TDC w/ heads still on??
08-30-2005, 06:14 PM
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TDC w/ heads still on?? How do I ensure #1 is at TDC with the heads on? im going to be doing a cam swap and need to make sure ive got it right. I put the stock cam back in till my new one comes and dont want to mess it up.
Nino
Nino
08-30-2005, 06:16 PM
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You can either make or buy a stop bolt that threads into the spark plug hole. They both look/work similarly.
If you want to make one, snap the porcelain off a spark plug, and then core the entire thing. Tap it to a convenient bolt size, and thread a relatively long bolt into it. Screw the new tool into the plug hole, and run the threaded bolt down a ways where it will contact the piston. Turn the motor one way, note the reading on the degree wheel. Turn it over the other, and again note the reading. TDC is half way between your marks.
If you want to make one, snap the porcelain off a spark plug, and then core the entire thing. Tap it to a convenient bolt size, and thread a relatively long bolt into it. Screw the new tool into the plug hole, and run the threaded bolt down a ways where it will contact the piston. Turn the motor one way, note the reading on the degree wheel. Turn it over the other, and again note the reading. TDC is half way between your marks.
08-30-2005, 11:34 PM
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Pull out the spark plugs, and stick a straw or pen or something like that in the #1 spark plug hole, turn the engine over until the pen sits at the highest position. Just know that TDC is when the crank gear is at 12. So put it at 12, and then you can play w/ it w/ the straw in the spark plug hole to verify its at TDC
08-30-2005, 11:53 PM
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Before I removed the heads I used the straw method. I found that I was real close to TDC but still a little off. The straw method works okay. Just remember when you turn the crank put your finger over the no. 1 hole and when you start to feel air insert the straw into hole 1 and when it comes out the whole way you have reached TDC. Look for my post on cam install probems, and educate yourself on what you should and should not do on a cam install. I'm still not finished, waiting on my heads to be finished. Good luck.
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08-31-2005, 11:45 AM
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i replaced the plugs, wires and coil packs and it was still misfiring. i swapped from my f10 114 to the stock cam. What all could i have messed up if I didnt align the dots correctly? i lined them up, but didnt turn the crank to see if they were good. I forgot about that step.. could my heads be shot? i dont really care if this cam is messed up cause of it. Im going to install the g5x2 114. im really really trying to avoid pulling the heads, but i do have replacements if needed.
08-31-2005, 11:50 AM
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If the cam was used it is possible that you have some bad lobes. Heard of that happening to a few cams. If it was installed off a couple degrees then the problem should be misfire on all cylinders not just two of them. Did you try a leak down test to see if the misfire cylinders are sealing up and not hanging a valve open a little bit.
08-31-2005, 11:57 AM
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no, i havent done that. i have to install the new cam. I hope that will take care of the problem. I dont know the history of the cam i just put in there. it was a spare my friend got out of a block he bought off of someone.
08-31-2005, 11:59 AM
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Originally Posted by strokedls1
. Did you try a leak down test to see if the misfire cylinders are sealing up and not hanging a valve open a little bit.
08-31-2005, 12:14 PM
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Originally Posted by ninobrn99
would that mean i need new springs? or new valves?
08-31-2005, 12:20 PM
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my pushrods are hardened 7.4's with prc dual springs. I just put the stock cam back in to do a swap with someone else. the lifters and heads are also stock.
08-31-2005, 03:58 PM
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What I was asking is after tightening the rocker arm to 0 lash, how many turns does it take to hit 22 lb-ft. Springs should already be set at the right installed height.
08-31-2005, 05:54 PM
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It is when the rocker tip is just touching valve. It should only take two turns max to get 22 lb-ft from there. You need to measure this when the cylinder is on it's compression stroke so both valves are closed.
08-31-2005, 06:04 PM
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i dont get it. cause when i put the rockers back on, they're already touching the top of the valve. the way i did it was, tighten the bolts till it began to get tough and the rocker wont move. then id get the torque wrench and torque them to 22lbft. i was under the impression that was all i had to do.
