Bad head gasket?

[FestYboy]

ok here come the pix:

[Movin]

Nice!!!

[Safety Guy]

Arty, are you recommending that I remove most of those valve guide extensions? I recall reading about that, and the valve stems still have plenty of bearing surface to operate well. Was it Mattdickmeyer who came up with this idea?

What tool would be best to take these off? I'm thinking to start with a larger than valve guide hole drill bit, taking care not to go too deep. Then use a Dremel to grind down the rest of the "shell" that's left and smooth it all out to a small hump.

After that, I'd follow the other posted guide to carefully work on grinding the flash and other unevenness out of the combustion chambers and entries/exits.

Does anyone have a link to that guide? I think Zanzer did it with pictures.

Karl

[Safety Guy]

I found this by Zanzer on the B3 head cutaway:

http://www.fordfestiva.com/forums/showthread.php?36336-B3-Cylinder-Head-Cross-Section-Pics&highlight=B6+head+grind

I think this may have what I want, but if anyone knows another thread, please link to it!

Thanks,

Karl

[FestYboy]

Karl i used a 3/8" half round carbide bur bit. it self centers and gets the job done quickly. you will need to go back and get at the thin wall that's left over by using the bit through the other end of the port. DO NOT try a drill bit, i did and it's a PITA to control and keep straight.

[Safety Guy]

Okay Arty. Gotcha on that.

Now don't the guides come out? Why couldn't new guides be turned to the correct length and installed? Or is this simply the easiest way to mod an existing head?

Also, this mod alone will increase power? Any idea how much?

Finally, a shop shouldn't have any trouble doing a valve job after I do this mod?

I will be getting out my '89 B3 head to practice on at some point. If I don't screw it up I will use that on my future B3 MPG build with Aspire rollers & cam. I won't be practicing on my current B6 head! I think I'll just take it in to get it checked and get the valve job.

Or I could tell the shop to use this tool to get rid of the guide length--if they'll do it.

Any time I could call you to talk about this? That'd be easier I think. Are you available mornings?

Thanks,

Karl

[FestYboy]

Karl, the guides CAN come out but this is the easiest way to mod them without removal. Matt quoted ~ 24% flow increase just with that mod. this will not affect a valve job whatsoever. havint a shop do it may net a different method, but if you ask them to level the guide to the runner, they shouldnt' have an issue with that, just cant say how long it will take them.

Please note: thee pix above are all still rough and unfinished. there is still a bit of blending to do, but if you kist level the guide you'll gain for sure.

[zoom zoom]

If you do it yourself Karl, just make sure your careful on the aluminum! Id polish off some of the casting flash on the outside to get a feel of how malable the aluminum is with the bit your using.

[FestYboy]

If you do it yourself Karl, just make sure your careful on the aluminum! Id polish off some of the casting flash on the outside to get a feel of how malable the aluminum is with the bit your using.

thats what i did!!! but remember to keep the RPMs up and the pressure low otherwise it'll grab and kick.

[Safety Guy]

One more question:

Level all the guides or just the exhaust guides?

Karl

[FestYboy]

all guides, it's all or nothing and the gain will be on the intake side anyway though if you do one, you have to do the other

[Safety Guy]

Well I think I'd better look for a good machine shop. Since I need Aqua back on the road by the middle of next week, here's what I'm thinking:

Have a machine shop check my head and valvetrain for wear, etc. Then have them do a three angle valve job and check and deck the head.

This head was tanked back when I installed it the first time, so I'll just clean it off a bit myself. I should also have a B6 head gasket in the garage to use.

I want Aqua back on the road so I better get going!

I have a spare B6 head that I can prep for next time, as well as multiple B3 heads to practice on and ready for B3 applications.

Thanks for all the information guys!

Karl

[Safety Guy]

I just dropped my head off at a machine shop (Randy's) I remember going to way back when.

Randy spotted some issue with one of the valve stems. He'll let me know more when he takes it apart.

Head was barely in spec height wise. I'm getting it cleaned and decked again, just in case. And then three way valve job.

When I told him about how I oiled the head bolts, he said that if any oil got in the holes the bolts may not torque properly. So that's probably what happened--I didn't torque them enough. The gasket failed between cylinders 3 and 4 where Matt (Zoomzoom) spotted it, and was failing between cylinders 2 and 3 as well.

I'm ordering a head gasket set and having it sent to his shop. I kinda like ordering my own parts.

Karl

[zoom zoom]

I'm not sure if you had time to upload any pics(haven't seen them :p ) but I got a few up..here's the gasket and block where it failed.

http://i844.photobucket.com/albums/a...7/IMAG0563.jpg <--full size




I still don't understand what made it fail, if the gasket material eroded away, being weak caused a soft spot on the fire rings, or if it was detonation or something going on in the cylinder?!

Are there any Multi Layer Steel options for a b6? There would have to be for the first gen miatas?


this stuff here: http://arp-bolts.com/pages/arpultratorque.shtml



Did he measure all four corners of the block to see if it was in spec height wise? I don't understand what your saying there, if you shave it .02" it's probably not going to be in spec, which changes valve timing, which is why you get an adjustable cam gear. The engine should still be non interference.

[blkfordsedan]

Hmmm.....I always oil the head bolts. Seems to me, if the threads are lubricated, it take less rotational torque to exert the same pull on the threads. So if you torque two bolts, one dry and one oiled, both to 50lbft, the oiled bolt will be exerting more clamping force...Just the opposite of what he said.