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Helfen
Samba Member
Joined: January 19, 2009
Posts: 3450
Location: Vulcania
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 Posted: Tue Jul 10, 2018 10:29 pm Post subject: Re: valve job - what info needed? |
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| Zundfolge1432 wrote: |
| When you are thinking of building 50 year old heads how much life even if everything’s right do they have left? How many heating and cooling cycles can they take? Curious but in the beginning VW treated heads as disposable, they did not rebuild and had no provisions for replacing guides. |
In the early 60's VW opened a Plant in Kassel. At the time all the plant did was remanufacture engines, transaxles, and beam front axle assy's. The used units came from all over the world. These parts all had the recycling logo stamped on them, engine cases had their old serial numbers routed off and they were re stamped. Everything in the engine was reused if it was re-serviceable including heads. In front of the serial number was the recycle emblem of two arrows chasing each other. The first time I had ever seen the arrows was in the late 60's. The recycling arrows we see today on everything mimic this design.
I have a 64 113 that I bought in 1974. The original owner had never owned a VW before and treated the car like someone would mistreat Detroit iron. He learned his lesson and in 1966 the engine locked up. The dealer that he originally bought the car from procured a re-manufactured 1966 40 hp 1200 that came from the Kassel re-man factory. As many of you know the 40 hp engine after 1965 and to 1978 came with cam bearings and the large oil pump. Anyroad when I bought the car in 1974 that engine was already in the car eight years and the car had 78,000 on the engine. I drove that car another 90,000 before I rebuilt it in 2012. Today it's running happily along for another 100k or so. Truth is, it will outlive me. |
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Zundfolge1432 
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Joined: June 13, 2004
Posts: 12466
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| Posted: Wed Jul 11, 2018 8:38 am Post subject: Re: valve job - what info needed? |
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Yes I was thinking of a time before that and it’s how Empi got started. They came up with a procedure later adopted by many others to replace the valve guides, prior to this VW treated heads as disposable. I’m not saying the Vittone brothers forced VWs hand rather these things happened around the same time frame. The replacement guides were made of a better material as well, silicon bronze and with a minimum of effort any good machine shop can replace guides. The big labor bugaboo with rebuilding heads is labor and before anything you’ve got to clean them well enough to inspect for cracks, back when VW was rebuilding them they weren’t 50+ years old so it was a lot easier.
So clean em up, ck for cracks, using a core drill Ream out the guide to weaken it and help release its hold on the head, tap the guide out, clean it more ck for cracks again around guide boss and the ports, when time comes for install guides heat the head in oven and freeze the guides using liquid nitrogen preferably, working quickly install the guide back into the head, check the fit of valve. Repeat 4 times ea. Head. This makes no consideration for stud repairs, damaged spark plug threads, head sealing surfaces, valve seats, very very labor intensive to repair a 50 year old part . Have at it  |
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Helfen
Samba Member
Joined: January 19, 2009
Posts: 3450
Location: Vulcania
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| Posted: Wed Jul 11, 2018 10:03 am Post subject: Re: valve job - what info needed? |
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| Zundfolge1432 wrote: |
Yes I was thinking of a time before that and it’s how Empi got started. They came up with a procedure later adopted by many others to replace the valve guides, prior to this VW treated heads as disposable. I’m not saying the Vittone brothers forced VWs hand rather these things happened around the same time frame. The replacement guides were made of a better material as well, silicon bronze and with a minimum of effort any good machine shop can replace guides. The big labor bugaboo with rebuilding heads is labor and before anything you’ve got to clean them well enough to inspect for cracks, back when VW was rebuilding them they weren’t 50+ years old so it was a lot easier.
So clean em up, ck for cracks, using a core drill Ream out the guide to weaken it and help release its hold on the head, tap the guide out, clean it more ck for cracks again around guide boss and the ports, when time comes for install guides heat the head in oven and freeze the guides using liquid nitrogen preferably, working quickly install the guide back into the head, check the fit of valve. Repeat 4 times ea. Head. This makes no consideration for stud repairs, damaged spark plug threads, head sealing surfaces, valve seats, very very labor intensive to repair a 50 year old part . Have at it |
At VW we never would not ream the guide and tap it out. The procedure is with a tap to thread the guide and use a puller to remove it.
