Gene jockey

I have a 63 FI car with newly refurbished FI unit just installed. On initial start up I had a lot of backfiring. Checked firing order, plug wires,and distributor alignment. All seemed OK. Then I pulled the valve covers and found many of the rockers very loose. I had set the valve lash according to spec a couple of months ago. I read somewhere that the nuts on the rocker arms are single use items. Is this true? What else would explain rockers loosening? the engine was not moved during the interval.

63split63

You probably did not set the valves correctly. Do them again 1 at a time .

Bill

PS who built the FI unit ?

Texaspilot180

The solid lifters do need checked and adjusted regularly. I don't drive my 65FI a lot, just weekends and car shows/cruises etc. and the occasional romp somewhere for lunch, but need to adjust them at least once a year, sometimes twice depending on amount of use, so check them at each oil change. Follow the procedure to rotate and adjust at TDC - 90 - 180 -270 and set to the proper specs for your engine and it will run great. I set mine cold, and have an adapter I bolt to the balancer to turn the engine with a breaker bar, all plugs out to inspect anyway makes it easier. Just that garage tinkering stuff we all like to do. While mine have needed some tweaking they never got loose enough to cause any misfire issues. Jeff

MikeM

You would have to have the valves WAAAAAAAAAAAAAAAAY out of adjustment to make the engine pop back out the carb or the exhaust. I would double check the firing order again. Especially #5 & #7.

I think it would be fair to say if you took the rocker nuts all the way off, just put new ones back on. If the only turning they see is an occasional adjustment every 10-12 thousand miles, they'll last the life of the car.

tuxnharley

When I replaced the head gasket on my ZZ4, I reused the old rocker nuts. I got valve noise shortly after start up, thought I had done something wrong, re tightened everything to spec.

Second start up produced the same result. Did some checking and found out that that nuts are intended as single use. Bought a new set, put everything back together, no problems.

Apparently the nuts are produced with some kind of very minor internal "crimp" in the threaded opening that produces a locking effect on first use. When you run 'em on and then off again that is lost. I don't fully understand that feature or exactly how it works - I just know from personal experience that it does!

Learn something new every day!

jim lockwood

If you have to adjust solids that often, you might have something wrong..... maybe the adjusting nuts are beyond their "use by" date.

I adjusted the solids on my '60 last summer out of necessity after having to remove and re-install one of the cylinder heads.

Prior to that the last time I adjusted them was...... well..... I really don't remember but sometime before Y2K.

Jim

Powershift

Frequent adjustments for a driver car are not required. Once every few years should be good.

Larry

climbabout

I'll ditto what Larry and others have said. Adjusted mine last year and still runs great.
Tim

Texaspilot180

I wasn't adjusting them to correct any sort of problem, more just checking and tweaking a little to make sure all was good and performance remained consistent. Never had to adjust all of them, sometimes only one and only just a little for better "feel" on that "feeler" gauge device. Could have probably just left them alone and kept driving but wanted to make sure things were staying as they should be as I tried to sort out a very slight low end miss. Car had other unrelated vibration problems which I eventually traced back to the engine and I recently had it rebuilt, a second time, as the first shop did a crap job on the internals and it was so out of balance that it vibrated badly. Then that project creep thing snagged me and I pulled the body off a month or so back, redid the frame, brake & fuel lines, etc. I'll start a thread with a few pics when I get a chance.

But anyway, if the OP finds them so loose his engine backfires there is something else going on, perhaps the one time use hardware problem as noted by others.

saopm

You might want to get a set of ARP Locking Nuts. They are the ones with the set screw in the middle. I found the standard nuts are stiff to turn and are difficult to get an accurate gap. The ARPs are loose until you sent the screw. I adjust mine hot and running, but you need the rocker clips so the oil does not shoot everywhere.

Larry Chilton

Hey, Texaspilot,

Is that crankshaft damper adapter you have for rotating the engine a "homemade" item or some tool that can be bought.

Thanks,

Larry

JohnZ

Probably looks like mine.

MikeM

If they are not stiff then they are past their service life.

Chuck Gongloff

Here's the method I've been using for many years. IMHO, this is the easiest way to do it.

I just did the solids on my 63 a few months ago. I hadn't touched them for 5-6 years, and they were still pretty close when I re-did them.

Rotate the motor until you have #1 cylinder at TDC on the compression stroke (both valves closed).

Adjust clearance on intake valves 1,2,5,7 and exhaust valves 1,3,4,8.

Then rotate the motor 1 revolution so you're on TDC on #6.

Then adjust intake valves 3,4,6,8 and exhaust valves 2,5,6,7.

I have an 097 Duntov cam, and it calls for .008I hot and .018E hot. I set them at .010I cold and .020E cold.

Powershift

Probably similar to ISKY Polylocks, which have been around since the early 1960's.

Larry

1966STER

Another very popular method of adjusting solid lifter valve lash is the EOIC method (exhaust open / intake closed).

This method is extremely simple providing it's done in conjunction with a remote "bump" starter switch which is available at Harbor freight for $11.00.

But I agree, you should DEFINITELY replace the adjusting nuts.

Note: there are a number of videos available on line that demonstrate this simple technique.

Good luck !

Frankie the Fink

EXACTLY how I do it; except I put the car in 4th gear with the parking brake off and push the front left tire by hand to get to TDC both times. I can set lash in about 20 minutes and without oil spraying around *****-nilly

I'm told this won't work well on a 30-30 cam but then I don't have one in either car...

MikeM

It doesn't. You just have to read the advanced course in how to do valve adjustment with one of those cams.

I put my 327/360 together about 8-9 years ago. I finally got around to changing the oil and adjusting the valves in it a few weeks ago.

Chuck Gongloff

I do the tire push too, Frank. I can align the mark to TDC on #1 and #6 easily that way.

Chuck

Texaspilot180

Yep - very similar. Got this one at Summit