Author Topic: Using vintage NOS engine parts  (Read 2602 times)

0 Members and 1 Guest are viewing this topic.

Offline y2kc0wb0y

  • B00msh0cka
  • Hot Shot
  • ***
  • Posts: 285
  • Shoot the pickle....
Using vintage NOS engine parts
« on: April 20, 2020, 04:34:58 am »
Looking at this "NOS" RC295 cam for use in a 836 build and notices it has rust lobe and journals and from review some appears to be pitting. My very basic engine building instinct says it needs to be set to artifact and not used but I'm wondering if others here have another opinion. Seems to be a lot of mix opinions if this issue can be restored or not. Thanks for any all input.

https://drive.google.com/open?id=1ZuMpSDe63BZSsLdgRb0QIErA8E1jnXr4
https://drive.google.com/open?id=1rZUQrWPfdL3VhnUhy468PyS572pCz2qR
https://drive.google.com/open?id=19EjVaCF8jz9J5HS717KXQc-Np14FFJx-




CB750K3 890cc| 2004 VFR800A| 76 CB550F| 77 CB750F| 73 CB350G| 79 XLH| 2007 BMW R1200GS| CB750K2

Offline y2kc0wb0y

  • B00msh0cka
  • Hot Shot
  • ***
  • Posts: 285
  • Shoot the pickle....
Re: Using vintage NOS engine parts
« Reply #1 on: April 20, 2020, 04:56:11 am »
Direct upload photo
CB750K3 890cc| 2004 VFR800A| 76 CB550F| 77 CB750F| 73 CB350G| 79 XLH| 2007 BMW R1200GS| CB750K2

Offline y2kc0wb0y

  • B00msh0cka
  • Hot Shot
  • ***
  • Posts: 285
  • Shoot the pickle....
Re: Using vintage NOS engine parts
« Reply #2 on: April 20, 2020, 04:57:56 am »
more
CB750K3 890cc| 2004 VFR800A| 76 CB550F| 77 CB750F| 73 CB350G| 79 XLH| 2007 BMW R1200GS| CB750K2

Offline simon#42

  • Old Timer
  • ******
  • Posts: 2,565
  • liverpool
Re: Using vintage NOS engine parts
« Reply #3 on: April 20, 2020, 05:33:55 am »
well i for one would not use that , it looks particularly bad in the first photo . might be handy for stirring paint !

Offline y2kc0wb0y

  • B00msh0cka
  • Hot Shot
  • ***
  • Posts: 285
  • Shoot the pickle....
Re: Using vintage NOS engine parts
« Reply #4 on: April 20, 2020, 06:13:14 am »
Thanks Simon#42. I kinda feel the same way. Internet would make you believe this can be polished out with emery cloth and WD40. Just curious if anyone has real world experience. Normally I wouldn't spend any time on this but its an interesting light performance cam with more duration on the exhaust lobe which I think would keep things on the cooler side. IDK; might be looking at this wrong. Not a lot of information out there about these and its look different than the RD295 current offered.
CB750K3 890cc| 2004 VFR800A| 76 CB550F| 77 CB750F| 73 CB350G| 79 XLH| 2007 BMW R1200GS| CB750K2

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,362
Re: Using vintage NOS engine parts
« Reply #5 on: April 20, 2020, 06:37:39 am »
Try cleaning it up really good first. Assessing the condition of what appears to be a dirty part will get you nowhere. Depending on your intended use for the cam (racing vs street riding) will play into your decision to use or not. Simon is right, for racing I would use something that is perfect on the journals and lobes. For street riding, a pit here or there or other small irregularities are likely no big concern, as long as they don't protrude above the surface. You could easily remove small burs and the like with a stone and it would run fine. That said, new cams are pretty cheap.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline Stev-o

  • Ain't no
  • Really Old Timer ...
  • *******
  • Posts: 33,920
  • Central Texas
Re: Using vintage NOS engine parts
« Reply #6 on: April 20, 2020, 06:55:19 am »
Try cleaning it up really good first.

+1.  I'd get it vapor blasted....
'74 "Big Bang" Honda 750K [836].....'71 Honda 750K project.....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline y2kc0wb0y

  • B00msh0cka
  • Hot Shot
  • ***
  • Posts: 285
  • Shoot the pickle....
Re: Using vintage NOS engine parts
« Reply #7 on: April 20, 2020, 07:24:14 am »
Try cleaning it up really good first. Assessing the condition of what appears to be a dirty part will get you nowhere. Depending on your intended use for the cam (racing vs street riding) will play into your decision to use or not. Simon is right, for racing I would use something that is perfect on the journals and lobes. For street riding, a pit here or there or other small irregularities are likely no big concern, as long as they don't protrude above the surface. You could easily remove small burs and the like with a stone and it would run fine. That said, new cams are pretty cheap.

