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45 WLA valves ?? which intake, exhaust

Piotra

Active Member
Hello
I just bought a pair of Harley WLA flathead cylinders with valves. But it was dissasemled. Now I do not know which valves are exhaust and which are intake. How to differentiate them?
I think these valves are not oryginal but are in very good shape so I can reuse them. Two of them has flat surface and two other a little bit concave.
Maybe you can halpe me diffrentiate intake and exhaus valves?
 
Check out the info in the attached. I am assuming OHVs, right?

TQ
 

Attachments

  • OHV info from Knucklehead_Manual.pdf
    603.2 KB · Views: 13
Piotra; I just found a restoration book online. It says valves are marked IN and EX. I guess you would have to clean them enough to see it on the face. It also says an exhaust CAN be used in place of an intake, but intakes MUST NOT be used in place of exh.because they can't take the heat. I found this info by searching "Google Books" then enter How to restore your Harley Davidson by Bruce Palmer. Info was on page 222. Hope this helps.
 
Hello TQuentin1
The cylinders are SV's, not OHV's

Hello Breeze3at. I found this book (How to restore ...) on google boks but pages between 205 an 292 are not shown :(
I'm just looking on the valves and there are any markings (eg IN, EX, etc).
But on the valves there are stamped dots. Each valve has other number of dots. Two with concave surfaces has 1 and 4 dots and two with flat surface has 2 and 3 dots. So maybe these dots mean the order placing of valves?
Whatever we start counting (from front or end of bike) it's looks like 1 and 4 are these Exhaust valves and these in the middle of bike (2 and 3) are Intake.

But it is only my suspicion, I'm not sure. Have you ever seen this kind of markings on valves??
 
Piotra; First let me tell you I'm in an area that I have no experience in. I just stumbled on that book when I did a search. I will try and cut and paste and send to your account.
I will try and get info on the dots meaning on the face. I do rememberform long ago that the concave and flat valve faces had meaning, but I can't remember what.
 
The info I sent you does cover the SV too. On page 47 right above the "Valve Seats" section, it does indicate that the valves are made of different materials, and that the exhaust and intake should NOT be interchanged. But it says that the EX and IN are located on the "head". Clean those up thoroughly to see if you can find those markings. The other indication is that the valves are supposed to be marked when dissassembling to return to original location. That may be what your punch marks are.

TQ
 
I think I am going out on a limb here, but the flat one is the exhaust (as blow down is the primary method spent gases are removed) and less likely deposits will adhere to surface, the dished valve is intake to promote turbulance and prevent A/F mixture from sticking to surfaces. Usually the exhaust was smaller and lighter to minimize float, and intakes were larger to allow more A/F for same reasons, been a long time since I was rebuilding engines...
 
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