How should I prepare for a head swap?

[Eikon]

I am still lost in trying to figure out what is making the strange sound from my RB20det head. Something is just not right.. makes a bit of squeeling or stuggling noise.. not from one of the belts though.

So, I picked up a new head from another NICO member.

I also have a head gasket coming that I bought from another NICO member.

What do you guys recommend doing with the head before I attempt to swap it?

It is a Cefiro head by the way, so I beleive the cams are slightly better from what I have read.

Should I bother taking it apart to check everything out? I have never taken cams out or messed with valves, lifters, etc.. but I am willing to try if there are some reasonably cheap upgrades to be had from doing it.

Should I find a shop to port and polish at least the exhaust side? How much do you think that should cost?

Do I need to find a machines shop to make sure the bottom of the head is perfectly flat, or will the new head gasket be ok?

So far I have spend $100 on a gasket kit, and $250 on the head... I don't want this to turn into a super expensive project.

Thanks!

[skillzilla]

I would leave the valvetrain alone if you are pretty positive it is OK. As for porting and polishing, that can be expensive for sure, depends on where you go. Most places charge around 250 for one head.

Since the head is off Id go ahead and get ARP head studs (order SR20 Main Studs, they are the exact same) it will make it easier to align the gasket and can save your head in the event of overheating. I did the upgrade and I gotta tell you the peace of mind is worth the price

Other than that, Id say youre good to go. One thing though, make sure you put the dipstick in its right place when putting the head back on, I didnt and now checking the oil is a PITA.

[themadscientist]

most important is find a head with a better looking face than yours, that's a lot of work, might as well trade up.

Oh, engine head, my bad, forget what I said you look ok

The steps you take largely depend on what you expect out of the motor when it's back together in the short term.

What do you expect from it in the long term?

what's your comfort zone budget?(what you want to spend)

what's your maximum budget?(what you are willing to spend if you have to)

If your goal for now and the near future is to have a running engine then I would do this.

Check the head for sludge, if it is really nasty bite the bullet and have a shop do a basic overhaul. Basically they take it apart, clean it up, check it for cracks, check the deck-mating surface for straightness and make sure all the moving parts are functional. They should check the seating of the valves and the spring pressures. If you are new to working on engines it is best to hand it off to a pro.

If the head looks like it just needs a little fomy and to clean the gasket surface go ahead, scrub all the carbon out of the chambers and do your best to clean out the water jacket. Keep the cam area buttoned up while you use water and don't get silly with it, the aluminum don't care but everything else in there is steel, bad juju. I assume you don't have the tools, knowledge or specs to check your valve spring pressures but you can ghetto check the valve seating by oiling and rotating the cams so the valve shuts and aiming a flashlight down the port and see if any light sneaks by the seats. You see light, machine shop for an overhaul. Check the mating surface after you clean it by using a known perfectly strainght straightedge and seeing if there are any gaps under it when you place it diagonally. do it both ways, an "X" pattern. Any gaps take it to a machine shop and get a qualified opinion.

[Eikon]

Thanks for the input guys.

I am pretty torn on my budget. At the moment I have already spent way too much on this car, and I don't want to spend another penny. However I still love it, and I can still rationalize spending some more $$$ on it for the right things. My budget... I have already sunk $350 into the project. I could probably do another $150 without stressing too much.. Beyond that I start to reach the point where just getting a new motor and selling off the turbo, injectors, coils, transmission, etc... would be more cost effective.

Now if I can reach a point where my engine is superior to a stock RB20det in good condition, then I can justify a few more of those dollars. I just can't go crazy. I am pretty strapped for cash at the moment cause I'm on commision and sales aren't the best, and I have a baby due in January 06. So I really shouldn't spend a lot on this right now. But...

A couple more questions if I may.. I can sure understand the value of ARP head studs.. But aren't they going to cost like $200... basically for bolts? They just seem so expensive... unless I am wrong about the price.

hey madscientist... I do have a face for radio, but I have heard that the spinal cord is the toughest part of the swap... lol

Question for you... You mentioned in another thead in Gen. Chat about RB vs. SR that solid lifters are the way to go for the RB. Can you teach this novice a little more about that? Lifters lift up the valves right? What do you mean by solid? What do they cost to acquire? Are they very hard to install? What performance gains do they afford?

You asked about my plans for the car... I really want 300+ WHP. From what I have read that requires fuel upgrade, MAF upgrade, Turbo upgrade and some serious tuning. But, you have to do the same exact things to approach 400 WHP... So you might as well right?

I am thinking that somewhere between 300 and 320 whp on a daily basis, with up to 400 available for an occasional "sactioned" drag race.

If i ever wanted to approach 400 would I have to have ARP studs, and/or solid lifters?

