A bit of back story- this is on my truck that I recently did a full rebuild on the engine and converted from a 360 to a 390. It was a full rebuild- machine shop fully worked the stock heads, crank checked and polished, rods all machined, all new bearings, new rings, new high compression pistons, etc. I also used a high volume oil pump and did all the normal FE oil mods- enlarged the galley from the pump to the filter, chamfered the main bearing oil feed holes, and added the recommended restrictors in the oil galleys to the rocker shafts. The only other relevant thing in the rebuild is that I did recycle the Summit brand cam and lifters as they only had about 2000 miles or so on them despite being three years old.

Initially, I had some issues tuning due to too low of octane fuel and forgetting to tighten the distributor down fully. Once I got the tune dialed in everything seemed fine and I have put about 200 miles on it so far, without issue until the last few days. Now the last three times I have started it, it runs fine at startup and then right about the time it hits normal operating temperature, I start getting a very noticeable noise that sounds like a pretty bad lifter. The first time it did it I turned around and went back home and ran the errand I was doing in my car. But when I started it back up to check- no noise. The second time, I pulled over and popped the hood and checked and it seemed to be coming from the driver's side valve cover. Closed the hood and started to head home and the noise just stopped. So I continued on where I was going. No issues on the return trip, but the truck did not fully cool down either. Fast forward to today when I was test driving after installing a new brake booster and the noise is back again, this time running noticeably bad too. Not terribly bad, but enough to definitely notice. Again, I headed home and this time I busted out the stethoscope. I really couldn't pinpoint the source of the noise more than before. Out of curiosity, I shut the truck off and immediately restarted- noise went away and truck is running normal again.

At this point, I am thinking that one or more of the lifters despite being almost new are giving up. I have never heard of them being intermittent like this though. Is that possible? Or is there something else I am missing? I am tempted to pull the restrictors out of the head galleys and see if that helps too, but I wouldn't think it would. Oil pressure is consistently about 2/3 towards the high side of the normal range and this does not change when the noise is present. A lot higher than it was with the tired, old stock oil pump which usually hovered about as far to the low side of normal range. (Sorry, only have a stock gauge so no real concrete pressure numbers). Or maybe is the opposite possible and they are getting too much pressure?

I am getting really aggravated after dumping two grand into a rebuild to start having issues again this soon. Any help or thought would be appreciated before I find the nearest cliff to push it off of!

 

the first thing I would do is make sure you're not hearing an exhaust leak. while your oil pressure is obviously important if your gauge is running about where it always has it's unlikely you have a problem. a mechanical gauge would confirm it if you have any doubts.

Did you get your lifter preload set properly ? this shouldn't cause an intermittent noise but it is important if you're getting noise. are you sure you got your rocker shafts turned down so they're lubricating correctly ? what did your shop do with the guides ? think about anything in the top end that could be sticking or difficult to move.

Lastly it could be a lifter. there are okay flat tappet lifters and there are junk lifters. I did a bunch of research a few years ago and found there are only two manufacturers left making flat tappet lifters. one is made in China and the other is Johnson made in the US. I called Johnson and they wouldn't tell me what brands they sell but I know they make Howard's cams lifters so that's what I'd use if I ever used a flat tappet again. I'm afraid Summit is the Chinese ones just looking at them but I cannot confirm it. in either event a bad lifter is a real possibility.

 

Are you sure you got the lifters back on the same cam lobes?

 

First thing I would do is pull the valve covers and check everything in the valve train.

 

I do have a leak on the header collector gasket that I still have not fixed, but it it a constant noise and not nearly as loud.
Unless I screwed something up, yes I check and set preload. I couldn't find stock length pushrods to match exactly what I needed so I ended up using valve shims under each pedestal to get in the correct range to avoid the expense and order time of custom pushrods. I am 99.9% sure that they are sealing the oil passage correctly, but as mentioned I do need to pull the valve cover to fully double check and verify while running too.
That's kind of what I am leaning towards, unfortunately. Getting really fed up with crap quality parts these days. If end up ordering replacements, I will look for Howard's. Made in USA is not a surefire guarantee either, but I sure trust that more than most Chinesium stuff right now.
Yes, I kept them meticulously labeled and matched with the same pushrod too.

Thanks for all the suggestions so far. This is only the second engine I have built and the first was over 30 years ago with a lot of help! I am not ruling out something I missed, which is what I love about these forums. I am really hoping for the confirmation of someone who has had the same intermittent issue and the solution that fixed it because I am really not looking forward to breaking in another set of lifters... and then with my luck so far, still having the noise. But I am pretty sure at this point that is the culprit.

