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Wayne 962's Avatar
Hydraulic Lifters: What's your opinion?

A friend of mine, let's call him BJ, is building a 2.0L motor from scratch. This is the poor fellow whose 1.7 dropped a valve seat (see the tech article). He is just about convinced that he wants to put hydraulic lifters in his 2.0L engine. I haven't personally had any experience with these types of lifters, and to be honest, I'm not even 100% sure of how they work.

The advantages that I've heard are that you don't have to adjust your valves any more. Supposedly, the hydraulic lifters place a certain amount of force on your valves no matter what the wear is on them. BJ drives several hundred miles in his 914 each week, so he doesn't like to adjust his valves every two months.

On the other hand, I hear that top end power is lost, and that some hydraulic setups flatten the cam prematurely.

What's your opinion. We want to know!

Thanks,

Wayne
Old 06-26-1998, 02:43 PM
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The 914 we bought last month is a 2.0 and the engine was from a totaled 914 that had about 4500 miles on it. It has the hydralic lifters and a cam MADE for them and they are adjusted as per the manufaturer's instructions(no valve lash). The big advantage is no valve adjustments required. If there is any loss in power, I would be hard pressed to find it and since the engine doesn't get revved over 5500, there is no problem. For a daily driver like your friends and our daughter's too, hydralics seem to be okay.
Old 06-27-1998, 08:52 AM
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My 914 came with an "extra" engine. It turned out to be a "GE" block 76-79 2.0L bus motor. The motor was pretty beat, the cam was wiped bad, and the hydralic lifters were concave. The block seems fine so I planned on using it. THen I read somewhere, either Tom Wilsons book or the Sermons of Bob Hoover or VW Trends Engine Rebuild special, that the oil galley to the lifters is different between the solid and hyd lifter motors. This made sense st the time because the pump up lifters need accurate oil volume and pressure to opperate. I have'nt had the time to compare the two blocks (I now have 3 "extra"914 motors, and one blown up case) as soon as I dig the bus block out of storage (it's gotta be 150 degrees it that shed) I'll tell you what I find or don't find. As for the power loss... In domestic small blocks anyway the hydro lifters actually gain low end torque over the solids because of lower lift at low oil pressure/low RPM. As RPM and pressure go up the hydro lifters act more like solids but without the noise. Don't forget to properly load the lifters with oil before installation, I think soaking them in oil overnight works, or remove the plunger and load them that way.
Old 06-28-1998, 09:11 AM
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Well, if Wayne says he's not sure how they work, I won't mind saying that in my case I am sure I do not know how they work.

JP, you seem to know about these things, are you able to explain (to me at least) what the mechanism is ?

Thank you.


Old 06-28-1998, 05:15 PM
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First--

I'm very interested to hear what JP finds when he digs his Bus case out of storage. It would be worthwhile to know exactly what the differences are.

Next, here is a LONG reply I wrote over on the Renegade Page's Forum to someone else with the same question. I hope the formatting works correctly in this forum. I have recently been in contact with Stan and received permission to post the quotes from him.

I'm the guy who posted the long negative reply on Tim's Fan Page. It was mostly a quote from Stan Hanks, former Porschephiles Listmeister and 914-head. I did not obtain his permission to re-post, as I can no longer contact him, but I sincerely believe that he wouldn't mind.

The short version is that Stan had a hydraulic-equipped 914 motor. Someone did a "normal" valve adjust on it, and the motor blew up. Then he researched the conversion kits, and didn't like what he found.

What Stan said was:

