The Stovebolt Site Forums The Shop Area Engine Shop Timed with Vac, now won't start

I will let someone else chime in with a specific answer to your question. You will likely get more than one. Lots of folks have their preferred method with hydraulics.

However, for what you are trying to do (just get the engine running decently)᠁.looser is much preferred to too tight. Something more than zero lash, certainly. But what you really need right now is to be sure that all the valves are closing.

Getting everything perfect and quiet can come later.

Thanks, I'm assuming 'too tight' valve lash means potentially valves not closing?

I wouldn’t trust anything Deve publishes. JMO

Correct.

Some further reading on the subject. Don’t overthink it. Loose side of spec is fine to get started.

https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=1068716

Split the difference? 3/4 turns?

And I'm assuming it needs to be hot? Oil pressure built up?

I would be surprised, no shocked, if the markings for TDC or 5 degrees before TDC would be located in different places on a 216 flywheel compared to that of your engine. The marks may differ in appearance, but not their location on the flywheels.
Your timing gears may not be lined up correctly, or the cam gear is damaged and jumped time.
You need to remove the valve cover and verify that neither of these has taken place.
At precisely TDC on the compression stroke for the #1 cylinder, the #6 valves (intake and exhaust) should be rocking. That means that one valve is opening while the other one is closing. If this is not occurring as the #1 piston is rolling through TDC, your timing gears are in need of inspection.

I'm going to be redoing the valve lash, so I will check this out.

Just verified TDC (not the 5 degree ball bearing). It's about 2 degrees on the opposite side of the flywheel's TDC mark. Is this a negligible amount? Just going by a stick in the piston, so could be 2 degree of error.

All plugs black and fuzzy, so super rich. I can also spin some of the pushrods, so I'm going to do the adjustment plus 3/4 turn and see how it goes...

Go ahead and do what Carl suggested and verify the #6 valves are rocking at the same point you have determined at TDC for the flywheel. Then you will know there’s no weirdness with the cam timing.

Ok, at TDC #6 valves are moving. Went through and adjusted each valve to no lash and about 3/4 turn, or as close as I can. Cleaned and gapped plugs again, hooked up the vac advance and started it.

I was able to see change in vac as I adjusted fuel mix and lower the rpm way down. Timing light is basically on the 'triangle', which I believe is way advanced. Vac pulling 22lbs. Has a loud clack, but definitely sounds better. I suppose next step should be to fine adjust timing with a test drive, but is there anyway to figure out which valves are making the noise?

https://photos.app.goo.gl/z8sAG9wVb5Kr8mzS9

Is it running better otherwise? Without the backfiring and such you were describing earlier?

You could use a long screwdriver as a stethoscope. Move it around the rocker shaft and the side cover. I’ve had limited success with that but worth a shot.

Vac needle is bouncing quite a bit but your idle is set really low, so that might not be a big deal.

I have a valve adjustment method that has worked well for me for over 50 years on everything from daily drivers to all-out racing engines, but it's difficult to explain with a keyboard. Can you make a cross-border phone call without having to take out a second mortgage on your house? I'd be glad to PM my phone number for a quick call if you're interested.
Jerry

Does this require a drive down the road? Because I don't have doors at the moment

Nope- - - -it involves the "companion cylinder" method of determining TDC on each cylinder, before adjusting the clearance or hydraulic lifter preload on the cylinder halfway around the firing order from the one that's "rocking" This must be done six times, not just establishing "rocking" of the valves for #6. Here's a short synopsis:

Turn the engine CW at the crankshaft pulley until the #6 valves "rock"- - -exhaust closing and intake opening.

Adjust cylinder #1 valves (NOT #6)

Turn the crankshaft 120 degrees CW- - - -#2 valves rock- - - -adjust #5

Turn 120 degrees- - - -#4 valves rock- - - -adjust #3

Turn 120 degrees- - - -#1 valves rock, adjust #6

Turn 120 degrees- - - -#5 valves rock, adjust #2

Turn 120 degrees- - - -#3 valves rock- - - -adjust #4

You can precisely adjust all 12 valves with only two turns of the crankshaft (hot or cold engine) if you pay attention to the firing order and the movement of the rocker arms.

Jerry

Thanks for that Jerry, I actually did adjust them this way, watching when the arms stopped rocking, the rotor was on the plug wire and using the flywheel markings Deve suggested on his site. 120 degrees at a time, twice around the flywheel. U think the problem I have now is a few valves were difficult to determine if they were at zero lash, as the push rods were 'catching' and difficult to do the spin and tighten test. Would it be bad to determine the clicking ones and adjust while running?

