So, my rebuilt 401 has run great since first startup. Having been completely balanced it is also the smoothest engine I have ever had. After having put a couple hundred miles on it, while idling in my garage, it started making a "hellatious" clattering noise, causing me to shut it down. After collecting my thoughts, I restarted it, ran nice, then the noise again. I pulled the intake, rocker covers, etc., and removed and inspected the rocker shafts (rebuilt by Rocker Arm Specialists) the pushrods, removed the lifters and examined the FACES and cam lobes, all looked great, returned lifters to their original bores. I removed the timing chain cover and examined the Cloyes double roller timing chain and gears, all looked brand new. I reassembled all and started up, ran well and then the clattering noise again! I pulled the pan next, super clean with no metal in pan, clean pump screen, all rod and main bearing torques spot on. Viewed from below, all bores look excellent, no contact marks, or signs of mishap. I will be reassembling as soon as I get a pan gasket, but I'm sure upon restarting it would run well for a bit then begin clattering. I believe that I must have a lifter that is collapsing on me, what do you guys think?? I'm not sure how to determine for sure which lifter(s) are the problem, thinking of getting a set from a known good supplier, perhaps TA. I welcome hearing your thoughts!
wonder if you have enough per load on the lifters. what cam you running. where did you get the double roller chain ?
Not sure what you mean about PRE load on the lifters. The cam is a pretty stock 4bbl grind, and I got all my parts from Carmen Faso.
Hydraulic lifters operate with Pre-load. The lifter plunger is pre-loaded about .030 beyond 0 lash. All hydraulic lifters need some preload. With the non adjustable Buick valve train, all stock parts should produce the proper pre-load when the rocker shafts are torqued down correctly. That isn't guaranteed once you change cams or push rods. It needs to be checked. http://www.cranecams.com/pdf-tech-tips/hydro-lift.pdf
I had a similar issue when I redid my 401. What it turned out being was that there were 3 different sizes of lifters in the kit I bought; and I made the dumb mistake of pulling the lifters straight out of the boxes, lubing them up and dropping them in the bore. Didn't know what was going on until all hell broke loose about 500 miles away from home. Because of the clattering and a few other mistakes, the rocker shaft on the driver's side split into 3 pieces, came home the last 300 miles on 5 cylinders. The car still would do 60. If the rockers, shafts and springs come up fine, then it has to be the lifters. Run the engine up with the valve cover off, stick a screw driver paddle in between the offending spring and rocker arm; if the noise stops, there's your issue, the lifter is wrong or junk.
3 different size lifters in a kit?? Never heard of this, I`m sure I`m out of touch. Please explain? Thanks, Tom
This all happened before I joined this forum and learned better. I had made the dumb newbie mistake of buying an engine kit off of a major supplier on eBay; the kit arrived late, and I essentially slapped the engine together. The lifters were proudly made in China, and there was a Chevy small block lifter and another different one in that kit. Instead of lining them up and inspecting them, I just assumed they'd be correct and took them straight from their individual boxes and plopped them in. Of course, to compound matters, we were drinking a bit too much that day; - it was hot. Anyway, dumb being lead by the even dumber, the rocker shaft ended up going on with the lifters primed and pumped up, so the torque was all wrong. So, it all came apart at 60 mph about 300 miles from home; rocker shaft snapped into 3 pieces, three rocker arms disintegrated, one rocker bolt snapped, and I thought for sure a pushrod would drop into the pan. The pushrods remained straight; the cam was saved because it was unloaded. The car limped home with a very terrified and humbled driver on 5 cylinders. It still did 60, and surprisingly enough, that's when it ran "round" and reasonably quiet. It sounded like a ball mill; it was hammering itself to death though, but I figured, "Ok, I've really shot-gunned this motor, every mile I make before the car quits is one less on the towing bill". I was actually pleasantly surprised how little damage the failure actually caused, I assumed I'd wrecked the block. The car still made it home at 60 mph. Buick builds a very robust motor that survives a lot of abuse at the hands of idiots. Once I figured out the lifter issue, I checked out the cam and it only had one slight scuff mark, otherwise it was fine. The pushrods were dead-straight. The broken bolt came out with a finger, and didn't need to be drilled. A quick trip to the wrecker and the rocker shaft was replaced, and it's all still in the car and working. Once the engine was back together and the filings cleared out, it ticked and rattled until I found the lifter issue. Plopped in an American made set, and the car has been quiet ever since. I learned a lot from this experience; how over confidence and alcohol do not mix, no, a Buick is nothing like a SBC, and that when it came to Nailheads, I didn't have a bloody clue what I was doing. I promise I won't do that again.
Again, thanks guys for posting. My cylinder heads, reworked by Carmen Faso have smooth valve movement, no hang ups, and no broken rocker arms. Just received 16 new Melling lifters, will be installing and reporting if my "clattering noise" is gone.
If you used the thicker composition head gaskets, they would reduce your lifter preload about 0.030". But there are other variables which will reduce or increase preload such as head/block surfacing, valve tip grinding, and the installed height of the valves. I even heard the rocker shaft stands are not always the identical height. If you do have inadequate preload, you best bet might be slightly longer pushrods. Thinner steel shim head gaskets are another option but lots more work. Do you have good oil pressure? 35-40 is typical. There is also a plug installed in the rear of the lifter gallery on the passenger side. Sometimes that gets left out and you won't have pressurized lifters on that side. Oil would pour back to the pan. Double check to be sure it's still there. There is also a plug in the rear of the block there too, but it's just there to access the gallery plug. Another plug in block on drivers side seals that sides' oil gallery. Plugs in the front too.
was the timing chain still tight. they say the double roller stays tight, never used one, but i dont believe anything anymore. the single roller after a few hours of run time will get real loose, believe it or not. also what was the piston to bore clearance, were new pistons put in.
I don't understand how "lifter preload" can come and go. You'd have to be right on the edge of "no preload" for engine temperature to make any difference, and I don't think that's likely. Air whipped into the oil, making a compressible mess, might come and go.
when you took the timing cover off did look inside the cover making sure the double row chain was not hitting the cover
Well, my engine is fixed and running great. I had replaced all of the lifters and upon startup it ran well..........and then the clattering noise again. I felt all that was left was the head, noise was on driver side, so that head was removed. I saw that the exhaust valve for the front cyl was grey and the others were tan, also that piston had a slight "eyebrow" mark in the soot in the valve relief. I took the head to the area's best engine machine shop for removing the valve, it came out a little and then was tight, it had to be driven out. What was happening was that after running a bit, the valve would stick open and the piston would tap it closed, hence the clattering noise. I ended up pulling the other head and ALL valves were checked for valve to guide clearance and others were too tight. Clearance was increased to specs recommended by others, including Russ Martin. I am now enjoying driving behind my NAILHEAD again.
I have had this problem, most often from reviving a long idle engine and especially with bad gas which encourages the valves to stick, hence post #9. I always get some lubricant on the valve stems and get fresh fuel into a motor before I fire up an engine if it has not been run in a long time. I`m surprised you didnt break a rocker arm. Great to hear you got her fixed Tom