#streetriding no organized racing ;) Unfortunately not owning yet makes managing assessing what's left challenging. Agree cams are cheap. 
CB750K3 890cc| 2004 VFR800A| 76 CB550F| 77 CB750F| 73 CB350G| 79 XLH| 2007 BMW R1200GS| CB750K2

Offline Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 14,842
  • Bought her new 4/75
Re: Using vintage NOS engine parts
« Reply #8 on: April 20, 2020, 07:53:39 am »
Polish it up and see what you actually have before deciding
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline Don R

  • My Sandcast is a
  • Really Old Timer ...
  • *******
  • Posts: 19,362
  • Saver of unloved motorcycles.
Re: Using vintage NOS engine parts
« Reply #9 on: April 20, 2020, 08:48:01 am »
 I polished a cam with a bit of rust but it wasn't black like that one. I wouldn't buy it to find out unless it was really cheap. Mine cleaned up with scotchbrite and WD40.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 I smell like Lilacs, I've got glitter on my cheeks and it's all Joe's fault, he told the stripper it was my birthday.

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,058
Re: Using vintage NOS engine parts
« Reply #10 on: April 20, 2020, 10:17:43 am »
When we work on bikes from the 20,s or older we call that oil retention marks..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline y2kc0wb0y

  • B00msh0cka
  • Hot Shot
  • ***
  • Posts: 285
  • Shoot the pickle....
Re: Using vintage NOS engine parts
« Reply #11 on: April 20, 2020, 01:59:16 pm »
Roger loud and clear! Does anyone have 125-65 cam or SS-1 they would like to sell :)
CB750K3 890cc| 2004 VFR800A| 76 CB550F| 77 CB750F| 73 CB350G| 79 XLH| 2007 BMW R1200GS| CB750K2

Offline low-side

  • Enthusiast
  • **
  • Posts: 214
Re: Using vintage NOS engine parts
« Reply #12 on: April 20, 2020, 06:41:43 pm »
The second line in the first picture looks to have a patch of pitting bad enough that it's likely through the nitriding.  I wouldn't use it.

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,058
Re: Using vintage NOS engine parts
« Reply #13 on: April 20, 2020, 07:06:06 pm »
It really depends on how much you got to pay and if you can install without pulling engine.  Worst case scenario you lose a few rockers, a few bux and some time., or you luck out and win..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 15,255
  • Bike almost back to the 70's 2015
Re: Using vintage NOS engine parts
« Reply #14 on: April 21, 2020, 12:32:40 am »
Polish it up and see what you actually have before deciding
+1
First photo look bad, the other not that bad.

Interesting RC295 engraving, look like mine that has it on its side where the washer is bolted.
photo below

From the thread I started when I had purchased that cam that is my favourite cam.
More photos to compare with
http://forums.sohc4.net/index.php/topic,149688.msg1707472.html?PHPSESSID=loh4gnj1pi8fh9svsdo1a21p64#msg1707472

Cam can be used as a master grinding a new cam.

RC295 is otherwise a good profile with usable power from low, no need to wait until after 6500 rpm when all suddenly wakes up as many other hot cams designed for racing.

Dynoman sell it as DP295, hardwelded possible too as the cams from Megacycle.
« Last Edit: April 21, 2020, 01:47:17 am by PeWe »
CB750 K6-76 1005cc JMR Billet block.
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 flatlander

  • Old Timer
  • ******
  • Posts: 2,602
Re: Using vintage NOS engine parts
« Reply #15 on: April 21, 2020, 01:29:57 am »
seeing as you don't have it in your hands in order to check its condition, i'd only buy it if it's dirt cheap (an amount of money you'd be ok to lose). there are new performance cams to be had for not an awful lot of money and those are a safe bet. 

Offline Sam Green Racing

  • Moderator
  • Really Old Timer ...
  • *****
  • Posts: 16,060
  • I REALLY? hate black rims.
Re: Using vintage NOS engine parts
« Reply #16 on: April 21, 2020, 04:19:59 am »
The 295 cam is ideal for the road and for drag racing, not so hot for road racing unless it's a twisty circuit with not many long straights.

What this cam looses over a high end power cam is only a few BHP but it more than makes up for it low down and mid range.

The DP295 is available from Dynoman and is made by Webcam. Here's a link.

https://dynoman.net/engine/cams/webcams_honda.html#sohc

Sam.
C95 sprint bike.
CB95 hybrid race bike
CB95 race bike
CB92
RS 175. sprint/land speed bike
JMR Racing CB750A street ET drag bike

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 15,255
  • Bike almost back to the 70's 2015
Re: Using vintage NOS engine parts
« Reply #17 on: April 21, 2020, 10:02:25 am »
Sam, you have much more experience of that cam and I have. I can feel your enthusiasm about RC/DP295.

I am really satisfied with it giving smooth power early with strong midrange. I do not feel any specific rpm where power suddenly increases very much. I do not need more power after 8000 rpm. Yes, it would be nice to let bike reach 220kmh just for fun.
8000 is almost 200 (18:48 gear)
Strong 4000-7000 rpm is very useful on a street bike. (Even lower comes with displacement.)

I'm just back from another carb verifying ride of 130 km at a very slow pace after work.
I have finally made the carbs to run the engine silky smooth with my "RC295" cam, 1005cc. Much smoother than my stock CB750 K2 with K7 cam! 

