Replacing K8 Heads

mazdags94 · Post by **mazdags94** » October 23rd, 2007, 8:37 am

As opposed to spending the money to have my K8 heads resurfaced and a valve job done, I decided to buy newer heads from someone with a lower mileage K8 (no burning, etc). However, I was wondering if anyone could tell me what I am getting myself into? I also bought a nice gasket set to redo the engine as well, and my thought is that I can unbolt my current heads, and bolt on the new ones (so long as the timing gears are lines up). I am also going to replace the timing belt while I'm at it. Is there anyone that has done this before? Please let me know as the project will be underway very soon.

This is just a temporary mod so that I can drive my car before I do my KL swap. I plan to run this engine into the ground then switch over. I may experiment with forced unduction on this engine so if I ruin it, I wont care, haha.

lakersfan1 · Post by **lakersfan1** » October 23rd, 2007, 8:43 pm

You'll need to have the other heads resurfaced anyways to get a new mating surface. You'll also need a 12 point 12mm socket and a torque wrench for the head repalcement. The rest of the tools should be standard type tools. You'll need to swap over the EGR to the new heads.

mazdags94 · Post by **mazdags94** » October 23rd, 2007, 9:45 pm

Time wise, I am probably looking at something like 5-8 hours of work, right? Also, does anyone know how much it would cost to have the heads resurfaced? I would imagine that they wouldn't be that expensive. Thanks for the infor so far.

PATDIESEL · Post by **PATDIESEL** » October 23rd, 2007, 10:02 pm

I have a brand new K8 rear head. Came from Mazda and the buyer never installed it. I'll sell it for 150 plus shipping if interested.
As for replacing the heads, you need to look at the mating side on the block too. It is pretty common that it needs to be shaved also. The issue is that the heads and block warp over time. Since the heads are torqued and mated cleanly when the car is new the heads and engine warp the same way so they still fit perfectly. However, any used engine and heads from a different engine will have warped differently. Thus they will not mate perfectly if you do not shave them. The head gasket can also dent the heads and block where it is seated. This will leave some old seal and indentations which will need to be shaved to make a clean surface. I do not think they can shave the block inside the car. With all this said, it is not 100% necessary to shave both unless you just want it to be 100% or the block or head is not in very good shape. I would shave the heads (used ones) and clean the block surface as best as I could.
I hope you have a DE waiting before you boost the K8, blow it up and leave yourself without a car. The K8 can take boost, but don't want you stranded...
Email me if interested in that head.

hgallegos915 · Post by **hgallegos915** » October 24th, 2007, 1:33 am

I got two kfze heads, with kf01 cams. You can sue the k8 cams.. its the same head but newer valves and valve seals. 40 k on the engine.

mazdags94 · Post by **mazdags94** » October 24th, 2007, 8:12 am

Thanks for that information Patdiesel, I knew I would have to have the heads resurfaced but I never thought about the block. I am sure that I'm not going to take the block out to have it surfaced. Here is what I am thinking:
I bought this 94 GS with 164,000 miles on it for 400 bucks. Its spits blue smoke like you wouldnt believe. It is an automatic as well. I dont have the funds to drop in the KL-DE or boost at the moment so I found it cheaper to get my current K8 in working order. I purchased two K8 heads from a gentleman who parted out a low mileage K8 engine for 195.00 shipped. I am going to swap to manual as well because, as I'm sure all of you know, auto's suck and are too costly to repair (my previous 92 gs was auto and the tranny went, costing me 1300 to rebuild). But that was before I knew better. So.... I want to be able to drive it next summer so in the meantime, I'm going to get all the part I need and get the beast started and functional before April/May.
My plans do extend to boosted DE, and theres a LOT of info on this site because of you guys so I appreciate that.
Out of curiosity, how much are you selling those heads and cams for hgallegos915 .

mazdags94 · Post by **mazdags94** » October 24th, 2007, 8:27 am

Just an update, I have gotten the blue smoke under control for the most part but the exhaust seems VERY rich (smelling pretty strong). The car was sitting for about 2 years before the guy sold it to me so the coolant resevoir has some gross stuff in it and the oil was pretty sludgy. I've done a couple of engine flushes courtesy of GUNK that have brought the blue emissions down quite a bit. I changed the oil and filter and then added in some Rieselone compression restorer with ring and seal repair. We'll see how that goes. The only problem is that you have to drive the car in order to get the stuff to work properly so it doesnt help that it sits in my garage with 4 neglected rims, bald tires, one flat, and a bald/flat doughnut in the trunk.
I just need to mention this to you guys because I know you'll get a kick out of it: This guy I bought the car from really left me some interesting stuff. Not only did I receive the MX-3 I've been searching for, I got some spare change, french fries, garbage, and drug paraphenalia as well. The interior was disgustingly dirty and the headrests were glossy with head grease!!!! UGH! Needless to say, shes clean now, and so am I (I immediately threw out the paraphenalia. Just unheard of to me!)

wytbishop · Post by **wytbishop** » October 24th, 2007, 10:45 am

When I went to install my new fuel pump I found something like $3 in loose change under the back seat of mine. I have had to replace almost the entire interior of my 94 GS because it was either too dirty to clean, to ratched to fix or painted silver. The previous owner of my car had both poor taste and hygene.

Around here, theres no such thing as a $400 MX-3 regardless of condition. Every time I read the one of you guys got your GS for a few hundred bucks I get jealous all over again.

hgallegos915 · Post by **hgallegos915** » October 24th, 2007, 1:48 pm

100 for both heads plus ship.

WOAh i thought you were about to say you found loose change in the fuel tank LOL

mazdags94 · Post by **mazdags94** » October 24th, 2007, 2:04 pm

I know, loose change in the fuel tank would suck, haha! I really did get lucky when I found tmy GS because I was planning on spending at least 800-1000, which is to say I wasnt planning on buying one until next spring but this deal came up and I took it. After I got through the rough talk from my wife about it, I was really excited to have my mx3 again. The MX-3 GS was my first car and I always told me friends that I will be 50 years old with the same car in my garage.

Post by **Mooneggs** » October 24th, 2007, 2:18 pm

mazdags94 wrote:The MX-3 GS was my first car and I always told me friends that I will be 50 years old with the same car in my garage.

heh I guess all us mx-3 guys think alike haha I always say that

hgallegos915 · Post by **hgallegos915** » October 25th, 2007, 1:49 am

I was very close of selling mine because turbo was to much for me.. but bleh im keeping it.

Audessy · Post by **Audessy** » October 25th, 2007, 2:04 am

OMG. Now I don't feel so retarded. My GS is my first and will be my last as well. Rock on man.

154k Miles
3rd Owner
Avoided being totaled at least 3 times.
Things that have failed killing my mx-3: A doe, a buck, a Sebring, a Pontiac, mother nature (ice), and 3 unknown because the cowards did a hit and run.

BTW, why are we saving a K8? The K8 discouraged me from keeping the mx-3. Until I saw the light of the beloved KLZE.

wytbishop · Post by **wytbishop** » October 29th, 2007, 7:34 pm

You guys aren't alone. I loved my first one so much that when it got written off I went and found another one. I will own this car till I die.

lakersfan1 · Post by **lakersfan1** » November 4th, 2007, 3:29 pm

Also, FYI for those looking at K8 head jobs, the head gaskets alone for the K8 usually run about $300 for the pair, whereas it's $110 for a KL set of head gaskets.