? lol.

[koukie180]

One more things to remember besides bleeding the lifters correctly and choosing a good headgasket. Remember to check the if the new oil pump is flushed with the block. If not flush, machine down the oil pump. If flush, remember to apply nissan gasket maker in the front where the headgasket meets the oil pump and head. Apply to both sides.

http://img704.imageshack.us/img704/5500/apexi814n10279424.jpg

For headgasket, buy APEXI period. Apexi uses a Full Grommet style, which means that the cylinder sealing is a full ring that encapsulates all three layers. This is the best possible protection for your engine.

Keep this in mind when buying Apexi headgaskets, 86mm means 87mm and 87mm means 88mm, etc. When you by 86 x 1.1mm, you'll get a 8711 (87x1.1) on the headgasket. The reason is that when you buy head gaskets, its bore size should be 1-2mm bigger than your cylinder bore.

[idamaster]

I have a cosworth 1.5mm HG and I havent had a problem yet with it. Installed with APR studs. All I did was clean the bottom and top end off with a dremel and plastic wire wheel, spray the HG with copper spray then add the sealant like stated above, worked great.

[CamryOnBronze]

Thanks for the input! A friend and I are just about to head out to pull the head now. I'll order the head gasket/studs tomorrow and post up if I run into any issues.

[CamryOnBronze]

OK, a couple of questions for you guys. I removed the head and had it decked, replaced the timing chain and front cover, dropped the head gasket, head, and studs on, etc.

1. The shop that did the head removed the rocker arms, oil squirters, and the small spacers that sit on the vale spring retainers. The valve/valve spring assemblies were not removed or anything- just the stuff on top that was loose and could fall out when the head was turned upside down to surface it.

Each rocker arm has two small round metal spacers that it sits on top of, in addition to the oil squirter. One of these spacers has a groove for the rocker arm to sit in, and the other is flat. Does the grooved spacer on each rocker arm face towards the front of the engine or the rear? Does it matter? I assume that it does, so I wanted to ask to be sure.

2. When I went to reinstall the crank pulley, it is about an inch away from the second notch on it- where we assured it was when we pulled the head. How screwed am I? I have no idea how it would have moved during this process, but obviously that is an issue. Currently the cam shafts are not installed because I am going with Tomei poncams. Before I install the cams, should I turn the crank pulley to the second notch? Will this somehow cause the valves to smack a piston?

I am really embarassed to say this has happened. I honestly have no idea what could have caused this. I feel like turning the crank pulley/crank an inch WITHOUT the cams installed would not hurt anything, but at the same time I am worried this will cause engine threatening issues. Thanks in advance for the feedback- I'd like to finish installing the camshafts tonight, assuming I haven't screwed anything up too bad.

[spiderlone]

Get a Apexi 1.2mm head gasket! Its the best

[aNskY]

OK, a couple of questions for you guys. I removed the head and had it decked, replaced the timing chain and front cover, dropped the head gasket, head, and studs on, etc.

1. The shop that did the head removed the rocker arms, oil squirters, and the small spacers that sit on the vale spring retainers. The valve/valve spring assemblies were not removed or anything- just the stuff on top that was loose and could fall out when the head was turned upside down to surface it.

Each rocker arm has two small round metal spacers that it sits on top of, in addition to the oil squirter. One of these spacers has a groove for the rocker arm to sit in, and the other is flat. Does the grooved spacer on each rocker arm face towards the front of the engine or the rear? Does it matter? I assume that it does, so I wanted to ask to be sure.

2. When I went to reinstall the crank pulley, it is about an inch away from the second notch on it- where we assured it was when we pulled the head. How screwed am I? I have no idea how it would have moved during this process, but obviously that is an issue. Currently the cam shafts are not installed because I am going with Tomei poncams. Before I install the cams, should I turn the crank pulley to the second notch? Will this somehow cause the valves to smack a piston?

I am really embarassed to say this has happened. I honestly have no idea what could have caused this. I feel like turning the crank pulley/crank an inch WITHOUT the cams installed would not hurt anything, but at the same time I am worried this will cause engine threatening issues. Thanks in advance for the feedback- I'd like to finish installing the camshafts tonight, assuming I haven't screwed anything up too bad.


1) intake side the guide (grooved shim) goes in front, exhaust side it goes rear. or it could be visa versa, i dont remember 100%. also every single one needs to go back exactly where it came from as other have already said, or youre going to need to measure them (which is a PITA). get an FSM.

2) crank needs to be TDC on #1. 2nd dot from the left on the pulley.

