Once had this similar problem and it was seats installed at little different height. Meaning valve seat was machined further out of head compared to factory. It changed rocker arm clearance and had to run a adjustable valve train like what your are discussing. We had headers at the time. Might not be the problem but something to consider. Hope this isn't your problem and good luck.

 

Thank you. Yes, that is what I believe is happening here - nothing wrong with them other than the rocker clearance like what you described...

OK then, sounds more and more like converting to an adjustable valve train is the way to go here for this issue...

Thanks all

 

Well, this is new to me but seems to be a perfect solution. I still have a set of magnum roller rockers for BBF/BBC in 7/16" from Comp and this set from Crane makes it easy to fit them - thank you for this info !

Please let us know about your progress and weather the adjustable rockers clear the ticking noise, furyus.

 

roll engine over by hand and check and see if valvetrain is good. Just do a sharpie black pen and mark the top of your valves and then adjust valve train and roll over engine. Pull rocker off and see pattern on valve stem. If centered on top good to go. If not need to work problem. could cause valve guide wear if pushing unevenly on stem. good luck and catch you later.

 

To anyone going to use the Crane kit on a clevland style head. Do as the instructions say and get the allen head head bolts (only 4 needed per side)
This way if you have to remove a head you don't have to remove half of the conversion kit first.
And be sure and use locktite on the studs.
polish the upper end of the pushrods with fine grit sandpaper. this will make the nylon inserts las a very long time.
I have part of one of these kits on my 300 six.

 

OK, after talking it over with some other folks, it was suggested to me to try and run longer pushrods - if there was a gap between the rocker and valve, a longer rod would take care of it.

So, I dug around and found some Comp Cams pushrods that are 9.560" long. I was initially concerned about the .060" over length but folks kept telling me I had nothing to worry about as the lifters would compensate - so, I bit the bullet and put them in.

I've been running them a little over a month now in various driving situations.

The good:

Holy Crap! It runs so much better now. It's "breathing" easier; has more power; and is getting slightly better gas mileage! The only holding it back right now is the timing set and 2bbl carb lol... There is a very definite change in it's behaviour and it's for the good.

The bad:

That damned infernal "ticking" is still there! It's not noticeable on a cold start and gets quite noticeably worse as it gets to normal operating temp. Everybody I've spoken to is at a complete loss to explain why it's doing this. And it's not just one chamber, it seems to be all of them...

The consensus, at this point, seems to be just to leave it alone and live with the noise. It doesn't seem to hurting anything, it's just annoying.

The Question:

What is the travel distance of the plunger in the lifter on a 400?

We can't seem to explain why the valve lift increased when I put the new pushrods in - yet, it's the only viable reason why we can think of it running like it is now.

So, it's either bottoming out the lifters and extending the valve lift, or the lifters are being pumped up to a point where there are doing this. Or something...

It doesn't seem to be hurting anything - the pushrods are just fine (I checked them to make sure they weren't getting bent) and the truck runs better than it has in the entire time I've had it...

It just seems strange to me - I have dubbed my truck "The Enigma"...

 

OK, I think I've finally found a possible answer, but I wanted to bounce it off the FTE to see what y'all thought...

Here is what is known (oil pressure readings are taken from a SunPro electric gauge - a mechanical gauge would be a much better option, but I have an aversion to running oil lines into the cab of my truck):Now, it seems to me that if it were pinging, I would be hearing it on both sides, not just the one side, correct? I'm not running headers - just stock manifolds however, the exhaust had been replaced with dual pipes.

I was talking to someone about this today, and he popped up with "well, are you sure your lifters are getting pumped up?" No, I'm not sure. Makes sense though, as the engine warms up, the oil thins out; pressure drops; and it's entirely possible there isn't enough pressure to keep the lifters pumped up causing them to bleed off and create slack in the valve train. If this is true, then the .060" overlength push rods I put in really aren't having any positive effect whatsoever. Although, I'm still stumped by the way they seem to have increased valve lift when the lifters should have compensated for it.

The oil I'm using currently is regular ol' 10W-30 non-synthetic. Would running heavier oil show me anything or does it matter?

Would running either a high-pressure or high-volume oil pump help?

It's a rebuilt engine so, the lifters shouldn't have that many miles on them, but both the P.O. and myself have been wondering just what exactly the rebuilders did to that engine and whether they did it right... The rebuilders have been out of business for a couple of years or so...

So, what do you all think? Does it sound like I'm on the right track or am I chasing another ghost?

