TheSamba.com :: View topic

Wed Jun 11, 2025 2:16 pm

Hi Guys,

Long time reader first time poster - I came across some heads on facebook marketplace near me for a decent price and the seller lists the below as superficial damage and I'm just looking for advice on if I should steer clear or if they are useable. New to modifying bug engines.

Below is the head in question with the damage pointed out. the small crack between the valves seems like a red flag for me, but could be wrong.

Wed Jun 11, 2025 2:46 pm

Stock valve, OE dual port heads are nothing but trouble. I would say 1 out of every 10 are a usable re-buildable core. I have a very small pile of possible good ones, and a huge pile of junk ones.

I know it seems expensive, but the cheapest route you can go, is to just get new heads. I would only use that head in the picture for a door stop.

Brian

Wed Jun 11, 2025 2:53 pm

The world is covered with old VW heads. Don't mess with cracked heads. You may end up with rooms full of "rebuildable" heads. Don't ask me how I know.

"Rebuildable" head disqualifiers:

#1, cracks between the valve seats sometimes accompanied by radial cracks around the spark plug(s).

#2, spark plug inserts.

#3, broken exhaust studs. Easier to fix than cracks but do you really want to use nasty patched up heads on your nice motor?

#4, I'm gettin' picky but it's annoying when there are broken screws and nothing left to secure your head tins. Again, easy fix but do I want to spend my money on more parts that need rework?

.
.

Wed Jun 11, 2025 3:17 pm

Brian_e wrote: Stock valve, OE dual port heads are nothing but trouble. I would say 1 out of every 10 are a usable re-buildable core. I have a very small pile of possible good ones, and a huge pile of junk ones.

I know it seems expensive, but the cheapest route you can go, is to just get new heads. I would only use that head in the picture for a door stop.

Brian

Yeah I've heard that, I have a 65 1300 Beetle that I was contemplating going 1600 with as the engine is out at the moment

Wed Jun 11, 2025 4:09 pm

Ya , i cant truly see it clear enough in the pic to be sure but the line between the valves TYPICALLY means there cracked there and good for scrap by my builder .

Wed Jun 11, 2025 4:36 pm

Buy new.

It makes the most economic sense and-insures reliable service, buying new Type 1 heads are a no-brainer. AA sells some decent quality heads and are likely cheaper to buy than the parts and labor cost to rebuild used heads.

The only good reason I can think of for rebuilding old stock dual port heads with or without cracking issues would be if you live in a dirt poor third world country with no other options.

Wed Jun 11, 2025 4:42 pm

#5 melted or cracked exhaust guide bosses IN the port.

#6 broken guide bosses on the spring side

#7 cracks in the rocker box

#8 anything that has ever been rebuilt before

#9 anything that has ever been welded on before

#10 deep flycuts wasting chamber volume

.................................. I could go on and on......

Someone should come and take the pile of dual port heads I have here. The stack recently fell over, and its not worth the gas money to haul them for scrap.

Brian

Wed Jun 11, 2025 5:22 pm

what everyone else said above.

Light cracks between valves are normal in a dual port head. Welded ones crack again. I used to peen them and that worked as well as tigging - and I worked in a machine shop at that time that built trophy winning engines, and had access to any equipment I needed. That said, yours has a crack that is more than a "crack." It is diving under the seat, and the seat is beginning to fail because of it. It could even appear around the valve guide and cause it to fail. There is also damage to the combustion chamber. I would say that if you are a good enough welder, and head porter, and have the equipment, it will cost you more in wasted time to fix them than you could earn taking a couple extra jobs this month. If you lack the equipment and skills, then it will cost you far more to have someone rebuild them, if you can find anyone that even wants the job, than a new set would cost you. I drove a 1971 dual port bus for 750,000 miles. Did all sorts of things to the engine and enjoyed every minute of it. I always figured that about 35,000 miles in I was going to be fixing cracks, replacing guides, doing some porting, and a valve job to keep it in tip top shape. Then about 60,000 heads were simply a maintenance item, and time to replace them. Someone would always buy them for some cheap sand rail they were building, and my used heads were still better than many used heads, but no longer up to my own personal standards for maintaining a like new engine. Buses are brutal on heads because they generate so much heat compared to a lighter car like a Ghia, Beetle, Type 3, Thing etc.. If you want to learn about the head life cycle, and the problems you can run into, buy a bus.

