Alex Trebek

iTrader: (2)

I have a K24A1 engine and cylinder head to swap into my 2000 coupe. It's a junkyard motor that I pulled. I
did a leakdown test and had 70% leakage on 2 and 3, and 30% on 1 and 4. Pulled the head. Looks like the
headgasket. I figured I'd freshen up the head while I had it out. I need to clean the carbon and old gasket crud
off so I can check it for flatness still. TBD on that one. And I have some questions.

In the past, I would have just dropped it all off at the machine shop and had them do the work, but I have the
rest of the fall and winter on my hands, so I wanted to mess around with this stuff myself. And I'm trying to
keep my costs down.

First thing I did was use a wire wheel to clean the intake valves. It worked pretty well and they cleaned up nicely.
A little pitting, but pretty minimal. I think they can be reused. I still need to mic out the stem diameter, but
visually they look OK.




The exhaust valves didn't clean up as well. Do you think I need to clean them more? Or is how they are OK?
Any tips on cleaning them the rest of the way?



The sealing face was pretty pitted, so I lapped it real quick with some lapping compound I had laying around, the
permatex water based bluish/grey stuff. The sealing face cleaned up pretty well (haven't cleaned the stem on this
one yet).

But there is a bit of a ridge now, if you can see. I'm not sure if it's just carbon to be honest. But if it's not, do I
need to be worried about that? I would think it would disrupt the airflow. Would they need to be replaced? Also,
the face is a little dull looking, not mirror shiny. I'm wondering if that is because the lapping compound I am using
is too coarse and I need to finish with a finer grit? Or just spend more time lapping.



Same dull kind of look on the seat.



One of the other exhaust seats that I haven't touched yet.


Ideally I could do all the work myself to freshen this up without having to replace anything, like valves. I know the
head doesn't flow the best, but I have it so it won't cost me really anything to just clean and recondition if I can
do it on my own. If it's shot, I'll look into a better head, but I'm trying to avoid it for now.

This engine will be replacing my Turbo D16 in NA form so I can get more tuning experience, and then get a turbo.
Not shooting for crazy high numbers. Maybe around the 500hp or so mark since I'm not planning on upgrading any
of the internals. It's not a DD.

Thanks!

TomCat39

If you are in the USA, Piston Kleen is a fabulous green hard carbon remover that is safe for metal. You might find it easier and better than wire wheel. It's pretty inexpensive until you try and ship it outside of the USA.

Ryanthegreat1

That ground valve is junk now and that seat is way too wide. Need seat cutters, cut the 45 then the top and bottom cuts to bring the seat to spec and land in the center of the valve's seat face.

Just pay the machine shop, super cheap, cheaper than buying the correct tools and it will be done correctly.

FSM for an 05-06 CR-V says the valve seat width should be 1.25-1.55mm with a service limit of 2.0mm. Angles are 35,45,67.5 intake and 30,45,67.5 exhaust.

JRCivic1

I love it when people are telling me all about their engine build and one of the bullet points is "A 3-Angle Valve Job"... and I think to myself, "Oh, it is stock then ?!?"

Dilbones

subd

motoxxxman

what I'm wondering is what in the heck did you do to remove so much metal just by lapping the valve? Lapping isn't supposed to remove anywhere near that much material.

Alex Trebek

iTrader: (2)

I've heard of this. There is another one by "gunk" that is a soak that you can do, but I don't think it's "green".

The valve was junk to begin with, is the problem. That's how far down I had to grind the valve to get through the pitting. Sucks because I mic'd out the stem diameter and all 16 valves are below the service limit. But the seats are so pitted by the time they get cleaned up they are out of spec. That exhaust seat width is over 2mm now.

You recommend a 5 angle?

I kept lapping the snot out of it until I got through the pitting. The pitting on the exhaust valves is pretty bad. Hard to capture accurately in a picture.
--------------------------------
So I know that by the time I get the pitting out of the exhaust valves they are going to be garbage. So new exhaust valves. I didn't try the intake valves, but they aren't as bad so maybe I could salvage them. I used my hole gauges and did the wobble test with my dial indicator - both results are that the guides are at the service limit. So it would need both intake and exhaust guides. And then to have the seats cut. And since the engine it came off of had a blown HG, I'd get the head decked for flatness. I didn't measure it with my machinists straight edge. But anything with a blown HG I'd get cut.

So now I'm getting to tipping point where spending money on this K24A1 head is probably not worth the cost vs. buying a less beat to heck better flowing head that measures everything within spec...

Unless anyone thinks otherwise, I think that would be the way to go. Still glad I did all the measuring and tinkering. That's (more than) half the fun. For me at least.

Thanks for all the good feedback so far!!

JRCivic1

I do not recommend a 5-angle valve job for the street... not enough contact surface area for pump gas to survive very long without leaking.

K7-1Ktrevor

You have a few options,

1, lap them to where they seat and run it like that. Less then ideal but will work better then it did with the valves not sealing.

2, have a machine shop do a valve job, probably around 200-400 bucks depending on the shop, should be on the cheaper side if you bring it cleaned and disassembled.

3, buy a valve seat cutting kit on eBay, you may **** the head up if your impatient. (I did on one of my heads, luckily they are d series and worth nothing)

4, get a healthy K20a2, z1 or z3 head and it will make more power everywhere.

bang for the buck I would say option 4 would be ideal. You can mess around with that head as a practice head to try porting or what ever you enjoy.

weekendboost

I'm still pretty curious about the valve with the ridges, I lapped my valve and it also has ridges and the valve contact is actually pretty narrow.

Alex Trebek

iTrader: (2)

I ended up going with option 4. Got a K20Z3 complete head including intake manifold for how much it would have cost to get the head back up shape. Seemed like an
easy choice.