[Gach]

Quick question, I know you said your initial timing is set at 18, so what is the total timing.

[slowbird]

Originally Posted by Gach

And when he did valve adjustment it went up to 175. So sounds like those valves was definitely hanging open for those cylinders he retested.

Sounds to me like the lifters bled down making the cam look small causing the cranking compression to go up. If he would have fired it up let it run for 5min then checked I bet it would've been 140-150 again.

[Gach]

Originally Posted by slowbird

Sounds to me like the lifters bled down making the cam look small causing the cranking compression to go up. If he would have fired it up let it run for 5min then checked I bet it would've been 140-150 again.

That makes sense

[Shockwave78]

Originally Posted by Gach

Quick question, I know you said your initial timing is set at 18, so what is the total timing.

I haven't checked yet, as we have already gotten a vulgar noise complaint, so that will be on the list for the weekend

[PunchT37]

Originally Posted by Shockwave78

I haven't checked yet, as we have already gotten a vulgar noise complaint, so that will be on the list for the weekend

Vulgar.


Reminds me of a Pantera album.

[slowbird]

Originally Posted by Gach

That makes sense

My posts usually do.

[Gach]

Originally Posted by Shockwave78

I haven't checked yet, as we have already gotten a vulgar noise complaint, so that will be on the list for the weekend

I hear you there, I usually call The neighbors hey I starting car today, some time I hear ok… others I get a click.

[Shockwave78]

Pulled the carb off and the intake walls and floor were covered in a gas film. This was with the mixture screws 2 turns out.

[Gach]

Going to definitely be interesting to see what the problem actually turns out to be.

[Dragncar]

Originally Posted by Shockwave78

I haven't checked yet, as we have already gotten a vulgar noise complaint, so that will be on the list for the weekend

I have never had a complaint, some even come out of their house and cheer when I laid rubber.
Hey, the guy might have been kinda a dirt bag, but at least I have a fan !

[steve25]

Sound like restricted Exh is the issue, or part of the issue.

[Jay S]

About all you can do is double check things now and make sure nothing was overlooked. Sounds like has a major issue if it won’t go over 60 when at WOT yet.

I have a 77 W72 with a lot of the original parts. The stock distributer has 20* of mechanical advance. The vacuum advance on them seems to vary some. My would put in 23*, they were suppose to add 25* at 16” . Your sounds like it barely will make 16” as it is.. My 400 was a 77 4 speed, it pumped pretty close to 150 lbs of compression bone stock, they had a small cam compared to the 60240, but all of the W72 engines ran the cams retard a bunch. Mine the ICL was 116, and at .006” tappet it had about 250* of. duration, the intake closing was 61* when I checked mine stock. Your’s with the 60240 should be 64*, not much difference. I would expect your pumping compression to be similar to stock, which it sounds like it is. Cam timing being off sounds like a long shot, but you may need to check it anyway, or check the pumping compression on all 8 cylinder.

The W72s ran R45S spark plugs from the factory, not 46’s like most of the 400 engines. Sometimes they get 46s install in them, I would run a 44 with the bigger cam. Not dropping the heat range of a plug is a pretty common mistake that people make when installing a bigger cam. If you want you can simply back of the timing and see if it runs better with less initial timing, if it does the engines is telling you it wants a colder plug. If it runs worse, keep looking, retracing your steps to see if you can find the issue.

I have had crazy issues in the past, various engine builds, the spark plugs (which I mentioned), have had hydraulic lifters that would not pump down, and had to be adjusted up against the plunger retainer to run. Another engine had several sticking lifters which would not self adjust, a couple plungers were stuck. One Crower cam the core had major shifting on the parting line when the core was poured. The lifters would drop several thousandths every time they went across that core line, it would have ran terrible if I didn’t catch that. I had another Crower that had 18* extra seat timing on the exhaust than what it was suppose to have. It would have ran ok, just had an extra rough idle, and a loss of bottom end power, I returned it. QC stinks these days, Chinese HEI’s that don’t have much dwell, faulty coils and rotor buttons, junk carb parts, never know when something causes trouble that you thought should be fine! Easy to get frustrated, most of the time it ends up being something simple though. Look at simple stuff, like ignition and fuel, before for you tear into the engine to look for a problem that isn’t there.

