I have a 396 BB in my '69 Camaro. The stamping on the front of the block (on the right bank) indicates the motor is probably a '67-'69 Chevelle 396, 325 HP Powerglide... originally.

The previous owner did some work on the engine, such as Edelbrock Performer 750 CFM carb with electric choke, DUI Street/Strip hi-energy ignition, Holly fuel pump. The car is also running 1-7/8" headers and a 2-1/2" Flowmaster exhaust system with cross-over pipe. Basically, the car was set up pretty nice by the previous guy from what I can tell. (I believe my car was originally a SS350 w/Muncie 4-spd... it still runs the Muncie.)

The motor has iron heads. I assume they are stock 396 Chevy heads. I don't know (yet) if the previous owner put a non-stock cam in the motor or not, but I'm guessing the cam is basically stock.

The motor runs quite strong and will spind the tires on command in 1st... big time if I want to. (That's a BB for you!)

When I first start the motor, everything sounds pretty good and tight... no appreciable valvetrain noise or bottom end noise... it sounds good.

But, once the engine is warmed up, after say 15 miles or so, then I notice what sounds like pronounced tappet noises coming from the valvetrain, especially on the right side bank.

My question is: Why does the valvetrain make noise after the motor is warmed up, but not initially? I would expect a noisy valvetrain when the motor is cold, but not hot. Is it that the valve springs loose some compression once they are hot?

The valve covers are held down with "T" wrench fasteners, but I don't know if this is for looks or not. I want to open up the valve covers to take a look, but I keep putting is off because it's still driving weather.

Is it a big hassle to pull the valve covers and check the lash, regardless of whether the motor has hydraulic or solids? (I'm assuming it has hydraulics, but maybe the previous guy built-up the heads... I don't know yet.)

Do old 396's make valvetrain noise when hot? Any problem with running the engine this way for another 500-600 miles or so? What's the worse that can happen?

Also, once the weather gets cold and I can tear into the motor a little bit, do you have any advice on whether I should have the iron heads rebuilt or go to a new set of heads, maybe Edelbrock heads? Any comments or advice?

Any tips or helpful information will be greatly appreciated.

Jim

it probly has roller rockers on and a soild cam so i would say you need to set the lash again it doesnt sound like they need reworked. it wont take more than a half hour to reset them. the more you run it the louder it will get

Jmar, use a long extension bar, broomstick, or something similar, rest one end against your ear, and move the other end around different spots along the offending head, You will be able to pin point where the noise is coming from, I would pay close attention to the fuel pump, they are known to make noise similar to valve train, as far as the lash on a solid lifter cam the noise would be there when cold, and decrease as the engine and componenets get warm, Is this noise loud that it can be heard from some one stading on the street as you drive by and very noticeable when it is at idle? If yes then I would be concerned and want to look at befor it becomes major, If the noise you are hearing is very slight then it could be valve guides.
When you remove the rocker cover use a screwdriver and lightly push against the valve spring when that valve is closed, if you find that the valve stem rocks back and forth more than half the thickness of the valve stem then the guides are shot, this means pulling the heads off the engine, It won't hurt to finish out this season.

Wouldn't something hollow, like a garden hose, work better? I've use the same theory to find exhaust leaks.........KZ

Hey Jmar,
I had a known 68 396 Chevelle engine that I traded for because of the exact noise you have discribed. I thought I could put cam,lifters,oil pump,and check plugs in front of block and fix this engine.This engine had less than 10K since major rebuild.anyway I did all the above,and guess what when it was cold it was still quiet as a mouse,but after 15 miles or so it sounded like it did have solid lifters. Now to answer your question about damaging something,I had this engine in a 1970 chev pickup and ran it REAL HARD for well over 100K,and thought well it's time to get it gone, and saw this truck over a year later STILL running. You can spend if you choose but I don't think the noise will ever go away. I have been told(no proof)that some of the early 396'S have cracked under the oil gallies (crankshaft side)and will be closed until the engine warms up enough to open the crackes enough to make lifter noise. And yes I did drill .040 holes in block plugs behind timing gear.

Good Luck
Larry

Larry and everybody else:
Thanks for the info... it helps.
I will be pulling the valve covers pretty soon... I'm real curious to find out what the valve train is... solids or hydraulics.

That will tell me a lot. But no matter what, at least I have been encouraged by your replies. I'll post my findings when I have something.

Have a good day!
Jim

Jim, guess what buddy. There is no way to tell whether you have a solid or hyd lifter cam in there by pulling the covers and inspecting, UNLESS the lash is properly set on the solid and you literally can feel the rocker arms being loose.

I use Rob's trick, but with a 5/16" fuel/vaccum line I have for "stethescope" analysis. Isolate your noise first, then...

it'll take 5 minutes to remove a cover. Just do it. Be careful not the rip the gasket when you do.

My guess is that you'll find nothing, or using the "stethescope" might find that your "valve noise" is actually an exahust gasket leak ( like I just did!).

In any rate, come back to the site and we'll help anyway we can.

Assuming you find nothing,I think you should run some motor flush and then change out the oil.

