Whats the best way and which direction (towards valve seats or towards cam journals/ valve cover) to get these stockers out? Are our stockers brass or cast iron? which is better?
thanks dudes...

EDIT for more info:

The head I am having rebuilt after stripping it down tonight, removing all the valves, springs, retainers, keepers, valve stem seals etc... I notice that one of the exhaust valve guides has a piece broken off of it in the bowl(?) of the head not the upper portion. After some searching I have read that when getting a head ported (Street port even) that some shops will machine down the remaining guide so it sits flush with the surrounding material.

End result? should i worry about this? Should I look into getting that 1 guide replaced? Can I do it myself? Am I screwed here?

EDIT 2... pics. Left my digi-cam at work so these phone pics will have to suffice for now. Help at this point would be greatly appreciated. This head was scheduled to FeDeX out tomorrow.

I thought valve guides were pressed in/out?

Brian

Edit: I found a good article that you and your machinist can talk about

http://www.aa1car.com/library/ar696.htm

Look towards the bottom

In the middle of this page there's a procedure on how they do it:

http://www.artsautomotive.com/machineservices.htm

They are pressed in typically. Unless they plan to ream and knurl (which is ancient) they will get them out. It doesn't take long and they can machine the guide to fit. It should be brass.
Edit: just saw the 2nd web page which has very good pics of the machinery. Valve seat grinding can be done both by hand and by machine. If you know what you are looking for, you "can" lap your own valves instead of having them cut on that machine. This WILL NOT produce any more angles though. I have no idea what your budget is and how workable your machine shop is either. I had my head tested, cleaned, and milled for $30 cash. I think they pulled out a broken stud too.

Sweet links, good reading. Thanks for that info.

Just curious as to what everythinks about this head, should i throw it off the roof and buy another "donor" off ebay or here? All I need is the head and the cam caps, everything else i have. Or should I have my machine shop attempt to replace that 1 guide. At $20 dollars plus parts a valve that adds up to way more than the head casting is even worth!

Personally, I would take the head with the matching caps as long as it isn't cracked or warped. If it needs a guide, then have all of them checked. The machine shop will just mic a few valves, and use an inside diameter mic to check the guides. If it's just that guide, then have it replaced. If you have the time, port-match the head while the valves are out. It's really not hard to do, and you will not mess with the flow values since you are not messing with combustion area. Don't over do it, and keep track of your water jackets. If they both have valves, have them both checked by your shop. They might catch something that you missed. Money spent now will be well worth the peace of mind.

I have planned all along that the head was going to get worked over. It wasn't until last night when I finally got around to pulling the valves, springs, retainers etc to get it ready to ship out that I found out that the guide was broken. That has made me hold off on sending the head out until I can get some opinions on whether or not I should dump money into this head. Its not a matter of me doing anything to it, but I don't even want to waste any monies on shipping it somewhere if its not salvageable or useable or worth my time.

Here are some higher res close up pics of the broken guide...

http://www.mustangmods.com/ims/u/514/2280/20468.jp g
http://www.mustangmods.com/ims/u/514/2280/20478.jp g

It's kinda rare if they can't machine the head for a new guide. If that head is straight, then the guide is just normal wear and tear. Usually they just wear out and you see alot of oil blow-by. Not to say that they can't break though. It's hard not seeing the head in person, but use your best judgement. If it seems like a good core, then use it.

punch out that guide with a removal tool and a brass hammer, clean the valve guide bore and check for excessive out of round. youll need a telescoping gauge and a micrometer, make sure its clean before you measure anything. measure the top, middle, and bottom. typicall the inside of the bores will look like an hour glass shape, tapered in the middle.

press in another one and make sure the height is to spec.

our heads use bronze guides, you dont want cast iron guides in an alluminum head.

edit:

oh, "I have read that when getting a head ported (Street port even) that some shops will machine down the remaining guide so it sits flush with the surrounding material."

and you don't want to do that. you can taper the valves by the face for less port flow restriction, unshroud the valves in the combustion chamber (especially helpful if you have oversize valves) and remove the casting flash in the combustion chamber and polish it up. most of the gains you'll see from a street port are going to be in the valve job though, so dont skimp out on that.

make sure you let someone who knows what theyre doing handle it

turbo that has to be one the most intellegent replies i've read in a while. thanks

Originally posted by 98starGS
turbo that has to be one the most intellegent replies i've read in a while. thanks

too bad its partially inaccurate. You dont measure the valve guide bore with a telescopic gauge. Keep reading!