[themadscientist]

for what you want in the short term IMO you should do the minimum to get the car up and running. It has been my experience, and yours too from the look of it that projects quickly spin out of control and you fun out of money. I hate hearing about these guys who save up just enough to get the engine and then something like this happens, they are tapped out and their car becomes a lawn ornament while they go sell blood to buy parts. Unfortunately it seems to be more the rule than the exception.You do not need head stud and solid lifters to reach 300hp reliably, 400+ and you should get them. The stock head bolts are fine it's just nice to overengineer and get some "oops" insurance. I have run several RB20DETs up to 250(dyno confirmed to the wheels) doing nothing more than;

1. starting with a healthy motor, properly maintained with good compression.

2. complete tune up; plugs, dressing the coil tips, set timing and idle, clean the AFM and throttlebody, new fuel filter, pop the cover off the plug valley so the coils can breath and mount the igniter box up on the firewall, reset the computer, pull the OEM SMIC and flush out the inside and outside as well as straighten the fins, same thing for all the intercooler piping, backflush the cooling system and clean the business-end of the radiator.3. Get the air in and out, high flow air filter (I prefer HKS power flow), aftermarket downpipe and muffler and punch the cat(sorry PETA). I replace the OEM BOV, it can open when you up the boost, kind of defeats the purpose.4.Add fuel, I have used things as complex as a single, five or supe AFC to simple as adjustable pressure regulators to straight ghetto, hose clamp on the fuel return line.5.up the boost, the RB turbos will endure settings of 0.9 bar without doing damage, past that is a bad idea.

this is the "basic light tune", good for a reliable 250hp

Were I to want more I would reccomend;

1. bigger turbo, an RB25DET or VG30ET OEM turbo is a great upgrade and a tubular outlet is a very good investment towards reponse and peak flow.

2. more and smarter fuel, the stock RB25DET injectors flow 370cc, you should have at least that CA18DET 370s but I would reccomend more for growth potential like RB26DETT 444s, 13B 450s, or 13BT 550s. You need a bigger pump to feed them reliable, GT-R or maybe an FD3S(not sure about the compatibility, I am speculating about the 7 pump). Ghetto fuel control has to give way to a minimum SAFC with high and low maps.

3. Get cold, time for a bigger and more efficient intercooler. For the RB20 and 25 I prefer "switchback" intercoolers where the outlet points back across the top. With the RB's intake it's the shortest route, the "passthrough" ones have to travel a longer distance to the intake. Whichever one you can get will be good, I just prefer that type. Replace the radiator with a better one, 20s run hot and an OEM GT-R radiator is just good enough, get a full aluminum one if you can.

This is the basic "medium tune" on the same healthy motor, should get you a reliable 300hp. You could get a metal head gasket but a cool-running RB under 1bar should be fine, I would hold off until it's time to get stupid.

The 300+ build is where we part company with the stock RB20 IMO. I would do a complete engine overhaul with forged pistons, mountain cams, solid lifters, $1000.00 oil pump, $300.00 head gasket, studs, standalone engine management, basically "the works" It is a little overkill in some areas but I am generally lazy and paranoid and don't like doing things twice. I don't want to have to go back in there so if I want 400hp I would build it to handle 600 because **** happens and can't afford for **** to happen ya know?

In your situation however I would assume the worst. Assume the motor and head you have are on their last legs and just do what it takes to get it up and running. If you really and truly want a strong realistic motor I would get this one back together as best as you can and get your car back on the road. If you still have the KA keep it in the corner for a backup and save your money for the buildup on the RB so when you go to do it you can do it to your satisfaction without cutting corners or doing things "good enough". You will be happier.

[Eikon]

That's a great write-up madscientist!

We should sticky that post.... Not the rest of my giberish in this thread.. just that post.

In response... I have new plugs, have cleaned the coil pack tips, idles smooth at 650ish, 300zx fuel filter, Walbro fuel pump, routinely reset the ECU as I have a tendancy to kill the battery while doing the stereo install without driving the car, have new water pump, radiator, thermostat, and fully tested the cooling system, have cold air intake, will soon have straight pipe and no cat,

Need to get custom downpipe/straightpipe done.. should be soon.

I have a front-mount IC and am having a custom front facing intake manifold made by Boost Flow Technologies.

Another question.. Would a bad/blown head gasket cause an exhaust smell inside the engine bay? I think I have an exhaust leak somewhere, but I am curious if it might be a headgasket?

Would a bad head gasket make a sound?

I still want to learn more about solid lifters?=

[themadscientist]

no a blown head gasket makes your radiator sound like your combustion chambers You likely have a bad exhuast gasket, check all the studs, I am willing to bet one of the #6 studs broke off, they do all the time. That or a gasket just failed, they do that, CAs, RBs, mine eat exhuast gaskets, I assuume SRs do to.

Here is the link to the Tomei page describing why they make the liftershttp://www.tomei-p.co.jp/_2003....html