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1975 Kombi
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PostPosted: Fri Oct 08, 2010 5:11 pm    Post subject: Reply with quote

That is what the "Hoff" is famous for. The no drop seat. He has had problem with the used 30 year old heads. So how he only works on the new AMC castings.
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Hoody
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PostPosted: Fri Oct 08, 2010 10:55 pm    Post subject: Reply with quote

I personally would not trust anyone but Len with my heads.Too many negative experiences from many people with those two other supposed experts in CA.
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raygreenwood
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PostPosted: Sat Oct 09, 2010 1:56 am    Post subject: Reply with quote

1975 Kombi wrote:
That is what the "Hoff" is famous for. The no drop seat. He has had problem with the used 30 year old heads. So how he only works on the new AMC castings.



Len Hoffman is probably the best type 4 head guy in the country. I would never take anything away from him. But I'm just trying to keep from spreading incorrect information when I can.

There is no exclusive special process for keeping seats in the heads. He might have his own variations in technique.....but the real issue is installing the seats in the head with proper interference fit.
You can also in rare cases where the head has lost some elasticity, turn the new seats for a slight reverse ledge to increase the tightnes of fit.

The big problem ...and the reasons why Len has gone to all new castings is that after a zillion miles, the vast majority of stock heads that have been run on a bus....not so much for 411/412 or 914....usulaly are cracked or have quite a bit of elasticity lost in the aluminum (requiring retempering/reannealing...which they don't always survive)....and require so much work to make a warrantable product its not worth it.

However...any good head shop.....not general automotive machine shop....I mean HEAD shop.....can do the seats properly. But the specifications and handling are different on AC heads than watercooled heads. The quality and difficulty is no more or less. You just need to be able to talk to the machinist and provide specs.
For stock heads...if you know what needs to be done....you can get it done at any excellent shop. For high performance heads....go to an expert.
Lets rephrase that. You should always go to an expert.....but I see far too many people skipping steps on type 4 heads....simply because they don't have the cash they need to go to Len or Adrian. They just slam it together without new seats or proper work.
If money is teh issue....do you research and learn what needs to be done. Find a good shop...consult, provide information and get an agreement on what needs to be done before you turn over the castings.
There are decent racing machine head shops in most major cities than can do exactly what you want....as long as you can ask for it and provide specs. Ray
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Hoody
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PostPosted: Sat Oct 09, 2010 2:19 am    Post subject: Reply with quote

Len Hoffman is the best of the best.Spend your money once.
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SGKent Premium Member
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PostPosted: Sat Oct 09, 2010 8:52 am    Post subject: Reply with quote

Hoody wrote:
I personally would not trust anyone but Len with my heads.Too many negative experiences from many people with those two other supposed experts in CA.


I'd trust RIMCO with my next set of used heads. Len decided not to work on used heads, that is one way to be sure you don't have any issues from them.
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raygreenwood
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PostPosted: Sat Oct 09, 2010 8:48 pm    Post subject: Reply with quote

Hoody wrote:
Len Hoffman is the best of the best.Spend your money once.




True...he probably is the best dedicated type 4 head mechanic.....but has no magic wand. There are plenty of people who can do the exact work he can if you simply know what to ask for. I've never used Len...and have never had to do the work twice. Never dropped a seat and never will. Ray
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Hoody
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PostPosted: Sun Oct 10, 2010 12:55 am    Post subject: Reply with quote

I agree with you Ray.The problem is that most people do not have your expertise.They do not know what to ask for, and are at the mercy of the machinist.They do not know what to look for when the job is done.No disrespect intended.Just trying to save some type 4 engines from the "ouchy momma" post.This a perfect opportunity for you to right a few pages of what people should know before they choose a machinist to build or rebuild their heads and what they need to know for the build.Some pics of good examples and bad examples would even be better.Richard has some info on his site.But I think you could shed some major light on this topic.
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1975 Kombi
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PostPosted: Mon Oct 11, 2010 6:53 am    Post subject: Reply with quote

Here's a reply from Len.



Brett the coating is a proprietary property. I attached a photo of a BMW bike head from a pair that I recently did for a mixed use bike (a hot street bike that will see some track use) The coatings really come in handy for the bikes that sit in traffic a lot with no air moving over the heads.

The coating has also made the difference between melting the chambers and not doing any damage to the chambers in a couple of specific cases where the state of tune was very badly out but loads were high, including a BMW bike that competed in the Iron Butt rally (10,000 mile in 12 days). Guy finished despite temps over 1600*! The coating is awesome for any aircooled heads.
Len
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1975 Kombi
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PostPosted: Tue Oct 19, 2010 7:29 pm    Post subject: Reply with quote

Here's another test and my coating guy says that the piston temps should go down. http://docs.google.com/viewer?a=v&q=cache:5pxN...M6UtJ0DxVQ
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Hoody
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PostPosted: Wed Oct 20, 2010 12:05 am    Post subject: Reply with quote

Used heads are used heads.
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tootype2crazy
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PostPosted: Wed May 30, 2012 10:59 am    Post subject: Reply with quote

