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Author Topic: 78 750F 836 build  (Read 2560 times)

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Offline iridebikes215

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78 750F 836 build
« on: November 02, 2010, 03:37:13 PM »
Im building up a f2 with an 836 kit. Im curious how far everyone else went in their build as far as coatings, transmission mods, and cooling mods. Im looking for an arm ripper but also reliability as its my daily driver.

Im looking into the f2 kit @ cyclex, im also planning on undercutting the trans, new carbs, exhaust, and ignition.

What exhausts have you f2 guys had good results with?

Has anyone tried both CR's and Mikuni's?

Anyhelp would be awesome.

Thanks!
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Offline rklystron

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Re: 78 750F 836 build
« Reply #1 on: April 03, 2011, 07:55:49 AM »
Hello iidebikes215.
I have built an 1977 F2. Many items were incorporated into this F2 build.  The crankshaft and rods I had APE lighten and balance the crank. I also had them install new Falicon rods. This should make this engine about as strong as you can get from a crank standpoint. The Carrillo H beams are also a fantastic rod that I am using in a current engine build. The cases I had wire shot peened and ultrasonic cleaned. I then coated the inside of the cases with Glyptal. This coating has been used for many years in engine building for oil shedding.
The transmission I had undercut by FAST by GAST. The head was shot peened and new guides and kimblewhite vales were installed with heavy duty springs and Ti retainers. The cam I decided to use is a 63b by Webcam. This cam is 370/240 on both the intake and exhaust with a LC of 98. In order to get this cam installed with the appropriate clearances I had to recess the intake and exhaust seats about .005. I then ported the head and unshrouded the valves. With this cam or any other performance cam you will have to degree the cam and with this use a slotted cam sprocket. New cam chain, cam chain guides and cam tensioner were also installed. New Pistons, rings, wrist pins and clips were also installed. The ignition system I decided to go with was a Power Arc ignition. This ignition is optical with 4 curves you can access on the fly. The curves can be programmed by you with the programming software and a USB cable. I am currently using the stock exhaust with all baffles removed. I have several other exhausts but have not tried them as of yet. Oh yes, new primary chains as well as tensioner. As for carbs I am using Keihin 29mm CR's. I have found that dialing in the CR's have been interesting. But with these carbs you have access to just about everything without removing the carbs themselves. Once dialed in they work flawlessly. To help me figure out what is going on with the engine and chassis I have 2 great devices installed on board. The first is a VELPOR VR2. This is essentially an on board Dyno with lots of great stuff to play with. It is easy to install with really two pick points. One is a magnetic sensor on the rear wheel that will give you true Speed and well as compute HP and RWT. The other is tied into the ignition system for RPM data. The other system I have installed is an Innovate LM-2 Dual channel A/F monitor. As you can see you can really go crazy on this stuff. If you would like to see a small video of this bike you can see it here. 1977 Honda CB750 F2 Rebuild
No matter what you have come to the right place to get great advice. I have used this forum to answer my questions countless times. I wish you the best in your build.
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1970 CB750 K0 (Bought in 73)
1972 XL250 (Bought new in 72)
1973 ST90 (Free)
1975 XL250 (Free)
1975 Rickman CR750
1982 CBX1000 Pro-link
1975 CB750 DRAG BIKE
1977 Custom Built CB750 Sturgis Bike (GL front end).
1977 CB750 F2 (Big Resto)
1977 CB750A (Auction Buy)
1978 CB750 K8 (My San Francisco ride)
1984 VFR750 (Bought New)

Offline tweakin

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Re: 78 750F 836 build
« Reply #2 on: April 03, 2011, 08:07:05 AM »
Don't want to derail the thread but awesome F2...
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Offline Bill/BentON Racing

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Re: 78 750F 836 build
« Reply #3 on: April 04, 2011, 05:24:53 PM »
Good luck on build.F2 a great place to start.And some good advice,nice build,Rk!
Wish you well,you are at the right place for SOHC knowledge.Bill
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Offline rklystron

  • I have not failed. I've just found 10,000 ways that won't work. Thomas A. Edison
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Re: 78 750F 836 build
« Reply #4 on: April 07, 2011, 06:12:11 AM »
Thanks Bellcow. I appreciate your comments. I just started building another motor. It's a K2 and I thought it might me fun to put together a video on the HD studs and crank install. Not real informative, but I think fun to watch. Take a peek if you are so inclined. CB750 K2 Engine Build
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1970 CB750 K0 (Bought in 73)
1972 XL250 (Bought new in 72)
1973 ST90 (Free)
1975 XL250 (Free)
1975 Rickman CR750
1982 CBX1000 Pro-link
1975 CB750 DRAG BIKE
1977 Custom Built CB750 Sturgis Bike (GL front end).
1977 CB750 F2 (Big Resto)
1977 CB750A (Auction Buy)
1978 CB750 K8 (My San Francisco ride)
1984 VFR750 (Bought New)

Offline Mandic

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Re: 78 750F 836 build
« Reply #5 on: April 10, 2011, 12:10:01 PM »
Just to be off topic, what are you filming with?

My 836 F2 has about 600 miles on the 836 motor now. 

I'm running the stock 4-1 with a Mac muffler, 135 main jets, stock needle position, and the factory "oil cooler". 

What have I found?  The pig runs HOT.  I just finally got it running right after some timing adjustments and haven't gotten it to my shop yet to check plugs and really figure it out.  I am certain I need to shim my needles up for one.  And maybe fatten up on the main jets. 