3) you can spin the crank with the cams out as all the valves will be closed. since youve already done this, youre not going to be able to use the marks on the chain for timing as youll never know when the gold link is on the crank dot. check out enthalpy's website for timing instructions without the marks. with cams in if youre not 100% sure that the timing is right dont spin it. sr's are interference. you will bend valves.

[CamryOnBronze]

1) intake side the guide (grooved shim) goes in front, exhaust side it goes rear. or it could be visa versa, i dont remember 100%. also every single one needs to go back exactly where it came from as other have already said, or youre going to need to measure them (which is a PITA). get an FSM.

2) crank needs to be TDC on #1. 2nd dot from the left on the pulley.

3) you can spin the crank with the cams out as all the valves will be closed. since youve already done this, youre not going to be able to use the marks on the chain for timing as youll never know when the gold link is on the crank dot. check out enthalpy's website for timing instructions without the marks. with cams in if youre not 100% sure that the timing is right dont spin it. sr's are interference. you will bend valves.

Thanks for the response!

1. I have the FSM, so I'll have to look that up. I didn't have it with me last night when I made this post- thanks for the heads up! All of the rockers/washers were bagged up and labeled specifically to where they were removed from, so I should be all set in that department.

2. Correct. We did have the crank pulley at the second notch (TDC) and all of the silver/gold links lined up when we removed the head. This was checked several times to be sure the motor was at TDC.

3. Before the front cover was reinstalled, the timing chain was installed with the gold link lined up with the crank dot. So, right now, I know that the gold dot at the bottom is lined up with the mark on the crank sprocket. If I know that, and I know that the motor/crank pulley were at top dead center when we pulled the head, is it ok to turn the crank pulley an inch so that it is lined up with the second notch again, assuming the cams are not installed (so the valves will not move at all?)

The fact that it is an interference motor is why I am concerned for sure. I just want to know the correct way to proceed so that I don't mess anything up/cause any issues when it is all reassembled.

Cliff Notes:
-Engine was at TDC (second notch on crank pulley with all 3 chain links lined up) when the head was removed.

-Head was decked and reinstalled. New timing chain was installed with gold link lined up with mark on crank sprocket.

-When crank pulley was reinstalled, it was observed that it was off by an inch from TDC. It must have been turned at some point while the head was off.

If it helps at all, here is a picture of the block after the head was removed:

http://img44.imageshack.us/img44/4199/graveyardpullday002.jpg

http://img208.imageshack.us/img208/4590/graveyardpullday004.jpg

And here is the head/valves before it was reinstalled:

http://img18.imageshack.us/img18/1017/cimg0556ff.jpg

[aNskY]

yeah you're fine to turn it, the only thing is you cant be sure if the gold dot is lined up anymore... i would just put it to tdc and use the link counting technique

[CamryOnBronze]

^ Okay, sounds good. I know that the gold link was lined up when we put the front cover back on, so it should not have moved at all. We have had it held at the top so that it wouldn't fall back in and fall off of the crank sprocket, even though I believe there is a dowell on the front cover that prevents that from happening. Thanks for the advice!

[jspaeth]

I have no experience taking the crank pully off.....

As far as shims and guides, as aNskY said, the shims and guides really should go back onto the EXACT same places they came off of.


on the ARPs, I am not sure which ones you have. Some people have gotten "the new" SR20 ones which "supposedly" are 105 ft-lbs.

I ordered mine from FRSport, and they sell VW studs, which I believe everyone with SR20 used before ARP started making SR-specific studs.

For the VW ones, I applied the supplied lube to the threads of the stud (top and bottom), to both surface of the washer, and also to the threads and bottom surface of the nut.

I put the studs in hand tight with an allen key, and then I did them in the proper sequence in increments....I believe I did 30-60-85 or something.

Then drove the car for a while, took cams off (I left my OEM cams on for a bit, knowing I would be taking them off shortly to replace with HKS) and retorqued the headstuds to 85......they DID actually take a little bit more rotation to get to 85 on the second time around.


Hope that helps
If the shop took them everything off and didn't label it, then this is not good.

Each valve, shim, guide, and rocker arm should go back into the same spot from which it was removed.....

[CamryOnBronze]

Thanks for responding, I appreciate it a lot!

I might not have been clear in my post, but the shop DID label and bag each rocker, shim(2 per rocker), and oil squirter individually and labeled where each one came from. He explained to me how he numbered them and I reinstalled them in the same locations he told me they were removed from. The only thing I didn't know was which side of the rocker the grooved spacer went on for the exhaust and intake sides respectively. The actual valves and springs themselves were never removed from the head to the best of my knowledge, so everything should be just peachy in that department.

