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If I already have the engine at top dead center and If put the cams in the same way they came out wouldn't that ensure that nothing would hit?
Also, I can't really turn the crank to get the engine at 45 dbtc because the pistons will be going up and down and the valves won't be moving. Wouldn't that pretty much guarantee that the valves are going to hit the pistons?
(Just saw this...)
If you put the cams in at TDC, two pistons will be up. Your initial cam position will be somewhat close to the correct timed position, but certainly not exact. Therefore, if a valve is open enough to hit the piston, you'll bend that valve when you tighten the cam caps. Note that if #1 is at TDC firing, #4 will be at TDC overlap (valves slightly open). It will be #4 valves that will be most likely to hit.
If you install the cams at around 45 deg. BTDC, no pistons are in range of open valves. At this point you rough adjust the cams like the photo in the manual. Once this is done, turning CW to TDC is safe. Just go slow, and if any resistance is felt, you likely have not pre-positioned the cams properly, so stop, turn the crank CCW to get the pistons out of the way, and re-adjust to match photo.
Here are two photos of the factory vario cam wire tool, one beside some home made cam insertion blocks and one next to a home made version of the wire tool.
The blocks are some oak, all thread, spark plug tdc tool (spark plug tdc tool can be bought at any speed shop like Jegs). Made by a guy in MN, think he sold his car and I bought them from him.
(Just saw this...)
If you put the cams in at TDC, two pistons will be up. Your initial cam position will be somewhat close to the correct timed position, but certainly not exact. Therefore, if a valve is open enough to hit the piston, you'll bend that valve when you tighten the cam caps. Note that if #1 is at TDC firing, #4 will be at TDC overlap (valves slightly open). It will be #4 valves that will be most likely to hit.
If you install the cams at around 45 deg. BTDC, no pistons are in range of open valves. At this point you rough adjust the cams like the photo in the manual. Once this is done, turning CW to TDC is safe. Just go slow, and if any resistance is felt, you likely have not pre-positioned the cams properly, so stop, turn the crank CCW to get the pistons out of the way, and re-adjust to match photo.
Here are two photos of the factory vario cam wire tool, one beside some home made cam insertion blocks and one next to a home made version of the wire tool.
The blocks are some oak, all thread, spark plug tdc tool (spark plug tdc tool can be bought at any speed shop like Jegs). Made by a guy in MN, think he sold his car and I bought them from him.
John
Thanks J. I made that wire tool last night. I don't think the coat hangar wire I used is really strong enough.
When you press the Variocam unit down to compress it. How much is it supposed to be compressed? Do you have to push the top piston all the way down?
Here are two photos of the factory vario cam wire tool, one beside some home made cam insertion blocks and one next to a home made version of the wire tool.
The blocks are some oak, all thread, spark plug tdc tool (spark plug tdc tool can be bought at any speed shop like Jegs). Made by a guy in MN, think he sold his car and I bought them from him.
John
Ill bet there are all manner of interesting cam hold down tools out there now for this car. I got a pair of OEM alloy blocks on eBay and was lucky enough to persuade a local aerospace orientated machine shop to turn me some pretty hold downs from 316 stainless offcuts for drinks money. Probably shinier than they need to be.
The Variocam chain tensioner only works for the correct direction of engine rotation. When I applied enough air pressure the piston went up. There was no up and down when turning the crank. No voltage applied here enables to fill the interior of the chain tensioner that supports the force of the springs. With +12V applied the solenoid forces the piston down.
you must be careful only using one 9248, Porsche says use two 9248 or you can break the camshafts.....cams are brittle if strained the wrong way !!!
It seems my posting was a bit misleading.
It is clear. I ordered the 9248 Tool, which of course comprises 2 clamps. And only one of the two had a wrong bore, as already posted.
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