A Yoshi replica exhaust is in my future to get those exhaust gasses out of there.  As well as a REAL oil cooler setup.  The cooler itself has been ordered I just need adapters and plumbing pieces yet.
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77 CB750F - Cafe/Daily Rider

Offline voxonda

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Re: 78 750F 836 build
« Reply #6 on: April 10, 2011, 12:37:15 PM »
Quote from: rklystron on April 07, 2011, 06:12:11 AM
Thanks Bellcow. I appreciate your comments. I just started building another motor. It's a K2 and I thought it might me fun to put together a video on the HD studs and crank install. Not real informative, but I think fun to watch. Take a peek if you are so inclined. CB750 K2 Engine Build

Very nice, what did you use to coat the inside with?

Thanks, rob
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Offline rklystron

  • I have not failed. I've just found 10,000 ways that won't work. Thomas A. Edison
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Re: 78 750F 836 build
« Reply #7 on: April 10, 2011, 01:48:17 PM »
The coating inside the engine is Giyptal. 1201-A. Its an insulating enamel used for armatures. The real secret is the prep work to make sure the cases are spotless. Giyptal allows the oil to run very quickly. This is the 2nd time I have used Giyptal and I am happy with the results.
Logged
1970 CB750 K0 (Bought in 73)
1972 XL250 (Bought new in 72)
1973 ST90 (Free)
1975 XL250 (Free)
1975 Rickman CR750
1982 CBX1000 Pro-link
1975 CB750 DRAG BIKE
1977 Custom Built CB750 Sturgis Bike (GL front end).
1977 CB750 F2 (Big Resto)
1977 CB750A (Auction Buy)
1978 CB750 K8 (My San Francisco ride)
1984 VFR750 (Bought New)

Offline mick7504

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Re: 78 750F 836 build
« Reply #8 on: April 10, 2011, 03:55:16 PM »
Nice job and enjoyed the video.
I bought this up once before and there were mixed views about offsetting the primary chain links.
Is there a definative answer/benefits for doing this or does it remain a matter of preference?
Keep up the good work.  ;)
Mick
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Offline rklystron

  • I have not failed. I've just found 10,000 ways that won't work. Thomas A. Edison
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  • Posts: 257
Re: 78 750F 836 build
« Reply #9 on: April 10, 2011, 04:16:22 PM »
Mick, I can not find a definitive answer on this. I even called DID and asked them what their take was on the topic. The engineer I talked to said, the only thing they thought was it may and I repeat may eliminate some harmonics between the 2 chains. After a long conversation with him I think it does not matter much, if at all and is a builders preference more than anything.
Logged
1970 CB750 K0 (Bought in 73)
1972 XL250 (Bought new in 72)
1973 ST90 (Free)
1975 XL250 (Free)
1975 Rickman CR750
1982 CBX1000 Pro-link
1975 CB750 DRAG BIKE
1977 Custom Built CB750 Sturgis Bike (GL front end).
1977 CB750 F2 (Big Resto)
1977 CB750A (Auction Buy)
1978 CB750 K8 (My San Francisco ride)
1984 VFR750 (Bought New)

Offline dragracer

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Re: 78 750F 836 build
« Reply #10 on: April 10, 2011, 05:51:18 PM »
Great advice/direction on that motor build. My compliments to you sir for sharing that information.

Quote from: rklystron on April 03, 2011, 07:55:49 AM
Hello iidebikes215.
I have built an 1977 F2. Many items were incorporated into this F2 build.  The crankshaft and rods I had APE lighten and balance the crank. I also had them install new Falicon rods. This should make this engine about as strong as you can get from a crank standpoint. The Carrillo H beams are also a fantastic rod that I am using in a current engine build. The cases I had wire shot peened and ultrasonic cleaned. I then coated the inside of the cases with Glyptal. This coating has been used for many years in engine building for oil shedding.
The transmission I had undercut by FAST by GAST. The head was shot peened and new guides and kimblewhite vales were installed with heavy duty springs and Ti retainers. The cam I decided to use is a 63b by Webcam. This cam is 370/240 on both the intake and exhaust with a LC of 98. In order to get this cam installed with the appropriate clearances I had to recess the intake and exhaust seats about .005. I then ported the head and unshrouded the valves. With this cam or any other performance cam you will have to degree the cam and with this use a slotted cam sprocket. New cam chain, cam chain guides and cam tensioner were also installed. New Pistons, rings, wrist pins and clips were also installed. The ignition system I decided to go with was a Power Arc ignition. This ignition is optical with 4 curves you can access on the fly. The curves can be programmed by you with the programming software and a USB cable. I am currently using the stock exhaust with all baffles removed. I have several other exhausts but have not tried them as of yet. Oh yes, new primary chains as well as tensioner. As for carbs I am using Keihin 29mm CR's. I have found that dialing in the CR's have been interesting. But with these carbs you have access to just about everything without removing the carbs themselves. Once dialed in they work flawlessly. To help me figure out what is going on with the engine and chassis I have 2 great devices installed on board. The first is a VELPOR VR2. This is essentially an on board Dyno with lots of great stuff to play with. It is easy to install with really two pick points. One is a magnetic sensor on the rear wheel that will give you true Speed and well as compute HP and RWT. The other is tied into the ignition system for RPM data. The other system I have installed is an Innovate LM-2 Dual channel A/F monitor. As you can see you can really go crazy on this stuff. If you would like to see a small video of this bike you can see it here. 1977 Honda CB750 F2 Rebuild
No matter what you have come to the right place to get great advice. I have used this forum to answer my questions countless times. I wish you the best in your build.
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