Chris, these were the studs that retain the cam box, so they were into the head. I think it was the nut that let go, but I replaced the stud as well. I had a few extra...

Thanks for clearing that up for me, the build looks excellent. Especially the hardware.

Welds?
 

Detroit,

I’d say your welds look better than mine do and I’m the father to a welder. I ask my son all the time and he says I have to pay for his time just like everyone else. I respond that he can pay for rent, boarding, gas, insurance etc… just like everyone else. Still hasn’t worked and think it’s his mom on the side thwarting me. :mad:

Okay... I've finally got this thing fully assembled. It's been wired and tested, etc., etc. I filled it with oil the other day, and with the plugs out spun it over to build some oil pressure. None.
Though sold to me as functioning, I wasn't dead certain my pressure gauge truly was, so I pulled the thermostat. Dry. After a bit of head scratching and review of the oil circuit in my shop manual, I came up with several potential causes. Then I gave Glenn Yee a ring. I didn't suspect his pump, but he rebuilt it for me. And, I figured he's probably seen or heard it all. He more or less ran through all the same possibilities. In no particular order, I've confirmed that the pump is spinning by viewing through the oil cooler (that's pretty convenient). The seals are all present after reviewing all of my assembly photographs. And, the pressure relief valves are installed in their proper locations, and move freely. Glenn mention the potential for one of the pump seals to be too short, and I've just been reading a thread where that prospect had been thrown around in another case. It sounds like Wayne has debunked that theory?... In any case, my build photos show that seal being quite proud of the pocket, and I think I'd have noticed any lack of compression during assembly.
That left the tank itself. I just removed that oil line from the tank, and sure enough there ain't no oil coming out of it. If I blow into that fitting, it sounds like a kazoo. I am unable to suck anything...
So... Does anyone out there have a picture of what one of these tanks looks like cut open. Mine is, in fact, a 914 tank, but I presume the 911 tank construction is fundamentally the same. I would have thought that the outlet fitting opened straight to the tank volume. Is there a pipe in there that might have collapsed?...
Many thanks!...

A google search didn't turn up anything for me.
It does sound like a plumbing problem. I've heard of people leaving a plug or rag in place on tanks, etc. It it possible someone stuffed a rag or something in there and it got pushed in? Maybe carefully probe with something flexible like a long tie wrap and see how far it goes in? It might tell you if the blockage is hard or soft too. If it's a soft blockage like a rag, a flexible/snake style grabber might be able to remove it.

Alright, another thought just occurred to me. I might just have been stupid enough to get the inlet and outlet on the tank mixed up. The shop manual suggests the fitting on the side of the tank is the feed to the pressure pump. That, of course, would make the other the line from the scavenge side of the pump. Do I have that right?...

On all the 911 and 914 tanks I have seen the fitting that goes to the oil cooler just opens into the bottom of the tank. There are some internal lines on the return that go to the oil filter housing and for the vent lines. If you search oil tank cut away you can find some pictures. Sounds like something is in the tank blocking the outlet.

john

Please, forgive my stupidity...
I had the lines backwards.
So embarrassing.

Haha I almost said that but didn't want to insult anyone :). Good it was a simple fix. Even better you didn't start the engine.

I've got oil pressure. Pushing 2 bar with the starter motor. Does that sound about right?
I didn't spin it for long, so I don't know if it would have built up anymore.

2 bar is more than I normally get with the starter motor, so it's plenty.

One question I just thought of. You mentioned the other fitting on the tank seemed plugged. Is it the one the from the scavenge line (or coming back from the external cooler, if you have one)? I wouldn't expect it to be plugged. It should lead to the oil filter and then dump into the tank. I'd expect resistance blowing/sucking, but it shouldn't feel plugged.

@stowenson914, I couldn't suck air from scavenge side fitting, but I didn't really try that hard. I didn't want a mouth full of oil. I could blow through it. As mentioned, it sounded a bit like some sickly woodwind instrument, but that makes sense as it was going through the filter...
And, thanks for the oil pressure confirmation.

Jesus... Apologies, @stownsen914

An update on this project is way overdue, but I was hoping to sort out a poor running issue before doing so. And, life keeps getting in the way...