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Gene C.
67 Chevelle SS 427/L88 (http://www.chevelles.com/showroom/chaas00.jpg)

[This message has been edited by 427TRI (edited 09-05-2000).]

If the engine has stock rockers and the stock crimped rocker arm nuts have been cranked on and off a bit, they can get loose where they won't hold an adjustment.
Also, The rocker arm can wear in the pushrod pocket that would prevent good oil passage to lubricate the rocker ball. But this would cause trouble more on startup. But could accelerate wear on the rocker ball, and put the adjustment on the loose side.

Also while you're in there, check that you don't have a valve spring that is broken near the end.
David

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Check my web page for First Gen Camaro suspension info:
David's Homepage (http://ourworld.compuserve.com/homepages/David_Pozzi/)
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

Thanks for the additional posts on this topic:
I have not pulled the valve covers yet, but the next time I get 5 minutes to work on my car, off they will come!

In the meanwhile, I've been absorbing and pondering the great ideas, information, advice and experience you've been sharing.

I got to thinking, my motor is a 66-68 Chevelle 396 and it has iron heads... so I'm pretty sure it's a pre-unleaded gas motor. Now that I'm thinking about that, I remember I used to add lead additive to the tank every couple of tank fulls. (Assumption: non-hardened valve seats.)

I know I have not been using lead additive since getting the car back on the road this summer.

Do you guys think that the rattle under heavy throttle at 40-50 mph when fully warmed up could be due to not adding lead additive in a while? (P.S. - I use Shell 93 Octane pump gas, although I don't know -yet- what the CR is for this motor.)

That reminds me... this motor has always sounded the same since I got the car... that is, quiet when cold and noisy when fully warmed up... even when I was using lead additive regularly. My point is that the noisy valve train issue is not apparently related to the discontinued use of lead additive.

Of course, as I have been following the dialog on ignition timing in some of the other posts, I'm also thinking I should check my timing... initial, manual,vacuum and total. Maybe something has changed since I first got the car. Hmmm. Maybe it's an ignition timing thing?

Well, thanks a whole lot for your feedback. David... I checked out your website. Impressive. Thanks for sharing your experience. Your pictures make me want to drop out my sub-frame this winter, weld it all up, and install a Tremec or a Richmond 5 or 6 speed.

BTW... which of those replacement trannies would you guys recommend to put behind my 396 BB?

Thanks. Later.
Jim

I'm back after pulling the valve cover off the passenger side last night. Guess what I found... a piece of the welded oil baffle was broken off!!!

Whew, the piece was broken off along one edge and then had broken in half? The broken piece was just laying in the head cavity. I hate to think what would have happened if the piece has gotten situated in a rocker, pushrod, or valve spring.

Anyway, I'm looking for a new set of valve covers now. The motor now has chrome valve covers with CHEVROLET stamped in the top. There is one breather hole in each cover and there are baffles welded under each breather hole.

Does anyone know: How can I tell if the covers are "low profile" or "tall"? BTW, I found out I have aluminum roller rockers. They look like Proform or Crane billet aluminum rockers, with full needle bearings and Poly locks. They are red anodized color. Also, there are Pushrod Guide Plates installed. The springs appear to be either double spring type or w/dampers.

So, what valve cover would work: "low profile" or "tall"?

BTW: The head is a '66-'67 396, oval port, 2-1/6" intake, used on both the 325 HP and 360 HP versions. But with roller rockers and guides, headers, Flowmasters w/crossover, HEI ignition, and 750 CFM Edelbrock w/electric choke, I figure I must be making more that 325 HP and maybe more than 360 HP.

What do you guys think?
Thanks.
Jim

Congratulations on finding your problem. In general roller rockers and poly locks will not clear short valve covers. I personally would not be to conserned with running a valve cover with an internal breather, I myself prefer to use one without.

Steve R.

Jmar,

Pdq67 here. Please advise what BTW means???

I'm not all that up on shorthand "lingo".

Thanks much and glad to see that you found some treasures under your valve covers and that no damage was done.

BTW= By The Way. http://www.camaros.net/forum/smile.gif

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Leo Paugh
MCC #017
www.clark.net/pub/chevelle/mcc.htm (http://www.clark.net/pub/chevelle/mcc.htm)
the bitterness of poor quality remains, long after the sweetness of the low price is forgotten

Jmar:

I've got a 1968 396 L35 (325 HP). Had the exact same lifter noise when hot. I found and replaced fuel pump, fuel pump rod, worn stock rockers, worn studs, a few slightly bent pushrods and replaced the lifters (hydraulic). Same noise. Reset lifter preload 1/4, 1/2, 3/4 and 1 turn but obtained no change. 30 PSI oil pressure at idle by the way! And the cam was clean - all lobes intact.

Rebuilt engine by very reputable Marine/Hi-Po shop here in Detroit. Magna fluxed, .030" over, pistons, resized rods/mains, Crower stainless rockers, blah, blah, blah. Same noise.

