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Join Date: Apr 2014
Location: Lewiston, ID
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Switching from hydraulic back to mech valves?

I'm new to the forum and am looking for information on converting my '73 2.0 back to mechanical valves. After 4 yrs of tinkering and having Porsche mechanics work on it, I have been unable to reach any meaningful performance or reliability. That being said, this is just the start and I'm sure quite a few other areas of the motor will also need to be addressed. Since the head is currently set up with hydraulic, will I need a new head in addition to new cams, valves and lifters?

Just looking for more info and suggestions.

Thanks.
Old 04-23-2014, 08:18 PM
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If you have aluminum push rods Solid lifters and a stock cam then you are good to go as is setting lash at .006 intake .008 Exhaust.

If you have steel push rods set lash to zero.

If you have hydraulic lifters then zero lash no matter what. There is not that much of a performance gain just changing lifters. At least not worth the effort unless you go all the way to the silly end of a rebuild with inake and exhaust mods.

No new head or anything needed. Lifters will come out after remove the heads and push rod tubes. Only way to do it and it requires dropping the motor / trans assy.

Are replacing the cam? Why? Because that is going to take you to a full rebuild because it requires opening up the case and then while you are in there "ya might as well just because".
Old 04-24-2014, 10:39 AM
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Let's get a few things clear here. If we're talking about a 914 with a T4 engine, there are 2 heads, not one, and they don't care whether you have hydraulic lifters or not. To properly change the valve train from hydraulic to solid, you'll have to replace the camshaft, the lifters, and the pushrods. Solid lifters don't work with hydraulic camshaft grinds, and it's a REALLY bad idea to use new lifters with an old cam, or vice versa. If it's a genuine VW conversion, there is also some work that needs to be done with the rocker shafts. Replacing the camshaft requires a complete teardown, so plan on bearings, rod nuts, a full engine gasket set, and a full on parts cleaning. If the heads are tired (and they may very well be, because hydraulic valve trains can beat up valves and seats), plan on throwing a bunch of money at them. Be forewarned that the retail costs could exceed 4 grand for a complete overhaul. (25-30 hours shop labor plus machine shop charges and parts.)

The Cap'n
Old 04-24-2014, 11:11 AM
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Thanks for the info. I'm planning on dropping the engine/tranny soon to do a complete rebuild and upgrade. Just trying to get things planned out to hopefully minimize the downtime. I read a post indicating the hydraulic conversion involved "drilling out the head" and required replacement for conversion back to mechanical. Once again, I appreciate you feedback.
Old 04-24-2014, 11:21 AM
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We read a lot of things on the web that may or may not be true. Your job, tough as it may be, is to separate the two ..................................... Keep asking good questions!

The Cap'n
Old 04-24-2014, 11:24 AM
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Think there may be further issues here,some conversions used non VW sized lifters so the bores were machined out to fit these,it also served to improve pressure to them as the stock bores would have some wear to start with.
This conversion wasn't really a great one for many reasons,if done as a factory conversion I would say it would be fine because the crankcase would be modified to suit for extra oiling to feed them.
The type 1 VW conversions were for lazy people who hated setting valve lash and offered little more than that.
Wasn't the hydraulic lifter motor from the last of the aircooled Vanagons (T25)?,never heard of one as a stock 914 motor
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Old 04-25-2014, 11:54 AM
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It wasn't a stock 914 motor. But it was a Type IV motor, so the parts "could be used" on a 914 motor. Some love using hydros, some hate them. I figure solids are the way for me to go, since the engine was originally designed for them. And it gives me the chance to look at the valve train of the engine periodically, which is generally a Good Thing.

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Old 04-25-2014, 01:51 PM
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The system was completed by the previous owner and I'm not sure on the specifics of the job. To the best of my knowledge it is the same 2.0 the car came from the factory with and then subsequent converted a few years before I purchased it. I'm putting a lift in the garage in the next 1-2 months and will drop the engine and tranny for rebuild. I'll have a lot more questions at that time I'm sure and hopefully encouraging answers as to prior work done on the car.

I originally purchased the car for a 3.0L conversion project, then found out the model is desirable in its stock form. If I find the engine is not original and/or requires replacement rather than rebuild, I may consider the 6 conversion again.

I've read the threads as a non-member for years and have appreciated the dialog and information. Now as a new member, I am thrilled with the feedback provided.

Thanks again
Old 04-25-2014, 02:14 PM
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