If you're adjusting non-OEM hydraulic lifters on a 235 engine, there are two chances of getting a good adjustment, no matter what method you use- - - - -"Slim and none". Do the bottoms of the pushrod balls have the grooves cut into them to allow a little oil to escape as the engine runs? Pre 68 Dave has a good illustration of how to do that modification on his blog to prevent a hydraulic lifter from getting a noisy air lock. If "Deve" says the sun is going to rise in the East tomorrow, I'd want a second opinion. A running adjustment almost never works well.
Jerry

Thanks Jerry - This is a Canadian 261, so the hydraulics are OEM. Hopefully no issues there. I guess I will try and determine which are the noisiest and adjust those with the procedure you shared above.

Is it running better now? Just noisy?

To my untrained mind, yes. I can see how the fuel/mix screw affects vacuum and was able to turn the RPMs down to 450 without ill effects. It's just the noise now, until I get it out on the road for a test.

https://photos.app.goo.gl/z8sAG9wVb5Kr8mzS9

The article Jerry was talking about with the pushrod modification is on Pre68Dave’s blog:

http://chev235guy.blogspot.com/

View the desktop version of site and you should be able to find it.

If you can’t locate and adjust-out the noise᠁.a couple other easy checks you could do before modifying pushrods or inspecting lifters.

1) Observe pushrods and see that they are all spinning roughly the same rate. A sharpie or paint mark on each one might help. If you find any that are not spinning or spinning at a much slower pace᠁.good chance that pushrod slightly bent. That would make proper adjustment near impossible.

2) What is the condition of the rocker tips? I had to resurface mine because they were dimpled. You can unbolt the rocker shaft and take a look without too much fuss. Dimpled rocker tips make it tough/impossible to get a good adjustment.

Sound never translates well on video, but that strikes me as a one rocker/lifter making nearly all the noise rather than an entire valve train making noise.

I'm currently in the process of building a stovebolt engine with hydraulic lifters for a MOPAR big block engine. That takes some pretty creative machining, since the lifter bores have to be sleeved to a slightly smaller diameter and honed for the correct sliding fit for the lifters. The 216 and early 235 engines need to have a lifter oil gallery gun-drilled the length of the block and a higher volume oil pump installed, also.
Jerry

JW51 some rods spin fast and some don't at all. Could these just be too loose and too tight? Some felt like they were catching when I was spinning to adjust.

Clarification - I meant the pushrods should rotate as the engine is running, not you rotati g them by hand.

That is what you are talking about, right?

All pushrods should rotate at a pace you can easily see at idle. If some are not, I would pull those and roll on an extremely flat surface᠁a big piece of glass or your wife’s granite countertop. A wobble indicates a bent pushrod.

Yes, while running one was spinning really fast and the others you had to look close to see them turn. Then there were a few that weren't spinning at all...

The ones that aren’t spinning at all᠁.pull and check those.

Pulled first rod, straight as an arrow. Do these look new? Would no rotation mean too tight?

[img]https://www.stovebolt.com/ubbthread...umber/42759/filename/20220521_132535.jpg[/img]
[img]https://www.stovebolt.com/ubbthread...umber/42760/filename/20220521_132546.jpg[/img]
[img]https://www.stovebolt.com/ubbthread...umber/42761/filename/20220521_132843.jpg[/img]

To check stovebolt pushrods for straightness, find a piece of glass slightly narrower than the length of the rod so you can roll it across the glass without getting either end involved. Also check the ball on the adjuster screw- - -it should be perfectly round, without a wear nub in the center. That nub will eventually catch in the depression in the female cup of the pushrod and break the lip off the cup. Rocker arm adjuster screws made for MOPAR V8's with solid lifter cams are the right thread to fit stovebolt rocker arms (7/16-20), and they're available on Ebay.
Jerry

Rolled it across an old windshield, looks straight. Adjuster is nice and round too. Too tight to spin?

I had a few that were not spinning. They were just dry. A drop of oil on the cup and away they went.

" So, what I have is a fully rebuilt 261"
"This is a Canadian 261, so the hydraulics are OEM"

It would be divine luck to find new OEM hydraulic lifters, so are your lifters used originals that have been resurfaced or new reproduction?
Which leads to the camshaft. Reconditioned or new reproduction?

I hope this discussion doesn't spin out of control into a regurgitation about lifter design and cam specs.
It all been discussed here before and can be found by searching Stovebolt. Especially noisy hydraulic lifters.

