Engine problem with 63 L84

[Monte M.]

Re: Engine problem with 63 L84

Duke,
I agree. Earlier in this thread I ask how it changed under a load and a few other situations, but your requests for particular information are much clearer and will give more information for a more correct analysis of the situation.

Some of what you ask is very difficult to determine if you have not delt with this situation before.

Mike, maybe you have someone close who can help you with some of Duke's questions if you are not comfortable determining all of the answers.

Once Again, Best of luck,
M

[Monte M.]

Re: Engine problem with 63 L84

Mike,

I have a few questions about the engine at the time this happened. If I am not mistaken you had the engine built stock. So, you have a dome piston of somewhere around 5cc? What gas were you running at the time.

Out here in California, as much as were would like to build our engines stock, we can only get gas in the 91 octane range. The engines out here that are built stock do not run very well without adding Nav gas or something similar. I myself took 5.2cc dome pistons and had them machined to a2cc dome. I then used a thicker gasket to drop the compression a little more. My heads were shaved so this brought my compression back up, but it is still lower than stock.

The reason I bring this up is, we all know what low octane gas does to these engines. Especially when we try to shult them off. Learning to use the clutch to slow the engine down just before turning the key helps, but then there is the bending your crank problem. I had a 69, 350/350 I shut off that way for ten years and never had a problem, but I never lent the car to anyone because of the issue.

Back to my original question. What gas were you running. I think JD hit it on the head when he used the term "hydraulic". What did the engine run like with the fuel you were running? How bad was it pinging. Was it shutting off on its own, or did you need to help it by using the clutch or any thing else.

This is not going to help solve your problem, but it might give a better idea of what might have happened.

Again, find out what rods are in the engine.

EDIT< EDIT< EDIT 91 Octane is what we can get out here, NOT 97. BIG DIFFERENCE
m

[Michael G.]

Re: Engine problem with 63 L84

Monte, the car had about 3/4 tank 90 octane, no-ethanol gasoline, mixed with 1/4 tank Sunoco 110 racing gas. It was running very well, as it has on any premium fuel since I insulated the whole fuel line earlier this year. I drove it a lot this Summer, many times on trips of 250 miles or more. It did not ping or run-on at all, no matter the temperature. That is what was surprising about this problem, the engine had been about as dependable as a new car, with no hint of any issues.I'll find out what rods are in it...Thanks,

[Monte M.]

Re: Engine problem with 63 L84

HUGE MISTAKE ON MY LAST POST>>>>>>>>>>>>>>>>

We get 91 octane out here on a good day. This makes quite a difference on how and engine runs. Quite often we are stuck with less.

[Duke W.]

Re: Engine problem with 63 L84

HUGE MISTAKE ON MY LAST POST>>>>>>>>>>>>>>>>

We get 91 octane out here on a good day. This makes quite a difference on how and engine runs. Quite often we are stuck with less.

What the hell are you talking about?

The highest PON available in California is 91, which is 96 RON, which is about what "discount premiums" were in the sixties. I've never run across a gas station in So Cal that didn't have 91 PON available.

Some areas of the country have 93 PON, and a few might still have 94 PON.

97???

In any event, I have not heard that any Southern Califronia Chapter members are experiencing detonation even on so-called 11:1 engines.

GM's advertised compression ratios in the sixties were about as realistic as their advertisesd horsepower ratings. As-built, typical "11:1 engines "are about 10.5 and the 327/300 is about 9.8, and with the OE spark advance maps they should all run detonation free on 91 PON fuel.

It is rare that we ever have a report here of a detonation problem, and when it does occur, it's usually a big block or an engine that has been modified in an inappropriate way.

Gasoline is not a big oil company conspiracy, and outside of octane, gasolines, today, are much higher quality than in the sixties.

And for yourCalifornians, the reason why gasoline prices have spiked is refinery problems. Despite our over-the-hill geezer senators asking for "federal investigations", the real problem is limited supply of California's unique gasoline blend due to refinery problems. It's always referred to as "cleaner burning", which is a myth - at least for any car with an oxygen sensor and three-way catalyst, which is just about every car build in the last 30 years.

There are only about half a dozen refineries that manufacture this unique and expensive blend, so if one or two refineries go down, there's a big supply crunch and prices spike. We can't bring in gasoline from Texas or Gulf Coast refineries. It doesn't meet Mary Nichols standards, which are a total croc...

Gasoline is about 348 on my list of the potential causes of the problem being discussed in this thread.

Duke

[Michael G.]

Re: Engine problem with 63 L84

Duke, I'd rather not tear into the engine until I'm very sure what I'm dealing with here. I'll try to get some of the answers regarding the noise/vibration tomorrow. Thanks ,

[Michael G.]

Re: Engine problem with 63 L84

Good news, I think. I put the push rods back in, reset the lash, and reassembled everything. The vibration and noise seem to have vanished. I can't imagine how, but maybe the backfire somehow affected one of the valve adjustments. One thing I've learned here is that the lash measurement with these roller- tipped rockers is inconsistent. You can set the lash, then rotate the roller and get a different gap. Not so good, I'm getting standard rockers today.We'll see if this lasts.Thanks, everyone

[Michael H.]

