A question on new head porting

This popped up this week and I was asked to look into it.To be sure I don't tell someone wrong.

How is the best way to remove the valve guides? The correct tools we have. I was told you have to drill them out by one party. and press new ones in.
Heating the head was also discussed But then you have to worry about a valve seat falling out while its hot..

Is there a correct procedure. and besides cracking a head what are the risk?

HMMMMM-right or wrong I can't ell you but I've done 100's just tapping them out. We also used a small "pneu. chatter gun" in the shop. Work'd fine=no problems

A experienced man with a hammer or an inexperienced man with a small press will do the trick easily. Pick up one of those neat tools to do it. They have a small diameter shaft to fit into the guide and a wide section to fit on top and drive it out OR install it. Really slick.

You'll need to dress the top of the new guide just a bit to remove the mushroom after you press/pound it in.

It's all kind of easy on motorcycles and VWs.

TC wrote: "You'll need to dress the top of the new guide just a bit to remove the mushroom after you press/pound it in."

Beautiful. If the top of the guide is mushroomed, just imagine what damage you've now done to the ID of the guide and how nicely it'll allow that precision-machined valve stem to just glide right through, especially when the head gets hot, not to mention stressing the area around the guide with the hammer blows.

The proper VW tool is two-part:

Part one is, essentialy, a long thread tap that inserts into the old valve guide and cuts a set of threads along it's length. Once that is done and the tap removed;

Part two is a threaded shaft that is screwed into the (now threaded) valve guide, the head is held stationary in a reverse press and the valve guide is pulled from the head. No heating of the head is necessary or recommended, as heating it that much will warp the head. Personally, I made this tool from a long bolt (it happens to be metric, but the right English size would be OK, too) and use the head of the bolt to attach to a puller.

Because of the lightweight aluminum head, it is HIGHLY recommended that you anchor the head to the press table with two longitudinal steel straps of at least 1/4" thickness, one on either side of the valve guide centerline, to distribute the force of the pulling press evenly across the head to prevent warping. Alternatively, the guide may be pulled from the bottom with the head resting evenly on the press table.

Inserting of the new valve guides should NEVER be done with a hammer for the reason mentioned above (although a lot of people seem to be able to use a hammer and get away with it) as well as possibly cracking the head. New guides should only be inserted with a press because of the lightness of the head material.

gn

I second Gordon's method. ~Alan

You're both right (from my point of view). Use the hammer for removal (didn't think I had to mention this but....when driving any object especially a tube of soft brass or bronze it should always be supported with a proper " tool" to insure even pressure.). but we always used a press when installing the guides, unheated. A very very simple operation.
That being said---I wouldn't hold up the task if a press wasn't available, pass me the hammer.

Nurling (sp?) the inside of valve guide (to make them tight again)used to be a popular way to keep using old valve guides - I take it on VW heads it isn't worth effort? (That was old MG/AH trick). Cost of new guides is so low can't see it as cost effective - perhaps guides were more difficult to replace in old steel heads?

Vestal's Auto repair has built heads before he has the guide tools and 2 presses.
But porting a new set that were C.N.C.ed with new everything /

He did have concerns about cracking the new heads that the customer brought in. and I can see why he,s jittery.

If I knew of a cryogenics specialist close by we even diccussed blowing liquid hydrogen through the guides to see if they would just fall out.

Tell me something guys he's done calle me back onceall ready.

Barry, I misunderstand you question.
He has new CNC'd after market heads that the customer wants ported?
He has new CNC heads that he has to remove the guides to gain access for porting?
He has new heads he just has to install the guides?

If they are in and you want them out--tap or press away. -no worres. Forget about cooling and heating-too fancy and not req'd.

Wolfgang, --internal "knurling" is done on steel heads without replaceable valve guides. By cutting into the metal ridges are formed narrowing the diameter of the bore. we used to knurl a small area on piston skirts in 2 stroke motors to help with piston slap.

I always thought that the part of the shaft that was inserted in the guide prevented the distortion from extending down into the guide. When we did the head on Biffs engine, all it took was new guides, that insert tool and a hand hone at the top. As I recall, I think that Mike (Banner) was over Gary's that day. He's so Ol' Skool, he's Pre-Skool. We did some work on reduction boxes as well. It's so cool to watch him work!

Seemed to work, to paraphrase Gordon, "Beautifully!"

Of course, we were just interested in getting his car back together as a VW driver, it wasn't a Speedster.

We used a technique very similar to Gordon's......Old guides were drilled all the way thru with the appropriate size for the tap we threaded the guide with....Then we flipped the head over,(combustion chamber side) and drilled 1/2 way down with a larger bit.....Flip the head again, drop on a "spacer" insert the proper size bolt and crank away.....As the guide is pulled out, it will stretch due to the weakened cross section....an easy extraction....

Instalation was done withe the head at 250+ deg. and the guides frozen over night in the fridge......Normaly you could do a quick install with minimal use of a hammer....Aluminum or brass hammer prefered.....A mandrel was used ( a bolt with the same dia as the guide ) to prevent mushrooming.....

I believe EMPI's founder started by marketing a kit with all the tools and parts required for the job......Or is this just a senior moment???

OK ! "Thank you, Bruce" Should I tell him to buy new guides just to play it safe?

