Engine problem with 63 L84

[Monte M.]

Re: Engine problem with 63 L84

Mike,

Onemore quick suggestion. Is you ignition shielding off. When you get a strong short off of a spark plug wire, it can sound very much like a tap or small knock. I know this is a reach, butit is very easy to look at.
The location of the knock is really interesting. Maybe thereis a bad push rod down that bank a little further.

Let us know how things turn out when you get a chance to look at it.

M

[Clem Z.]

Re: Engine problem with 63 L84

a rod knock with be at engine speed and valve train noise will be a 1/2 engine speed. run a compression test to make sure you did hydraulic a rod on start up

[Michael G.]

Re: Engine problem with 63 L84

Thanks guys. All the suggestions are greatly appreciated. I'll be able to start testing tomorrow, late afternoon. I'll do a drop test first, then, if I identify a cylinder, I'll look at spark and compression, before I take things apart again. I'll post results as I get them.

[Paul J.]

Re: Engine problem with 63 L84

...Start the engine and get a pair of insolated pilers and pull each wire off one at a time to see if any cylinder makes a significant change....

Monte

Monte, I love your old school ways. You can also tell if a cylinder is not firing by dripping cool water on the exhaust manifold at each port ( the one not firing won't steam), or get high tech and point an IR gun at it.

Paul

[Michael G.]

Re: Engine problem with 63 L84

Test results so far:

Drop test: Removing and grounding the # 1 wire does not seem to make a difference in the way the engine runs.

Exhaust Manifold Gun Temperature: Temperature of manifold near #1 warms up slower and does not get as hot as all others

Distributor output: all wires firing regularly

Wires: All wires have good resistance. #1 works well with timing light

Compression #1: 162 , #2: 165, #3:155, #4:180, #5: 168, #6:172, #7: 151, #8: 160

Plug inspection: Plugs 2-6 & 8 look great. Plug 7 has some carbon. Plug # 1 is a bit wet.



I'd guess that I fouled #1 plug when the wire came off. I'll change the plugs and see what happens.

Thanks,

[Tim S.]

Re: Engine problem with 63 L84

Michael,

What ever came of your intake manifold discussion? I know you have been fighting this car.

Tim

[Michael G.]

Re: Engine problem with 63 L84

Hi Tim, actually, since I got a few issues resulting from the engine rebuild out of the way (back in 2009), this car's been running like a top. (except for this weeK) I'm not sure what intake issue your speaking of, maybe the 63 L84 prototype intake I had for a while? If so, that part's now on the first salable 63 car (#3.)

In any case, I changed the plugs and it now seems to be running well, but the noise didn't go away. Something else must've been damaged by the backfire, but I can't image what... I'm mystified. I'm going to get out the stethoscope and see if I can pinpoint the source of the sound. Wish me luck...

Thanks,

[William C.]

Re: Engine problem with 63 L84

I'm with the "bent rod" contingent sorry to say. Been away for a week and didn't really expect to see this discussion active... Bent rod is from experience...

[Monte M.]

Re: Engine problem with 63 L84

Mike,

What kind of rods did you use. This exact reason is why everybody suggests to NEVER use stock rods. I do not know if you did or not, but if they are stock, yes, bent rod sounds correct.
I hope I am wrong in even suggesting you used stock rods.

Best of luck,
M

[Michael G.]

Re: Engine problem with 63 L84

Monte, I don't know what rods were used, I didn't do the rebuild. I'm beginning to wish I had.

Wouldn't a bent rod affect the compression readings?

[Monte M.]

Re: Engine problem with 63 L84

No,
In many cases is does not, but in a lot of cases you loose just a little. Really bad cases, yes, it affects the compression reading quite a bit. That being said, if it did not break any rings when it happened, the piston will still ride up and down in the bore just like nothing happened.
Take all the plugs out. Use the starter to turn the engine over. See if you can still hear the knock. It might be a little hard to hear, but it is worth a shot. There is a chance you may not be able to hear it just because it is not under a load. This is the next thing I would try.

Befrore doing anything else, find out which rods were used. Make sure they did not use stock. I am sure they did not. That is usually the first change made to these engines. Plus, it is a very cheap to replace them.

Again, best of luck,
M

[Tim S.]

Re: Engine problem with 63 L84

I'm with the "bent rod" contingent sorry to say. Been away for a week and didn't really expect to see this discussion active... Bent rod is from experience...

x2 on both counts

[John D.]

Re: Engine problem with 63 L84

Michael, I am just starting to get caught up after the Fall Carlisle show this past week. Sorry to hear about your engine problems.
As soon as I read your post I immediately thought of hydraulic lockup aka bent rod, etc. Then I read all the posts and see others agree.
The puzzling thing is your said you have a shut off solenoid on your unit.
So you have several things going on with the FI unit. #1. The anti-siphon valve in the fuel meter must be stuck in the open position. Or the anti-siphon valve is wore out and not holding. #2. You have an issue with the check valve in the spider not holding. #3. The installation of the shut off solenoid is incorrect or the solenoid is not working.
But at least you did not blow the engine.
Take the FI unit off and do a flow test with it. Then fill up the fuel bowl with gas and let it set a day or so with paper towels under the 4 corners/nozzle blocks.
If the nozzles are dripping the FI unit has issues. John

[Michael G.]

Re: Engine problem with 63 L84

Thanks Guys.

Monte, it'll take a week for the lacerations on my hands to recover from taking those plugs out once, I don't know if I've got another plug change in me.

John, I'll check the unit for leaks before I put it back on, thanks.

Because the noise seems closer to #5 than #1, and #5 was the cylinder with the bent push rod last time, I thought I'd take out the push rods and check them, just in case. All of them are fine. I'm now also thinking you guys are correct about the bent rod.

Looks like it may be time to pull the engine. Yeachhhhh.

Thanks,

[Duke W.]

Re: Engine problem with 63 L84

Before you press ahead with tearing the engine apart, I suggest you give us a more definitive analysis of the noise and vibration.

Using the noise at idle as a baseline how does if vary with increasing engine revs at no load - intensity and frequency?

Same as above only under load. At a given RPM does anything change with increasing load.

How about the vibration. Is the frequency equal to engine RPM or something else - like half or double engine RPM.

Place you fingers at various points of the engine and try to determine if the engine is vibrating up and down? Sideways? Or is it rocking about some axis?

Everyone seems ready to analyze your situation, but we have precious little information to go on.

Duke