The Aftermarket Cylinder Head Thread!!

[aholic]

heads cleaning issue

Ok I have another thing to contribute to the heads cleaning issue:

I tried many things like brake cleaner, engine cleaners, steam cleaner to get the heads clean - none worked. Then I came up with a great idea and it worked perfectly! Oven cleaner! It's a spray sort of cleaner, you should get it in every mall and it is very cheap (3 Dollars over here in Germany). You spray everything and let it sit for 24h then wash it clean with a steam cleaner.

Looks like new check the pictures. Very easy to do by yourself. Works also on Oil Pump, inner side of Valve Covers, Oil takeup and other parts that have burned in oil!

http://home.arcor.de/johi123/klze/heads.jpg
http://home.arcor.de/johi123/klze/backofenreiniger.jpg

[StreetThisMX6]

Or you can just take it to any machine shop and have them throw the heads in a hot tank for a hour or so.

[Fastest95PGT]

I tried many things like brake cleaner, engine cleaners, steam cleaner to get the heads clean - none worked. Then I came up with a great idea and it worked perfectly! Oven cleaner! It's a spray sort of cleaner, you should get it in every mall and it is very cheap (3 Dollars over here in Germany). You spray everything and let it sit for 24h then wash it clean with a steam cleaner.

Wow, those are clean! That's a good and cheap idea! That makes me wonder what oven cleaner would do to the valve covers and other engine bay things that have a lot of grime.

[lakersfan1]

Hey. I didn't see this on this thread. For anyone wanting to do thier own head work, here's the full writup I used:

http://www.miata.net/hakuna/port2.html

It's for a 4 cyl Miata, but the design of the heads is pretty much exactly like ours with the HLA holes and valve removal and such.

[aholic]

Dont valves have some sort of alloy on them in order to make them more resistant to heat (esp. exhaust valves). And "polishing" them to get them clean remove this alloy?

[lakersfan1]

Dont valves have some sort of alloy on them in order to make them more resistant to heat (esp. exhaust valves).

There are valves that have coatings or special alloys or whatnot, but our valves are not one of them. About the only thing you can do on our stock valves to resist heat without getting them coated is to shine the valve heat to a nice shiney finish.

[skelly]

Some aftermarket exhaust valves are "sodium filled" which makes them lighter weight and dissipate heat better. Ours are run of the mill stainless, nothing special to them.

[jon93PGT]

Yes, Ferrea makes some of their valves with a hollow stem, and then sodium filled. This, as skelly said, helps with heat dissipation, and also makes for a lighter valve, which makes higher revs a little easier and safer.

[rurockn]

I remember when I was a kid we used to cut old OEM 302 valves my Dad would bring homefrom work in half with a hacksaw and then throw them in a bucket of water to watch them explode form the sodium/water reaction.

[track6]

Well, I sifted through this thread and have some questions that searching the 2.5 forums didn't give me an answer to.
Where and how (if at all) do the MX3 V6 heads play into this?
Based on the posts I did find, they have smaller combustion chambers = higher compression.
Will they bolt onto a KL 03 or ZE?
If they do fit, will the 03 or ZE manifold bolt up?


Thanks.

[lakersfan1]

Will they bolt onto a KL 03 or ZE?
If they do fit, will the 03 or ZE manifold bolt up?


Thanks.

Yes and yes. The K8 is still a K series engine, so all the bolt holes and such still spaced properly and use the same head bolts and everything. And plenty of K8 owners upgrade to KL intake manifolds.

I believe the valves are smaller, though. I'll know when I finish screwing with my KL install, I'm going to pull the K8 heads off my old engine and scrap the rest. I'll probably make a fun side project out of the K8 heads.

[track6]

Cool, thanks.
So since the K8 heads bolt up, then is there room to increase the valve size to the 03 size? The cylinder bore is greater in the 03/ZE (83mm vs 75mm) so you pick up some room, but the valve spacing could be an issue. Are the centerline measurements the same?
From what I've found the difference is about 4 mm on both I & E.
Is it worth the effort to gain the compression?

I guess I'm weighing a top end change vs. a bottom end change. In the end, I'd like to see that magical 2 hp per cubic inch in a NA motor. Oh, and do it for $10.

Thanks again.

[lakersfan1]

I'm sure you could go up in size a mm or two, but probably not to full KLDE size. I'm sure you could get them to flowbench similar numbers to a factopry KLDE head with a little headwork.

[jon93PGT]

If you are looking for high power in a KL engine with high compression, your best bet is to pump the shit out of a ZE... get the heads reworked, and then mod it to all hell with some nice cams...

You can have custom higher compression pistons done as well, but you start getting into an interference engine and things get tricky..

Good luck...

[Fastest95PGT]

Where and how (if at all) do the MX3 V6 heads play into this?

Smaller bore diameter = smaller valves. That's bad.

Based on the posts I did find, they have smaller combustion chambers = higher compression.

No, no reason to suspect that. Then you'd think that any 3.8L V6 (lets say the T-Bird engine) has super low compression since it's 50% larger.

Will they bolt onto a KL 03 or ZE?

I'd suspect so, since all 3 are KL blocks.

If they do fit, will the 03 or ZE manifold bolt up?

Yes.

I'm pretty sure the above responses are right, someone please correct if not.