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Top dead center

Posted: April 28th, 2012, 1:27 pm
by Grego
I am currently tearing down a 4.0 block out of a 97 jeep grand Cherokee to instal into a 93 jeep wrangler and stroked to a 4.6. With all my covers removed I am spinning the crankshaft with a socket and watching the valve springs and rockers. At tdc of the compression stroke I see everything relaxed except intake open on #4 and exhaust on #5 fully. All the pushrods you can spin with very little effort except these two. At this point this is where I would want to instal my distributor pointing at the #1 plug wire?

Re: Top dead center

Posted: April 28th, 2012, 5:09 pm
by SilverXJ
How are you finding TDC on #1 if the timing cover and harmonic balancer is off?

Re: Top dead center

Posted: April 28th, 2012, 9:15 pm
by Grego
By turning the crankshaft with a socket and lining up the timing marks on the timing gears.

Re: Top dead center

Posted: April 29th, 2012, 6:50 am
by SilverXJ
That should work, but i would check it with the timing cover on.

Re: Top dead center

Posted: April 29th, 2012, 8:03 am
by Grego
Just thinking ahead to putting this thing back together. As I was putting my first non stroker motor together, I remember these two valves being in this same position. Yes, wene the timing cover and the balancer went back on they were pointing at tdc at this position. Wene I went to fire my motor for the fist time, it cranked fine for a few seconds but did not sound like it was going to fire. right off I suspected the distributor being 180* off. Adjusted the distributor and boom got ignition. I thought I might have maybe lost my posision when I removed the distributor to instal my modified distributor to prime the system. Then, instaling the engine and turning the crank to try line up the transmission input shaft. But I thought I was being very careful keeping track of my timing.

Re: Top dead center

Posted: April 29th, 2012, 8:39 am
by SilverXJ
Don't try to keep track of where the crank is. Best bet is to find TDC on the compression stroke again. Put finger over #1 plug hole and while cranking wait to feel pressure. Your on the compression stroke now and then just rotate crank until on 0*.