Author Topic: The Vacillator build - F3 Engine (Read 8280 times)

flybox1 · « **on:** February 18, 2013, 09:42:12 AM »

The thought of rebuilding an engine first popped into my mind after I got my ($700) CB750 K8 last summer. Well, I though it was a K8, until I discovered one of the previous 3 PO's had slid a rebuilt K1 motor into my K8 everything else. Rebuilt with seeping red RTV at nearly all gasket areas. Luckily I came to find very little red stuff in the oil pan, and only a really slow leak from the right side of the valve cover. Re-torquing wouldn't help as it needs a helicoil. Other than that, the bike runs great. I'm just a little hesitant on taking in past the AAA 200 mi towing radius from my house

So, armed with determination, this great forum, and copy of HondaMan's book, I began the search for an engine I could take my time to 'refresh' while I enjoy riding. This will be my first complete engine build....

Enter last weeks $100 CL find. My son and I went and picked it up. The PO had taken this motor down and split the cases, right after it had the top end rebuilt, with plans to do a big bore. And as has happened to many, life got in the way, and it sat in heated storage. Lucky me

He said everything was there. We'll see.

I was pleased to find very little rust as the slight coating of oil and dust had preserved everything as I spread everything out. I soon noticed I had no front sprocket cover in the lot

small hurdle.

PO threw in a complete wiring harness, including battery tray and a set of rebuilt PD42A's.

flybox1 · « **Reply #1 on:** February 18, 2013, 09:44:14 AM »

After clearing shelf-space, and putting everything up, cleaning everything would give me the time to think what I want the final product to be. There are too many ufking options

Is it just me, or does anyone else loose sleep thinking of paint color schemes, or cam grind options and if or how big to bore

I'll be leaning on you guys for advice. Please point out any pitfalls or parts/items you see needing attention.

Hence the project name. I'm sure i'll change direction more than just a few times. But for now I do the tedious stuff.
..cleaning/organizing the bolts, screws, washers, etc., were all thrown together. $:-\$

flybox1 · « **Reply #2 on:** February 18, 2013, 09:46:04 AM »

Luckily I came across another complete, nicer set of rockers and shafts.

All bolts, etc., labeled by size and baggied up.

flybox1 · « **Reply #3 on:** February 18, 2013, 09:47:35 AM »

Soaked these overnight, face down in seafoam.
Domes then simple green scrubbed, rings removed and all holes/ring channels cleared of carbon (wrist pin oil holes also chamfered per HM) lightly coated with 12 year virgin baby seal oil and put away safe.

flybox1 · « **Reply #4 on:** February 18, 2013, 09:49:16 AM »

internally clean, but coming apart for paint and to verify valve guides/seals were done properly

flybox1 · « **Reply #5 on:** February 18, 2013, 09:53:40 AM »

OK done cleaning dirty isht for now. Needed to make something purdy

Thats all the time I had this weekend. Kids and wife need attention

More scrubbing, cleaning and planning to come....

iron_worker · « **Reply #6 on:** February 18, 2013, 09:55:27 AM »

Don't worry. You're not the only one who loses sleep over these bikes.

Good luck with your basket case. Trying to sort through someone else's dis assembly work is my worst nightmare.

IW

flybox1 · « **Reply #7 on:** February 18, 2013, 10:07:11 AM »

Cases will need deep cleaning, Glyptal, and paint.

Duanob · « **Reply #8 on:** February 21, 2013, 09:35:20 AM »

Nice score on the motor. Looks like you got a heck of a winter project to keep you out of trouble

Hope you got a bench grinder with a buffing wheel. It will make all that effort look real purdy on the outside.

flybox1 · « **Reply #9 on:** February 24, 2013, 07:14:27 PM »

Finished these parts off with an acetone wipe down and waiting for primer....
Started on my top upper case. You guys who have finished removing every last spec of paint from cases without blasting, my hats off to you. Stripper, brass brushes and elbow grease will take some time....

brandEn · « **Reply #10 on:** February 24, 2013, 07:35:24 PM »

Subscribed!

Whats the name mean?

flybox1 · « **Reply #11 on:** February 24, 2013, 07:47:03 PM »

'To waiver between different options'

flybox1 · « **Reply #12 on:** March 02, 2013, 08:42:13 AM »

The wife pulled her normal 24hr shift. Freed up the kitchen for some baking...
All parts prep washed with acetone.
2 light, 1 heavy coat, Duplicator DE1634 satin black.
2 cycles of 30 min @ 200F

deafcaferacer · « **Reply #13 on:** March 02, 2013, 09:36:27 AM »

Looking very nice!

brandEn · « **Reply #14 on:** March 02, 2013, 11:57:22 AM »

Like it!

flybox1 · « **Reply #15 on:** October 07, 2013, 12:22:01 PM »

