Replacing Valves on New AMC heads ~ Update #3

[Lanval]

Update here:


New (used) case in hand, and off to RIMCO next week. I'll post pix of the case tonight or tomorrow. Thanks to Interstate for timely and cost effective intervention!

Lanval


Case came back from RIMCO ~ it's already been overbored or something; anyway, it's no good. I'm calling Interstate today to see if I can get a decent one for a reasonable price. If not, I'm going to abandon the rebuild for the moment, and decide which direction is best.

One underlying problem is the need for bodywork. Since good bodies aren't that hard to come by (i.e. little/no rust) here in SoCal, in inclined to wait for another bus with engine/body, but destroyed interior.

Thanks guys,

Lanval


Greetings ~ I've got ahold of some new AMC heads, for my engine rebuild in my '82 Vanagon Westy (air-cooled). Another Sambanite suggested I check into the valve quality, which I did. From what I understand, I need to / ought to swap out the AMC valves for German valves now, in order to avoid quality control problems with the AMC valves. Thus I have a few questions for the Air-Cooled experts here:

Where do I source new valves (i.e. recommendations)?
Do I want sodium filled valves?
Do I then need to send the heads and valves to a machine shop to maximize flow and fit?
If so, has anyone experience with this shop: http://www.rimcovw.com/
I saw them mentioned in a post on this same issue using the search, so I wanted to see if someone has used them before, and could let me know who to talk to/what to ask for....

Thanks in advance.

I'll update the build info in my original post about this issue, but wanted to get a thread on the AMC Valve issue separately.

Thanks,

Lanval

[iltis74]

You do not want sodium filled valves. I've used Rimco for case work before with good luck, never head work. There is talk that they are not what they once were but I have not experienced this. If you are going to the trouble of replacing the valves you want to think about the seats also. Your best bet is to call up and talk to Len here-

http://www.haminc.biz/

He's probably not cheap and probably far away, but also a very nice guy and very, very well informed.


Here's an edit- Perhaps better wording would have been "Metallurgy being what it is these days you are better off going with a modern stainless steel valve." Sodium filled valves do in fact run cooler, at the head. The valve stem and guide are where the extra heat goes to. My father was a pilot and I remember conversations about sodium valves leading to increased guide wear and valve sticking. Also I've read since recently aquiring a Type IV posts from Raby that they have a habit of breaking, and he won't use them. I still haven't decided whether I love him or hate him, but I easily conceid he knows more about this crap than me. After a few beers all that comes out to "You don't want them." That may not hold for every application, but if there are better for cheaper out there, why would you?

Not meant to be a rant, just explaining my thoughts a little better.

[devesvws]

[quote="iltis74"]You do not want sodium filled valves. thats funny back years ago a few of my 914s had sodium filled valves. that was the way to go it keeps the valves cooler if i remember right when it came to the 2.0 914s. btw check this guy out they have come a long way since i last checked them out 20 yrs ago. http://www.pauter.com/

[D Clymer]

Lanval,

I used Rimco to rebuild some AMC wasserboxer heads for me. The price was decent and the turn around was pretty quick. I had them replace the valves because of the reputation of the AMC valves. The shop foreman is Todd, and he is fine to deal with. I wouldn't say I was bowled over by the quality of their rebuild work, but it certainly was acceptable.

You don't need to have the heads flowed and modified. Unless you're building a performance motor, the stock port flow is fine. The valve guides should probably be changed since I've heard that the AMC valve guide to stem tolerances are sometimes loose. If you do go with Rimco make sure you find out specifically what kind of valves they are using. They told me the ones they used on my heads are TRW, but the valves only cost like $11.00 a piece and TRW valves should be more expensive than that. So now I'm kind of wondering what kind of valves I ended up with.

You should also check with Rocky Jennings at www.rockyjennings.com. He does very high quality machine work and is completely knowledgeable about air cooleds. He specializes more in Type 1 and wbx, but I'm sure he could also do Type 4 heads. I don't think he could beat the Rimco prices, but I don't know of a better machinest.

David

[FNGRUVN]

I put new AMC heads on when I rebuilt mine. I didn't know they had any problems. Could you tell me all the bad stuff you know about them? I'm getting ready to take my engine apart because of an oil leak at the case halves and I'd like to address any issues like the heads at this time.

