Valve Springs recommendation

[50Panhead]

Referring to the Thread (Intake Leak or ???) I have pulled the heads back off my 50FL. The shop manual recommends part # 18201-57 and 18202-57 as replacements.
Those numbers are no longer listed with HD. Do you guys have any recommendations for replacements? Suppliers? Part Numbers?

Thanks
Herman

[duffeycycles]

did you do a leak test?What did plugs look like?I've seen similar probelems with bikes that just had poor top end work,had to be redone
often if you do valve job only the rings can bite you next

[50Panhead]

did you do a leak test?What did plugs look like?I've seen similar probelems with bikes that just had poor top end work,had to be redone
often if you do valve job only the rings can bite you next

When I started working on it last fall I did a leak down test and compression test They both failed. I had the valve seats dressed up and I honed the cylinders and installed new rings also. This brought the compression back up to where it was supposed to be. I did a soap bubble test for intake leakage, That failed also. Cotton refurbish the intake manifold and I solved those problems also

I do not have a accurate way of testing the springs. They "look" OK, but looks don't mean anything.
Now that I have the heads back off I'm going to replace the springs regardless.

Just would like your input as to Suppler and part numbers.

[T. Cotten]

50Panhead!

You can test your springs with a valve, bathroom scale, dialcaliper, and a drillpress.

First, please measure the spring's installed height, which is the distance between collars.
(I use an old brake cylinder spring to make it easy.)

It is common that the springs do not get properly shimmed after the seat has been "sunk", reducing their installed pressure.

I think its 90 lbs or so installed, for the big spring alone.
Rad cams require more I hear...

....Cotten

[rousseau]

Herman,
I am in no way associated with them, but J&P Cycle is hard to beat. They will have brand names (Andrews S&S Cycle Manley JIMS). The prices are full blown retail , but they have a hassle free return policy.

[Adam M]

You need to check your stem protusion in the head , with that number you can then formulate the spring tensions . At installed height, use that number to test springs, after subtracting collars . after adding the cam lift , add 0.030 for possible float, subtract the upper and lower collars , install springs in tester and measure max lift and test pressure there. Check for bind.
Adam

[T. Cotten]

Adam!

The rough guestimate of 90 pounds (FLH) was for installed pressure, not at lift.
What do you suggest for pressure at maximum lift?

....Cotten
PS: I found that variances between collars, and the common need to cut guides for seals, free travel (to avoid coilbind), etc., made calculating subject to great error.
Its safest, and a lot quicker, to just measure each assembly direct.
PPS: Beware Folks, that although things may have changed in the last decade, but there was a time when stock-length H-D late OHV springs were not available, in favor of pricey "performance" kits. Please make certain your provider has what you really want, even if listed by an OEM number!

[50Panhead]

I took the heads back to guy who did the work on them last winter. I told him about the problem I was having and he was about as stumped as I am. He told me he has a friend with a valve spring tester, so he was to take the springs to his shop and test them. He copied the valve spring specifications from my shop manual and will get back to me. So for now I wait.
While I got it apart I went back through the carburetor and check all the details that was suggested here. Nothing looks like a smoking gun. or makes me go huh.

[Adam M]

Adam!

The rough guestimate of 90 pounds (FLH) was for installed pressure, not at lift.
What do you suggest for pressure at maximum lift?

....Cotten
PS: I found that variances between collars, and the common need to cut guides for seals, free travel (to avoid coilbind), etc., made calculating subject to great error.
Its safest, and a lot quicker, to just measure each assembly direct.
PPS: Beware Folks, that although things may have changed in the last decade, but there was a time when stock-length H-D late OHV springs were not available, in favor of pricey "performance" kits. Please make certain your provider has what you really want, even if listed by an OEM number!

Tom , just add lift in to factor , use a caliper at that equation and check spring tension.
Adam

[T. Cotten]

My question Adam,...

...Is what spec do you want to shim up to, for say, a stock FLH cam?

"Factor"?
Got a number?

....Cotten

[50Panhead]

Lets see if this works.
From page 83-84 of the shop manual

Page 83-84.jpg

[50Panhead]

Lets see if this works.
From page 83-84 of the shop manual

[ATTACH=CONFIG]15476[/ATTACH]

That's small!

[T. Cotten]

50Panhead!

You will note that those are specs for judging an individual spring at stock installed and lift height.
(With their spec of 105-115, it would seem my 90 recollection would be a minimum.)

That does not, however, tell you the installed tension for a spring at your installed height (distance between collars).
It tells you what it should be shimmed up to....

....Cotten

[50Panhead]

Machinist took his machining into consideration and shimmed according.

[T. Cotten]

I would bet then, 50Panhead,

...that there is yet another worm in the can.

....Cotten