Back on track now. I'm curious. Why do pushrods rotate? Maybe it's because the lifters also rotate?
I'm not a engine man like Jerry but I recall that you want the lifter to rotate a little bit for lubrication and to have and even wear.

I just now found this from jalopyjournal.com talking about a "F@rd":

New hyd. and solid lifters have a 96 inch spherical radius ground on them and the cam lobe has approx. 0.002" taper so that it contacts the lifter off center and spins the lifter.
Proper operation means that the lobe and lifter don't rub but roll together at the same surface speed.

Yep, you nailed it- - - -BUT- - - -the brand new milk can lifters we put in John's 261 when we assembled it were perfectly flat on the bottom (I checked). I'm not sure about stovebolt hydraulic lifters. The cam lobes on almost all engines contact the bottom of the lifter slightly off center so the lifter spins and equalizes the wear on the cam lobe and the lifter. Putting a slight radius on the lifter helps the spin action happen if a lifter happens to be designed that way. Yes, the pushrod spins because it's following the motion of the lifter.

I'm building a fixture for my lathe to allow me to use an electric die grinder and a Roloc grinding disc to resurface lifter bottoms and put the radius back into one that's worn flat. With the length of the lathe ways I have currently, I'll only be able to put about a 48" radius onto the lifter bottom. I do have an extra set of ways available that will double that length once I get them grafted together.
Jerry

Go it. Thanks Jerry.
So I take it that the rotation of the pushrods MAY be a source of concern but it's not the cause of the original problem.
I would think the engine needs to run, varying speeds, on the road (loading the engine), for an extended period of time (circulate the oil).
What I'm trying to say is that maybe the lifters lost their pre-load of oil if the valve adjustment was too tight.
Hopefully they will recover as the engine runs in the future. If they don't, there is information on Stovebolt on how to manually pre-load.
I would only do the pre-load NOW if a lifter sounds like it is going to self-destruct.
My 2 pennies.

Adjusted a few valves again, seems to be quite a bit quieter. I think it might have needed more warm up time. Timing was on the triangle, until it warmed up and now it's around the ball-bearing, so 6-7 degrees advanced. I think road test is my best bet to dial it in now.

The preload is there to allow the inner plunger of the lifter to run in the center of its travel. That way, there is never any loss of contact between the cam lobe and the lifter, and the overall length of the lifter and pushrod is able to compensate for pushrod and valve stem stretch and shrink due to heating and cooling without rattling or holding the valve open. The internal alignment of the lifter body and plunger is also best with the proper preload so any seepage of oil can be replenished by the oil pressure when the lifter is on the base circle of the cam with minimum load on the valve train. Since each lifter operates 60 times per second at 2K RPM, there's very little refill time available with the cam lobe unloaded.
Jerry

Preload is the amount that the valves are adjusted, which slightly compresses the lifter?

Yes, as you tighten the adjuster after taking out any slack at top dead center, the "preload" is the distance the lifter plunger is compressed. On a 20 thread per inch thread like the stovebolt adjuster uses, 1 turn of the adjuster after reaching the "zero-lash" point would compress the lifter plunger 1/20 of an inch, or approximately .050". That would allow the lifter height to compress or expand a little to compensate for length changes due to temperature.
Jerry

Pre-load with oil. Pre-load of oil.
The procedure with lifter in a container of oil, plunger pressed down to expel any trapped air then slowly release to intake only oil.
It's possible the valves were adjusted too tight squeezing the oil out. If so it may have lost it's pre-load of oil. There may be trapped air inside the lifters.
After some decent running time the trapped air may work itself out...fingers crossed.

Since stovebolt hydraulic lifters do not lube the rocker arms with hollow pushrods, air can get trapped in the lifter body and be very difficult to purge. That's the reason for the grooves in the bottom of the pushrod, and a vent hole or groove in the pushrod seat if there's not a weep hole in the center of the plunger. Dave's blog gives us some very useful procedures to make the lifters self-purging. Wherever an engine stops, a few valves will be open, with valve spring pressure trying to collapse the lifter. There might be a little bit of rattle on startup when those collapsed lifters are refilling, but it should go away in a few seconds, or a minute or two at most. Once the small block V8's and the 3rd. generation sixes started using hollow pushrods and oil flow through the lifters and pushrods to lube the top end, most of the hydraulic lifter problems disappeared. Unfortunately, it's difficult to modify a 235 or 261 engine to use tubular pushrods. (Not impossible- - - -I'm doing it on one engine I'm building).
Jerry