Wed Jun 11, 2025 8:16 pm

Do the new modern big valve heads ever crack between the valves?

Wed Jun 11, 2025 9:36 pm

SGKent wrote: what everyone else said above.

Light cracks between valves are normal in a dual port head. Welded ones crack again. I used to peen them and that worked as well as tigging - and I worked in a machine shop at that time that built trophy winning engines, and had access to any equipment I needed. That said, yours has a crack that is more than a "crack." It is diving under the seat, and the seat is beginning to fail because of it. It could even appear around the valve guide and cause it to fail. There is also damage to the combustion chamber. I would say that if you are a good enough welder, and head porter, and have the equipment, it will cost you more in wasted time to fix them than you could earn taking a couple extra jobs this month. If you lack the equipment and skills, then it will cost you far more to have someone rebuild them, if you can find anyone that even wants the job, than a new set would cost you. I drove a 1971 dual port bus for 750,000 miles. Did all sorts of things to the engine and enjoyed every minute of it. I always figured that about 35,000 miles in I was going to be fixing cracks, replacing guides, doing some porting, and a valve job to keep it in tip top shape. Then about 60,000 heads were simply a maintenance item, and time to replace them. Someone would always buy them for some cheap sand rail they were building, and my used heads were still better than many used heads, but no longer up to my own personal standards for maintaining a like new engine. Buses are brutal on heads because they generate so much heat compared to a lighter car like a Ghia, Beetle, Type 3, Thing etc.. If you want to learn about the head life cycle, and the problems you can run into, buy a bus.

Yep I figured it was worse than what the seller had thought. Easier to go new heads - or even just machine the 1300 heads to accept 85.5 cylinders. But then again that could cause some troubles. Comes back to new heads every time doesn't it

Wed Jun 11, 2025 9:45 pm

The helicoil in the other side is a red flag for me :wink:
Been decked before, and bead blasted to the extreme too.
I already got a lifetime supply of antique junk heads, but if you don't, then offer twenty bucks.

Fine cracks between the valve are ok
Cracks into the spark plug hole, BAD news

Thu Jun 12, 2025 6:16 am

Chunky_t wrote: Yep I figured it was worse than what the seller had thought. Easier to go new heads - or even just machine the 1300 heads to accept 85.5 cylinders. But then again that could cause some troubles. Comes back to new heads every time doesn't it

1300s are great little motors. I like to keep one around with its 6v generator and 6v flywheel to instantly make a non- running 6v Bug into a runner.

I'm gathering parts to build a 12v single port 1300 w/ case savers and doghouse cooling probably on one of the numerous "AE" cases I have.

Brian_e wrote:

#10 deep flycuts wasting chamber volume

Deep flycuts are a sneaky one. There are a lot of good lookin' heads that have had a lot of work done to them except they've been flycut to death.

If they haven't been cut for big bore I have a shelf full of 85.5 "fuel injection" low compression pistons to make unworkable combinations... work.

.
.

Sat Jun 14, 2025 7:09 pm

Well, futher to the hunt for 1600 DP heads to make my 1300 into a 1600, I discovered that some time in the past someone had installed 1600 P&C's with the stock 1300 heads, running 12v and a 31pict 3 carb.

Which brings me to a new question (thought I'd continue this thread rather than make another)

I have sourced good used 311 DP heads, and along with going to doghouse cooling, what carb could I run with this setup? I gather 31pict is too small for DP and I'd like to stay single carb to keep cost and tuning headaches to a minimum.

Sat Jun 14, 2025 9:55 pm

34-pict-3

Since they are used, have them checked out before you use them. Heads are a weak spot on VW engines due to the heat involved.