[devesvws]

[tencentlife]

I can only speak of the AMC wbx heads out of the box, but I imagine their supplier is of similarly poor quality on the exhaust valves, so I would be sure at the least to invest in some good TRW or German-sourced valves on the exhausts. I have been using the AMC intakes on the wbx's, as the intakes run very cool. A reground VW intake may be a small step up in quality. There isn't any good reason to buy new intakes as long as the regrinds are straight, not too much stem wear, and the valve head margin is still within spec.

I have found the AMC seat grinding to be just fine. It's a two-angle job, but the angles and widths are correct. If you want to aid breathing a bit you can have a machinist add a 30deg. cut on the intake seats, but there wouldn't be much benefit to doing the same on the exhausts. So far every AMC guide clearance I've checked has been just fine; the final measure there must be done with the valves you will install. So overall, no actual machining is normally required, just disassembly/reassembly with better exhaust valves. While apart, always check stem rock in the guides, and at the least blue the seats to be sure the valves make full and even contact. I'm of the old school and hand-lap my valves after checking, but this is a matter of taste.

Other than the exhausts, there are two things I always do to make the AMC's serviceable. One is to to blend the bowls, as there is always a bit of casting flash just under the seats. This is just cleaning up the ports and a long way from a port'n'polish, but a few minutes with a high speed burr and the airflow will be much cleaner. The other is to check their valve stem keepers carefully. This is also mentioned in GW's article. They use a keeper that doesn't clasp on the stem, instead the keeper pairs come together to make a ring slightly larger than the stem. This lets the stem rattle within the keepers and will eventually wear down the stem grooves with the possibility of catastrophic keeper failure, leaving the valve open where it will be struck by the next piston stroke. A quick buzz on a grinding wheel with the flat side of each keeper will fix the problem. A pair of keepers should close on a valve stem with a tiny gap.

That's what I've seen with the wbx heads. iI imagine the aircooleds are similar.
_________________
Shop for unique Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/

Please don't PM here, I will not reply.

Experience is kryptonite to doctrine.

[FNGRUVN]

That's some great info. Thanks guys. I removed my engine today to fix an oil leak between the case halves, so I'll be doing some head work too.

[Lanval]

Thanks guys ~ I did some searching here and on the Bay Window forum, and basically came to this conclusion:

Not replacing the valves, seats and springs on a new AMC head amounts to rolling the dice. Some have put the heads on stock and had no problems; others put them on stock and saw the valves kiss the pistons way early (like in the 0-40K range).

Best choice seems to be stainless valves

Best practice seems to be send the heads to a shop to have them do the valves, seats and springs (i.e. headmasters, Rimco, etc.)

I sent an email to Jake Raby asking if he has valves/seats/springs sets that I can buy ~ I'll then either take the heads + parts to Rimco or use another shop if my mechanic has somebody he likes. If Raby doesn't have the parts for sale, Air-cooled.net has valves.

I'm awaiting delivery of my Kohlberschmidt pistons and Fibi lifters. When I take them over to the shop, I'll pick up the old heads and pistons, and post some pix so you guys can see what they looked like.

Best,

Lanval

[tencentlife]

Valves kissing the pistons was probably due to the bad fit of the keepers. Ten minutes with a bench grinder and that problem is fixed. Gotta be sure to check the fit of those.

One problem that T4 heads have that you wouldn't encounter with a wbx would be seats falling out. Any incidence of that on any of the other forums? I said that the AMC seat-cutting was fine, no need for further treatment, but that says nothing about how well the seats are fitted in the casting. You can't tell anything about that just by looking; you pretty much need to know the exact procedure and components that were used. If there were any instances of that reported, I would have someone refit different seats with a liquid nitrogen cold fit.

I used Rimco awhile back for some case and head work. The case work was fine, but due to some miscommunication I wasn't happy with the heads and had my local guy finish them up.

You can't go wrong with a quality two-piece SS exhaust valve. Put in a CHT gauge and you can avoid damaging the heads and get the longest life from the motor.
_________________
Shop for unique Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/

Please don't PM here, I will not reply.

Experience is kryptonite to doctrine.

[Jake Raby]

The valves, springs and etc are available through my online store at www.type4store.com

There you will find everything from a complete valvetrain kit with cam, lifters and all the other RAT valve train parts.

We get hundreds of emails per day, so if you don't get a response ASAP don't be too alarmed- this is our busiest time of the year. If you are looking for near immediate responses please post questions on my forums.

With the AMC heads the valves aren't the only crappy parts, the retainers are horrible and so are the springs...

