Adjusting Valves part II

[steveplym]

Okay, I readjusted the valves over the weekend and I still have some noise. It is starting to concern me as I have the clearances right at spec and did this with the engine hot. Seems to be noise at idle and it decreases quite a bit when clutch is out and veh in gear. Noise is not prevalent going down the road.

I had the engine running with the side covers off and could tell the noise was in that area. It is a tapping noise.

If I had clearances that were too tight would it make noise? I wouldn't think so.

Any ideas what else I can look for, or do to lessen the noise?

I'll try to get a clip of the motor running later this week and post it.

[Jerry Roberts]

Steve , You can often tell which one is clicking by running the engine and sticking a feeler guage into each gap , one by one , and listening .

[Normspeed]

That's a good tip Jerry, works great on the flatheads.

Steve, what's the condition of the valve guides?

[steveplym]

That's a good tip Jerry, works great on the flatheads.

Steve, what's the condition of the valve guides?

Entire valve train, guides and all only have about 5,000 miles on them. They all seemed to check out okay when reassembling this last time.

[steveplym]

Don't know if it has been mentioned in your first thread, but cupping of the tappets has been mentioned and shown before. Measures good with the feeler gauge, but when the gauge is removed the clearance is again out of adjustment.

Not sure how common it is.

These are fairly new tappets, but how could you tell they were cupped?

[Normspeed]

Did you set them with the engine running, or just warmed up and shut off?

[steveplym]

Did you set them with the engine running, or just warmed up and shut off?

Engine warmed up and shut off. Figured it would be hard to do it with the engine running.

[Allan Faust]

I don't know if this may help or not, but in 1980 when we crossed Canada, an odd sounding noise started... a tapping of sorts, worse when the vehicle was idling.... and it was a broken rod... i know there are no rods (except part of the valves), so could it be a broken valve (where the tapped hits it?)

Allan

[Normspeed]

I used some instructions that were in the tech section on the forum, and I think there may have been a typo in there. Using that method, I ended up with at least one valve pretty far out on the loose side. I think one of the lifters was partially on a lobe, and to gap it I ended up backing off too far. I eventually bit the bullet and did it with the motor running and that worked much better. Gotta protect your hands and forearms from the hot exhaust though.

[steveplym]

I used some instructions that were in the tech section on the forum, and I think there may have been a typo in there. Using that method, I ended up with at least one valve pretty far out on the loose side. I think one of the lifters was partially on a lobe, and to gap it I ended up backing off too far. I eventually bit the bullet and did it with the motor running and that worked much better. Gotta protect your hands and forearms from the hot exhaust though.

Can you adjust the tappets with the motor running? and how do you do it?

I would think getting the feeler gauge in between the valve and tappet would not be hard with the motor running.

[Normspeed]

Best way is to use a go-no go feeler guage, it's in steps of thickness so if it just slips in it's adjusted, and if adjusted too tight the next step won't slip in. I got one on ebay for just a few bucks.

You won't lose much oil running it with the valve covers off so that's not a problem.

If you have trouble doing the adjusting with the tappet going up and down, shout to your assistant to turn off the motor, then do a little adjusting, and have assistant restart it to verify you got it right.

Wear arm and hand heat protection. They sell heat proof kevlar sleeves or you can try a long sleeved shirt, covered with a large wool sock. And a mechanic's glove for the back of your hand.

As always, make sure it's up securely on jackstands with the rear wheels chocked or also on stands.

Here's the place where I got my feeler guage:

http://cgi.ebay.com/ebaymotors/GO-NO-GO-FEELER-GUAGE-22-Blades-For-Adj-Tappets-Etc_W0QQcmdZViewItemQQcategoryZ43991QQihZ007QQitemZ170144269003QQrdZ1QQsspagenameZWD1VQQtrksidZp1638Q2em118Q2el1247

[steveplym]

I just ordered this Norm. Hope it helps my dilemma. Thanks!

[Jim Saraceno]

Here is a picture of a cupped tappet. If your tappets are new this should not be a problem.

If you want to be right on the gnat's patootie, you need to adjust the valves while the engine is hot and running.

As Norm said, the go-no go feelers make it easier and tappet wrenches make it easier, but it can be done with regular feelers and open end wrenches. Get a cheap pair of work gloves and cut the fingers off to save burnt hands from the manifold.

Am old timer that I talked to (the one who told me about the cupped tappets) said they used to tighten the gap until he could hear the tick disappear then loosen them just a hair. Personally I'd stick with the feeler gauges.

[grey beard]

Pilothouse Dodge trucks do not have a removable inner fender panel, and if you are built like I am - short and fat, actually rather squatty - it is nigh unto impossible to even see the valve covers, let alone adjust the valves, when the front end sheet metal is on the vehicle.

Having said this, I found it very eaxy to adjust tappet clearance on a cold engine, with the nose removed, because I could see each tappet move, and be certain I was in the right spot for each valve's adjustment position. Since this adjustment is so important to these engines, and since it is so tough to do accurately on a hot truck enigne, I decided to set mine cold - just ambient room temperature - and added four thousandths to specs for expansion.

What I have since done, now that I can run the engine and drive the vehicle, was to once again remove the valve covers when the engine was indeed warmed up to full operating temperature, shut it down, and checked a few of the clearances. Each was within one thou of spec - hot too shabby for a fat old guy.

With this in mind, I have no reservation in recommending this practice to anyone who rebuilds their engine - or for that matter - anyone who has their nose sheetmetal removed. It's the best time to do the job - and the easiest way to get it accurate.

One other question I have for those of you who have owned operational vehicles for some years who still use the original style road draft tube crankcas vent - have any of you had the courage to remove a valve pan and check to see how clean your engine is staying in this critical area, now that it is getting collector-quality treatment and regular oil changes?

It is my belief that unless these engines are run up to operating temperature each time they are used, that sludge will continue to form in this area, regardless of how often oil is changed - unless you have a full-flow oil filter system, as I know a few of you do have on the larger sixes. Sure would be good to get a report from someone who is honest enough to tell what is really happening in there eengine right now, today. Mabye the better quality oils we use now will help solve this sludge problem. I know that a 180 degree stat will suely help. JMHO

[Young Ed]

Dave can't say I've removed a side cover to check for deposits but I haven't touched my valves since the engines were built. Both have about 3K miles since rebuild.

[Merle Coggins]

Dave, the whole inner fender panel is removable on the Pilot House trucks. There are around a dozen bolts and they WILL slide up and out of the way. Then remove the tire and you should be able to crawl right in there.

Merle

[Reg Evans]

Yup, I took mine off a few months back for an adjustment. It did require lots of genuflecting while swearing though.