 

Not likely a problem, but are you sure the shims you used will allow full oil flow around the bolt and are you sure you have the tapered bolt on the oil feed stand ? ? and are you sure the notches on the rocker shaft are down ?

It's easy to get too little preload when shimming. but it shouldn't be real loud unless it way off.

An exhaust leak at the exhaust port can create a tap that can really sound like a top end problem. just make sure you're not chasing that because you wouldn't be the first who did.

 

I get the intermittent lifter noise on my 390 FE maybe once or twice a year on average, the mostly minor ticking noise in most cases and once in a great while a moderate lifter noise, but not lasting any more than a 1 minute to a 5 minute duration on my engine - then no issues ever reoccurring again for months on end as it does not happen hardly ever....and I don't know what causes it to do that either, wish I had an answer.

Just reached the 70,000th rebuilt mile mark a week ago as I rebuilt the engine back in May/June 2006....I spent a total of $2700 on this FE back then - while it never cost me any more than $1500 rebuilding any 429 or 460 engine, or any of my two slant 6 Dodge engines with premium parts back in the day either - I sure found out how expensive rebuilding an FE was.

This 390 FE that was rebuilt is in one of my two 1970 F250 Sport Custom Trucks that I own....as it was strictly a cabover camper hauler from April 1996 thru September 2016, and has been an everyday driver since the past four years.

Rocker arms are all brand new, pushrods new, I did install solid aluminum spacers in place of those stupid spring type spacers on the new shafts though....

Lifters, damper dual springs and mild cam (.270 I .280 E) I chose are that SSI brand (super stock industries - unknown true manufacturer) which came with the PAW engine kit - I went with .030 over Silv-O-Lite cast 8.6:1 CR, Milodon true double roller, reconned rods that are good for 3500 rpm, exhaust valve seats, Manley stock valves, crank was grounded .010 under, also went with HI Volume oil pump and ARP oil pump shaft....I did not modify or restrict any oil galleries of the sort.

The only major issue that I had so far with this FE engine not too long ago was the Fel Pro composite exhaust manifold gaskets leaking after the 56,000+ mile mark - as I should have had the heads and manifolds true surfaced at the exhaust ports during the rebuild but didn't know the significance of it back then....although I did purchase those made in china new exhaust manifolds that were only readily available and are still holding up very well.....I since installed the Fel Pro steel exhaust manifold gaskets last spring (installing two put together on each side) and thank god no more exhaust manifold leaks to deal with (hopefully)...although the upper #4 cylinder exhaust bolt broke off at the head and I got a vise grip in place for the time being (blue and yellow cannister heat torch didn't loosen the broken bolt) ..... all the other exhaust bolts (which were all new) came off with ease as I anti seize lubed the male bolt and female hole threads during the rebuild.

 

So this gets even weirder. I drove it again today to test drive after working on the brakes again and just like clockwork as it hit normal temperature range, the noise comes back. This time I pulled over and shut the engine off and then fired it right back up. Apparently, it was not a fluke and this stops the noise every time so far. WTF? Why only when it gets warm and why does it go away restarting the engine? This is a weird one.

 

I have a similar problem with my 390 Rebuild. Ran amazing at break in after a few hundred miles it started to tick when it was hot. I took the valve covers off and filmed it in slow motion with my phone camera. This let me see that the exhaust valve guide on the #8 cylinder had worn itself out.

The machine shop who did my engine work looked at my video and then reworked the heads and fixed the problem. But after a few hundred miles The same guide wore through again.

I don't know why this is happening. My first guess is that the valve is getting oil starved under certain conditions. My second guess which I think is probably right is that the machine shop messed up the geometry of the valve seat, causing the valve stem to wear through the guide prematurely.

I haven't fixed the problem yet because the truck is in storage. But you might try filming your valve train in slow motion and seeing if you can figure out which components are actually making the noise.

 

I have a similar problem with my 390 Rebuild. Ran amazing at break in after a few hundred miles it started to tick when it was hot. I took the valve covers off and filmed it in slow motion with my phone camera. This let me see that the exhaust valve guide on the #8 cylinder had worn itself out.

The machine shop who did my engine work looked at my video and then reworked the heads and fixed the problem. But after a few hundred miles The same guide wore through again.

I don't know why this is happening. My first guess is that the valve is getting oil starved under certain conditions. My second guess which I think is probably right is that the machine shop messed up the geometry of the valve seat, causing the valve stem to wear through the guide prematurely.

I haven't fixed the problem yet because the truck is in storage. But you might try filming your valve train in slow motion and seeing if you can figure out which components are actually making the noise.