273 valve lash / hydraulic lifters?

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islandsound

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Working on a transplant motor from a 67 Barracuda to a 63 Valiant. I am wanting to set the valve lash on the engine. Upon inspection of the current lash I am not able to get a feeler in between any of the rockers and the valve tops. I am working on the engine hot as the manual suggest. The heads look to be the originals, the casting numbers are for the 67 year of 2658920. I am wondering if whomever had the car previous installed hydraulic lifters and just set the preload on all the valves the same because of this? Is there anyway to tell what I am working/looking at without pulling the intake manifold off on the engine? I find it hard to believe the engine would be running at all if all of lifters were solid and set this way. Thanks in advance for any advice.
 
If you look at the cam lobe profile on a dial indicator. I believe the hydro has a pretty flat base circle compared to the long ramp of a solid lifter cam. The long ramps help set the valve down instead of having it bounce. Worth a shot. Otherwise, measure a pushrod. The mechanical cams used a longer pushrod as the seat was farther in the lifter. Check a T/A pushrod length (mechanical rockers and hydro) to a 65 273 pushrod (mech/solid).
 

As pishta says, removing a pushrod to measure is fairly easy. I changed to hydraulic lifters & cam in my 65 Dart 273. I bought Summit G6420 pushrods. I didn't measure the length, but attach a photo with an original pushrod in a hydraulic (left) and solid (right) lifter that shows how much shorter is needed.

Perhaps an easier way is to push on the pushrod. A solid lifter won't budge whereas you should be able to push the spring down in a hydraulic lifter. Or you might tap with a hammer.
 

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Thanks for the info guys. I guess I'll pull a push rod one of these days and check it out. I hate to even bother with it at the moment as it's running well and not making any noises. For what it's worth my pushrods look exactly like these with the taper at the top. The pushrods you got were the ball ends correct? Also I imagine the engine would run pretty crappy if I did have solid lifters and I had no measurable gaps to adjust at all. I read a few other forums that people have claimed to have used the same push rods with hydraulic lifters and that they have measured the preload with counting the number of threads visible on the crush nuts on the tops of the rockers. Does that sound like it's possible to anyone? I looked at the nuts today and they indeed all have about 4 visible threads, horrible way to measure if you ask me, as they all seem to be adjusted about the same distance out of the rockers. This is what you get for not knowing the history of things. I pulled the timing chain cover off and someone had at least released the chain with a double roller. I just don't know how much of the rest of the engine was mucked with over the years... Thanks again all, I appreciate it.
 
islandsound,

I got the same ball-cup pushrod type for use with the hydraulic lifters, just shorter pmes. I kept the adjustable rocker arms, which are much preferred to the later stamped steel ones.

If the engine runs good, it is unlikely the valves are not fully closing. More important is the compression measurement. I think ~150 psig is good for a factory cam, with all cylinders within 10 psi. A wild cam could be much different. Of course the risk is that you could burn up an exhaust valve, which means pulling a head.

You only need to remove the valve cover to check. Next time you do so, try the simple press test above, or remove and measure a pushrod. On some engines it is possible to remove hydraulic lifters thru the top, using a special tool that hooks the wire clips. I am thinking not on SBM since I recall the pushrods pass thru small holes, but all you need is to view them or even feel for the clip by trying to hook it with another wire. Solid lifters have no such wire clip.
 
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