I have gotten used heads redone by Archway Import Auto Parts here in St. Louis for 15 years now and the quality is excellent. I have never had a single problem with them in all that time and they have gone through some serious abuse. Last time I got some - which was last summer - it was $800 for the pair. That is reasonable to me. The owner, Jim, has been in the business for 40 years.
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PostPosted: Wed May 30, 2012 11:37 am    Post subject: Reply with quote

Hoody wrote:
I agree with you Ray.The problem is that most people do not have your expertise.They do not know what to ask for, and are at the mercy of the machinist.They do not know what to look for when the job is done.
That would be my position. I don't know what to ask for particularly -- I have different areas of expertise in my life, and I do not really want or need to be come an expert on head machining. Given that, is Len one who could be trusted to do right by a customer who does not know how to make sure that is work is excellent? That's the sign of a craftsman of high integrity, there. Alas - they are few and far between.
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PostPosted: Wed May 30, 2012 12:24 pm    Post subject: Reply with quote

tootype2crazy wrote:
I have gotten used heads redone by Archway Import Auto Parts here in St. Louis for 15 years now and the quality is excellent. I have never had a single problem with them in all that time and they have gone through some serious abuse. Last time I got some - which was last summer - it was $800 for the pair. That is reasonable to me. The owner, Jim, has been in the business for 40 years.


what year bus do you have? T1 head work is easy to find. T4 head work done right is not so easy. The two are not comparable because of all the heat a T4 head sees.
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PostPosted: Wed May 30, 2012 12:26 pm    Post subject: Reply with quote

It's a 79. All the heads I've bought have been type 4. I haven't messed with a type 1 engine since I was a kid.
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PostPosted: Thu May 31, 2012 12:44 am    Post subject: Reply with quote

He is the salt of the earth . Few back up their work like Len. Perfection is expensive and nearly non-existent
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PostPosted: Thu May 31, 2012 4:57 am    Post subject: Reply with quote

In regards to the original question, $250 for professional work sounds like a great deal to me...

It would be great some one that has used the coatings could post some concrete numbers as to the benefits of each coating...

With all the new DIY engine coating products out there it seems that collectively the T2 community should be further along, meaning that "we" thrifty DIY T2 owners have come up with some coating processes that are beneficial to the longevity or our cool rids ;0)

Below is just some FYI from one of Bob Hovers chat room posts; too bad he could not pass on the knowledge he accumulated on coatings :0(
-------------------------------------------------------------------------------

Ceramic coatings Tue Jan 21, 2003 8:10 am
>a while back you said you would have a report on the
> ceramic coatings and their effect on engine performance. Anything
on that
> front yet?

--------------------------------------------

No.

I've proven to myself that cer-met coatings work. But it has taken
me nearly three years to come up with a method of applying the stuff
that may be suitable for use by individuals.

The most recent development (or lack of it) was the discovery that
while an oven made out of cement-board, using the burner from a
defunct water heater, works perfectly well, controlling the thing
manually by bobbing about peering through holes at an array of oven
thermometers -- does not, in that it simply isn't practical. I saved
up for a thermostatically controlled over and it is now on-order.
This will hopefully allow me to stuff a coated part into the thing,
set the timer and forget about it.

(You can't use your household oven for the more exotic coatings.
They contain some seriously lethal poisons that will diffuse into
the lining of the oven... and back into your cookies when you're done
baking pistons. So you need a spare oven. Since gas is the cheapest
source of heat, I made a gas oven using junked parts. But the curing
temperature has to be kept within a fairly narrow range [narrower than
most domestic ovens allow] with is difficult to do without expensive
controls. So I did it manually. And while it worked, it was a major
pain in the ass. So I'm trying something else.)

Another reason I'm not ready to post anything on TBC's is because I
don't have any quantified data for full-size engines. I've seen some
rather remarkable improvements in the one-cylinder lawnmower engines
I used for testing but I don't think the data from a 6cid one-lunger
can be extrapolated to big-bore VW stroker.

For anyone who isn't familiar with Thermal Barrier Coatings you'll
find lots of information on TechLine's website. TBC's were
originally developed to protect the turbine blades in the hot-section
of a turbojet engine. And they do. But what's really exciting are
the hyper-eutectic coatings. Just as an alloy of lead and tin can be
ratio'd to melt at a temperature lower than either of the base
metals, it is possible to obtain a unique hybrid coating of ceramic
and metal which fuses to the substrate at relatively low
temperatures, allowing the stuff to be applied to aluminum engine
parts.

In theory, you can build yourself a better engine by simply spraying
on some magic stuff then baking it in the oven. In fact, the material
has to be extremely clean, the surface to be coated must have a
certain texture, the coating must be applied in the right thickness,
dried to the right hardness then baked at the right temperature.
Some coatings require post-baking procedures. Developed a system for
forged mild steel, such a VW crankshaft, and it's liable not to work
for cast iron (such as a VW cam shaft) And what works on a cast iron
cam shaft may not work on a cast iron cylinder barrel. Most
frustrating of all, there is no manual for any of this.