>Section II: I Just Want to PUMP... You Up: Hydrualic Lifters
>
>The Type IV engine was designed to be flexible. It was *NOT* a Porsche
>design, and was really not even built to Porsche specs -- it just happened
>to be on the shelf and handy when the original VW-Porsche handshake deal
>was done that created the 914. On the VW side of the house, the target was
>to do a couple of things: increase the life of the core engine, deal with
>SIGNIFICANTLY hotter running environment (the 411/412) than the Type I,
>and provide the evolution for the next generation Type II engine. That's
>why the case is thicker, made of aluminium instead of magnesium, has bigger
>oil passages, etc. On the Porsche side, that turned to be an advantage
>as it let you put in more power.
>
>The hydraulic setup was designed for the 412, where service was effectively
>impossible. (Ever worked on one? I have. Girlfriend in high school had one.
>Nice car, impossible to work on..) There was *SIGNIFICANT* motivation to
>keep from having to adjust the valves. ****, even I would lie about having
>done so... Alas, the 412 died out, and as the engine went into the Type II,
>the hydraulic cam was kept for the same reasons. Now, NOTE THIS: both of
>these applications had several things in common: low engine speed, high
>heat, VW owners where the motivation to follow the service manual seemed
>inbred. We'll get back to that...
>
>What you do when you put a hydraulic cam in a 914 is use something that
>was *NEVER* engineered by the factory to do this job. And further, I can
>just about certify that it was *NOT* engineered by anyone in the aftermarket.
>They just said, roughly, "oh cool -- we can take this part from here, and
>this part from there, and hey, it's a 914 hydraulic cam kit!"
>
>So how do you make sure that the followers track the cam? Well, you design
>them so that they just do. *OR* you put in *BIG* springs to make damn sure
>that they do (which may wear the bottom surfaces off the followers or just
>eat the surface of the lobes, which ever is softer). How do you keep the
>lifters from either pumping up solid, or going soft (depending on the
>design flaw you wish to exploit here)?? Well, if this is engineered for the
>application, you know what sort of specific heat you have to face, the
>oil recommended, the filtration used, etc and you cope with it. *OR*
>you have a part that is for a different application and can't as a result
>say for sure that won't happen.
>
>This is not to say that all hydraulic lifters are evil -- if they're designed
>in by the engine's designers, and you operate the engine within its service
>envelope, they're GREAT. I've even built dragster engines with hydraulic
>lifters...
>
>But it very much *IS* to say that you gotta have the right stuff. In this
>case, you want the right cam grind to start with, and the right valve timing.
>Then you gotta have the right slope on the lobe, so that you don't dig in
>too much and cause the internal bits of the lifter to drag on each other and
>stick. Then you gotta make sure -- really sure -- that the oil is as thick
>as it needs to be, and as clean as it needs to be so that it meters out of
>the internal lifter valving just right. And then the pushrods have to be
>right so that they aren't 100% stiff so as to somewhat cushion the load
>but don't collapse from being overly flexible, and you gotta get the
>valve springs right to make sure that the valve closes properly and the
>follower tracks the lobe with the right pressure.
>
>No one has ever convinced me that they had all this for the 914.
>
>Now, if that's not enough, consider this: you have a car that is supposed
>to have the valves adjusted with some frequency -- 3000 to 6000 miles or
>so. So you put in the new hydraulic cam. You're happy -- that's your
>last ever valve adjustment. Now lets say that for some reason -- you're
>busy, you sell the car, your regular mechanic is out sick, whatever --
>someone that does not know that this car has hydraulic lifters is the
>next to adjust the valves. Ever look at the specs on how to adjust hydrualic
>valves? They're *VERY* different than mechanical valves. And just looking from
>the heads, you *CAN'T* *TELL* that it has a hydraulic cam. So it get's a
>regular mechanical cam adjustment. If you're really lucky it makes enough
>noise that you figure it out before you get to see the next valve adjustment
>happen on an engine rebuild stand.

RD Rick, on the other hand, has hydraulic lifters on one of his 914s. He loves them, and reports no problems. His reply was:

>I have a Weber cam with '79 bus hyd lifters in a GB case in my '76 914.
>Otherwise it is stock 2.0. It has about 35K milestotal since
>rebuild, and 15K since top end rebuild. A 96 mm piston broke, causing
>the premature top overhaul.

>The hyd lifters make the engine very quiet. Kuby will attest to the
>difference compared to his '74 2.0. They can be noisy at startup, after the
>car has been sitting a few days, especially if the oil is more than a
>pint low. It's a nice reminder, actually.

>A friend put hyd lifters with a Webcam in his 1.8, and pulled it back out
>because he could not get it to idle. Weber gave him too hot a cam, I
>believe. He pitched them shortly before he died, so I'll never know more
>about them.

>My next engine for a commuter will also get hyd lifters.
>RD

Stan's opinions may be biased as a result of the engine failure. Or, he may be too picky about "engineering work". Maybe not. RD may simply be lucky, or perhaps 35K miles is not a long-duration enough test. Or maybe it is. All we know for sure are that there are some people running the hydraulic lifters without problems so far. (BTW, RD reports no valve float all the way up to 6000 RPM, which is higher than any stock-cammed 914 really needs to go.)

In the final analysis, it's your motor. You'll have to live with the uncertainty that just *maybe* the engineering wasn't completely done, or you'll have to live with the noise and the frequent need to get grubby or to pay someone to get grubby.

Personally, I'm in the "get grubby" camp. I'd worry far too much about it if I had a hyraulic cam, and I've done them enough that a valve adjust isn't such a chore for me.

