69_340_GTS
Well-Known Member
Oh, it's moving. If you could check the piston with a dial indicator you'd see it.
Only runs 40 Degrees advanced
- Thread starter mr65cuda
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Yeah I thought about that also the distributor is still turning and compression test was pretty good so it doesn’t seem like if the cam was broke that the compression would still be good. It’s a stock rebuild 30 over I had the crank balanced probably 9 to 1 and it has 155 pounds on all the cylinders but one and it had 160 and that wasn’t your regular warm test
MobileCustoms
Well-Known Member
I'll bet that "loud clunk clunk clunk" from your first post was the noise it made when your timing chain jumped a tooth.
I think you really need to use an actual piston stop in the spark plug hole to precisely verify your true top dead center.
I think you really need to use an actual piston stop in the spark plug hole to precisely verify your true top dead center.
Now why in the world would he want to do something like THAT? Are you crazy?
yellow rose
Overnight Sensation
Or, he can pull the valve cover and VERIFY that the cam is timed at least half assed close before he wastes any more time.
It's actually even more simple than finding TDC.
Unless one valve is open way further than the other, the timing chain is on half assed close.
Again, another thread about th TWO MOST IMPORTANT things when building an engine.
Verifying TDC and degreeing the cam. Neither one is hard, but I'm betting 95% of engines assembled neither one is done.
That's why a GOOD shop that does compete assembly charges 1000 and up for assembly. The engine goes together 3-4 or more times before final assembly.
It's actually even more simple than finding TDC.
Unless one valve is open way further than the other, the timing chain is on half assed close.
Again, another thread about th TWO MOST IMPORTANT things when building an engine.
Verifying TDC and degreeing the cam. Neither one is hard, but I'm betting 95% of engines assembled neither one is done.
That's why a GOOD shop that does compete assembly charges 1000 and up for assembly. The engine goes together 3-4 or more times before final assembly.
The clunk clunk noise was when I tried to start it after I had dropped the piece in the distributor and I didn’t know it was locked up. So when I hit the starter the Distributor shaft twisted. That made it like a screw so it just unthreaded it self out of the slot in the intermediate shaft meaning it pushed up against the clamp and then slammed it self back down when the slot came around again. The top of the intermediate shaft slot was kind of eat up from it pushing it self out and then slam it self back down. That was the clunk clunk. Now I thought maybe it jumped the timing chain too after I replaced the distributor and got it timed again. And I don’t think Degreeing the cam has anything to do with it at this point the Cam ran fine for the last four years and I just did 800 miles that day. Now if I was putting in a new cam that would be good insurance to make sure it’s in right.
I put it on TDC and both valves on number one are shut and the rocker will slide back-and-forth Stock rocker arms Huges pump up lifters with adjustable pushrods Whiplash Cam
So I am about Done with this. I’ve exhausted every possible thing I could think of. I’m thinking now whether to make a 408 out of it or go shopping for a G3 hemi. It ran great I was really happy with it. but it’s no good to me like this.
MobileCustoms
Well-Known Member
So, when you had it at TDC and both valves were closed, did you also check to see where the rotor was pointing to in the dist. cap at that point and position?
I have the distributor out but the slot is pointing to where I put it Which is per manual pointing at the first bolt in the intake manifold
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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That is called the one spark test and proves everything ignition wise is working.
So what happens when the new 408 or Hemi break down?
B'cuda
Well-Known Member
Damn, Rusty got me on that one!
Op, I know I read somewhere that you changed the intermediate shaft and gear, did it have a hardened tip one before?
I would swap the cam, lifters, get rid of the adjustable push rods, use whatever you have lying around,
If your gonna yank it as junk you don't have anything to lose. I'd check the oil pump drive too.
Whatever you decide, good luck, that's a nice little ride to be down in pain.
Op, I know I read somewhere that you changed the intermediate shaft and gear, did it have a hardened tip one before?
I would swap the cam, lifters, get rid of the adjustable push rods, use whatever you have lying around,
If your gonna yank it as junk you don't have anything to lose. I'd check the oil pump drive too.
Whatever you decide, good luck, that's a nice little ride to be down in pain.
You have a point I guess I should figure out what it is and not just give up
Try a known good distributor?
Reluctor on upside down?
Rotor has correct alignment to reluctor? Dont know how to check, but someone should know.
Could something in the efi be causing a delay in the spark?
The efi needs a signal as well,maybe its the part that needs the 40 degrees.
Reluctor on upside down?
Rotor has correct alignment to reluctor? Dont know how to check, but someone should know.
Could something in the efi be causing a delay in the spark?
The efi needs a signal as well,maybe its the part that needs the 40 degrees.
No it did not have a harden tip I don’t have any old cams laying around but I could buy a cheap one and put in.Because the block is good I drove it 800 miles that day didn’t burn a drop Oil. I had it balanced when I rebuild it. I ported the heads myself and put big valves in it. It was running real good. The intermediate shaft is the oil drive. And that wasn’t hurt except cosmetically where the distributor shaft jumped in and out of the slot. When it does start it sounds real good and starts real fast. As long as the timing is Jacked way up.
Two new hyper spark distributors and a MSD pro billet all acted the same way. This sniper is not controlling timing anymore it gets a speed signal from the CD box so. The distributor and the CD (6AL) box control the timing completely
Thinking the cd may be giving bad info...
dicksmidlac
Well-Known Member
Was just gonna ask if you tried another msd box?
B'cuda
Well-Known Member
You say with the timing up to 38-40 it runs real good. Ok, does it make power? Idle in gear? In other words if the 38-40 is just a reference and not a specific number is it good? And you did change or removed and inspected the intermediate shaft and gear teeth?
Maybe a given, but did you rotate the chain and sprockets more than once and check the alignment of the dots each time?
Maybe a given, but did you rotate the chain and sprockets more than once and check the alignment of the dots each time?
Would you happen to have a good points distributor and ballast resistor around? Sometimes it helps (well, me anyway) if it can be dumbed down to lowest common denominator. Take the variables out of the equation of bad ignition box/reluctor/pickup. I would probably do that first and if that didn’t work,try degreeing the cam like it was a new installation. Use the piston stop, degree wheel, dial indicator, the whole nine like it was a fresh build. Check number eight after setting number one. Make sure there isn’t an inadequate heat treatment in the camshaft between lobes that could have caused it to twist. Check TDC on multiple cylinders to make sure it didn’t bend the crank in a misfire. Sometimes, Chinese parts sneak into brand name boxes. You are doing investigative work, using a known technique to confirm that TDC and cam timing is consistent and correct is crucial. Hopefully, it is just an ignition box.
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Even still, unless TDC is verified 100%.......100% not 99%, you don't know "where you are". This is the first thing that should have been done and you need to do it. A piston stop is not difficult to use. I'm not trying to be a smartass about any of this. Only trying to help you.
So msd feeds coil and fuel control. Its what hasnt been ruled out.
I have seen gm hei throw timing way out.
I have seen gm hei throw timing way out.
Have not tried another box but this box seems to work perfect when you first turn it on it flashes three or four times that is supposed to be a self check and then when you spin the distributor in your hand you can see the LED flash meaning the box is getting triggered and it puts out a great spark.
You have to remember that this all started after the distributor got jammed so I don’t think it would affect the electronics it Has to be something mechanical but when I checked everything appears to still be lined up top dead center on the timing cover and balancer Still agree piston looks to be at top dead center also. When I took the timing cover off the cam is still dot to dot like I put it in five years ago. I tried two different hyper spark distributors hooked up with timing control same issue I unhooked timing control and set up a MSD pro billet with weights to let it control timing but still have the same issue. So something gave when the distributor got locked up and I hit the starter and it cranked over making the Clunk Clock noise but never fired somehow that caused all this because it has not run right sense. Now when I do get it running at 35 or 40° it sounds good but if you drop it in gear it will die immediately. It will rev up and sounds OK but again that’s with no load And the distributor bumped the timing up to 50 or 60° But the motor doesn’t care because it’s just been reved up and coming back down with no load. I had the intake off looked at the lobes looked at the cam gear it looked fine. I had the head off looked at number one piston on top dead center looked right at the top of the deck couldn’t be no more than a few thousands off if it is. I change the intermediate shaft just because the slot look messed up some. the gear was just fine. The other end of the Cam the timing set all look just fine Could there be a Soft spot in the Cam maybe but it seems like it would have failed before now.
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