Do it right, you end up with a piston & combustion chamber that
withstands higher temps and pressures. Or bearing journals that are
self-lubricating. Or exhaust valves that shrug off heat. Or an
exhaust pipe that runs cool to the touch (!) Or surfaces that radiate
8% more heat. Modern-day magic... once you figure out how to do it :-
)

The stuff -- a water-based slurry in most cases -- is fairly
expensive. Do it wrong, you end up with a mess. An expensive mess.
I haven't spent much in actual dollars -- maybe five hundred bucks --
but it has eaten up hundreds of hours and all sorts of little jigs
and fixtures to hold or rotate a particular part.

For those of you with the money, there are shops that will apply your
coatings for you. But as I said, it's fairly expensive. On the VW
heads, for example, you may elect to use a barrier coating on the
chamber, valve heads and exhaust port, plus a friction reducing
coating on the valve guides & stems, plus a thermal disbursant on the
outer fins and the floor of the valve gallery. Unfortunately, none
of the shops I've talked to had ever applied thermal disbursants to
finned aluminum heads. (And now I know why Smile

Since the stuff ends up becoming a part of the metal to which it is
applied, it is also useful as a surfactant, allowing you to protect
parts against corrosion. The self-lubricating properties are
especially interesting to gunsmiths and machinists.


-R.S.Hoover
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VW technical information sights
thesamba - www.ratwell.com - www.shoptalkforums.com/ - www.vw-resource.com - http://www.type2.com/
http://bobhooversblog.blogspot.com/ - www.aircooled.net/gnrlsite/resource/articles.htm
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udidwht
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PostPosted: Sat Jun 02, 2012 12:02 am    Post subject: Reply with quote

tootype2crazy wrote:
I have gotten used heads redone by Archway Import Auto Parts here in St. Louis for 15 years now and the quality is excellent. I have never had a single problem with them in all that time and they have gone through some serious abuse. Last time I got some - which was last summer - it was $800 for the pair. That is reasonable to me. The owner, Jim, has been in the business for 40 years.



15 years and never a problem (gotten used heads)...just got another set last summer.

Based on what you wrote I take it your bus loves heads.

There are only a few competent Type-4 head builders in the U.S. To put it simple I can count how many on (1) hand. Len and Adrian would be at the top. Both do excellent work and come highly recommended by Jake.
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Last edited by udidwht on Sat Jun 02, 2012 9:19 pm; edited 1 time in total
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ccpalmer
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PostPosted: Sat Jun 02, 2012 6:46 am    Post subject: Reply with quote

Stories obviously vary! I used to just take my T4 heads to the local machine shop and for $30 they'd do a valve job. No idea what they did but they'd last 30,000 miles no problem!

Guess I was dumb + lucky! Driving 55mph probably helped...
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PostPosted: Sat Jun 02, 2012 8:17 pm    Post subject: Reply with quote

ccpalmer wrote:
Stories obviously vary! I used to just take my T4 heads to the local machine shop and for $30 they'd do a valve job. No idea what they did but they'd last 30,000 miles no problem!

Guess I was dumb + lucky! Driving 55mph probably helped...


I wouldn't necessarily say, Lucky. T-4 heads built correctly should live a lot longer than 30,000 miles. Luck alone can hit just the pocket book without a roadside failure.
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1972 Westy Hardtop/Type-4 2056cc
96mm Biral AA P/C's~7.8:1CR
Headflow Masters New AMC 42x36mm heads w/Porsche swivel adjusters
71mm Stroke
73 Web Cam w/Web solids
Dual 40mm IDF Webers - LM-2 - 47.5 idles/125 mains/190 air corr./F11 tubes/28mm Vents - Float height 10.45mm/Drop 32mm
Bosch SVDA w/Pertronix module (7.5 initial 28 total @ 3400rpm)
Bosch W8CC plugs
Pertronix Flamethrower 40K coil
S&S 4-1 w/Walker QP 17862
3 rib 002 Trans
185R14 Hankook tires
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PostPosted: Sat Jun 02, 2012 8:41 pm    Post subject: Reply with quote

ccpalmer wrote:
Stories obviously vary! I used to just take my T4 heads to the local machine shop and for $30 they'd do a valve job. No idea what they did but they'd last 30,000 miles no problem!

Guess I was dumb + lucky! Driving 55mph probably helped...


Supply and demand. When there were 10,000 machine shops in the USA doing T4 heads and trying to stay in business, when T4 heads only had 70,000 miles on them instead of 200,000+ miles, and when the wrecking yards were full of low mile wrecked buses then prices like that were doable. Gas was $1.25 a gallon then too. Today it isn't so and most of those machinists are retired or in the grave. Today you may not even speak the language of the guy who actually does the work. Len Hoffman is still the best guy to go to as to buying new heads.

As to RIMCO - based on a recent story from a friend with a T4 engine, I am not sure RIMCO does as good of work as they did several years ago.
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