Here's the combo: '72 440, edelbrock heads, isky cam .505" lift, (new) stock shafts and newish HD mopar stamped rockers. Stock replacement summit pushrods. 3000 stall hughes converter. It's not an exhaust leak, it has remflex gaskets on the Schumacher headers and the connection pipes.

The motor is making a ticking sound that is much more noticeable when hot. Also it seems like when I start the car after it sits for ~30+ minutes, it still fires right up but it runs poorly until I start driving it, get the RPMS up for a few hundred feet. Before that, it may die as I am coasting to a stop or when I put it in reverse. When it's cold or when I've been driving it for a minute or so, it never does that.

Other than the ticking noise, the car runs great and does not seem to miss or have any running problem.

I am thinking it has something to do with the lifters, maybe the hot oil is not allowing them to open the valves properly? I am not sure what's happening, I just know it only happens when its hot. A friend suggested that maybe the pushrod length isn't right, and when the heat expands the heads/motor, it is pushing the valvetrain out of the zone where things work right.

The noise seems to be coming from the passenger side.. I pulled the valve cover, nothing looked out of the ordinary, the shaft was still torqued to 25 lbs. I think the noise has come on over the past year or so.

Any ideas? I have thought maybe switching to adjustable rockers might help, since I know I can set the lifters with the right amount of preload. But then I thought, why would the noise come on only in the past year, in which case I think maybe one or more of the lifters isn't working right.

I would say it's lifter tick first did you use a fel pro gasket as they are .020 thinker than stock then the aluminum heads grow .010 or so more than iron so if so you just took .030 out of the pre load. Now if the summit pushrods are shorter than stock that is more out of the pushrods.

It will never hurt anything but fixes are by longer pushrods .030 or so mill the heads .030 and gain some pop at the same time :-) or get adjustable rockers and pushrods.

Yes, I used the cheap blue felpro head gaskets.

If it's a pushrod length thing I think I will try the adjustable rockers, which (I think) I can do without disassembling too much of the engine.

Or, is there a way (other than just getting some that are .030" longer) to check the length I need if I wanted to get longer ones and keep using the stock stamped rockers?

If it sounds like one(from your post it seems that way) it could be a bad lifter. Warm the engine,pop off the rocker arm cover,start it and touch your thumb to the push rod side of the rocker arm. You'll be able to feel the difference in the bad one(s).
Ron

Adjustable may be the ticket! How long where those pushrods?? think stock is 9.31

pull the valve cover & eng idling push straight down on each rocker arm on the pushrod end w a wooden hammer handle. This will quiet a bad lifter if it's making the noise so you can ID it. if so replace it & repeat the cam breakin procedure. Make sure the lifter has proper clearance so it can turn on mockup EDIT check your preload also

Summit lists the pushrods at 9.315".

I re-read my original post and forgot to mention it seems to get louder and quieter at times but is always nosier when its hot. Does that point to lifter?

Other than the noise, it runs super strong, would it run that well if it was a lifter?

I cant say for sure. I'd do some checks & see what you come up with.

Before diving into the motor do a quick check of the exhaust gaskets! It is amazing how an exhaust leak can sound like a lifter - and can be temperature dependent.

Scott

I just measured the preload using the method of rotating to cam base circle, putting a piece of tape around the pushrod, making a mark. Then completely loosen rocker shaft bolts, keeping pushrod in the lifter cup, then made another mark.

I measured between them and it was at least .090", probably closer to .100".

So seems to be quite excessive preload, which now that I read about it, explains quite a lot, including not allowing the lifters to completely pump-up.

I have some adjustable pushrods on the way from Crower (chrome moly heat treated HD stuff) and hope this will take care of it.

Maybe typically you want .030 to .040 pre load so maybe!

I read that the adjustable pushrods were a PITA to adjust, so I cancelled the crowers and ordered some summit brand (pn SUM-G6405 for the archives, 18.95 for 8 ) BB Chevy exhaust pushrods, 9.252" and a beefy 3/8" tapered pushrod, so I should have around ~.040" preload.

The rods are in, plenty of clearance in my Edelbrock heads with the Mopar HD stamped rockers. Tomorrow I'll fire it up and post the result.

When putting the rods in, I did notice 3-4 of the drivers side lifters were spongy. I think due to all that preload they were not pumping up properly, explaining why it ran like crap at certain times.

Sounds like a longshot getting the lifters to quiet down with less pre-load, but more power to ya. The only thing I can think of is that alot of alum headed vehicles carry more noise "out". If it is a very quiet valve train noise, some times it is hard to locate, especially when engine runs great otherwise.

I don't think it's a long shot at all. I had a 318 that rattled and clattered like a diesel. turns out the pre-load was also around .090-.100

shorter pushrods and the noise went away.

The 9.252 pushrods worked! After starting it, hearing some tap tap tap for a bit, got the oil hot, drove it around, finally a quiet running engine just like it should be. It also feels torquier and revs up faster.

same here , set the preload using the base circle method on a noisy XE comp with adjustable pushrods and it is much quieter now .

that's another thing with hydro cams, some guys will run less pre-load to give more RPM and torque.

it's beyond my understanding of what's going on, but they all say that it works! they'll take a magnum hydro roller, replace the innards with a solid spacer, and end up with a semi-solid cam that has maybe .005 of "give" to it, then treat it like a solid cam. it clatters like a solid cam, but they get a LOT more RPM out of the valve train with those modified lifters

Well I'm going to go ahead and document as the saga continues.

The shorter pushrods (BB chevy) worked well to quiet the engine down however it sounded like there was a lifter or two making noise on the driver's side.

So I ordered up a set of 16 Sealed Power HT-976 lifters. When I received them, 15 of them had a pushrod cup height of 1.544", and 1 of them - a slightly different design had a height of 1.587". A difference of around .040". The former have a small indentation on the bottom of the pushrod cup and the latter had a smooth cup with no indentation. All boxes are marked Made in the USA which is nice. I guess the single one was old stock of some kind.



Which makes me wonder about the lifters that are in my engine now. If the .100" preload measurement was any indication, they are probably the kind with the height of 1.587".

When I get the old lifters out, I'll make the same measure of them and decide whether to use my BB chevy pushrods at 9.252" or the Summit mopar pushrods (assuming they roll true) at 9.315" with the new lifters. To be continued.

Make sure to do a cam break in again right after the new lifters are put in.