While we are on the subject; When you get your heads back from the machinist you should have a specification sheet on the heads. The spec. sheet should tell you the valve angles/ interference angle, the valve height, installed valve height, The closed and open spring pressures. |
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bugheadred
Samba Member
Joined: January 23, 2003
Posts: 666
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| Posted: Wed Jul 11, 2018 10:07 am Post subject: Re: valve job - what info needed? |
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| Zundfolge1432 wrote: |
Yes I was thinking of a time before that and it’s how Empi got started. They came up with a procedure later adopted by many others to replace the valve guides, prior to this VW treated heads as disposable. I’m not saying the Vittone brothers forced VWs hand rather these things happened around the same time frame. The replacement guides were made of a better material as well, silicon bronze and with a minimum of effort any good machine shop can replace guides. The big labor bugaboo with rebuilding heads is labor and before anything you’ve got to clean them well enough to inspect for cracks, back when VW was rebuilding them they weren’t 50+ years old so it was a lot easier.
So clean em up, ck for cracks, using a core drill Ream out the guide to weaken it and help release its hold on the head, tap the guide out, clean it more ck for cracks again around guide boss and the ports, when time comes for install guides heat the head in oven and freeze the guides using liquid nitrogen preferably, working quickly install the guide back into the head, check the fit of valve. Repeat 4 times ea. Head. This makes no consideration for stud repairs, damaged spark plug threads, head sealing surfaces, valve seats, very very labor intensive to repair a 50 year old part . Have at it |
I used to do all my own heads still have all the tools (I buy replacement heads ) its just not worth it to do all that work to have a 50 yo heads |
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Helfen
Samba Member
Joined: January 19, 2009
Posts: 3450
Location: Vulcania
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| Posted: Wed Jul 11, 2018 10:12 am Post subject: Re: valve job - what info needed? |
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| [email protected] wrote: |
| Zundfolge1432 wrote: |
Yes I was thinking of a time before that and it’s how Empi got started. They came up with a procedure later adopted by many others to replace the valve guides, prior to this VW treated heads as disposable. I’m not saying the Vittone brothers forced VWs hand rather these things happened around the same time frame. The replacement guides were made of a better material as well, silicon bronze and with a minimum of effort any good machine shop can replace guides. The big labor bugaboo with rebuilding heads is labor and before anything you’ve got to clean them well enough to inspect for cracks, back when VW was rebuilding them they weren’t 50+ years old so it was a lot easier.
So clean em up, ck for cracks, using a core drill Ream out the guide to weaken it and help release its hold on the head, tap the guide out, clean it more ck for cracks again around guide boss and the ports, when time comes for install guides heat the head in oven and freeze the guides using liquid nitrogen preferably, working quickly install the guide back into the head, check the fit of valve. Repeat 4 times ea. Head. This makes no consideration for stud repairs, damaged spark plug threads, head sealing surfaces, valve seats, very very labor intensive to repair a 50 year old part . Have at it |
I used to do all my own heads still have all the tools (I buy replacement heads ) its just not worth it to do all that work to have a 50 yo heads |
Pretty hard to buy new replacement heads for my 36hp 65 111. What about 40hp heads? |
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Abscate
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Joined: October 05, 2014
Posts: 22639
Location: NYC/Upstate/ROW
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| Posted: Wed Jul 11, 2018 10:30 am Post subject: Re: valve job - what info needed? |
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$300 heads that are deemed too expensive is what has ruined the supply chain in this brand.
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Zundfolge1432
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Joined: June 13, 2004
Posts: 12466
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| Posted: Wed Jul 11, 2018 3:07 pm Post subject: Re: valve job - what info needed? |
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| I can’t imagine why anyone would tool up to make real German heads again so it falls on the aftermarket in this case the chinese. Everyone including myself is ok with fit and finish of these. All you can do now is try to locate suitable cores and try to do as much as you can to keep costs down. VW people have always been cheap and that will never change. |
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crankbait09
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Joined: October 10, 2016
Posts: 1304
Location: Cincinnati, Ohio
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| Posted: Thu Jul 12, 2018 10:19 am Post subject: Re: valve job - what info needed? |
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I called a local shop and they actually broke down the costs to do a valve job. From labor, machining, each valve guide needed, valves, springs, etc. That adds up fast! You are definitely at a higher price rebuilding than going the new route.
I certainly see why one would buy a new head from a cost stand point.
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[email protected]
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Joined: August 15, 2002
Posts: 4394
Location: Brew City
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| Posted: Thu Jul 12, 2018 10:48 am Post subject: Re: valve job - what info needed? |
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I flat out refuse to sell, rebuild or build an engine with the "new" singleport heads. Back when they came out, I built three engines with them and got all three engines returned for warranty. Two engines had the valve guides break apart and the other burned a hole in the exhaust port.
I recently sold, ironically enough, three single port engines to one customer who had the same problem with engines he bought from another builder with the "new" single port heads. The engines I am building for him will have OE German rebuilt single port heads.
The problem with the new single port heads is that the parts they use are not good and the port walls are paper thin.....which is a problem with a few of the other manufacturers dual port heads as well.
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