I really dislike the AMC seat installation procedures, but if you keep them cool a failure shouldn't occur...
_________________
Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

[jalopyjockey]

lanval- just a reminder to take the time to check your rocker geometry when the time comes...those febi lifters are almost 2mm longer than stock iirc......oh and heres something i heard the other day you might could try with your old parts....a friend works on harleys and when they do upgrades they end up with nice new left over heads, slugs and jugs that no one wants so they take em out to the field put an m80 or suitable explosive in the chamber, bolt the cylinder to the head(valves still in), point er at the sky and ignite thru the spark plug whole.....

[Dogpilot]

One thing to keep in mind about valve seats dropping. There is a regional difference in fuel blends. We had a problem with valve seat dropping out of large block aircraft cylinders. Nobody was doing anything different then what had been done for the last 30 years. One of my buddies in Porterville did some tests and found that the AvGas distributed by Chevron was up to the allowable limit on Toluene. This makes the fuel burn hotter, so hot it was heating the heads around the valves to the temp we use to insert the seats, so they just fell out. Toluene is a normal byproduct of gasoline refining. There where other uses for it, but EPA regulations have made it a more restricted use chemical.

So the fuel supplier are blending as much of it as they can get away with into our fuel. This varies by region, as bends are different according to average temps, altitudes and local air quality regulations. The fuel you get may have more to do with the valve seat and valve/guide life than you may think. So somebody's experience in New York may contrast greatly with somebody in Texas or California.
_________________
Geology with a Syncro rocks!
86 Syncro Westy AKA "The Bughunter"
98 Disco I
08 Range Rover SC
08 VW Rabbit S
1951 O-1G

[Lanval]

Thanks guys ~

TenCent: Only one guy posted a response on the Bay Window forum (I figured there'd be some hard-nosed air-cooled guys ready to take up the challenge ~ maybe they don't consider Vanagons 'real' like some don't consider the Eurovan 'real' here...), by Busman78; he said:

"First off, RIMCO is top notch. There is also Hoffman and Headmaster that can do outstanding work on T4 heads.

The valves & seats seem to be a point of contention, some say they are junk, some have had no problems. Stainless steel valves seems to be the overall winner when it comes to which valves to use. Personally I would have the seats and valves changed, nothing like a dropped seat or busted valve to ruin your day."

I also saw similar comments in a search on "AMC head valves" in the bay window forum.

TenCent ~ do you know of anyone in the area that you'd recommend? I assume my guy will have a local machine shop he uses, but it's always nice to have another option...

You: Unfortunately, I don't get to do this rebuild ~ my mechanic asked for the Fibi rockers specifically, so I assume he knows what he's doing... I'll ask him about it, though.

Dogpilot: Is that one more reason to run the lower octane? The PO of my van admonished me to always use super.... I couldn't for the life of me figure out why; theoretically, the engine in question wasn't designed for the quality of gas we're using now, and high burn temps, while equaling more power, are also detrimental to the air cooled engine. I use the lowest octane we have around here ~ 87 I think. Is there anything you can do to the gas to limit it's burn temps? How 'bout using MMO/ATF fluid to think the mix a bit?

Finally, no one seems to think highly of the sodium filled valves, eh? They were used on the Volvo oil cooled turbo 4 cylinders... the purpose was to help cool the engine with the hotter burning turbo system. Seems like they'd work here too; is this an old technology that's been bypassed, or something along those lines? I'd like to know, if anyone has an informed opinion on it....

Anyway, I'll talk to my guy about doing the valves/seats/springs and then get ahold of them if he thinks it's a go.

Thanks again,

Lanval

[remraf]

Why don't you see if the shop gowesty uses to do their heads will do them. The article linked above mentioned lesco. They're in central CA. Think their website is 4-lesco.com. Wonder if they're affiliation with gowesty means they're pricey??

[Dogpilot]

Octane has to do with burn speed, not actual burn temperature. Lower octane is faster burning, higher octane has a retarded burn rate. This is more to control the rate as you increase the compression (avoiding detonation). The temp has to do with the actual blend. Blending is kind of a secret between refineries. As long as the specs, which have a blending latitude, are met, it is what they call it. The octane rating is a rather complex number. It has to do with a standard cylinder.

My crude, and I mean crude, understanding has to do with burning it in this cylinder is observed in a window into the cylinder and the color is the indicator. This is part of the reason it is difficult for the Bureau of Standards figuring out if the gas station is ripping you off on the octane labeled vice what is actually going into your tank. The actual chemical proportions in the blend vary from brand to brand and by season and location for vending.

