Hot front head

Northman
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Re: Hot front head

#16

Post by Northman »

Don't forget, you may have to adjust your timer. The idea is to get the plug to fire AT full advance.
Hope this helps...
awander
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Re: Hot front head

#17

Post by awander »

The way you are describing your difficulty in turning the engine over, makes me think there is something wrong.

I can easily kick my '52 FL, and even turn it over by hand if I push hard.
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Re: Hot front head

#18

Post by chadu607 »

I went over the Panhead yesterday with the first few free hours I had all week. I found the timing was ok so I just fine tuned it using the timing mark in the center of the hole and adjusting the timer with a light. This brings the spark much closer to the timing mark on the cam than before.

I have a leak down tester and used that to pressurize the cylinders one at a time. with the front valves closed I was still able to hear air in the exhaust. I had to shorten the front exhaust pushrod almost 3 full turns to get it to seal. BTW... I found this to be the source of my "knocking" problem I have had all summer.. Overall my rear valves are adjusted to 1.5 turns from bottom (hydraulic lifters). The front intake is at about 2 turns and the front exhaust now at almost 4 full turns from bottom!.. BUT I get much better compression.

With these adjustments the bike started up much easier and ran a little smoother.. However in the process I noticed that I was not getting that nice stream of gas from the acc pump nipple but getting either nothing or just a little spurt. I pulled the accelerator pump and found that the leather had folded back on itself and was allowing gas back up through the plunger and out the boot. New "genuine" rebuilt kit on order for that.. so in about a week I should be able to fire it up again and complete the "tuning".
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Re: Hot front head

#19

Post by Bigincher »

chadu607 wrote: Sun Oct 29, 2017 3:05 pm I went over the Panhead yesterday with the first few free hours I had all week.
A lot of times, problems are a combination of several different little issue that add up.
Glad you're getting it sorted, and now you see why we always seem to be fussing around on these bikes.
For a fine-running machine, everything has to be right.
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Re: Hot front head

#20

Post by chadu607 »

As is normally the case, the moment after I reach out for help I find the answer on my own. Probably good in this case that NJ has taken 3 weeks so far and I still didn't get my renewed registration. So while waiting for the paperwork I decided to go over it again. I had reached out to another local guy who was willing to come take a look but wanted to ride it on the road.. in my town the cop would absolutely impound it for expired registration... I have seen it happen!

http://www.60panhead.com/2017-11-05-2-Panhead-Noise.mp4

1. Moved the jugs closer together and installed the intake manifold adjusting the heads for tightest fit. My bubble tester came in handy here.. no bubbles means no leak!
2. Installed the felts in the heads. I put two in each head to make it much quieter in there. That "ring" I would hear was the harmonics inside the pan covers bouncing around. I got this idea from watching about 16 hours of Tatro Machine videos on YouTube.
3. Re-installed the push rods and hydraulic lifters dry and adjusted for 1.5 turns from bottom.
4. Sealed up the rear exhaust leak using a tin can wrapped around the port.
5. Replaced the fauty acceleration pump.

my valve knock is gone now.. been chasing that all summer. AND without having to change the adjustment on that rod.. Also the heads are MUCH cooler now.. before that front head would heat up very fast and very hot. Now even after idling a few minutes I can put my hands on the heads without burning them. It also starts up MUCH easier now. Just a few kicks.

Its a shame it's so late in the season and hopefully i'll get my paperwork this week so I can take it out on the road. I put a total of about 40 miles on it all summer.. Next year will be different.
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Re: Hot front head

#21

Post by Mark44 »

chadu607 wrote: Sun Oct 22, 2017 10:33 pm I put the pressure at about 15lbs and sprayed the clamps with soapy water and listened for any bubbles.
Something you might already know -- you don't need to listen for the bubbles. With the soapy water mixture, any bubbles can be seen very easily.

