Hello everyone,

Read this for more COMPLETE and COMPREHENSIVE guide.http://www.nicoclub.com/articles.php?id=238409

This will be my project thread where I show you how I prepare a SR20DET head to rev over 9000 RPM. I will post information/pics as they come by. When I am done, this thread should be a massive DIY on how to work with SR20DET head.

I will show you how to disassemble a SR head properly, replace valve stem seals, upgrade valve springs + retainers, install aftermarket cams, install Tomei solid lifters and shim them properly, and how to assemble everything together properly.

All the work that I am doing is with the head out of the motor. But you do pretty much the same thing except if you are doing this with it still attached to the block, you NEED to pressurize the cylinders so that the valves don't drop.

Ok here it goes...

Information regarding solid lifters start on PAGE 2!!

I've decided to switch cams to Tomei solid 270 cams as opposed to BC cams. New pics and info on PAGE 4 *scroll down*!!

The head that I will be working onIt is a little grimy and nasty... But the rocker pads and cam lobes are actually pretty shiny when cleaned.

Brian Crower Stage 2 cams 264 duration and 12.05mm lift

It even came with Redline Assembly Lube. Sweet.

Redline Assy Lube

Cams

Casting Marks

Brian Crower Valve Springs + Titanium Retianers

Stock spring to the left. BC to the right.BC spring is considerably stiffer than the stock unit. I can barely compress it when I try it with my fingers. Also notice that stock spring's top and bottom (green paint) are shaped differently but BC unit is the same. This means you can install this with no specific orientation unlike the stock ones.

Stock retainer to the left. BC to the right.The BC unit is much lighter than the stock. I measured the both with a caliper and they are both with-in .001" of each other except for the retainer height. There was about .015" of difference where the BC unit was shorter.

Valve Stem SealsOnes in the baggie are the intake ones and the ones in the blue packaging are exhaust ones. If you want to order them, intake ones get it from 91 Nissan Sentra and the exhaust ones you can get from any DOHC KA.

This is why int & exh valve seals are different.Exhaust valves are filled with sodium. Hence thicker.

Intake valve

Now let's start taking things apart. But before you do... EVERYTHING THAT YOU TAKE OUT MUST GO BACK IN THE SAME PLACE. I can't stress this enough. This includes Cam caps, rocker arms, shims, rocker guides, lifters, valves, etc etc Unless you are going to re-shim everything this is VERY VERY important. I am going to re-shim everything due to going solid lifters but if you are not you need to keep that in mind. But regardless, cam caps must be in order.

If you haven't already done so, mark your cam caps if there are no markings already. Mine came makred with 2,3,4 as shown below so this makes things easier for me but I've seen many cam caps that does not come marked like that.

Start loosening things in the order shown below.

Take the cams out by simply lifting on them.

Now take the rocker arms out along with rocker guides/shims and lifters. Once again, keep them in order.Using a magnetic wand on the shims makes it alot easier to take them out.

Sometimes, lifters are very stubborn to come out. Gently, pull it with a plier. I stress gently.

Everything in Order. For some reason, this head was missing a rocker arm and everything else on 3rd exhaust bank. This is not a big deal for me as I need to re-shim everything.

Everything is in a labeled bag. For example, Rocker arm+rocker guide/shim + lifter that came out of the 1st bank of the exhaust size is labeled with E1 and so forth to help me keep track of where it came from. I do not need to do this for this head but you need to if you are re-using those parts.

Oh and did you ever wonder what a lifter looks like when it needs to be bled? See the movie.http://www-personal.umich.edu/...3.aviI will show you how to take care of this later on

The head as it sits now...

Next will be removing valve springs and bleeding lifters.

Modified by ILikeMy240sx at 4:43 PM 2/5/2007

Modified by ILikeMy240sx at 10:27 PM 2/20/2007
Modified by ILikeMy240sx at 7:44 PM 4/3/2007

You're doing the exact same thing I am, very awesome.

Just curious, where did you buy everything from? Also, when you expecting it to be done?

I got the cams from a member from NICO. The head as well.

Valve springs + retainers I got it from Enjuku with their special pricing on FA memebers.

Tomei lifters from RHD Japan but they are taking forever to ship these farkers our.

Ohhhooooo! I am pitching a 12 person tent.

hell yeah, extremely well written begining to a great write up.

Wow...well written!!!

i feel a little dumb asking this but to remove the head out of the car do i need to remove the cams first, or just take the timing chain off.

you need to remove more than the "timing chain" but the cam's can obviously stay in the head, as he has shown.

Lawl

xsublimefrekx wrote:i feel a little dumb asking this but to remove the head out of the car do i need to remove the cams first, or just take the timing chain off.

just take off the chain tensioner and move the chain off but be careful not to drop the chain to the bottom

thats what i thought i just wanted to make sure. Thanks for the help and sorry to hijack the thread.

I have a question, if I were to install some new BC valves do I need to install new valve guides or will the old ones work fine?

Old ones will do unless your guides are worn out. You need to go to a machine shop to have them press it out and also press them in. Its a pain.

To figure out whether you need to replace, measure the OD of the valve stem and measure the ID of the valve guides and if the clearance (ID-OD) is not with in spec you need to replace the guides.

To remove the timing chain off the cam pulleys.

1. Take the tensioner off

2. Take the CAS off but you might want to mark the orientation so that when you install it, its close to 15 deg of timing.

3. Loosen the cam pulleys with the following tools

4. There is a pin on the front cover that prevents the chain from skipping a toooth on the crank sprocket but I would still try to prevent it from falling down the front cover.

I'm basically doing the same set up. How much did the tomei lifters run? Are you going +1mm valves or not? Any port and polish?