Certain things do change the burn temperature. Additives, like Techron do make the fuel burn hotter, part of the magic in removing the carbon from the valves. If you read the label you cannot have too much per gallon, or your engine can be damaged. Used properly, it does work, but it can be too much of a good thing if abused.
_________________
Geology with a Syncro rocks!
86 Syncro Westy AKA "The Bughunter"
98 Disco I
08 Range Rover SC
08 VW Rabbit S
1951 O-1G

[Randy in Maine]

Just my 2 cents here, but IMO the thing that is tough on the cylinder heads on a type 4 engine is the load on the engine whicyh equals CHTs. Over 400º is a problem. Quick changes in head temps from 400º+ (like going up a long grade in 4th gear) and then cresting the hill and enjoying some rapid cool down is what makes the valve seats drop out.

Right from the factory the AC vanagons were tough of on the CHTs with higher gearing and more weight than a baywindow (which is a close second when it comes to engine load). Factors that can make that worse are taller than stock tires, more weight, air conditioning, pulling a trailer,a dn going up hill.

I trust you have been here.....

http://www.ratwell.com/technical/Heads.html

Whatever you decide do for camshaft/lifters, take the time to set the rocker arm geometry correctly.

[Alan Brase]

Well, I guess I'll be the only guy to stand up for sodium cooled valves.
They were introduced in late 1973 in the 1.7 engines to counteract the habit of dropping the valve heads off that plagued the 72 and early 73 buses. And the 74's used them too, but they were 1mm bigger.
Pretty much every Porsche ever made (at least since mid 50's) had sodium cooled exhausts, clear up till the end of the air cooled 911's I think. (And a lot of the water cooled ones too.)
I had one break off once in a 911 engine that had been sitting unused for about a decade. It just FELL OFF. Musta corroded. I guess that's the best kind of failure, but it taught me to beware of old valves!
There ought to be no reason to change the guides or seats, but the best thing would be to rely on the aadvice of the head guy.
And my favorite for a road driven air cooled VW in the whole US is Bob Donalds, Boston Bob. He's been doing machine work on air cooled VW's since I was in junior high school and has learned quite a bit.
I'm sure most of those others mentioned do really fine work, but he's been in a place to see a LOT of failed heads.
Yes, he's a super nice guy, too. Look at his website: http://www.bostonengine.com/ He has a lot of good stuff up there.
Al
_________________
Al Brase
Projects: 67 sunroof bug, 67 Porsche 912 Targa, 70 Westy
Dec 1955 Single Cab pickup WANT 15" BUS RIMS dated 8/55, thru 12/55
To New owners: 1969 doublecab, 1971 Dormobile
Vanagons:
80 P27 Westy JUL 1979, 3rd oldest known US
83 1.6TD Vanagon, 87 Wolfie Westy daily driver, swap meet home

[jalopyjockey]

regarding the sodium valves....a few years ago i got curious about them and started window shopping for prices but couldnt find any anywhere....i ended up calling the local porsche dealer to see if he could find some for a 914(1.8 i think) and they were ridiculously expensive, something like 150 a piece....but thats also a dealer.....pelican parts might have them for much cheaper but i dunno.....the cost might make your decision quick and easy

[Lanval]

I delivered the new pistons and lifters to my mechanic the other day, and picked up the old heads and pistons. Thought I'd throw them up here so we could look at them, and discuss them. Since I don't really know much about this stuff (i.e. I don't know what is a significant problem, and what is minor by visual inspection), this would be a huge help to me in terms of education.

Here are the pix

Head 1
http://picasaweb.google.com/Lanval.de.logres/Heads...9273884338

Head 1 valves
http://picasaweb.google.com/Lanval.de.logres/Heads...9273884354

Head 2
http://picasaweb.google.com/Lanval.de.logres/Heads...7863818962

Head 2 valves
http://picasaweb.google.com/Lanval.de.logres/Heads...7863818978

Pistons Side 1
http://picasaweb.google.com/Lanval.de.logres/Heads...6453753586

Pistons Side 2
http://picasaweb.google.com/Lanval.de.logres/Heads...0748720898

Pistons Top
http://picasaweb.google.com/Lanval.de.logres/Heads...5043688210

Pistons Top Close Up
http://picasaweb.google.com/Lanval.de.logres/Heads...5043688226

Thanks guys,

Lanval