This engine is driving me crazy!!

[1980RS]

Did you make sure you really have 4-7 swapped? not trying to be mean or anything but my NHRA stocker friend did that at the track as he forgot about it. Car only ran 11.40's and they scratched their heads for a while, then realized that the 4-7 were not swapped. Car ran 10.70 after swapping the two wires. It happens.

[FC-Pilot]

I keep a couple sets of cheap copper core plugs around as I have had multiple dead plugs in a set before. I have also seen a long time boat racer put his plugs on counter clockwise instead of clockwise. I also keep a cheap set of plug wires around as a sanity check as well. I have screwed up a bunch of stuff before in my
Life so I can’t list all the Things I have done so start thinking outside the box and you will find it.

[rebelrouser]

Can't tell you why you're missing cylinders on the scope pattern but the high firing line is indicating several possibilities. One would be a high resistance, in this case since it's affecting all cylinders possibly a bad coil wire or an issue with the contact in the cap. Another is a large gap, for ex, the incorrect length of rotor which would give you a large gap between the rotor tip and the cap. It also could be caused by a lean mixture or perhaps a combination of these things. The spark line also indicates a lean mixture.

The high multiple firing lines are common MSD ignition patterns. Not sure what KV I had the scope set on. The KV setting will change thelength of the patterns. The main thing is I have 8 active fairly equal patterns, which tells me the box is firing the cylinders.

[rebelrouser]

Did you make sure you really have 4-7 swapped? not trying to be mean or anything but my NHRA stocker friend did that at the track as he forgot about it. Car only ran 11.40's and they scratched their heads for a while, then realized that the 4-7 were not swapped. Car ran 10.70 after swapping the two wires. It happens.

Yes I have run into the 47 swap issue. One time the cam card said it was a 47 swap, engine was a little sour, but it was not a 47 swap the cam company made a mistake in the grind they put in the box.

[roadrunner]

Is there any chance that the he is using sewing machine oil in the engine, which could allow the lifters to bleed down too much? 2 flat lobes on the previous cam hint at light weight oil as a possibility. The only other thing I can think of is maybe check the distributor shaft end play for too much wear.

[Tom68]

I’d put a single carb intake on it with a “known good” carb before I pulled the cam out.

Did you check the duration @.006 on the cam?

Yer, may need some basics thrown at it.

s-l500 (1).jpg

[rebelrouser]

Is there any chance that the he is using sewing machine oil in the engine, which could allow the lifters to bleed down too much? 2 flat lobes on the previous cam hint at light weight oil as a possibility. The only other thing I can think of is maybe check the distributor shaft end play for too much wear.

No it is on my dyno VR1 10w 30 racing oil, I even loosened the valve adjustment thinking the lifters were pumping up and holding the valves open.

[BobbyB]

Any news?

[Schurkey]

The main thing is I have 8 active fairly equal patterns, which tells me the box is firing the cylinders.

LOOK AGAIN. You DO NOT have "fairly equal patterns".

Second from the right is a mess.



(Better photo(s) would be helpful.)

[rebelrouser]

Any news?

I ordered a different camshaft will let everybody know after I get it installed.

[rebelrouser]

I think it is important that if you post a problem or question, you provide the results of how that worked out for the project. So you guys can laugh at me or with me, but the issue was it had oval port heads and a square port intake and the intake gaskets did not seal at the top of the ports for the intake. I knew it had a square port intake, and I used an aftermarket intake gasket that I thought would seal, but it only sealed on two ports, the ones that had the normal exhaust temps. Funny I thought it would have made enough noise at the leak that, I could have heard it, but it did not. The engine turned out well it made 546 ft lbs @ 4,250 and 511 HP @ 5500 The owner wanted peak torque at 4,500 to match his impeller on the boat, and it idles good at 800rpm so he can load on the trailer easy, so it worked out well.

[skinny z]

I think it is important that if you post a problem or question, you provide the results of how that worked out for the project.

Absolutely.
And happy to hear of a resolution.

[FC-Pilot]

Glad to hear the issue was found. It just gives us all another place to look when our stuff has issues. Thanks for the report.

Paul

[mag2555]

Good to hear it was resolved and that’s all that matters.

[PRH]

So, what was the actual solution....... different gaskets?