I am down to the most disassembly this supposed build will hopefully have, and I need some help before reassembly starts and I begin to post some how to's on what I have learned. Pretty much everything here is a first time for me, so take it easy.

I completed by kelford cam install and cosworth single springs. Upon doing so I noticed more air coming out of cylinder #1 than the others, and some may recall my post about that. I did the leak down test and confirmed cylinder #1 was leaking out of the intake ports at 20%. After some comments and suggestions I decided to remove the head to see if I could clean and or lap the valves to shore up that leaky cylinder. I have the head off, and some pics.

I don't know what I was expecting to see, so I need some help identifying the build up on the top of the pistons, and the pink/beige/mauve build up on the valves, and how and what to do about it properly. So if the engine builder gurus could give some guidance that would be awesome, I can write it up later with tons of pics.

I have watched and read about lapping the valves, but nothing about how to clean the faces of them or the pistons. On the lapping I don't know what compound I should or could use on our engines, and details like that. I am a die hard DIYer, and want to learn, so for the guys that will just suggest sending it to a shop for a 2k head job, that's not the point here. And, I don't have any more money.

Here is a shot of the valve side of the head, and you can see the odd build up colors.


Then the top of the pistons.


Some close ups of cylinder #1 and #4




The discoloration on the valves is the same color as the inside of the o2 housing and therefore my o2 sensor, which I suspect is bad (more on that later).

 

buy a valve lapping set at auto zone
usually comes with the tool and the lapping compound.

We did this to my 2g when I pulled the dead because of a failed gasket.

It gets annoying pulling the spring and retainers if you didnt get it right the first time but its well worth the trouble just for the peace of mind.

 

Oil or water-based compound works fine. Lapping will leave a shiny surface on the valve and head, the thinner the surface(maybe 2-3mm) the better IMO as it puts more pressure on a smaller surface therefore sealing better.

Cleaning up the mess with brake cleaner works fine. Use any fuel injector cleaner in the ports along with compressed air around the face of the valve to check for leaks(bubbles).

For cleaning the head and pistons, the cheap way is using foaming oven cleaner, it'll turn aluminum darker but it gets the job done. Let it sit and blast it off with a water hose or better yet, a pressure washer.

 

I would lap the head and block while your at it. Use a sand block and 600 grit sand paper then finish with a 1500, make sure you wet sand the whole time.

Of course a valve job and cleaning of the head would be the really smart beneficial thing to do.

Lapping the valves won't necessarily mean they will stop leaking, a valve job and cleaning of the head might be really worth looking into if you can spare the extra down time.

 

Also check for bent valves.

 

I'm at the same stage but you're going to need a tool to take the valves out(OHC valve spring compressor) if you don't have one, I just got mine for $60ish or can get one on ebay for $70ish and is easier to use. Get valve lapping compound and the wooden stick with suction cups on the end, I got both from advance. I brought my head to work tonight so I can wirewheel all the valves, steam clean the head and lap the valves. Keep all the valves in the same guide too. Do a search on yahoo and you'll find plenty of DIY articles on how to do everything.

Depending on how much of a budget or crafty you are you can make your own compressor but even I didn't wanna go thru the hassle so I just bought one. Actually I think Lisle makes a handheld one that should be cheap. Search youtube how to use it and how to lap the valves too

 

my03evo - I bought this one a while back, and it works great. Simple and fast. That was theoretically just to change the springs with the head on the motor. When I did that I noticed more air coming out of cylinder 1 than any of the others, which eventually led me to pull the head.

http://www.euroexportinc.com/store/m...ompressor.html

Project-skyline - I can definitely spare the downtime, but its the cost I can't suck up anymore. Any head work I looked at was expensive. Don't know if there is a SoCal local shop that is cheaper, if there is I didn't find it. Basically I spent all my wad at ShepTrans, so the rest is getting the short end.

okevolution VIII - Do I puddle up the fuel injector cleaner on the valve face, or do you pour it into the intake runner to see if it leaks? And, do you mean to just blow compressed air in the runner to provide some pressure, because there is no seal.

 

a valve job isnt $2k. this is one of those time where paying a machine shop $500 to refurb the head is a wise investment. that is unless you like high leakdown and pulling the head again to get it fixed correctly.

 

n2oiroc - Can you provide a little more detail to support that comment. What exactly is a machine shop doing for 500 bucks that makes it better than what can be done at home. Are they going to grind the valves and valve seats for that price? Is there something about their chemicals? Why is it implied that I will have more leak down after a DIY job than a machine shop?

 

I made a valve tool out of a large C Clamp and an 18mm deep socket i didnt need.

 

I bought that same tool... def well worth the investment

 

Exactly what I did with a 13/16" spark plug socket with about a 1/3 cut out of the side. Welding the 2 together would have helped a lot but the setup didn't cost me anything.

 

if the guides are worn, you will never get a good seal. also, lapping enough to get bad seats and valves to seal will give you really wide valve margains. i dont know what shops around you charge, but here is a price list of a good reputable shop by me. what i would consider is

degrease
bead blast
resurface
valve job
and whatever else is needed. if some guides are loose, they can often be knurled back to size. i doubt it would be over $500 to completely bring the head to as good as new assuming it needs all that work.

http://www.cs-performance.com/index....&id=1&Itemid=2

 

I had mine welded but i can see how you could get away without it.