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Fri Jan 13, 2017 9:55 am

1641 SP, Stock T3 bottom end, I just installed new pistons/cylinders. While valve train assembly I stumbled on a #1 intake valve and rocker issue. It seems that there is a lot more of adjustment that is needed for this particular valve. So I swapped rocker assemblies and have same issue. Swapped heads with the same issue. checked to make sure all push rods are the same length. When it is adjusted @ .006 with all others, the adjustment screw on #1 intake is more that 3/4 of the way in vs the others. It also seems to push the valve at the same amount as the other rockers when adjusted.

Just doesn't seem right, hopefully by the photos you guys can see the larger gap between the valve stem and adjuster. This is weird to me because I do not recall it being this way before disassemble. This engine was a decent runner and I just wanted to give it a freshen up since it was out. I swapped Rockers, I swapped Heads, I also took a straight edge to the valve springs thinking it may be a valve seat issue. But when adjusted it seems to move the same amount as all the other valves its just this one requires a lot more screw in. If that makes any sense

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Fri Jan 13, 2017 10:07 am

Check the rockers to make sure they are the same ratio. Maybe you have one 40hp rocker on there with a shorter ratio? 1600 rockers have 2 dashes or lines cast into the side of them.
Only thing left would be a worn lifter or worn cam lobe. If it was the cam lobe, it would be the same on the other side of the engine.

Brian

Fri Jan 13, 2017 10:32 am

Rockers are All the same ratio. I even took the rocker assembly from the other 3-4 side along with the push rods and had the same out come. 3-4 side does not do it when assembled.

Dallas

Fri Jan 13, 2017 10:33 am

Dallas DuPont wrote: checked to make sure all push rods are the same length.

Out of the engine? or in the engine?

I think you might have a lifter with the head wore down. Its not the cam lobe or the opposite rocker would be the same since they share lobes...

Fri Jan 13, 2017 10:37 am

I took all the push rods out and checked them. If its a lifter that SUCKS!!!, This was a good runner. Never skipped a beat.

Fri Jan 13, 2017 11:03 am

are the cylinders all the same height? is the head maybe sitting a little crooked due to one cylinder being shorter than the other?

Fri Jan 13, 2017 11:16 am

Nope, Deck height was all the same, Even went as far as putting a straight edge on the cylinders because I thought about that theory, But also I would think if that was the case the exhaust valve would do it and be even worse right??

Fri Jan 13, 2017 11:32 am

Pretty long shot, but one lifter might have a different cup height inside the body? I am voting on a bad lifter head.

It always sucks to find something like this, but now at least now you have an excuse to put that new cam you always wanted in. You are better off opening the case and replacing at least the rod bearings now also. If a lifter head is trashed, all the material had to go somewhere, and it most likely went through all your bearings.

Sorry dude.

Brian

Fri Jan 13, 2017 11:36 am

It is what it is, Thanks guys

Fri Jan 13, 2017 11:47 am

Maybe the valve stuck in the guide from carbon deposits?

Fri Jan 13, 2017 3:22 pm

I wish, but I swapped heads with the same out come :cry: :cry:

Fri Jan 13, 2017 4:13 pm

Check the lift on the valve retainer with a dial gauge and compare it with the opposite side and also with a valve without the issue.
See if you have the same lift. That will eliminate the cam at least.

Fri Jan 13, 2017 6:19 pm

"Swapped heads"....... Its all right there....

Dale

Fri Jan 13, 2017 6:56 pm

Pull the cylinder on that side. With that piston at TDC you will be able to see inside the case. Look at the cam and lifter.

Fri Jan 13, 2017 7:08 pm

If one of the lifters failed how good are the others? It's out of the car right? Why not take a look? What is the history of that engine's bottom end?

Sun Jan 15, 2017 9:46 pm

How many years/miles are on those "well-worn" heads?

Mon Jan 16, 2017 7:31 pm

Brian_e wrote: You are better off opening the case and replacing at least the rod bearings now also.
I would never recommend doing this! That is a recipe for a ruined bottom end. What happens is that new rod bearings have less wear and tighter clearances. The oil takes the path of least resistance and goes out the worn mains and cam bearings leaving the rods starved for oil. Now couple this with a well used oil pump that is no longer able to deliver as much volume or pressure and I will guarantee the result will be a turned bearing and a broken rod. Do the whole bottom end or leave it all alone!
Ask me how I know this!

Mon Jan 16, 2017 7:41 pm

Good advice in some cases.
I would say a more advanced idea would be actually check the sizes of old and new, and both ends of the rod, and the alignment of the rod. OR, leave it alone. What you don't know will hurt you.

New bearings might be tighter than old or they might not, BUT, just as often when you loosen those rod bolts after long service the cap will be sprung and won't be able to get it bolted back on same as it was, this means it's out of round and THAT will cause problems, which is why the size should be checked any time it's apart after long service.

Wed Jan 18, 2017 7:08 pm

There are really only 2 legitimate reasons to change bearings.

#1) wear, if the new bearings are not tighter than the old ones then you are wasting your time and money.

#2) dirt has gone through the system and is imbedded in the babbit on the bearing surface. In which case the dirt had to get past the mains to get to the rod bearings so all should be replaced along with the cam bearings and oil pump.