Of course you should replace them. Once tapped you toss. This CNC stuff you speak of---this is a totally new non VW head?

I have to ask and don't want to sound disrespectful but...
If someone is trusting this engine builder to port CNC heads (which are pretty clean to start with)shouldn't he already be intimately familiar with the VW head, build up and flow properties before "hogging away".
More damage than good could come of that.--Just a thought.

I looked at the cb site " Racing Valve Guides, and Valve Seats"--Marketing talk or actual goods? I say leave them alone and installed and do a little clean up/port matching. You won't notice the difference I'm sure.

So I have to ask with no disrespect--why the secret?

Ok I will let the cat out of the bag they are a set of CB performace heads and they are mine The Los Bandidos are brand new. But I was expecting them to have already been ported. I have a set of flex hones waiting. to port them.

I am upgrading the mileage motor from 85.5 to 87s changing out the rods to CBs race H beams. so I can turn her up a little from time to time. Also having a set of custom race pistons made to remove all the case shims to correct the valve geometry back to factory specs. It was never as quiet as I thought it should be.

CB, Also got me a set of Idle shut of valves for my 34 Solex/Brosol's so it should be a lot better all a round ..
At last fill up before I pulled it I was getting 42,2MPG But I was just not happy with the rocker noise and did NOT want to damage this engine.

All of it was paid for before Thanksgiving. And now I'm on short time so I just barely got away with it before the money got tight. I will have to wait for my year end bonus before I call CB back about a new set of Guides .

But the pistons are not made yeat but have been ordered so I still have to wait anyway. But at least I can port them while I wait..

I'm only going to slick them up some any deep marks or numbering will be left. this is a very near stock engine. and I only want to improve the flow some. back to the way it was before with the smaller valve heads.

It was just plan cold natured before. I'm thinking it could easily handle a little more displacemet to balance that out. But I'm still keeping the compresson low, and keepimg the T-4 oilcooler setup I put on the fanshroud on this engine.

It never got over 210. even in mid summer..and I did dog it quite a bit. and it was still always cold natured.

But now that the speedster D is handling sweetly with the new re engineered rack,, Its time for this motor to go where it was intended..

I now have 4 vw engines counting the T-4 still on the
stand waiting for some kind of a cam and lifter set. before can build it back. but everything is in storage.or running.

I just didn't want to hear Jake's rederick. We don't exzacty get along. and these heads don't show any sign of any kind of port work,, They are rough in the ports. no disrespect to CB.P but I expected better..

At the very least they could have flappered them some. this is a case of pull um off the shelf and ship um.

I already cleaned up the fin area's there were some rough uneven places that are suppose to be open enough to allow the air to pass freely.. Some were partly blocked .

I compared them to a set of factory Old stock heads to see what was needed removed ,,but as is they would have had hot spots.

I did correct that with a piano wire file. Easy pezzy. But I should not have had to.. the castings are less than perfect. and Im being polite..

In any case thank you Bruce you answer All my questions and a couple I didn't ask.

Gordan and Leon. Thank You both, for your help. I like and appreciate your suggestions. and they sound like the right way to go with this and that's what I'm showing Mr Vestal. He does have a reverse press, but has never used it..

But I will match port and slick the head ports myself . But I WILL be using the ones that were on the engine as my guide. They flow very nice. but are stock valve heads.

I will be trying very hard to match the port and polish job on them exactly as I possibly can.

Thank you again Gentlemen..

You can purchase a valve guide drill from us to do the job. The drill bit is stepped and has the tip demension I.D of the guide. You drill the guide about 3/4 of the way through. This will leave about .040 wall thickness of the guide left. doing this relieves the "press" of the guide. You can tap the guide out from this point on.

Hi Pat , I do thank you for stopping by and I know your pretty busy.

I will do that I'll call later next week When I get my bonus check

I"m not fussing about the heads .But I wish I had spoke up when I ordered them and had requested the port work then.

That's my fault. Not CB-P.

But the castings are still not as good as the old VW stuff. And I know we are never going to see that kind of Quality anymore.

I do have some nice ones in th stack to compare to But they don't have the bigger valves I wanted The combustion chamber work is however.

"Excellent." on the Los Bandidos No complaints their.. we are still talking about building a 5th engine next year following in this cofiguration.

I do like how this engine sound a lot like a certain Beck engine you Built. I did like that engine.. she was and is sweet.. I swore I would not say who got it. so I have to keep that promise. But I did like it!!!!!!!

"I just didn't want to hear Jake's rederick."
Meaning he didn't want to hear a **possibly** opposing view substantiated by Science.

NO. But we just don't have the same veiws

Ok I found a supplier that can make a stepped 13/32 drill bit with a non cutting straight 5/16s nose 5 inches long. Now comes the hard part. seeing if they will make um.

I made a 1/2 thick plate 3&11/16s round.

I will need a LK class 10 bolt 7mm-1.50 X 5 inches long to use to pull new guides into the heads in a very controled manner useing that plate..

The same bolt with a 2&1/2 long 3/4 spool with 9/16s bore will be used to extract guides . this should make a very decent valve guide tool kit. Thanks Guys for your help. I.m just hoping i have a job to go back to after Christmas so I can finish paying for this engine upgrade. I wanted to build another engine like this. But now I'll be happy and darn lucky if i can just finish this one..