I'm not really keen on the idea of pulling the intake back off to pull the lifters and I don't have any way of checking the lifters to see if they're any good anyway but, if I have to then, I guess I'll have to. Is there any other check that can be performed?

 

Well to make sure I would pull the intake and do a cam inspection! Make sure cam is good and no worn lobes? Have to pull each lifter and inspect each hole to verify. then once this is proven good cam and lifter move on. Set your lifters back in place and set push rod in lifter. make sure push rod isn't sinking into lifter, bad lifter. If setting on top of lifter in the center install rocker arm and watch and see if lifter/pushrod sinks into lifter. gonna have to watch each lifter and verify each lifter and make sure each cam lobe in on the no lift side of cam during each setup. Its a tedious procedure but the only way to be positive of a good installation. good luck and talk soon.

 

I became intimately familiar with how an engine runs with worn cam lobes when it happened to my Fury - It's still sitting in the driveway waiting for me to do something about it...

I believe the cam in the truck is fine however, your method for checking the lifters does make sense. Thanks for the info.

Unfortunately, I doubt I'll be able to pull the intake again until next spring/summer as this is my daily driver and winter is just around the bend...

I guess I'm trying to find out if what is happening is damaging the engine, but I don't know for sure what is going on and that bothers me... I just know something isn't right...

 

The ways to check lifter preload aren't hard. Remove the spark plug, bump the starter over till you feel the compression with your finger over the hole. Put a ratchet on the cranks snout bolt and a screw driver in the spark plug hole. Turn it up to the cylinders tdc. One way, you can set up a dial indicator with a magnetic stand to check preload. Loosen the rocker up and get it set so there is no lash. Set the indicator up on the rockers tip and zero it. Then tighten the bolt down and note the reading on the indicator. 2nd way, you can take a marker and black out a area on the pushrod so you can easily see the lines you will scribe. Find a stationary point on the head where you can scribe, put the rod back in and set it so there is no lash. Scribe a line then tighten it down and scribe another line. Measure the difference between the two lines with a machinist scale to see how much preload you have. Just throwing a over length set of push rods in is nothing more than a shot in the dark. It is very important that the machinist control all the valve tip heights when grinding the seats. You don't want one valve tip higher than another, that will cause problems when it comes time to measure for push rods. You need .020-.060 and it has to be right. You may be loosing a cam lobe or lobes. Incorrect valve train geometry or improper break in can lead to cam failure. Did you use a good paste on the cam and lifters and a cam oil additive before starting it up the first time ? Have you taken the exhaust manifold or header off and inspected it closely ? If you are running headers, I've seen more than one set of cheaper brands that wasn't ground true on the head sealing surface.

 

Noted. Looks like I'll be adding a dial indicator to my tool collection - should probably have one of those anyway. Thanks.

I kinda figured it was. I put them in based on a couple of suggestions I got - the idea was to use them as a "quick-n-dirty" check to see if there was any excessive valve lash. I'll most likely put the original push rods back in at some point.

It was a rebuilt crate engine. The P.O. put it in and it was already assembled when he got it. I have no way of knowing what was done for the break-in.

No headers - stock manifolds with dual pipes and mufflers. I had looked at them and they looked like 30-year old exhaust manifolds - I didn't check to see if they were true. I put new gaskets in, but it didn't seem to make much of a difference. I think, though, that may be part of the problem as I didn't get that "popping" noise with the 400 heads (same manifolds) so that might indicate the 351C head isn't true with the manifold, yes?

 

I've never had a problem with manifolds being true, just cheep headers.

 

75 to >0 huh? on a rebuilt engine?

SOMETHING'S WRONG

possible that:
oil pump relief is stuck open
bearing clearances are way out
an internal plug was left out behind the timing sprocket
cheap lifters are flowing way too much oil to the top
wrong bearings are installed

 

Yes, but I thought it was normal for the 351M/400 to exhibit low oil pressure - there's a ton of posts on these forums from folks asking about that.

 

at around 200k it is normal but not after a rebuild. with near 0 oil pressure i'd expect to be hearing lifter & rocker noise due to the lifters collapsing from lack of oil pressure

what did your rebuild consist of?

many times for whatever reason a fresh machined crank and new correct undersize bearings produce out of spec clearances. have you tried a heavy grade of oil like 20-50? if 20-50 holds decent hot pressure at idle, it's an indication that the bearing clearances are kinda big but will also cover some of the other possibilities too. it's not uncommon for a new oil pump relief valve to hang up on a burr or gremlin

i can't see persuing your ticking noise knowing that you have little-no oil pressure, it's like treating the symptom instead of the cause