Smooth engine in the entire registry, especially 1200-3000 rpm is a must for me and make the ride to a sheer joy.

Idles 1000-1200rpm like a well adjusted stock bike with good internal chains, maybe better!
Also thanks to APE balanced crank.
//Per
CB750 K6-76 1005cc JMR Billet block.
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 y2kc0wb0y

  • B00msh0cka
  • Hot Shot
  • ***
  • Posts: 285
  • Shoot the pickle....
Re: Using vintage NOS engine parts
« Reply #18 on: April 21, 2020, 06:28:29 pm »
Bailed on this cam as the gentleman was asking $250 for historical purposes. No
CB750K3 890cc| 2004 VFR800A| 76 CB550F| 77 CB750F| 73 CB350G| 79 XLH| 2007 BMW R1200GS| CB750K2

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 15,255
  • Bike almost back to the 70's 2015
Re: Using vintage NOS engine parts
« Reply #19 on: April 21, 2020, 10:24:06 pm »
CB750 K6-76 1005cc JMR Billet block.
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 simon#42

  • Old Timer
  • ******
  • Posts: 2,565
  • liverpool
Re: Using vintage NOS engine parts
« Reply #20 on: April 22, 2020, 01:39:56 am »
Bailed on this cam as the gentleman was asking $250 for historical purposes. No

you are a wise man .

Offline y2kc0wb0y

  • B00msh0cka
  • Hot Shot
  • ***
  • Posts: 285
  • Shoot the pickle....
Re: Using vintage NOS engine parts
« Reply #21 on: April 22, 2020, 04:25:03 am »
Lemme start another thread about the DP295
CB750K3 890cc| 2004 VFR800A| 76 CB550F| 77 CB750F| 73 CB350G| 79 XLH| 2007 BMW R1200GS| CB750K2

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 15,255
  • Bike almost back to the 70's 2015
Re: Using vintage NOS engine parts
« Reply #22 on: April 22, 2020, 09:00:57 am »
That cam is mentioned in older threads. Sam's comment before says all.
Perfect for tuned street bikes with ported head, race springs, higher compression pistons with valvepockets for higher lift cams (10 something:1 OK). Still a cam for touring as well as first from red light to next ;)

Higher lift and relatively short duration is often mentioned as a good cam for street where power is welcome early.

CB750 K6-76 1005cc JMR Billet block.
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 Sam Green Racing

  • Moderator
  • Really Old Timer ...
  • *****
  • Posts: 16,060
  • I REALLY? hate black rims.
Re: Using vintage NOS engine parts
« Reply #23 on: April 22, 2020, 09:09:40 am »
That cam is mentioned in older threads. Sam's comment before says all.
Perfect for tuned street bikes with ported head, race springs, higher compression pistons with valvepockets for higher lift cams (10 something:1 OK). Still a cam for touring as well as first from red light to next ;)

Higher lift and relatively short duration is often mentioned as a good cam for street where power is welcome early.

To be honest PeWe, unless you are circuit racing where there are plenty of long straights or land speed racing, the DP295 is far and away the  best all round cam for the money.

Sam. ;)
C95 sprint bike.
CB95 hybrid race bike
CB95 race bike
CB92
RS 175. sprint/land speed bike
JMR Racing CB750A street ET drag bike

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 15,255
  • Bike almost back to the 70's 2015
Re: Using vintage NOS engine parts
« Reply #24 on: April 22, 2020, 09:56:00 am »
Most of the designed cams have a purpose.

Cam specs on this site describes many cams and what made for.
http://www.satanicmechanic.org/cams.shtml

Only lift and duration numbers do not say all.
1 cam with slow lift to max, shorter time (crank degrees) with much opened valves, gently closing. Slimmer pointy lobes.

Another cam very aggressive, quickly to high lift and almost vertical drop when closing. Lobes like Mickey mouse, almost square shaped. Much more time where valves are really opened.

Same numbers on the card  but soo different.
The aggressive one need to be checked, valve to valve and piston clearance. High wear on cam, rockers, holders.

The first can almost be used in a stock engine.

Dynamic compression will suffer too when letting out the pressure with opened valves, in and ex at the same time (overlap). Need pistons with higher domes, even deeper pockets for the often opened valves.

Action Fours had a good explanaion about this in their catalog.

Satanic Mechanic mention it too with drawings.

Racers could use different cams for different race tracks and durations?
24 hour Le Mans need an engine that will hold up to the finish as all races, right?  Not a KH Super F in that one ! :D
« Last Edit: April 22, 2020, 10:47:33 am by PeWe »
CB750 K6-76 1005cc JMR Billet block.
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 754

  • Really Old Timer ...
  • *******
  • Posts: 29,058
Re: Using vintage NOS engine parts
« Reply #25 on: April 22, 2020, 11:01:08 am »
I installed a vintage A grind Andrews, in a stock motor.
 I was surprised to lose so much below 3,000 rpm.. almost nothing till you hit over that. And it did not pull a lot harder unless you got it past 6 or 6.5 K.... a bit weird I thought.
 Had far more midrange with my RC 315 836 with Webers and unsorted head. .hmm..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way