Two cars, my K8, and all the kids toys in a small garage makes little room for a work space. Luckily after our kitchen reconstruction, I saved the center island from the scrap heap. Four locking casters from HF, a couple of rattle cans and some recycled rubber floor mats and I have a non-slip rolling workbench with storage space, and my HM book, to FINALLY start putting this F3 engine back together.
Never done anything like this before, but fall is here and its time to work...
The bottom end came intact, with the top case off. (Currently wrestling with 3 stuck studs) Just with a visual, the gears all look to be in really good condition. No broken or nicked teeth. Still all will be coming out, getting cleaned, and a coating redline, before doing back in.
This weekend I separated the head and barrels. I had no history on the gasket, so it had to go.
The head does look like it was rebuilt. Here’s the question I’m struggling with….do I trust the head work and leave it alone, or do I further disassemble, and start fresh?
Seals look new. Guides are NOT bronze, and I don’t know that I trust this as most seem to steer towards the bronze APE valve guides.
Pistons have been cleaned, but not marked which cylinder they came out of.
Cam and primary chain look NEW, but I will measure. This would be a nice score.

I'm NOT looking to build a performance engine. I want longevity. What direction would you guys take this?
It’s all in pieces, and I’m open for suggestions on this as its all new territory.
Hone and re-ring? bronze guides? new seals? decked? cycle x springs?
Any reason I should NOT do a .25 over? 836? Cam, porting, big overbore…while super cool, would lead me down a financial path that might get me in hot water with the missus.

For now, finishing up the bottom end work while I get some input from the experts.
Thanks…
Fly.

oh yeah....i've also got this lizard keeping an eye on things!

lwahples · « **Reply #16 on:** October 07, 2013, 01:09:28 PM »

Sweet deal on the F parts.I found that finding parts is different then with the K engines.Will be interested to see how this turns out.

Jerilee · « **Reply #17 on:** October 07, 2013, 03:38:46 PM »

I am *very* interested to see what you dig up for this engine build. I'll be building an F2 motor in the future myself and these are half the questions I wanted to ask myself!

Good luck and thanks for sharing!

70CB750 · « **Reply #18 on:** October 07, 2013, 04:20:12 PM »

Subscribed.

Are you going with the original F3 valve train? I had to replace my guides and my exhaust valves were shot - dimpled on the top end from the arm - I will most likely go with CycleX components.

brandEn · « **Reply #19 on:** October 07, 2013, 04:30:41 PM »

That thing looks like its reads to button up!
I have lots of bottom end parts so let me know if you need any parts before you start searching. Remember the weak spot with these F2-F3 top ends were the guides particularly the exhaust side and I think the retainers, so if it were me I would at least replace those.

Here is a good thread
http://forums.sohc4.net/index.php?topic=10540.0;nowap

70CB750 · « **Reply #20 on:** October 07, 2013, 04:51:54 PM »

I think to change retainers, valves have to be changed too?

http://forums.sohc4.net/index.php?action=dlattach;topic=115305.0;attach=233182;image

Jerry Rxman Griffin aka MuthaF'er · « **Reply #21 on:** October 07, 2013, 06:05:21 PM »

Let the fun begin again!

Is that a 410 head or a 392 head? It wasn't/isn't black? What size are the intake and exhaust valves? Are there numbers cast onto the top fin intake side by #3?

flybox1 · « **Reply #22 on:** October 08, 2013, 07:28:46 AM »

brandEn you've gone through TAO twice (sorry $:-\$ ) I wish I had the 'Obi-wan' force, like you to see what is good/bad, and could wave my hands and say 'this bottom end is ready to go'

but yeah, seals were on my list. Where'd you go for bearings? I'm going to start there....
Fasteners for the WHOLE engine were in a big plastic cup. $:-\$ another hurdle. Does Tacoma Screw have a punch card?

70CB750 i'll take a look at the thread. thank you, and yes, I plan on using the stock valve train, but might opt for new springs.

Jerry yes, I too noticed the head was not black like the rest of it. lemme check for 410/392 cast on it.
Valve size - are you looking for the size of the face of the IN/Ex valves, just so i know where to measure?
Might this lead me down a different path if its not an F3 head?

Guys...i appreciate your knowledge and i'll get back this evening.

70CB750 · « **Reply #23 on:** October 08, 2013, 07:44:34 AM »

This will help you decide what you have.

brandEn · « **Reply #24 on:** October 08, 2013, 07:49:29 AM »

I just put "bearings" into Google and hit maps. Found a place near me that sells them and went down there. For the grooved bearings I ordered from Yamiya. If you do this make sure they don't use UPS or you will have a TON of customs paperwork to fill out.

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Author Topic: The Vacillator build - F3 Engine (Read 8280 times)