--DD
Old 06-29-1998, 04:40 PM
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Why don't people just paint a WARNING HYD CAM on the rocker covers. Nothing is fool proof but... Also I forgat to say that the hydro lifter block did indeed have shorter and I think thicker (also in the shed) pushrods. The heads are at my mechinist friends place, he is going to check the springs to see what the installed and open pressures are compared to the sets of 1.7L and 1.8L springs I gave him. I pulled apart a few of the lifters back when I was tearing down the motor, its hard to explain (the Chiltons air cooled VW book I think has diagrams) but it is basicly a solid lifter shell with a spring, a valve, and a tightly machined piston retained in the bore of the lifter. The valving and spring pressure of the internal spring vary according to the application, so I see where bus liftersa may not be the best thing for a 914, however they may be the only ones out there.
Old 06-30-1998, 07:50 AM
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I'm Bee Jay, Waynes friend. I plan on using the 914 with the 2.0 liter we are building as a daily driver. I commute to Lompoc (170 miles) every weekend, and to work every day when I am in LA. I can adjust valves in my sleep now, but my time is very limited. I have house work, yard work, other cars to maintain, and I need time to chase ladies and get to the gym occasionally. If a hydraulic cam and lifters eliminates one tedious non-fun task from my life, I'm all for it. Now, I need to know who makes the best hydraulic cam and lifters. I plan on running Weber 40s and I don't go over 5500 rpm very often. Once the cam and lifters are obtained, Wayne and I can start putting this engine together. Thanks for any advise.
Bee Jay
Old 07-08-1998, 09:44 AM
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I just got back from Ohio where the 2.0L bus heads were and have the following to report...
The bus valves springs are MUCH stiffer than the 1.7-1.8 or I had 3 sets of equally bad 1.7-1.8 springs (not likely). The 1.8 springs have an open pressure (the presure the spring exerts when the valve is open) in the 180# range (I have found no less then three books with three different specs. but they all were close to 180#) the 2.0L bus with hydralic lifters had valve springs in the 210# range.
Sooooo if you switch to hydralic lifters you need a compatible cam, lifters, correct length pushrods, and heavier springs. Now these springs did come from a 77-79 bus so maybe by then all VW typeIV engines, solid or hydro, would have the stiffer springs. But I think it is a safe bet the springs match the lifters, personally I plan on using the heavier springs on my solid lifter engine, maybe rev a little higher?
One more thing... The hydralic lifter heads have different types of spacers between rockers. I read somwhere that you also need these spacers when converting to a hydralic cam. You might consider buying a set of 2.0L bus heads and pushrods, the PO of my car bought the whole motor for $200.
Old 07-08-1998, 12:35 PM
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Just got in from the shed (who said I never did anything for you people) found the bus block, fan shroud, and rockers. Haven't got to the block yet but the rockers do have solid spacers between them instead of springs. Those tricky VW folks also seem to have figured out the lash adjustment problem also. The shroud doesn't have a removable plug in it, therefore the fan has no timing marks which makes it impossible to adjust the lash as we are used to. Maybe this has something to do with the way the motor sits in the bus, interference of some kind but I doubt it. Also on the shroud is a sticker (in german) with pictographs explaining that the valves should not be adjusted, and how to set base timing (I don't know how without timing marks but thats not my problem). I'll get back to everyone on the oil passages once I get it all cleaned up.
Old 07-09-1998, 01:48 PM
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On the 1973 bus we had with a 1.7, the timing marks were on the fan pulley, visible from the back of the van with the rear hatch up. This was how I used to time it with a timing light until I put in a 009 distributor and then did it static with a piece of wrapper from a pack of cigs. There is also, or at least there used to be available a stick-on degree wheel that the off-roaders used and I had one of those and it gave a full 360 incrementation. you could use one of these on a 914 but would have to use a mirror to see the marks.
Old 07-10-1998, 01:20 PM
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Damn, moving stinks!! I finally set up my work bench and took apart a badly used "W" block 1.7L and compared it to both the "GE" 2.0L bus block that came with hyd lifters and to a crack "E?" 1.8L that came from a 75. To the best that I can tell the oil passages are the same, and the lifter bores are the same length and diameter, however there are little diiferences.
The GE block has a cavity formed under the cam bearing closest to the front of the engine. This cavity is formed because of reinforcments made into the case, this should make the case stronger. The GE block also has the windage tray "boss" cast into the block so a windage tray can be used. The W block does not have a "boss" cast into it though I'm not sure that te motor came from a 914, maybe from a Type IV sedan. The E block has the boss. I guess the W is an old casting and somewhere along the line VW changed the casting.
What does this all have to do with the cost of tea in China??? It would appear hyd lifters can be used in a 914 block, and a windage tray can be used in a bus block.
Old 08-10-1998, 07:10 AM
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I have installed 'web cam' hydraulic cam conversions in two different VW buses (Buses timing marks are on the flywheel end of the motor). I would only purchase/install a hydraulic cam as a KIT. Most firms will only warranty valvetrain components when installed as a set with their recommended parts, i.e. springs, pushrods, etc. I had great success. Much quieter!! As I did not rev my bus over 5K I can not attest to any high RPM power loss. A critical step in any hydraulic installation is the proper 'pumping-up' of the lifters and setting the lash. Use a plastic oil bottle partially filled with your motor oil, leave the lifters in the oil over night if possible. Prior to installation use a push rod to 'pump' the lifter while still in the oil. Air bubbles will come out of the hole in the side of the lifter body. One final note: I know from prior experience that if you set the lash to zero on a hydraulic lifter that is not completely 'pumped-up', when the engine oil pressure does fully expand the lifter that valve will stay partially open. If this valve happens to be a exhaust valve and the engine has even a small exhaust leak at the head (those oval copper washers)the engine will suck in cold air into the combustion chamber. Within 100 miles you have burned a hole in the top of you piston much like a cutting torch. Don't let this discourage you. A hydraulic conversion is a viable upgrade to your daily driver.
Old 08-11-1998, 07:09 AM
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