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Well, there goes this head
https://slantsix.org/forum/viewtopic.php?t=50367
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Author:  robertob [ Mon Nov 19, 2012 12:12 pm ]
Post subject:  Well, there goes this head

I was working on the bowls of my head and broke through into the water jacket in the side of the #6 exhaust port. I don't think I was being particularly aggressive with the cut, but I guess I was. I was trying to open the wall up to the ID of the larger valve seat.

Not sure what to do next, I am really frustrated right now. I have about 4-5 hours into the porting (this was the last bowl I was roughing in). And I already have $240 into this head with the seats and guides.

[img]<a%20href="http://www.flickr.com/photos/34753005@N05/8201095964/"%20title="IMG_5531%20by%20robertybowen,%20on%20Flickr"><img%20src="http://farm9.staticflickr.com/8338/8201095964_d54bbe8272.jpg"%20width="500"%20height="333"%20alt="IMG_5531"></a>[/img]

Author:  Joshie225 [ Mon Nov 19, 2012 12:19 pm ]
Post subject: 

Yeah, sorry, but that's junk.

Author:  robertob [ Mon Nov 19, 2012 12:56 pm ]
Post subject: 

Yep. It looked like a tiny little line but when I pushed on it with a screwdriver the whole side caved in.

I thought (wrongly) I could grind a bunch on there but I guess not.

Author:  hyper_pak [ Mon Nov 19, 2012 4:24 pm ]
Post subject:  Hole in yer Head!

STOP!!!!!
Take it to a good head shop, there are space age materials that will save the head. You might not want to go 100000 miles but drag or limited use the head can be saved.

Author:  kielbasa [ Mon Nov 19, 2012 5:31 pm ]
Post subject: 

WHOOOOPS!

Author:  CNC-Dude [ Mon Nov 19, 2012 11:18 pm ]
Post subject: 

Go ahead and saw it up into different segments to find all the spots not to do that to again. Slant heads are anywhere from free-up to $20 bucks max, so don't waste any money trying to fix it.

Author:  emsvitil [ Tue Nov 20, 2012 12:58 am ]
Post subject: 

What I learned from this thread............


Do the port and bowl work


BEFORE


seats and guides.......


:idea:

Author:  robertob [ Tue Nov 20, 2012 6:00 am ]
Post subject: 

Yeah I'm not going to fix it. This is for my vintage road rally car, so it has to be able to handle hours and hours of hard driving at a time.

I have another head, it's the early-style combustion chambers though, but I talked to Mike Jeffries and he said it doesn't matter for power.

You can't really do the bowl work first because you don't know where the seats are going to end up if you go with bigger valves. And to install the bigger valves the machine shop needs to install the guides first. Plus you won't know if the head is cracked unless you bring it to the machine shop.

Fact is I just got too aggressive with my grinder. I will bring the second head to the machine shop this week and if it checks out, have them get started on that one.

Author:  slantzilla [ Tue Nov 20, 2012 7:35 am ]
Post subject: 

Most really good Slant heads don't have much grinding in them. :D

Author:  75valiant [ Tue Nov 20, 2012 2:10 pm ]
Post subject: 

unlike the head on the ford 300. you CAN hurt them, but there's a LOT of room for imrovement, particularly on the intake side. just gotta watch that short turn radius.

Author:  Dart270 [ Tue Nov 20, 2012 2:13 pm ]
Post subject: 

You need to be really careful between the I and E ports where they are closest (where you broke through). There is a quasi-rectangular water jacket in that area.

Lou

Author:  Supercharged SL6 [ Wed Nov 21, 2012 6:55 pm ]
Post subject: 

Looks familiar, did that also, is head a peanut plug or a tube style

Author:  robertob [ Wed Nov 21, 2012 7:34 pm ]
Post subject: 

Tube style, 1970 ish.

I brought a second head to the machinist today, funny thing is, the bowls actually seem a little less choked on it already. I will for sure be very careful on this one!

Author:  kielbasa [ Wed Nov 21, 2012 10:16 pm ]
Post subject: 

If they are that close to begin with I'd just get rid of the casting flash do a quick fluff and buff and be done with it.

Author:  robertob [ Thu Nov 22, 2012 6:11 am ]
Post subject: 

Quote:
If they are that close to begin with I'd just get rid of the casting flash do a quick fluff and buff and be done with it.
That's the plan. Clean out any mis-match after they install seats, clean up any lumps & bumps, match the gaskets and hit it with a cartridge roll.

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