Re: Bob, a question on the HVX mods

Q1: you groove only the shaft, not the inside bore of the rockers > themselves?

------------------------------------------------------------------------- Using the lathe, I groove the rocker-arm shafts in the locations shown. Inside the rockers, I use a Dremel tool (or similar) and a carbide burr to CONNECT the two oil passages.

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Q2: Why do you make that groove in the first place? I thought you were > trying to solve the shaft galling problem? Doesn't that shortcut groove > between rocker oil holes actually reduce the oil that is available for > the UNDERSIDE of the shaft, where the most friction and wear occurs? You > get more oil to the adjuster screw, which is fine of course, but at the > cost of reducing shaft lubrication where it is needed most.

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The HVX mods begin with a full-flow oil filter. Then the crankcase is modified so as to INCREASE the amount of oil reaching the heads by eight-fold. There is no sense in making mods to the valve train until you have made the mods to ensure an adequate flow of lubricant to the heads.

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Q3: if you do not use swivel head adjusters...

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The full set of HVX drawings is NOT included in the blog. The HVX mods includes the use of the Soobie/Ford type swivel-foot adjuster, for which the adjuster-end of the rocker-arm must be thinned down... as shown in the drawing you've cited.

All tolled, there's about 125 CAD drawings, a bit much for the blog. But every time I've posted them publicly someone starts flogging them on eBay. I'm trying to get all of this information into a POD book but the size of the book (more than 3 Megs) and the small size of the market (ie, there's not that many owners of air-coolled VW's) makes it a tough sell.

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Any comments would be most appreciated...

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It is a waste of time to do ONLY the valve-train mods -- there simply isn't enough oil to do the job. The key is to get more oil out to the heads. Once you've done that, you'll see the need for the grooved rocker-arm and connecting the oil channels in the rockers. The internal oil channel in the Ford/Soobie-type adjusters allows them to function as SPRAY BARS, allowing the extra oil to pick up a lot more heat.

As for the grooves and other mods, you will find their functional equivalent inside EVERY modern-day engine (including the Type IV).

The lubrication system was marginal in the 1300. For larger engines operating at higher rpm, you have to go back to basics and resolve the root problem. A big advantage of doing so is that once you've provided more oil to the heads you will eliminate the snapping hair- pins, worn washers and galled rocker shafts, which means you can leave all that expensive after-market valve-train stuff on the counter.

-Bob Hoover

Reply to
Veeduber
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Any chance of buying a set directly from you, payable via PayPal(f.ex.) ? Either paper copies, pdf's or any other format you find handy.

Not that I need them currently, would like to store/save/conserve(you get the idea) for the future though, along with the Sermons.

Jørn.

Reply to
P.J.Berg

Ok, so the overall increase in volume more than makes up for the potential loss from the connecting groove. There's just more oil to put to good use.

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Ok. I have had to thin that part for the typical aftermarket crappy swivel feet in the same way.

I get that, I am looking at the whole picture, it was just this one detail that puzzled me, and since the aftermarket rocker assembly I'm looking at, will not have adjusters at the valve end, there's no second oil hole/passage on the rocker. Only a solid lever on the valve side.

I didn't think oil could 'spray out' of them, the passage is still blocked more or less completely by the rocker, even after thinning the underside. On stock rockers, the last oil hole on the rocker was drilled from the outside, and the hole at the tip is welded/brazed shut. If I was to use that type of rockers, couldn't I drill a hole into the rocker tip to tap into the oil filled space around the grooved adjuster shank? a tiny hole could be drilled at any convenient angle, aiming it at some convenient spot in the head.

Still, with no adjusters at the valve end, the furthest the oil would ever get, is to the shaft via the push rod end of the rocker. No swivel heads there, you'd have to drill a hole into the rocker to get the sprayer effect, and then it would be located under the shaft instead of above. Better than nothing I suppose. Or... one could do your groove modification and drill the hole on the topside :)

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Someone will still want 1.4:1 rocker ratio, stronger shafts & rockers and peace of mind from the bolt-type shafts.

The only downside to the rockers above, is the flat, wide valve pressing arm. I don't think it would make the valve rotate anymore. In a race engine it may not be so important, I'm sure they would get a rebuild or a valve lapping before any major wear would occur.

Reply to
Jan Andersson

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I think the main problem here is that they simply don't understand the engineering. Attempts to apply water-cooled technology to an air- cooled engine, especially one that uses only four head-stays per cylinder, is the start of an expensive trip down a slippery slope.

The other thing they tend to overlook is that it isn't the fastest car that wins but the one that finishes first. Until they realize that they have to FINISH in order to win, the hucksters will keep selling them high-lift cams, valves the size of dinner plates, tales of enormous horsepower and other useless shit.

-Bob Hoover

Reply to
Veeduber

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No. While the lubrication mods are about 3Mb, the complete file is over 12Mb.

Contact me directly. With a valid email address.

-Bob

Reply to
Veeduber

Will do.

I will keep the subject line the same as above, I know you do not like unsolicited e-mail..

J.

Reply to
P.J.Berg

Thanx Bob.

J.

Reply to
P.J.Berg

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