Anyway, it sounds like you got things sorted out on your own. It's always a good feeling to figure out what's not working right, and correct the problem!
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Re: Hot front head

#22

Post by chadu607 »

thanks Mark44
the first time I used the bubble tester I had no bubbles but could hear some tiny snaps like bubbles popping. I added detergent to the solution and then it blew nice big bubbles..

I do feel a great sense of accomplishment going from zero knowledge to a working Panhead from a basket of parts. Now looking to get a shovelhead to play with. would love a knuckle, but i haven't wont the lottery yet.!
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Re: Hot front head

#23

Post by Mark44 »

chadu607 wrote: Sun Nov 05, 2017 8:04 pmNow looking to get a shovelhead to play with. would love a knuckle, but i haven't wont the lottery yet.!
Shovelheads are a lot cheaper than Panheads, and way less than Knucks! I sold my '84 FXLR for under $5000 a couple of years ago. It was in need of paint, but the bike was mechanically very sound.
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Re: Hot front head

#24

Post by chadu607 »

In the end it turned out to be the oil pump. Now measuring about 200 deg on front and rear head after 5 minutes of idle. No more bang bang either. Just need to do some more fine tune adjustments and then take it out.
I replaced the stock pump with an S&S Oil pump part number 31-6048. It required no engine mods to fit but i had to cut the return oil line and replace with a braided hose. the feed like connects via the bottom of the pump with no modification needed.

its been a long 2 years of troubleshooting, learning, asking, and trying the many suggestions I got here and other places. Thanks to all of you for your imput on this.
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Re: Hot front head

#25

Post by Larry »

So the original pump was incapable of feeding the lifters?
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Re: Hot front head

#26

Post by chadu607 »

Hi Larry,
I don't think it was a lifter problem because it happened even with the solid set i have. I think the old oil pump was just unable to pump enough oil to that front head. It was a significant difference. The real test will be when I take it out for a ride. just have to button up a few things first.
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Re: Hot front head

#27

Post by roterhals »

Same deal with my pan. Bubble tested, etc. but nothing changed. Mine has an S&S carb and a few days ago a buddy said the intake manifolds will begin to wear under the clamps causing an intake leak (my front clamp does tend to "ride" off of the manifold). Bubble testing should show if there's an intake leak though, nevertheless wonder if anyone else has experienced this? I have not considered the oil pump until reading chadu607's post, I have outside oilers so I'll have a look-see at least to eliminate another potential cause. I was pretty much resigned to having to wait until taking the head off to see if something else was up, in the meantime the bike runs well, I have pretty much found the sweet spot in the carb adjustment between front and rear cylinders, although that's hardly a fix.
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Re: Hot front head

#28

Post by RooDog »

$&$ Intake, Bendix carb, O rings with aircraft clamps, outside oiler heads on a 74" '50 Panny,. It works for me....
....
DSC02149 (3).JPG
RooDog....
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Re: Hot front head

#29

Post by chadu607 »

RooDog
the problem with mine also came with a loud knock in the front head. I checked everything too, even replaced the intake manifold and entire valve train including the cam. solid, hydraulic lifters, didn't matter, but i was able to get it to "work" once in a while. All the head work was new and new pistons / cylinder bore. I tore it down 3 times I think measuring and re-measuring. did bubble check and leak down tests on the cylinders and even the intake. went over timing 100 times and had help by people in my area including Larry.
I then saw an ad on facebook for an ol shovelhead where the guy said the front head knocked bad and they were about to do a full rebuild even though it was recently done. then he found a broken woodruf key in the oil pump. in my case, the oil pump is old and worn and i had to weld a chip in it. It was the most likely cause of the overheating and banging.
i'm just trying to complete a few more things so i can take it out and test drive it . replacing internal kicker gears now, just waiting on gaskets. I'm crossing my fingers that I got it finally beat, because i have had false hopes before with this issue.

I hope this helps with your problems too, I had used a scope to peer into the front head and it was getting oil before. maybe not enough, fast enough.. will find out for sure soon.
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