Ladies and Gents. I just finished taking all the pictures for write up on how to remove and install valve springs...

I just got to put it together now.

Thanks for being patient. I will have it up soon.

Uploading the pictures and resizing them as I write this...
Modified by ILikeMy240sx at 11:22 PM 1/20/2007

This write up is great. I literally refresh the page every ten minutes to see if it is updated

are you going solid lifter? Hydrolic lifer wont hold up to those rpms without getting valve float.

Wow... someone needs to brush up on his reading skills.

JK no offense ;-)

Yes, Tomei ones. I havent gotten them because they are on back order and RHDJapan is taking forever to ship them out.

sorry didnt want to read that all and I saw you posted a vid of needing to bleed hydrolic lifters.

Blown240sx wrote:sorry didnt want to read that all and I saw you posted a vid of needing to bleed hydrolic lifters.

Yeah Im trying to gear this write up towards everyone even for people who are doing a simple valve seal replacement. So, Im trying to show every thing possible.

this thread makes me hot

Ok, this post will focus mainly on replacing and installing valve springs. It will also cover removing valve stem seals.

There are many tools available for removing valve springs but here are my personal favorite two. Other ones just take too much effort to get them to work. The one you see in the red box is from Snap-on and the one on the bottom is from Matco but Snap-on also sells them.

The small tool is composed of two pieces.

Now taking the valve springs offSo, to use the small tool, take only the silver part of the tool and put it over the retainer.

Then give it a good wack with a rubber mallet as shown. Please dont use a hard surface hammer as that will damage the tools. You might have to give it multiple hits because sometimes only one valve keeper will come out.You can also push on the tool very hard. Its more effective when you push but requires more strength and effort.

When both valve keepers come off, you will see this because the end of the tool is magnetic.

Take the retainer off and inside you will see both keepers.

Now I will show you how to use the snap-on tool. (MY RECOMMENDATION)

First remove the 1st and 5th cam caps from both the intake and the exhaust side as shown.

Install one end of the leg with supplied bolts and washers.

Install the other end of the leg but do not tighten the bolts yet.

Insert the bar through the top holes and align the left leg so that the bar is straight. Now tighten the bolts on the left leg.

Assemble the remaining pieces as shown. I found number 2 hole to work the best

Stuff a tower underneath the valves that you are working on so that the valves do not move. If you are doing this with the head still on the motor, you NEED to pressurize the combustion chamber so that the valves dont fall down.

Use the bar and put the tool on top of the retainer like this

Now grab the handle and push down hard. Compress until the keepers are loose like this.

Take a magnetic wand and get the keepers out.

All springs taken out on the exhaust side.

Now Installing Valve SpringsJust for a reference, how keepers go on the valve.

Ok now for the steps... First put the keepers in the retainer as shown

Put it over the spring that you want to install.

So its sitting on the spring waiting for you to compress it :-)

Silver tool sucks for this job. Basically you put the black end on, and compress it using your own force... which does not work every well especially with aftermarket springs which are HARD to compress.

Using that tool, you will end up with something retarded like this... Ugh

Now lets use the snap-on tool. MY RECOMMENDATIONPlace the tool over the retainer/spring that you want to install

Compress the tool and the keepers will want to come loose like this

Use your fingers like this through the side and try to keep those keepers on the valve stem.

Now the spring is compressed enough so that I can use my finger to place those keepers on the stem either ON the groove or past the groove.

Let go of the tool and voila!

Now let's do that with Brian Crower Retainers and Springs.Once again, put the keepers in the retainer like shown.

Put it on the valve you want to install it on.

Once agian, you need to use your fingers as you compress the tool

Like shown, compress the springs far enough so that you can use your fingers to place the keepers on the valve.

Let go of your tool and voila! There is your BC retainer and spring.
Modified by ILikeMy240sx at 12:53 AM 1/21/2007

Now taking the valve seals off.

If your head is still on the motor, you cant take the vales off. So you can use a plier like this but I highly recommend taking the seals off using a special valve seal remover. With the valve still in, its very difficult.

Push the valves out for easy removal. Here they are. All eight valves on the exh side.

Take a plier and grab on it. Now twist and pull. You need to keep twisting as you pull because these suckers are on there tight. This is why with the valves in there, you need a special plier that removes valve seals.

Its like pulling a damn tooth out.

All eight of these farkers taken out.

Head as it sits now...

Now you do not need to do this if you are just replacing seals or valve springs but if you are taking this head for a machine work (like I am) pr going to clean it (like I am) then you need to take the valve spring seats out. Use a magnetic wand for this as well.

It will come out like this.

All eight of them out. Keep them in order if possible.

How I keep everything together for storage

In the box, in order.

Just got a word that my Tomei solid lifters will be shipped out on Monday. I still need to get a rocker arm some how... Anyone have a spare one in good condition for sale?

wow love the build up... what turbo are you going to use seeing thzt you are going to be spinning that motor out so far... also you are going to hot tank the head before you reinstall all the componets right

GT2871R if the .64 a/r has too much torque drop up there then I will swap it out for .86 a/r

Yes, I am going to hot tank that sucker... that thing is way too dirty haha.

awsome work. i will keep this page in mind when i pull my head back out... now are you going to build up the bottom end? or with all this head work it should be okay for 9g rev?

Im not touching the bottom end until something goes boom haha. I want to find the limit of the stock bottom end before I go forged internals. I do have a fresh stock rebuild tho... only 5k miles ago.

When I do go forged internals, I should probably have spare trannies laying around for the amt of power I want to make haha.

BTW, My Tomei Sold Lifters and Shims have been shipped YAY!!!!!
Modified by ILikeMy240sx at 11:56 PM 1/21/2007

great post