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Author Topic: Where's Terry?? Custom 836 Pistons for an F2 head!!  (Read 3040 times)

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Offline bhkrause

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Where's Terry?? Custom 836 Pistons for an F2 head!!
« on: August 21, 2007, 08:34:48 PM »
Available now at
http://www.dynoman.net/bikepages/F2/index.html

Get yer wallet out, mate!!    :D :D :D :D :D


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Offline Terry in Australia

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #1 on: August 21, 2007, 10:21:00 PM »
Very nice Bernie, and better still, Dynoman is selling stainless F2 valves! Woohoo! :D
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Offline Wheelhorse77

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #2 on: August 22, 2007, 06:44:36 AM »
Before you guys go blowing your loads, let's organize a group buy.

How many would be interested and when to purchase an 836 kit.

Don't forget that APE has the pistons as well. We have options gentlemen, let's be wise about our future decisions.

How do we get a dedicated group buy section on this forum?

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Offline TwoTired

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #3 on: August 22, 2007, 08:14:35 AM »
Are the hardened valve guides available from somewhere?

Cheers,
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Offline mick750F

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #4 on: August 22, 2007, 10:08:03 AM »
Quote from: TwoTired on August 22, 2007, 08:14:35 AM
Are the hardened valve guides available from somewhere?

Cheers,

   That was my first thought. Without them the same problem will be back no matter what else goes into the engine. With high performance upgrades maybe even quicker?

Mike
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Offline Terry in Australia

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #5 on: August 22, 2007, 02:26:04 PM »
Get an engineering shop to turn some guides up for you, that way you can specify the material that you think is most suitable.

It's got to be a heck of a lot easier than it's been finding new valves, surely? Cheers, Terry. ;D
« Last Edit: August 22, 2007, 02:28:47 PM by Terry in Australia »
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I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline MRieck

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #6 on: August 22, 2007, 07:11:51 PM »
Personally I have a problem with the F2 replacement guides. Bronze dissapates heat better and stainless valves are lighter. That in itself will solve many problems IMO. Hardened guides (.....and what is the material) will certainly not shed heat. I feel you will never solve F2/3 valve problems through materials. Honda screwed up and that is that. Bandaids never solve anything. I'd go with the bronze Kibblewhite and the Dynoman stainless and be good for 20,000 miles.
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Offline MRieck

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #7 on: August 22, 2007, 07:38:27 PM »
 I also remember RC Engineering putting out hard guides. They were made of steel. Unfortunately the beat the valve stems up pretty good. Like I said....I tough situation though there are choices now.
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Offline TwoTired

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #8 on: August 22, 2007, 11:52:45 PM »
Thinking out loud here. A few things I don't understand. 

Just what is the benefit of a valve guide material that dissipates heat better.  I can guess, but I'd rather hear from someone else.
And, if steel is used as a material, why does this cause the valve stem to get beat up?  Is the valve seizing in the guide?  I thought the valve stem was getting beat up due to it rocking in the worn guide.
What material were the stock valves made from?

What are the problems of using bronze guides with a steel liner for a wearing surface?

When the valve guides do wear, do the valve seats deform, too?  Or, is it only the stem end of the guide that wears quickly?

Could an expensive cure be titanium valves and steel guides?

I think it was Mike Nixon who mentioned that Honda upgraded to hardened guides to extend the F2/3 valve life.  (I'd like to know what the material was, too.)  What did they know that we don't, I wonder.

And lastly, just why is it I'm trying so hard to keep that black engine operating? (rhetorical question, I guess)

Cheers,
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Offline pablo78cb550

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #9 on: August 23, 2007, 12:07:30 AM »
ceramic valve guides........
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Offline Terry in Australia

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #10 on: August 23, 2007, 02:19:58 AM »
Quote from: MRieck on August 22, 2007, 07:11:51 PM
I'd go with the bronze Kibblewhite and the Dynoman stainless and be good for 20,000 miles.

Sounds good to me Mike, 20K miles for me equates to about half my remaining lifetime right now.............. Ha ha, Cheers, Terry. ;D
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I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline jtb

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #11 on: August 23, 2007, 05:22:13 AM »
Quote from: TwoTired on August 22, 2007, 11:52:45 PM
And lastly, just why is it I'm trying so hard to keep that black engine operating? (rhetorical question, I guess)

Cheers,

I surely wish I could answer that one, TT ;D ;D
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Offline KB02

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #12 on: August 23, 2007, 06:07:44 AM »
Got a quick question on this one. I tried checking the tech section of the main site, but didn't really find my answer. Are the Valves of the F2-3 head the same as the K7-8? I know that the latest K models received changes over the previous ones, but checking out the Dynoman website I couldn't find values for the K8, only the F2 (and previous K-models).
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Offline MRieck

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #13 on: August 23, 2007, 06:13:25 AM »
Quote from: KB02 on August 23, 2007, 06:07:44 AM
Got a quick question on this one. I tried checking the tech section of the main site, but didn't really find my answer. Are the Valves of the F2-3 head the same as the K7-8? I know that the latest K models received changes over the previous ones, but checking out the Dynoman website I couldn't find values for the K8, only the F2 (and previous K-models).
The K7/8 valves are not as large as the F2/3 BUT the keeper groove/retainers are the same as the F2/3.
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Offline Lumbee

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #14 on: August 23, 2007, 07:38:02 AM »
Quote from: TwoTired on August 22, 2007, 11:52:45 PM
Thinking out loud here. A few things I don't understand. 