Small hole gauge and 1" micrometer.

Typical removal and install is done with a driver and hammer, install from the spring side. Keep in mind there is a small gauge placed on the valve to determine how far the guide should be. Its a small trial and adjustment concept. Some guides have an actual lip they that bottoms out on the spring side.

Many porting machinest's do remove all of the guide in the bowl area.



Terry

Originally posted by Star Turbo Talon

Originally posted by 98starGS turbo that has to be one the most intellegent replies i've read in a while. thanks

too bad its partially inaccurate. You dont measure the valve guide bore with a telescopic gauge. Keep reading! Small hole gauge and 1" micrometer. Typical removal and install is done with a driver and hammer, install from the spring side. Keep in mind there is a small gauge placed on the valve to determine how far the guide should be. Its a small trial and adjustment concept. Some guides have an actual lip they that bottoms out on the spring side. Many porting machinest's do remove all of the guide in the bowl area. Terry

agreed. And for the record, the stock 420A head comes with cast guides standard. The bronze guides are an upgrade. Anywho... the machinist who is going to work on my head says he regularly grinds down the bowl portion of the valves and hasn't seen any issues with the race heads he has produded thus far. here are some pics of his work...





I am not going to attempt to remove the guides myself. I can't fit the head in my oven to heat it so the aluminum will expand enough to get the guides out...

^^wow, that's good work. Can't wait til i get my head back from the shop.

Originally posted by djtrickee
I can't fit the head in my oven

One of these days, you should really consider taking those two German children out of there. You'd have room for the head and maybe a headlight!

/Just checking in to see what, if any help, you got. I managed to find the same article as someone else had already posted. Damnit.

Ummm DJ did you say this head came without cam caps??? If that statement is true... the head is worthless. The Cam caps and head are head specific. Meaning you can't use cam caps from any other head on that one. I hope that's not what your saying tho.

Originally posted by Star Turbo Talon

Originally posted by 98starGS turbo that has to be one the most intellegent replies i've read in a while. thanks

too bad its partially inaccurate. You dont measure the valve guide bore with a telescopic gauge. Keep reading! Many porting machinest's do remove all of the guide in the bowl area. Terry

Originally posted by turbo8u
check for excessive out of round. youll need a telescoping gauge and a micrometer

keep reading indeed.

a small hole gauge and a telescoping gauge serve the same purpose, but for smaller holes, and yes, the gauge itself doesnt measure...it gauges....the micrometer measures. thats why i said youre going to need a micrometer.

i still stand with the removal of the valve guide being a bad idea, you're likely going to have problems with valve guides leaking eventually...and your longevity just gets thrown out the window. an experienced head porter can get 90+ percent flow out of a port on a flowbench without removing the valve guide. its not nearly as much of a restriction as the valve itself, so thats why i said taper it by the face. the most important thing to consider when building it however, is what its going to be used for. if you're building it for the street, and reliability with low end power...do not take out the guide material. your "machinist"...does he use a flowbench? or magical fairy dust line of sight porting skills? if he uses a flowbench, post up the flow numbers because id love to see them. also you said he hasnt had problems with RACE heads....your clipse isnt a race car, sorry.


edit: and just because the head might have cast guides from the factory, doesnt mean you want them in there. if you ask me, the factory fucked up when they didnt use bronze in the first place.

like i said, most your gains are going to be in the valve job

Originally posted by turbo8u: a small hole gauge and a telescoping gauge serve the same purpose, but for smaller holes, and yes, the gauge itself doesnt measure...it gauges....the micrometer measures.

HOw do you get a telescopic gauge that will "measure" the diameter of a valve guide hole.....PLEASE show me one that small.

come down to the shop and i will

wyotech

west sacramento

edit: and like i said, the gauge does NOT measure. thatd be nice though. the go or no go gauges work great too but they dont measure really

edit2: here you go, far left

Post the gauge with ruler....that one appears much larger than 1/4"

smallest ID the little one can gauge is 5/16" or 8mm

the valve seat guide bore diameter spec is .4330"-.4338", or 11.00mm-11.02mm

lates

We are talking valve guides genius. not valve seats.

whoops looked up the wrong spec

whats the guide bore diameter then? not the ID of the valve guide

use a no, or no go gauge for the guide itself