[steve25]

I have had a set of brand new spark plugs idle just fine and make normal power until about 2500 rpm and then the motor felt like it was down 75 hp!

Put the old ugly plugs back in and all was fine, re-installed the new ones and once again down the motor was down theb huge amount of power!

I did not check them before I tossed them, but I would bet that many if not all of those new plugs had extremely high resistance.

[Stan Weiss]

I know you have a vacuum gauge so lets go old school. These are taken from a book that was published about 60 year ago,

Stan

[Stan Weiss]

Here are the rest since I couldn't attach them all to one post

Stan

[Shockwave78]

Originally Posted by Stan Weiss

Here are the rest since I couldn't attach them all to one post

Stan

Out of all those, it is closest to late valve and late ignition timing. I am not sure which because I do not know what the vacuum should be with that cam. At idle the Vacuum I saw was 10" +/- .5". I disassembled the carb and the float was bent in the wrong way, so as the fuel level dropped, the needle never opened. With constant fuel pressure, I'm sure the needle was never seating. Everything else looked good so I reset the float and will be putting the carb back on today, if that doesn't fix the issue I will probably end up pulling the cam and reinstalling the stock one.

[Stan Weiss]

Originally Posted by Shockwave78

Out of all those, it is closest to late valve and late ignition timing. I am not sure which because I do not know what the vacuum should be with that cam. At idle the Vacuum I saw was 10" +/- .5". I disassembled the carb and the float was bent in the wrong way, so as the fuel level dropped, the needle never opened. With constant fuel pressure, I'm sure the needle was never seating. Everything else looked good so I reset the float and will be putting the carb back on today, if that doesn't fix the issue I will probably end up pulling the cam and reinstalling the stock one.

I am sure that a number of people here have different opinions able what may or may not be going on here. I don't know what the problem is. But JMO I think changing back the cam will not fix what is wrong.

Do you have a positive piston stop and a degree wheel? Is it possible that the timing mark on you dampener is not located correctly?

Stan

[Shockwave78]

Originally Posted by Stan Weiss

I am sure that a number of people here have different opinions able what may or may not be going on here. I don't know what the problem is. But JMO I think changing back the cam will fix what is wrong.

Do you have a positive piston stop and a degree wheel? Is it possible that the timing mark on you dampener is not located correctly?

Stan

Stan

I do not have a degree wheel, but I did rotate the #1 piston to tdc with a dowel down the plug hole and checked the mark on the balancer and it was dead on

[Stan Weiss]

Originally Posted by Shockwave78

I do not have a degree wheel, but I did rotate the #1 piston to tdc with a dowel down the plug hole and checked the mark on the balancer and it was dead on

The amount of piston movement around TDC is very small. You could be off 10 or so degrees and not see it checking that way.

Do you know the diameter of you dampener? If not can you measure the dampener's circumference? I could than make you a pdf of a timing tape.

Stan

[PunchT37]

Originally Posted by Shockwave78

Out of all those, it is closest to late valve and late ignition timing. I am not sure which because I do not know what the vacuum should be with that cam. At idle the Vacuum I saw was 10" +/- .5". I disassembled the carb and the float was bent in the wrong way, so as the fuel level dropped, the needle never opened. With constant fuel pressure, I'm sure the needle was never seating. Everything else looked good so I reset the float and will be putting the carb back on today, if that doesn't fix the issue I will probably end up pulling the cam and reinstalling the stock one.

Or, if no degree wheel, if I were to pull the cover again, I would use the 4 degree advance symbols and go from there. If you have a multiple key crank gear.