OK, I have a rebuilt 400 that was bored .060" over but is otherwise stock (or as close to stock as the rebuilders took it).

Over the weekend, I put on a set of 2V Cleveland heads that had been rebuilt with hardened seats, new valves, etc...

It's running great! I'm loving the feel of it now. No leaks; it runs smooth (no vibration); the oil pressure is good; good throttle response; etc...

Except... I've got this weird pinging coming from the right bank (passenger side) - it's not valvetrain noise (clatter), it's definitely sounding like it's being generated in the exhaust manifold and works it way down the pipe on that side...

Is this something to worry about? I'm curious why it's only happening on the one side and not the other... Will it hurt anything?

I'm not running headers - just the stock manifolds - the exhaust had been redone before and I can't find any indication of a valve in the manifold anywhere... Doesn't seem the exhaust is being restricted - it's flowing evenly out both sides...

I've read the quench chamber is slightly smaller on the Cleveland heads, but I didn't think the difference in compression would create pinging like this... Although, with gas being what it is, it wouldn't surprise me...

Any ideas?

 

Unless you put Austrailian 2v heads on it you don't have quench heads.

 

You could have an exhaust leak, but the sound would be more like a ticking..

 

It always helps to have someone else listen to it...

When I installed them, I used the rockers that were on the Cleveland heads - When I checked them over, they seemed okay...

We got to listening to it better today and it seems to be a ticking noise - not a bad one, but it is noticeable... I'm thinking of putting the 400 rockers back on and see if that makes any difference - If the engine rebuilders put new rockers on, they should still be in good shape...

The ticking is from up top - sounds like it's under the valve cover...

 

My engine has some ticking too. Put some new roller rockers on when built last year. The strange thing is, it doesn't tick when the engine is cold, only after it's warmed up.

 

All the rockers are the same. Did you check the lifters preload ?

 

Were you asking me that question or the OP?

 

If he was asking me - I'm thinking one or more of the old Cleveland rockers I put on are worn. I'll know for sure when I swap them for the 400 rockers I should have put back on in the first place lol... I'll also be checking the pushrods, but I think they're fine...

 

I'd check really close for an exhaust leak. Maybe a cracked manifold. Does it change sound as it warms up?

 

Doesn't seem to - it's pretty consistent.

 

Well, I swapped the rockers on that side and got the ticking to subside somewhat - There's still a slight tick on that side, but it doesn't seem to be as bad. I tried re-tightening the exhaust manifold bolts, but that didn't seem to make any difference.

I'll do the rockers on the other side later, when it's not so damned hot outside...

I'll have to get a stethoscope and see if I can pinpoint where the sound is coming from... It almost sounds to me like it is coming from the exhaust - it didn't do this until after I swapped the heads, though...

 

Well, I am now completely stumped...

It does get worse after it warms up so, I started thinking along the lines of it being an exhaust leak. I went through and re-tightened all the exhaust manifold bolts (I did find a couple that were somewhat loose), but that didn't seem to do any good... Couldn't find any indications of breaks or cracks and I don't see any visible sign of a leak...

Using a stethoscope, and checking everywhere from the valve cover all the way down to the exhaust pipe, it seems the noise is coming from the valve train. I hardly get any noise from the manifolds - it gets noisier as I get toward the top of the head...

The part that stumps me is that it's "broadcasting" the noise down through the manifolds and into the tail pipes - I crawled under the truck while it was running and you can clearly hear it in the exhaust... Almost sounds like a Diesel...

The oil looks good - no foaming or anything else abnormal. The pressure is good according to the gauge I put in (Sunpro electric gauge - I won't run a pressurized oil line to the interior of my cab)...

So, the questions now are:

1) Is there enough of a design change between the 351C and 400 heads to cause this sort of thing? I wouldn't think so...
2) The lifters, being hydraulic, should automatically clear up any gap between rockers, push rods, and valve stems yes? Self adjusting? If the valve stems were a few thousandths too short, would that cause this? Do I need to run lash caps?
3) Will this hurt anything?
4) Could timing cause this? I set it back to 10* when I put it all back together...

I'm starting to think this is something I'm just going to have to live with - The truck seems to run fine regardless, in fact, it runs better now than it has in a long time...

 

Well, I'm back to it being caused by the valve train. I've had 2 different people, besides myself, look/listen to it after it's warmed up and none of us can find any indication of an exhaust leak...

What it sounds like is the rockers hitting the valves. It's very slight and gets worse after the engine warms up. It's more of an annoyance at this point than anything. I didn't have this problem before with the 400 heads, but the Cleveland heads have had hardened valve seats installed and I'm running new valves so, I'm assuming there is a slight clearance issue there somewhere...

Lifter preload has not been checked. I don't know how to do it. I've gone back through and read the posts relating to the preload setting on the 400 and it's just not clicking in mind, for some reason... It seems to be a great deal easier to set the preload on stud mounted rockers than on the fulcrum mounted ones, though...

I'm now looking into the possibility of doing a stud conversion. I found the Crane kit (without rockers) on Summit for $99... I've got a guy here locally who has a good set of stud-mount rockers that should fit and he'll give them to me, if he can find them - they're off a '73 Chevy 454, but Summit sells a bunch of rockers for both Ford and Chevy applications and it seems most of their 454 and 400 rockers interchange - these rockers are also for the .3125 diameter push rods...

I checked the push rods and they all seem fine - no abnormalities detected...

I also found, after going back over one of my old posts that the D1AE (76.2cc chamber) came from the Cleveland, and the D1AE-A (78.4cc chamber) came from the 400. My Cleveland heads have 2A19 and 2A21 codes on them saying they are from Jan 19/21 of 1972. Would that 2.2cc difference per chamber be noticeable in any way?

 

I also have a tickling noise on my 400 right after a rebuild - see the goodies in the bottom line. I also agree with [I]smokeyb97[I] it starts when the engine warms up.

First I thought about pinging and did some changes, as there are a cooler thermostat, some more rich on the carb and some less advance ( it´s now 12 BTDC with a special recurved duraspark dizzy ) and tried with a tankful of high octane fuel but no real advancement. I´m not sure a cooler plug can affect.

Because I fitted a set of headers during the rebuild I also checked well for a exhaust leak - nothing to find.

Next suspect was a valve hitting the piston because the new flattops from TMI were slightly over the deck top but following some other thread here mine were inside of tolerance.

Meanwhile I bet it´s the valvetrain. The valves (multigroove) are revised, the valve springs, keys etc. are new, matching to the 265 comp cam. I still use the old rockers although I had planned a stud conversion first. But the extra cost of machining and the disadvice from the machine shop doing this kept me away. Meanwhile I`ve seen there is a set of roller rockers from scorpion with no machining. This will be the next thing to buy.

Next to do is check the preload but don´t wanna do this by myself and take some advice from a mechanic.


@ smokeyb97 : your build seems similar to mine, may I ask you for some details on pistons, cam etc. ?

 

The stud conversion kit I'm looking at does not require machining of the heads.

Crane Cams 52655-16 - Crane Rocker Arm Guideplate Conversion Kits - Overview - SummitRacing.com

If you look at the instruction sheet on this link, you'll see what's needed. The rockers will have to be changed to 7/16" stud type rockers, but that's the only real change I see...

I changed to single-groove valves, keepers, and retainers when I rebuilt these Cleveland heads.