Good to hear about re-torquing the head bolts- I will have to do that. I got my ARP set from FR Sport as well, but I believe the box said they were for the SR20. The instructions said 80 ft lbs, so I tightened them to those specs in sequence in three (or pretty much equal to get to 80) steps, so hopefully I am in good shape in that department. As long as the whole crank pulley thing goes alright, everything should be fine (knocks on wood).

[CamryOnBronze]

Just for the sake of information, I found in the FSM that the shim (flat, circular spacer) faces the front of the engine on the intake side, and the rear of the engine on the exhaust side (from what I can gather, but this should be correct).

My plan is to install the shim/guides correctly, check the lifters one more time to make sure the shop bled them properly, turn the crank pulley an inch back to TDC, install the cams with the chain links lined up, and hope for the best- unless someone posts up in here and tells me NOT to do so and why. Thanks again for all of the feedback/responses!

[jspaeth]

Just for the sake of information, I found in the FSM that the shim (flat, circular spacer) faces the front of the engine on the intake side, and the rear of the engine on the exhaust side (from what I can gather, but this should be correct).

Yes that is where I was going to point you for that info, that's where I found it, and I had forgotten since.

[aNskY]

ahem

. or it could be visa versa, get an FSM.
.



i knew it was in there :)

[CamryOnBronze]

^ I wasn't doubting you. :) Like I said, I didn't have it with me when I first posted. You were right though! I just wanted to post it for anyone else that might stumble upon this thread someday. :)

[Mister.E]

i asked this in another thread and wasn't really satisfied by the one answer i received. since there is intelligent discussion going on here i'll ask you guys.

when doing head work, if you only replace the springs and retainers do you need to re-shim everything or will the stock shims still suffice?

i.e. replacing stock springs and retainers with BC springs and retainers

[greenman100]

i asked this in another thread and wasn't really satisfied by the one answer i received. since there is intelligent discussion going on here i'll ask you guys.

when doing head work, if you only replace the springs and retainers do you need to re-shim everything or will the stock shims still suffice?

i.e. replacing stock springs and retainers with BC springs and retainers


stock shims are fine. bleed the HLAs and they'll make up the difference.

[jspaeth]

i asked this in another thread and wasn't really satisfied by the one answer i received. since there is intelligent discussion going on here i'll ask you guys.

when doing head work, if you only replace the springs and retainers do you need to re-shim everything or will the stock shims still suffice?

i.e. replacing stock springs and retainers with BC springs and retainers

No, having a stiffer spring or thicker retainer will not effect where the top of the valves are when they are closed, so no re-shimming is necessary at all.

stock shims are fine. bleed the HLAs and they'll make up the difference.


There is no "make up the difference". Unless you change valves or change cams, the top of the valvestem is still physically in the same place when it is fully open or fully closed, regardless of how stiff the springs are or what retainers you are using, since the shims sit right on the top of the valve stem.

[Mister.E]

thanks for the info, that's just the answer i was looking for.

[aNskY]

i asked this in another thread and wasn't really satisfied by the one answer i received. since there is intelligent discussion going on here i'll ask you guys.

when doing head work, if you only replace the springs and retainers do you need to re-shim everything or will the stock shims still suffice?

i.e. replacing stock springs and retainers with BC springs and retainers

valve height wont change. just make sure you label each and every one when you take em out

[Mister.E]

yeah, i have heard that several times. i plan to separate everything into marked sandwich baggy's because i want to get the head deck and hot tanked.

[yabeet]

Is the OEM SR head gasket .8mm or 1.1mm? I am finding conflicting results.

Reason being the block I bought needed to be decked .25mm! :eek3d:

I will also have to remember to shave the front cover, good thing I looked through this thread to remind me.

PS sorry for bumping an old thread.

[mystacarlo]

I have a stock bore block 86m, so the general idea from this thread is i shouldnt have any problems using a 87m head gasket from apexi

[daryl337]

Is the OEM SR head gasket .8mm or 1.1mm? I am finding conflicting results.

Reason being the block I bought needed to be decked .25mm! :eek3d:

I will also have to remember to shave the front cover, good thing I looked through this thread to remind me.

PS sorry for bumping an old thread.


Limit is .2mm between head and block iirc.

If you decide to increase your chances with a larger head gasket, I'd highly recommend you still check valve clearances.


By you even looking for the information though, you may already know that. Just checking.

[Turb]

So I want to order a head gasket kit from frsport and the head gasket is 87mm bore and my motor is completely stock which I'm pretty positive is 86mm bore, am I going to run into any problems?

[harrypotter]

way to revive a way old thread...but here you go


****FOR 86MM (STOCK BORE) ORDER 87MM GASKET****




http://www.enjukuracing.com/products/tomei-sr20det-headgasket.html