Just what is the benefit of a valve guide material that dissipates heat better.  I can guess, but I'd rather hear from someone else.
And, if steel is used as a material, why does this cause the valve stem to get beat up?  Is the valve seizing in the guide?  I thought the valve stem was getting beat up due to it rocking in the worn guide.
What material were the stock valves made from?

What are the problems of using bronze guides with a steel liner for a wearing surface?

When the valve guides do wear, do the valve seats deform, too?  Or, is it only the stem end of the guide that wears quickly?

Could an expensive cure be titanium valves and steel guides?

I think it was Mike Nixon who mentioned that Honda upgraded to hardened guides to extend the F2/3 valve life.  (I'd like to know what the material was, too.)  What did they know that we don't, I wonder.

And lastly, just why is it I'm trying so hard to keep that black engine operating? (rhetorical question, I guess)

Cheers,

I don't think you'll get many responses on the specific questions you ask because there aren't' that many examples out there.  I've always felt the F2/3 valve guide problem was overstated.  Theres no question it was a problem as honda did a recall, but over the years I can only recall one person who admitted to having a F2/3 that actually had the problem.  I've had 2 F's, and have not had problems with either bike.  Admittedly I only put a few thousand miles a year on the bikes.  Also both bikes had 20-30K miles on them.  Like someone posted, do the work and be happy with 20K miles...I think that will suffice for most guys out there...
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Offline TwoTired

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #15 on: August 23, 2007, 12:03:29 PM »
Quote from: The great "Lumbee" on August 23, 2007, 07:38:02 AM

I don't think you'll get many responses on the specific questions you ask because there aren't that many examples out there.  I've always felt the F2/3 valve guide problem was overstated.  Theres no question it was a problem as honda did a recall, but over the years I can only recall one person who admitted to having a F2/3 that actually had the problem.  I've had 2 F's, and have not had problems with either bike.  Admittedly I only put a few thousand miles a year on the bikes.  Also both bikes had 20-30K miles on them.  Like someone posted, do the work and be happy with 20K miles...I think that will suffice for most guys out there...

I suspect you are probably right about the responses. The standard 750 was good for about 100,000 miles of normal use.  It seems an 80% hit in longevity is a pretty stiff penalty for the modest performance increase it offers.  Seems like Honda tried to solve or improve the problem with a materials change approach.  Field techs/mechanics simply abandon the head geometry.  So, the examples are a diminishing breed, and getting ever less interesting to aftermarket suppliers.  My F2 already had a K8 engine in it when dragged home.  My F3 with the potential issue didn't come to me with a speedometer.  I've acquired a bunch of parts to make it go and look like Honda original again.  Almost ready to see if there is life left in it.  Or, if  the engine has to come out of the frame.
Like Terry says, though I'll not likely ever put 20K on it.

Perhaps it does make more sense to ebay the Honda brand new body work, tank, exhaust system, etc?  Pity when plans fall through. :(   
(So much for my attempted foray into the CB750 world.)

Cheers,
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Offline tramp

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #16 on: August 23, 2007, 04:02:44 PM »
got a 78 750f stock
is there a real difference to goto 836
do they sell a complete kit for a 750f?
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Offline Lumbee

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #17 on: August 23, 2007, 06:40:54 PM »
Quote from: tramp on August 23, 2007, 04:02:44 PM
got a 78 750f stock
is there a real difference to goto 836
do they sell a complete kit for a 750f?

...another 100cc's, so another 10hp.  Check the link in the 1st post of this thread for the kit...
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Offline rbmgf7

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #18 on: August 23, 2007, 06:50:24 PM »
would a group buy be cheaper?

what does a typical bore and hone cost for some people? just wondering how much to include into my budget so i can get my spare f2 running.

makes you wonder what kinda monster an f2 with a b.b kit will be like? especially with a sportier cam and s.s valves, CR carbs...the whole shibang :o
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Offline MRieck

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #19 on: August 23, 2007, 07:42:52 PM »
Quote from: gearbot on August 23, 2007, 06:50:24 PM
would a group buy be cheaper?

what does a typical bore and hone cost for some people? just wondering how much to include into my budget so i can get my spare f2 running.

makes you wonder what kinda monster an f2 with a b.b kit will be like? especially with a sportier cam and s.s valves, CR carbs...the whole shibang :o
It would be real fun. ;)
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Offline KB02

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #20 on: August 24, 2007, 04:57:05 AM »
Quote from: MRieck on August 23, 2007, 07:42:52 PM
It would be real fun. ;)

Not that you have any experience doing the "Whole Shebang" to a SOHC, right?  ;) :D :D :D
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Offline Wheelhorse77

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #21 on: August 24, 2007, 06:46:43 AM »
I wonder if mini roller rockers would help to eliminate some of the wear on the guides?
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Offline Big Jay

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Re: Where's Terry?? Custom 836 Pistons for an F2 head!!
« Reply #22 on: August 25, 2007, 01:11:33 PM »
Rocker arm motors wear valve guides out faster that bucket/tappet style engines. Rocker arms side load the valve. Virtually every rocker style head that comes thru here has to have the guides replaced. This includes all of the old oil/air cooled Suzuki GS and GSXR motors.

It is just how that design works.

The bronze guides seem to be the best for these engines, but will also wear in time because of the rockers.

http://cbrzone.com/valves.html

Jay

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