Author Topic: 750 manley valve train parts info  (Read 994 times)

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Offline Garage_guy_chris

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750 manley valve train parts info
« on: June 13, 2014, 06:18:54 AM »
Hey everybody. I bought a built head a while ago with a full NOS manley stainless valve train in it. I was just looking for some info on the parts. I havent been able to find any specifications or info on these goodies. Im mainly curious about the valve springs and what sorta seat pressure and opening pressure they have
1971 Cb450 Cafe  (on the road)
1974 Cb750 Restomod (on the road)

Online Don R

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Re: 750 manley valve train parts info
« Reply #1 on: June 13, 2014, 08:54:42 AM »
We'd love to see a picture of that!  You would probably need to measure the spring pressure as installed.
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Offline Garage_guy_chris

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Re: 750 manley valve train parts info
« Reply #2 on: January 20, 2015, 09:30:00 PM »
Well im finally getting back to the engine build at hand. its been a rough go for the last while... anyways i took a look at this head today and snapped some photo's.

I don't think this head has ever been used i took it down and found:
-Intake valves marked      "MANLEY 9-8"
-Exhaust valves marked    "MANLEY 1-8"
-Look to be iron/stellite guides both intake and exhaust have seals
-Retainers i believe are stainless? Not sure of origin maybe Manley
-springs seem a fair bit stiffer than stock but i really need to measure them to be sure.

Ive also had time to dredge through google and here sohc4.net to find some more info on these Manley valves..

-early valves had soft stem tops and would mushroom from the lash adjuster.
-adding lash caps remedied this
-later valves were hardened? the stem tips on these look a little different then the rest of the stem i think these may be later....
-Found one report "I wanted to reuse the Manley valves that already had 50,000+ miles on them"
-Found another report "It has long had Manley SS valves so those were OK to regrind"

Couple questions:
- The head has stainless retainers and possibly hd springs are these likely manley too?
- Was this Manley gear a package deal or individual parts?

Here are the photos.






« Last Edit: January 21, 2015, 10:18:25 PM by Garage_guy_chris »
1971 Cb450 Cafe  (on the road)
1974 Cb750 Restomod (on the road)

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: 750 manley valve train parts info
« Reply #3 on: January 21, 2015, 12:35:02 AM »
When I used 32mm Manleys as intake replacements in late 76 I purchased my stuff from Yoshimura. At least I think all of it came from them. The springs were S & W. No appearance of mushrooming as they were prone to after almost 30,000 miles.
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline PeWe

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Re: 750 manley valve train parts info
« Reply #4 on: January 21, 2015, 04:02:08 AM »
Lash caps if the valve stems mushrooming. My inlet valves like to do that (F2 34mm used as over size valves). These valves might have softer tips?
MRieck helped me to get correct lash caps. Valve stems tips grinded flat by the machine shop when refurbish the head and replaced all valves.  Easy to replace the caps when they have got dimples. Exhaust valves no caps.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Garage_guy_chris

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Re: 750 manley valve train parts info
« Reply #5 on: January 21, 2015, 10:17:17 PM »
I measured up the springs tonight and came up with:

Mystery springs possibly Manley   
@ 1.440                          60 lbs seat pressure
@ .345 lift                       180 lbs seat pressure
@ .325 lift                       170 lbs seat pressure

Also figured out the valve retainers are likely stainless steel Not titanium.

Would love to know exactly what the springs and retainers are? they may be Manley or maybe something else. It would be nice to know but will likely never know. 

after all my measuring and messing around this is the head going on the engine. I will keep an eye on the valve stems annually and if theres a problem deal with it then.
« Last Edit: January 21, 2015, 10:19:23 PM by Garage_guy_chris »
1971 Cb450 Cafe  (on the road)
1974 Cb750 Restomod (on the road)