Itinerant Air-Cooled

Here they be.






neal

ruckman101 wrote:Here they be.

[/img]

neal

They look so fine . . . .
Colin
(my Yuma heads would be shy to be around such a shine)

So it begins.

[/url]

Here's the "easy" side after an evening of tedium. It would seem I should be able to drag my file effortlessly between the cooling fins at the seam points, so this still needs a bit of work. Every time I rack my brain trying to think of an easier way.



Here's the much worse side before any effort has been put in.



I did resort to using a small hammer and a square ended file to tap out the thinner bits that I could. Still working on it.

Here's the old exhaust valve from cylinder #2 next to the new one.



Weird pitting on the seating surface my friend had never seen before. It can't be good. At a glance, the seating area appears to be the same width as the new one. The stem end looks like this:



So the next question, is which intake valves to use. Am I correct in that the valves are the same for the single and dual port heads? The stem ends look a little smaller on some of the DPs. Many of the valves are pitted, all exhibit wear. Here are a couple that are dished in:





The better ones look like this:



Anything else I should be paying attention to?



neal

Can you get a Dremel cutting wheel in there to grind those down easier?

Won't go deep enough, but could knock off the outer bit easier.

So I pulled the first of what I thought were viable intake valves off, from the other dead head that I had been running. Same, but more pronounced pitting/waffling on the seating area the exhaust valve displayed, and, the valve guide is loose in the head. With fingers alone it moves back and forth a good 5/8ths of an inch. That can't be good. They were all tight on the other head. I'm not encouraged. How would you even figure that out without pulling the valve?


neal

So additional valve extraction based on the condition of the stem revealed secrets.





Not pretty. Those are the only two valves of the lot, exhaust or intake, with a VW logo on the top. The rest seem to be TRW Brazilian. The new ones with the TRW at the base of the stem in ink or etch, black. The ones pulled from the head have the TRW stamped into the base of the stem.

Finding trace media from the blasting cabinet everywhere despite efforts to blow it all away with compressed air.

Here are the boat anchor DP heads on the table in the shop, less one, which is on the other table. Odd, I have an odd number of DP heads, seven, one I overlooked when I lugged them all south for assessment. Maybe I have a good one.



Then there's the other table with the boat anchor single ports and the one DP that had VW's logo on the heads of the intake valves.



So it goes. The grandkid says my father-in-law thinks I'm nuts to bother with filing out the cast flashings from between the cooling fins of my new heads. I disagree.

Conventional wisdom, from what I've heard, is to replace the exhaust valves, but intakes rarely need to be replaced as they run cooler. I'm beginning to question that conventional wisdom. I mean the contact area looks too wide on one, about right on the other but dented in. Machine shop? Or invest and save these for Betty Baja. It could be a rarely moment.


neal

Just get some new damned valves, button it up, and come to Hambone next week. They're not that expensive, why ruin new heads?

Tuesday would be the earliest I could pick up new intake valves. Tight window. At the weekend we get the apex of camp Easter family overlaps, and a bit of a Sunday obligation to deliver a rocket to a toddler turning three. Not looking good. Still got the bell-housing transaxle swap change out on top of it all.


neal

Are they boat anchors? Nope. Good fodder for learning to fly-cut, valve and seat reconditioning efforts. Why ransack efforts trying to find machine shops to do the work when with invitations to use those machines are open to you. DIY. It's an aviation shop, and the folks using it are rebuilding Franklin engines from the 19 oughts. Never throw anything away. They could be your best option in the future.


neal

Since you have access to a machine shop install the old intakes and new exhausts and do a 3 way cut on them. Same on the valve seats so you get the perfect seat width.

ruckman101 wrote: So it goes. The grandkid says my father-in-law thinks I'm nuts to bother with filing out the cast flashings from between the cooling fins of my new heads. I disagree.

I agree with you on this one. BUT the original German castings were significantly tidier in the flashings department. One of your engine threads where you did it to the cylinders was an "Aha!" moment for me last year, and I've been inspecting fins ever since. If the seams are vertical/with the airflow direction, I'll leave them because it increases surface area. If they block or inhibit airflow in the exit direction, I make them smooth smooth smooth.

Why are the single-port heads boat anchors?

Robbie

ruckman101 wrote: Here's the "easy" side after an evening of tedium. It would seem I should be able to drag my file effortlessly between the cooling fins at the seam points, so this still needs a bit of work. Every time I rack my brain trying to think of an easier way.



Here's the much worse side before any effort has been put in.

Maybe a hacksaw tensioned up real good might help with the initial flashing removal between the fins. Just be careful how far you saw...

I also recall Bob Hoover talking about "riffler files" as being the bee's knees for dressing up aircooled heads. Might be worth looking into.

Persevere.

A band saw at high speed with a sharp blade, pressing the head through VERY slowly might work.

EDIT: Other bad ideas (in hindsight) removed…

Boat anchors because of cracks in the combustion chambers asiab3. Either between the valves, or valves and spark plug. Unfortunately, power tools provide the opportunity for power mistakes. I'm leery.

I have a set of swiss files. I've never heard of riffler files.

If I were plusher, I'd order up a set of SP heads from air-cooled.net to compare the Chinese to the Brazilian.


neal

ruckman101 wrote:Boat anchors because of cracks in the combustion chambers asiab3. Either between the valves, or valves and spark plug. Unfortunately, power tools provide the opportunity for power mistakes. I'm leery.

I have a set of swiss files. I've never heard of riffler files.

If I were plusher, I'd order up a set of SP heads from air-cooled.net to compare the Chinese to the Brazilian.


neal

Heads are repairable. You may not want them, but Rimco might.

Filing the flashing is a good idea, grandpa. You know I have a German dualport head from my Squareback ready to go back in, and I have an Autolinea head currently installed in the Squareback. The German head is clearly superior in most every way, even the exhaust studs look more robust, the plug threads look smoother, the cooling passages are broader. Keep a keen mind as to what would make the heads happier and execute. Yes to Bleyseng's suggestion that valves can be easily cleaned up and seats cut to keep the valve margins/contact width within factory recommendations . . .
Colin