Gas comes from 2 different areas 38 miles apart.  Not ruling out but...

It does seem to resemble the reason I built this engine in the first place.  Some may remember that the car came with a 305 from PO that had a cam take a dump.  This engine has less than 2k miles on it, but I'm not ruling anything out. 

I'll compression test when we get back.  I have a shim (paper) that went under the distributor stem when installed. 

The problem is, I have been sorting out so many problems, most due to the screwy intake that came from the builder, that I don't know where we are.

Guys, after the compression test, assuming it is a valve or cam, what's next.  If the cam, I assume I have to get lifters to match, but do I have to have anything else?  Springs?  Valves?

If it is a valve, do I need do anything for that head other than replace that valve/spring/clip?  Just trying to think ahead.  What about push tubes?

The heads are the old non-Mexican 993 (last three numbers) heads.  The intake is from an L-82 (aluminum). 

Thanks for all the help so far.  I'll check back in and try to get the compression test done tomorrow.

did this problem start after youinstalled the new MSD Streetfire  distributor? Was the dielectric placed under the electronic control module in the distributer?

Bob;

The MSD was, for a short time, installed in the previous engine.  I did use the dielectric grease under the module.  The guy I bought it from was adamant about using it.

Popping out the exhaust means the exhaust valve is open when there is combustion. This can be for any one of several reasons,
1) Ign. Timing is way off
2) Cam timing is off
3) Exh Valve is "sticking" open(or adjusted too tight)
4) Valve/seat has burnt spot on the face
5) Ign. spark is "jumping", either inside the dist cap, or across the plug wires

Scenarios 1 & 2 would effect both sides of the engine, not just the driver side. The others could be isolated to one side only.
Since you did just replace the intake, it's possible the gasket slipped out of place, but...that wouldn't create a back-fire in the exhaust.
You never said if the engine was running rough or not...just popping, and then "bogging down the motor(engine)".
A bad valve, if that is the issue, will cause it to run rough/miss, and they do seem to get worse with temp.
An ign miss/cross-fire may or may not cause a rough idle, depending on the severity, but it can also get worse with temp.
I'd have to check all of the plugging wires first, then go for a comp. test. You might want to "ohm" out all of the plugging wires, just to make sure they are all within the same reading.
I have seen ignition spark "jump" from a plug wire to vacuum(rubber) lines...so don't rule that out.

http://www.c3vr.com/member_uploads/8201_8300/8263/#7.JPG

http://www.c3vr.com/member_uploads/8201_8300/8263/2%20&%203.JPG

Here are two pix of the plugs.  The first is from #7, the second are #4 in back and #3 in front.

The following were the results of the compression test:
1 - 115
3 - 116
5 - 115
7 - 110

2 - 115
4 - 119
6 - 115
8 - 120

Looks like the drivers side head was the better build but about 4% +/- difference.  Hopefully this means this isn't the cam. 

With the new plugs over 38 miles, it seems to be running better

Ok, time to fess up.  When we changed to the L-82 intake to stop the oil leakage into the valves, we forgot to change the plugs as we had just changed the plugs along with wires at Bowling Green.

I will put about 200 miles on this week, then if all is well, I'll try for about 400 this weekend, then pull plugs week after next.  If ok, then she goes to Ardmore, if not, I will try to find something else that could be the problem.

Thoughts?
dnv2008-01-27 19:33:24

I give up... the second pic works, but the first pic won't and I used the same convention    

Any ideas?

Dennis, delete the #7 pic, rename it WITHOUT the "#" symbol, and reload it...you can't use symbols in the pic/file names.

Soooooo...looks like you have some really bad plugs....#3 looks completely fouled with build-up/deposits. Looks like bad fuel to me on that... just going by the fuzzy pic...
#4 plug looks perfectly normal.
Compression looks otay, too.
So, are ya saying ya put some new sparkle plugs in, and it runs fine now...so far?

http://www.c3vr.com/member_uploads/8201_8300/8263/7.JPG

You just thought #3 looked bad...  Check out #7.

So far, so good.  I'll have her out again tomorrow nite for a little 100mile round trip cruise (fergot sum stuff from 71Sharks vehicle we took up to Eureka and need to stop by to get it).

So, what do the compression numbers really tell me, other than that they are well within the 10% difference danger zone of a cam going down?  Is there a way to do the math to figure out either the Compression Ratio or some hint at supposed horsepower?  Only dyno around here is $100/run, minimum $500, so that ain't likely to happen too soon.

BTW, we still don't have a clue about Tim's car.

Should I put in some HEET gas dryer, or Octane Boost or any other of that hocus pocus stuff to fix the fuel problem?  It is fresh from the pump and as I put in almost 21 gals, there were only a couple left in there and they were only a couple of weeks old.

So..what did the other two(#1 & 5) on that side look like?
That is cumulative deposits...they have been building for a while. #7 looks like you may have an alien hiding out in that cylinder!
It appears that the plugs may have had the dry deposits on them when you swapped the intake. It could be, that the intake is leaking at the bottoms of the ports, and sucking oil up into the cylinder, causing the wet look on #7, or some other liquid has wetted it...maybe just wet fuel, since it hasn't been firing too well. I'd venture a bet on that. Those deposits look like bad fuel, plain and simple. It doesn't explain why the other plugs are not deposited, tho. Would those cylinders be the same ones you were burning plug wires on? Hmmm?


btw..the comp #s look otay, as far as all of them being close. 120 ain't bad for a low comp engine to start with. Compression tests depend on having a good, hot battery, throttle wide open, all plugs out, and the same number of spins on each cyl test, to be accurate. I think what your's shows is decent engine health, compression-wise. There are ways to measure the comp ratio without removing the heads, but they are not exactly 100% accurate.Adams' Apple2008-01-27 22:18:15

That looks alot like what you had when we were at NCM. Is it the same plugs as then, I can't remeber. Are you still using oil?