Anyway, I need some help.
The engine is running, but it coughs and farts. I should mention that in addition to rebuilding the motor itself, I rebuilt the Webers. The process of which I found to be rather enjoyable. As a result, I picked up a couple of other sets of to restore while I was waiting for parts, etc. Back to the poor running, I stuck a timing light on it, and It looks pretty damned close Though it's tough to get a really accurate number as the engine doesn't want to idle. I was pretty confident that I assembled the motor correctly, so I then swapped carbs. My fuel pressure gauge reads 3.5 psi, incidentally. No difference in running with the second set. Nor the third set. The carbs that are on it now are NOS Weber 40 IDA's that I stumbled upon locally for cheap. Also no difference in running. I've pretty much ruled out fueling as the issue.

So.... I went back to the base engine build. Thinking maybe that I had a camshaft 180 degrees out, the first thing I did was pull off the upper rocker covers to check the cam timing. I know I only need to do cylinders one and four for this, but just to rule out any anomaly with the cams themselves, I checked overlap on every cylinder. These are DC40 cams, and the number John D gave me is 4.5mm lift at TDC. I started with cylinder one, and then went through the firing order.
Cylinder one at TDC: 4.5mm
120 degrees/cylinder six: 4.4mm
240 degrees/cylinder two: 4.4mm
360 degrees/cylinder four: 4.32mm
480 degrees/cylinder three: 4.36mm
600 degrees/cylinder five: 4.3mm
I might have a touch too much lash on a few of those, but I don't think so much as to cause the poor running.

I then pulled off the lower rocker covers to recheck the valve lash. All (intake and exhaust) are within my measurable spec.

Next I ran a leak down test:
Cyl 1: 3 percent
Cyl 2: 4 percent
Cyl 3: 2 percent
Cyl 4: 2 percent
Cyl 5: 2 percent
Cyl 6: 2 percent

My gauges aren't particularly high quality, so I'd put a few percent tolerance on all of those numbers.

From that data can all y'all spot anything I've done incorrectly? Or missed?
At this point, the only cause for the poor running I can think of is ignition. It's a 123 Distributor with their Big Fat Spark CDI unit. I installed it all per the destructions, but I've never worked with one before.

Many thanks in advance.

Lots of information missing to tell what might be wrong. Did you go thru all the steps to setup and balance the carbs?. Do you have the correct venturi and jets for the engine setup? good information here on tunning.

Performance Oriented

Your description of coughs and farts sounds lean.

i would install a wide band O2 sensor and verify that the mixture on both sides is good.

You can also use a temperature gun to check each exhaust and see if there is a big difference in temperature that might indicate a misfiring cylinder.
I don't know what 123 uses for trigger but with standard 3.0 distributor its possible to hook up the trigger wires backwards. The engine will run but the CD box will fire at the wrong times or twice.

john

Give us the time chart you set up for the 123 dizzy..

Eric: I had some problems with my 123 dizzy causing similar symptoms, especially in the 2000-3000 RPM range. Put a timing light on the engine and check that the timing advances smoothly and shows the advance the 123 App indicates on the gauges screen. Make sure the timing is steady at each RPM and does not jump around.

Please report what you find here.

Thanks for the replies, fellas. I will indeed report back. I'm currently waiting for some new rocker cover gaskets to show up, as mine tore upon removal. Once I get it put back together I'll get stuck back in.

Targa72E, I do have O2 sensors in the system, but I'm not going to try to recall exactly what they read while running. I only recently pulled it apart to take the above measurements, however, it's been some time since I actually ran the engine. I have not gone through the process of syncing the carbs yet. Frankly, it just wasn't running well enough to try. I am predicting that it's not the carbs based on a another set that I restored and sold on BaT. The guy who purchased them sent me a video of his first start. It fired up instantly, and ran really, really smoothly. The Webers on my motor have 36mm chokes with a brand new matching jet pack, the sizes of which were given to me by Henry Schmidt. Yesterday, was pretty hectic, so I didn't have a chance to dig them up, but I'll post the jet sizes when I get a chance.
Old H2S, same goes for the ignition curve.
PeteKz, thanks for that input. When I get the motor back up and running, I'll try to get a video of my start cart's dashboard. It has gauges for the O2 sensors, a phone mount so I can read the 123 info, etc.

@PeteKz, what was the issue with your 123? And, what did you do to fix the problem?

Duh... I forgot the dizzy curve is on my phone.

http://forums.pelicanparts.com/uploa...1741180663.jpg