Re: Engine problem with 63 L84

Good news, I think. I put the push rods back in, reset the lash, and reassembled everything. The vibration and noise seem to have vanished. I can't imagine how, but maybe the backfire somehow affected one of the valve adjustments. One thing I've learned here is that the lash measurement with these roller- tipped rockers is inconsistent. You can set the lash, then rotate the roller and get a different gap. Not so good, I'm getting standard rockers today.We'll see if this lasts.Thanks, everyone

Great news !! And a good idea on the stamped rocker arms.

[Duke W.]

Re: Engine problem with 63 L84

I'm getting standard rockers today.We'll see if this lasts.Thanks, everyone

Congratulations of getting rid of those overhyped, overpriced abominations - the biggest piece of junk ever foisted on car guys by the aftermarket. Maybe your experience will help others see the light.

I hope you realize that current OE replacement rocker arms are of the later "slotted" design and will not work with mechnaical lifter cams.

So what rocker arms are you acquiring?

Duke

[Joe C.]

Re: Engine problem with 63 L84

Good news, I think. I put the push rods back in, reset the lash, and reassembled everything. The vibration and noise seem to have vanished. I can't imagine how, but maybe the backfire somehow affected one of the valve adjustments. One thing I've learned here is that the lash measurement with these roller- tipped rockers is inconsistent. You can set the lash, then rotate the roller and get a different gap. Not so good, I'm getting standard rockers today.We'll see if this lasts.Thanks, everyone

It's not the rotation of the roller that's affecting your reading; it's the rocker repositioning itself on it's ball pivot. Standard rockers will do the same thing. They have two degrees of freedom and rock on the pivot point. You're better off buying brand new rocker nuts (GM part still available) so as to ensure that there's no unwanted loosening. Even full roller trunnion rockers will give some variation depending on its position, but nowhere near as much as ball pivot rockers, whether roller tipped or not.

Roller TIPPED rockers don't do any good, but neither do they do any harm. Save your money. Be sure to set your lash by getting the engine up to full operating temp, then shut and let it cool for about 45 minutes before setting your lash to .008"/.018". If you want some extra idle vacuum for the Rochester unit, then set the intakes at .012" instead of .008".

[Michael G.]

Re: Engine problem with 63 L84

Duke, I haven't gone out to get the new one's yet, but I'm open to suggestions on source....

Joe, Actually, the rocker itself did not even move significantly between measurements. I slipped the gauge under the roller and out the backside, the roller turning as the feeler passed. I then tried again (the roller was now perhaps 120 degrees from where I started my first pass). The same gauge would not go in, no matter how much I tried. So I tried a .001 smaller gauge and it wound not go in either. Same with .002 smaller. This happen with several valves, both intake and exhaust. Either the pin the roller rides on is worn, or the roller surface is not concentric with its own center hole.

I don't know how much variation is acceptable, (I'm sure you're correct about stamped ones varying too) but this much variation means that sometimes I set the intake gap to .008 and actually got .006 when the tip roller turned.

Thanks,

[Edward J.]

Re: Engine problem with 63 L84

Congratulations of getting rid of those overhyped, overpriced abominations - the biggest piece of junk ever foisted on car guys by the aftermarket. Maybe your experience will help others see the light.

I hope you realize that current OE replacement rocker arms are of the later "slotted" design and will not work with mechnaical lifter cams.

So what rocker arms are you acquiring?

Duke

Duke saw your post on the O.E. rocker arms. what is the difference? will the after market work? (TRW, Perfect circle) Thanks Ed

[Clem Z.]

Re: Engine problem with 63 L84

roller rockers with poly locks need a stud with a machined flat top so the locking allen screw will bite into the stud.

[John D.]

Re: Engine problem with 63 L84

Qt for you engine guru's. One of Monte's comments on Mike's engine is the quality of the connecting rods. My question is would the strength of a connecting rod keep it from bending if it were up against a hydraulic lockup crisis?
My guess is that the worlds greatest connecting rod would still be trashed. But that is just a guess.
Your thoughts please. John

[Duke W.]

Re: Engine problem with 63 L84

A used set of matched rockers/balls that show no evidence of galling or other abnormal wear will work fine.

I think Crane makes a vintage OE type stamped rocker that will work with mechanical lifter cams.

Most OE replacement rockers have a slot on the valve end that fits over the end of the valve stem to act as a guide. I'm sure if you visualize this you will realize that these will not work with mechanical lifters.

My experience is that OE rockers show consistent valve clearance. Variation is usually due to base circle runnout. OE cams typically allow a total runout of .002", but most are much less.

The early connecting rods have a fatigue issue due to insufficient material in the vicinity of the bolt seat, and this is where they typically fail. They have plenty of strength in the beam area. Any connecting rod, no matter how strong, will bend from hydraulic lockup.

Duke