LT5 Assembly Project

[LGAFF]

Spoke to my contact at Mercury...he said that he did not think that the valves or rings would be impacted by using the stand....and he was right.
I tried doing it by supporting the engine and it made 0 difference.

He stated that the engines he referred to as green were low hours/miles....and that he does not recall doing unfired engine.

He did mention that he has seen issues with people not checking to see if the valves were being hung open after valve jobs.

He also mentioned that it was a known problem that the liners did disort at the bottom and it sometimes resulted in piston slap but performance was not affected.

Changing the guides can make it difficult seal the valves also......this is addressed apparently by lapping the valves with varying degrees of compound working through to lighter grits.

In the end, he agreed...if the valves hold fluid....if the bores are round...and pistons are ok...put it together and see what happens.

[LGAFF]

Just for shits and grins I did the factoray cam timing procedure, but did not torque the cam bolts to spec....surprising after a few rotations..the timing held true.

In talking with my contact at Mercury...apparently the cam timing slippage actually occurred at the initial start of each engine...

The #1 exhaust valve still has me very concerned....

[Pete]

Lee,check leak down with cams on,just to make sure no valves are hanging open.

Pete

[LGAFF]

Pete, this is the same valve that I checked last time.....and it leaks air and the other exhaust valve on #1 does not.....odd since both held fluid.

[A26B]

It wouldn't be odd if the valve stem on the leaking exhaust valve was too high or oil was trapped in the lifter.

[LGAFF]

These lifters are new, no oil.....stems were all cut to the same height and when I removed the cams last time it still leaked......will look at it more today


Some day this thread will say....fired up the engine no problems car ran great

[tomtom72]

Originally Posted by LGAFF

These lifters are new, no oil.....stems were all cut to the same height and when I removed the cams last time it still leaked......will look at it more today


Some day this thread will say....fired up the engine no problems car ran great

Man I hope so. Sincerely I do. My brain hurts from reading about all the "quirks" that our motors seem to have. I can't remember ever having this many Q's while assembling my first sbc. Man what a different animal our stuff seems to be.

Lee, straight up, thanks for this thread!


Tom

[LGAFF]

Did the factory cam timing and then used some basic math to set exhaust at 108......I did not lock them down yet. I bought two different dial gauges and none will sit on the lifter.

Once I can get the dial gauge to verify the specs I will lock them in...

[LGAFF]

Checked all my timing, I am at max lift at 114 intake,which is the stock pinned setting, and 108 max lift on the exhaust.

I used a flexible dial indicator from Harbor Freight....remove the flex arm from the vise grip and the arm threads into the IH and other bolt holes.



I had trouble putting the indicator on the lifter. To address remove the small point at the bottom on the dial gauge(it unscrews) cut a piece of coat hanger about 7.5-7.75"long, put a slight curve at the tip(rest it on the lifter)....the coat hanger will slide in nicely against the cam, there is even a small groove it can rest in.

pic of dial mounted ......you can see coat hanger



Wheel at 51 degrees, top cams pinned...


curved bottom of hanger on the lifter:

[LGAFF]

timing exhaust cams: