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1970 GTX breaking up after 2500 rpm. Failing cam?

So I just got off the phone with him He drove home and apparently the lifters/rockers got loud again on his way home. Then got quiet again. I told him the holes being covered probably forced more oil to the driver side head at a higher oil pressure and now that the holes were corrected on the passenger side it allowed that pressure to release through the shaft. And in doing so might have shown that the driver side is the same way. I will check and fix that one tomorrow.

The engine was built by this company CME in South Carolina. Hes going to call them tomorrow and bitch them out. Not sure what good thats going to do but here is their website. http://www.cmengines.com/
 
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When you had the valve covers off , with those heads , you could of easily checked the camshaft and lifters if needed


Now onto the 2500 RPM issue
 
When you had the valve covers off , with those heads , you could of easily checked the camshaft and lifters if needed


Now onto the 2500 RPM issue
I know but it got dark and I had to get it back together so he could drive home. So tomorrow I will pull the driver side valve cover and check from there. I guess pull a lifter out with a magnet and look at the cam lobe?
 
I also had found the fuel pump push rod badly worn out, causing the engine to stall when going for it.
It idled fine, drove fine, but as soon as you demand some power it just fell on its nose.
Replaced the push rod with a NOS one and all was good, i did check the lobe on the cam which was still in good shape...lucky!
Maybe check the lobe on that cam as well as it might have worn out badly as well.
 
I told him the holes being covered probably forced more oil to the driver side head at a higher oil pressure and now that the holes were corrected on the passenger side it allowed that pressure to release through the shaft.

The rockers on one head are oiled independently from the rockers on the other head.

Yes, you should check the other rockers.

Also note that there are two different downward facing shaft hole orientations, one is correct the other is incorrect.
 
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So what is the correct rocker shaft orientation? A diagram would be great.
 
Found some from the manual.

Schermafbeelding 2021-09-14 om 17.28.06.png Schermafbeelding 2021-09-14 om 17.28.22.png
 
UPDATE:

OK finally have a resolution to the problem. JJ went to Summit Racing and purchased a complete pickup with the board and wires.. Tore it down removed the roll pin and the bushing. Pushed the shaft out of the top. Removed the upper collar and removed the vacuum advance rod. Also removed a C-clip. Then I cut off the plug and resoldered and heat shrunk everything back. Replaced the distributor and got it all nice and neat. Also removed the driver side valve cover to check the shaft and it was on correct. So that was solved. Anyhow the car runs fantastic once again and everything is in order. The guy at summit already knew what part as soon as he said it was running like crap over 2000 rpms. They only had one in stock so JJ burned 45 minutes to drive down and get it. But it fixed the issue.
MSD Ignition ASY19970
msd-asy19970_xl.jpg
 
Great, so now MSD is crap too.
He bought the part but it was under warranty he will get a full refund. But yes its all China made now I believe. I also believe it might have been something he did. He had the grey tach wire hooked up to power his automatic choke. So I can not blame MSD for this. I believe he thought he was doing it correct. It was not. lol
 
So I just got off the phone with him He drove home and apparently the lifters/rockers got loud again on his way home. Then got quiet again. I told him the holes being covered probably forced more oil to the driver side head at a higher oil pressure and now that the holes were corrected on the passenger side it allowed that pressure to release through the shaft. And in doing so might have shown that the driver side is the same way. I will check and fix that one tomorrow.

The engine was built by this company CME in South Carolina. Hes going to call them tomorrow and bitch them out. Not sure what good thats going to do but here is their website. http://www.cmengines.com/
Wonder if the oil pressure dropped when this happened? I recently had an issue with my oil pump having a sticking relief valve. Wasn’t all the time, but intermittently. Tore the pump apart and found a small burr on the casting, just enough to catch the slider portion of the relief valve.
 
Wonder if the oil pressure dropped when this happened? I recently had an issue with my oil pump having a sticking relief valve. Wasn’t all the time, but intermittently. Tore the pump apart and found a small burr on the casting, just enough to catch the slider portion of the relief valve.
WHen he first got the car it ran 80 psi he changed gauges and it still read 80 psi. Once I found that shaft like that and fixed the issue its now running at 50 psi from what he told me.
 
The rocker shafts do not have a continues/direct oil supply anyway, it should not affect oil pressure that much.
Maybe he did not mention hot or cold pressure?
Hard to believe he lost 30psi by installing the rocker shaft correctly, if any difference at all he should have gained, lol.

Aye, but it's still not a good sign that the summit rep knew what the problem was right away.

Seems like this electronic board is standard for most (if not all) their models of the RTR dizzy, so including Ford, Chevy, Oldsmoblie, etc.
Probably the most common part to fail as well as the rest of these distributers are rock solid.

I think 80-90% of stuff going through our hands is made in China now days, bear in mind they manufacture a lot under license and not everything is crap.
Most people get pissed off with Chinese stuff that lets them down, but ask yourself..... "how much did you pay for it"?
You get what you pay for!
 
The rocker shafts do not have a continues/direct oil supply anyway, it should not affect oil pressure that much.
Maybe he did not mention hot or cold pressure?
Hard to believe he lost 30psi by installing the rocker shaft correctly, if any difference at all he should have gained, lol.
Yea again not sure if this is the case. These rocker shafts get their oil from the number 4 cam bearing. I dont see how you say they don't get constant pressure? If the number 4 cam bearing was worn it would not. But If you look at a map of the oil passages in a big block they do get pressurized oil. I'm just spit balling here.

440-engine-oiling-diagram-jpg.jpg
 
The oil passage flow is depending on the camshaft position, once the holes line up there will be a short boost of oil allowed to flow to the rocker shaft and therefore will not have a constant oil pressure as the rest of the engine.
If it had a direct line of the pressurized oil gallery i would class that as constant.
If it had a direct line feeding the rocker shaft it would barely had any oil pressure with a rocker shaft installed incorrect with the holes facing up as that are 8 open holes for the oil pressure to drop.
 
Most people get pissed off with Chinese stuff that lets them down, but ask yourself..... "how much did you pay for it"?
You get what you pay for!

And if it wasnt made in China, it probably would not get made at all.
 
The oil passage flow is depending on the camshaft position, once the holes line up there will be a short boost of oil allowed to flow to the rocker shaft and therefore will not have a constant oil pressure as the rest of the engine.
If it had a direct line of the pressurized oil gallery i would class that as constant.
If it had a direct line feeding the rocker shaft it would barely had any oil pressure with a rocker shaft installed incorrect with the holes facing up as that are 8 open holes for the oil pressure to drop.
That makes sense.. So since the cam is turning its more of a pulse flow. :)
 
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