Engine builder says it's because of the "radical" hydraulic cam I installed (290/292 - .527/.554) but he can't explain why it made the same noise with original wimpy cam!

Anyway, that was 3 years and 2500 miles ago. No problems with the engine. Seems the quietest with Mobil1 15W50.

I'm thinking of installing a Solid cam (more duration - same or slightly less lift) this winter. If it sounds like a solid, it may as well have one!

Don't be surprised if your engine makes the same noises when you pop the valve covers back on!!!

Thanks for the feedback and advice guys.

Here's what else I found out after taking off my driver's side valve cover. I could see the outline of the hexagon shaped Polylok nuts from the exhaust rockers on the inside surface of the valve covers. This indicated to me that the Polylok nuts are very, very close to touching the inside of the valve covers.

After some reading of my favorite car mags, I began to understand that it is very possible for a standard, low-profile valve cover to have an interference problem when after-market roller rockers are installed... which is my case.

After examining my left side valve cover even further, I noticed that there was actually a small indentation from the Polylok on the exhaust rocker for cylinder #1. In addition, I noticed another interference location where an intake rocker was obviously rubbing on the inside of the cover near where a bolt "boss" is located.

So, I was able to conclude that as a matter of fact, my roller-rocker after-market valve train was running very close to, and in some cases was interfering, with the inside surface of the standard "low-profile" valve covers.

This could obviously explain why the valve train sounds noisy. I am now looking for a good set of "tall" BB valve covers.

By the way, or "BTW", does anyone know who makes a good, reasonably priced set of "tall" valve covers for a 396 BB, with internal oil baffles, that will fit my '69 Camaro. The cover needs to clear the power brake vacuum assembly, so I may need to have an indentation.

Thanks again for your feedback.
I'll keep you posted if I find a "tall" set of valve covers and if that makes my "valvetrain noise" go away.

Jim

Steve / Tech Team:
Sorry that I did not acknowledge your comments. Thanks for the input. You said that you prefer to use valve covers that do not have the internal oil baffle.

Can you elaborate please. What are the pros and cons of internal oil baffles inside valve covers? It seems to me that if oil baffles are always advantageous, then all valve covers would feature them. But, this is of course not the case. So, I'm wondering...what are pros and cons?

My understanding is that the oil baffles will prevent oil from spashing up inside the oil breather which, presumably, could result in excess oil loss. The baffle's job is to prevent positive crankcase ventilation, but also prevent oil loss.

So, why do you prefer not to use internal oil baffles?

Thanks again for any experience or knowledge you can share. This is a very interesting hobby... there's always something for someone to learn even after all these years and all the cars that have been built.

Jim

Het my 67 396 does this & it is a brand new rebuilt with a comp cam extereme engry 268 cam & lifters, crane push rods& guide plates & new hi po GM rocker arms, everthing looks good & my engine has done this since day one I just fiqured it was normal!It run's good! My Brothers 468 has the same sounds in his 69 camaro & it has a comp 280 mag. cam & lifters in it!

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johnny

I use Mr. Gasket's extra-thick valve cover gaskets. I too have aftermarket rollers (Crower Stainless) but the Crower's are physically smaller than aluminum. I have plenty of clearance with stock valve covers and extra-thick gaskets. If your running the big aluminum rockers, you may need to run a tall valve cover.

I use Mr. Gasket's extra-thick valve cover gaskets. I too have aftermarket rollers (Crower Stainless) but the Crower's are physically smaller than aluminum. I have plenty of clearance with stock valve covers and extra-thick gaskets. If your running the big aluminum rockers, you may need to run a tall valve cover.

Thanks for the comments on how your engines are setup and running. I really like have information like this to compare to. After all, how many 396 1st gen Camaros can I pull up to in a day to ask questions? Like, usually none!

Anyway, after looking at the BB "tall" valve covers available, I'm not sure many will fit my '69 Camaro, especially on the cramped brake booster side.

So, I purchased a set of extra thick valve cover gaskets. Judging from the fact that my low profile covers almost don't interfere with anything, the extra thickness should do the job for me.

Thanks again for the info on your motors and after-market setups.

Enjoy the ride.
Jim

Thanks for enlightening me about "by the way" = "BTW".
Pdq67

Yesterday I finally got my new valve covers in the repo of the orginals! I got the one's with the oil drippers in them & didn;t get the power brake slant on them they fit perfect & I have good clearance on the power brake booster! U have heard that Chevelle's were the only one's with the need for the power brake slant! Any way the noise that i was hearing has almost diappeared in my engine! I remove both covers today & checked the rockers & push rods & saw no wear still looked like brand new! So try the ones with drppers on your camaro.

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johnny

Hey Johnny, sounds like drippin oil on the rockers has quieted things down a bit. Congradulations.

Because I've got aftermarket aluminum roller tipped rockers, I'm sure I don't have room under the stock repo valve covers to use drippers. I think they would hit my rockers.

Question: What is your valve train? Stock Chevy 396?

Thanks.
Jim

Yes my valve train is stock GM & the drippers did help a lot. I checked the rocker's & push rods to see if they had wore any & they looked new

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johnny