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Measuring tappets


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I tried searching and came up with nothing.

 

I am running a P90A hydraulic lifter head. I just installed a new cam and followers. Cam from Schneider (I am ordering the matching spring kit), resurfaced followers from Delta.

 

I need to know where I need to measure the tappets. From the bottom recess to the top groove or the bottom lip to the groove?

 

Right now I have .035 between the cam and follower(with the factory springs and tappets). I am not going for big power so I'm not changing out the hydraulic lifters, they work fine for my application. I have already taken them apart and cleaned them.

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Was your cam specifically ground for the hydro head? If I remember correctly, the mech and hydro cams are not really interchangeable. I would do a search to be sure. Also, the conversion to mech pivots on your P90a is relatively cheap and easy. The Timeserts were only about $35.

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Um, did you buy a hydraulic grind from Schneider? I was unaware of anybody grinding aftermarket cams for the juiced heads. As you can see reading your FSM, the juiced head is self-adjusting, measurement is not possible, you just fire it up and run it. If you have a cam card which specifies anything other than 'zero lash' methinks you done bought a mechanical cam, and have some experimentation to do to see if it will work at all, I don't know anybody who has put a mechanical grind into a hydraulic head and run it before...

 

Praytel, please keep us posted on the results! :blink:

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Per Motorsport auto this is for the 83 ONLY turbo head. I might try the Timeserts. Do you have the sizes or the part number?

 

I just read on another site about MSA providing the wrong cam grind. So, it probably is a mechanical. I'd really like to keep the hydraulics. Nismo offers different size tappets up to 7mm. I'm thinking of ordering some, but I need to know where to measure the tappets from.

Edited by macambra
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I just converted a P90 hydraulic to mechanical lifters and it's very simple. The part you need is Time-Sert M18x1.5 x18 @ 0.3mm. part #18153.

 

You determine the correct lash pad by trial and error on the bench by measuring the wipe pattern of the lobe on the rocker. This has been well documented elsewhere on this site so I won't repeat it.

 

I don't remember seeing any turbo cam grinds for hydraulic heads when I was looking. If you found one please let us know. I wouldn't miss adjusting valves :)

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I just converted a P90 hydraulic to mechanical lifters and it's very simple. The part you need is Time-Sert M18x1.5 x18 @ 0.3mm. part #18153.

 

You determine the correct lash pad by trial and error on the bench by measuring the wipe pattern of the lobe on the rocker. This has been well documented elsewhere on this site so I won't repeat it.

 

I don't remember seeing any turbo cam grinds for hydraulic heads when I was looking. If you found one please let us know. I wouldn't miss adjusting valves :)

I searched for articles but was unsucessful. Do you have a link available? Or a key word? I searched for tappet.

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"lash pad" is the more common term used with our L engines.

 

I'd also search on "wipe pattern" as that's what you're measuring/observing.

 

Sorry I don't have the time right now to search for it myself. Good luck!

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I don't remember seeing any turbo cam grinds for hydraulic heads when I was looking. If you found one please let us know. I wouldn't miss adjusting valves

 

Same boat here! Late model VW engines were produced with hydraulics and their implementation took some of the soul away from owning an air-cooled Type-1... But there are some times that not having to crack the valve covers every 3,000 miles is welcome (Yes, you read it right, you will do 10 valve adjustments in the time you will do one on a Z!)

 

As far as conversion articles, it's common sense: buy the timeserts, unscrew the hydraulic lifters, screw in the adapters and ballstuds/locknuts from a donor mechanical head.....adjust and run.

 

Synopsis, admittedly, but I too don't have time to search for someone else right now...

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So, this is a dead horse. I ordered the time-serts from ebay. 10 for $35. I have the donor head in my garage from the NA motor I was playing with. I should be on the road by the middle of next week. Thanks for the help guys!!!

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Zmanco, the oil galleys flow such that if you block the lifter bores, you'll also starve the cam towers IIRC. I haven't looked at a P90 hydraulic head in a year or so, so if i'm wrong, I'm wrong, but I'm pretty sure it's the case.

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When I looked down into the bore, I only saw a small hole at the bottom edge where oil entered. I didn't see any other passages, but I didn't check every one, and wasn't looking for a second hole either. Maybe someone who has a head disassembled can take a closer look?

 

In any event, the time-sert is shorter than the threads on the mechanical lifter so I threaded them all the way to the top and then screwed them into the head. Use this approach and the time-sert will not go down far enough to block the oil port.

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Macambra, I have 2 extra if you need them. Paypal $5 for shipping to me daniel at bailin dot org along with your address and I'll send them out.

 

I ordered 20. But thanks for the offer.

So, if anyone needs the extra 8, let me know.

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I just converted a P90 hydraulic to mechanical lifters and it's very simple. The part you need is Time-Sert M18x1.5 x18 @ 0.3mm. part #18153.

 

You determine the correct lash pad by trial and error on the bench by measuring the wipe pattern of the lobe on the rocker. This has been well documented elsewhere on this site so I won't repeat it.

 

I don't remember seeing any turbo cam grinds for hydraulic heads when I was looking. If you found one please let us know. I wouldn't miss adjusting valves :)

 

I ordered time-sert part number 48153. I received them today. They are labeled as spark plug repair inserts and are copper plated steel. I installed them on the mechanical lifters and they are just slightly longer than the lifter. When I receive the new valve springs, I'll insatll them.

Again, thanks for the help!!!

 

So, If anybody cares, I am posting pics of the timesert install.

post-9176-098649300 1310581414_thumb.jpg

Edited by macambra
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  • 2 weeks later...

Update:

 

Timeserts, mechanical lifters, and new valve springs installed. Runs better than anticipated. Starts making power around 2500rpm and goes crazy!! Going to the shop tomorrow for 3" exhaust, and then on to find an LSD.

Edited by macambra
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  • 9 months later...

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