Down under, an idiot and a 400F

[neevo]

Morning in the shed prepping the motor for blasting (removing valve train, rockers, degreasing and a final clean. Checking over the head I noticed something strange, a very shiny section in each port.

I bought this head from an ex racer and was wondering if it might have had a mild port? Checking it against my other 2 heads it certainly appears to have had the casting marks removed. What do people think?

 

[o1marc]

Looks massaged to me. If it was a racers head odds are better that it has been.

Reminds me of when I used to race Fiats and our heads got pulled and they found that stuff which would have been against the rules to do. But Fiat factory cleaned up the bowls before assembling the motors. It wasn't something we did. To try and convince them of that we invited the track owner/official to our car yard and had him pick random cars that we would pull the heads off to sow him. It was in all the heads and he accused us of planting the cars there even though he picked the cars from about 20-30 cars and it was obvious they all still had 30 years old dirt and grime on them. They then would not allow us to run the 1600cc motor anymore and had to run the 1800 which didn't have the "porting", we still kicked ass even though the 1600 was a better motor.

 

[neevo]

That's what I thought Marc. That's a pleasant surprise then

Here's what I was planning for the cam chain locking bolt (although with a shorter thinned section), I assume if I add a washer underneath the locking nut, this along with removing the slits in the case should be enough to get that functional again and not leaking:

Is the top bolt for the tensioner arm just a blanking bolt to stop oil leaking out?

Also cleaned up the engine parts that will be vapour blasted including the exterior of the oil pump:

Also managed to get that stuck oil gallery bolt out thank god.

 

[Rick4004]

In regards to your cam chain bolt. I had a customer bike in once where the customer had drilled into the bolt and then tried to remove it with an Easy-out, but instead snapped off the hardened Easy-Out in the bolt. I looked at having it EDM'd out but they couldn't quote me a firm price, only that it would be in the $400 - $800 range.

I built a small hole saw out of hardened steel, and was able to core out the bolt and hardened tool all in one shot. It left about a 10mm hole in the cases, so I turned up a flanged sleeve on the lathe with a 6mm thread on the inside, 12mm outside, and threaded the hole in the cases to accept the sleeve. Loctited it in place, and it used the stock locking bolt and nut again.

Rick Denoon

 

[crazypj]

That will work, short section with threads removed is so it doesn't mushroom and chew everything up when you try to remove it.
You already know it holds the flat section on tensioner plunger
The top bolt is a blanking plug but there is a 'special tool' (long 3mm screw) that fits into the tensioner plunger for engine strip (not sure if anyone has ever used it? ;D )
Head has had some 'pocket' porting, personally I would do a little more on the exhaust side outlet and valve guide boss
There really should be more of an anti-reversion 'step' at bottom so don't open it up
Have valve seats re-cut, 3 angle, 0.030" on intakes, 0.060" exhaust

 

[neevo]

Head has had some 'pocket' porting, personally I would do a little more on the exhaust side outlet and valve guide boss

Might leave that alone as I have no idea what I'm doing.

Do the valve seats need recutting or is it just a sensible move? I'm reusing the valves from one of the old heads I have as they were in good condition and also kept the valves, rockers and cam together which I heard was a sensible move as they bed in as a set.

 

[crazypj]

It looks like a little surface rust on seats?
It's a good idea to have them cut, if it's done properly you don't grind valves with lapping compund

 

[o1marc]

If you're mixing used parts from different motors it would be wise to have a valve job done by a competent shop that would entail cutting both the valve and the seats. If you don't know what you are doing when it comes to porting you are making another wise decision not too. Most people who attempt this usually end up destroying a head and end up with something that makes less power. It is almost rocket science doing porting and polishing.
If that motor came from someone who raced it, doing what pj recommends was probably against the rules that probably only allowed cleaning of casting marks and no porting or blending.

 

[crazypj]

You don't touch the valves, the face hardening isn't thick enough

 

[crazypj]

You don't touch the valves, the face hardening is too thin, particularly on intake's

 

[neevo]

You don't touch the valves, the face hardening isn't thick enough

If you've got brand new valve seats cut, how does it seal with old valves? I would have thought the valve face would have been slightly worn and hence would not seal properly.

That's why I thought you had to lap after a valve seat job, to bed the valve into the seat.

 

[kopcicle]

I've ground Honda valves and reused them before . (wait for it Peter...) I had several parts engines and a pile of spares so the valves got ground and worked well , to a point . I only used the reground valves briefly and in well maintained engines no matter how throttle abused they were . it only took one set of reground valves in street bike to find that valves would close up with weekly predictability . I got less than 10 k out of that head . As time passed the small fours by and they were relegated to hobby bikes the seats were swapped out for bronze . The bronze seats would not terrorize the valves and actually held up much better than the previous steel on steel let alone the reground valves on the stelite seats .

I suspect the exhaust valves were induction hardened (a deeper localized hardening process) and the intakes were just lightly nitrided (A shallow but tough treatment that is what it sounds like . a molten metallic salt bath) .

Okay now to be unabashedly subjective . . Nitriding is a poor substitute for quality metallurgy in mass produced engineering . It has no place in an internal combustion engine used in a "production motorcycle." I've experienced soft valves , cranks , cams , rockers , the whole gamut of half assed , half hard predictable failure in all four Japanese MoCo's over 40 years . It is the one thing that has consistently pissed me off about the Japanese since I opened my first CT-90 .

~kop

 

[crazypj]

100% 8)
intakes are Nitrided exhausts have a stellite layer probably 0.010"~0.015" thick
It's quite interesting how the valves are made, they now form the heads like a giant rivet from a piece of wire ( I think they now do intake and exhaust, used to be just intakes)
Honda invented the process to save time and cut costs, forged one piece sounds good (they work OK in stock engines to 100,000+ miles)
Previously they were friction welded exhaust valves, one piece intake
I know one guy who tried to save money by re-facing valves, went a bit too far and got less than 1000 miles
He was pretty pissed at himself as the gasket set cost him almost $100.00 ;D
Oh, if the seats are cut to correct width, set valve clearance +0.001" then re- set after about 150~200 miles, they 'hammer' together and form perfect seal plus work harden I've never worried about 100% perfect seal with used valves and re-cut seats as I know they will bed in
If you decide to have valve face ground, re-set tappets after 3rd~4th fire up/heat cycle, they will have tightened up as faces bed in

 

[neevo]

100% 8)
If you decide to have valve face ground, re-set tappets after 3rd~4th fire up/heat cycle, they will have tightened up as faces bed in

Got it. Nice a simple. Given the surface rust on the seats I think a recut would be a good move.

 

[neevo]

Before:

... to be continued

 

[hillsy]

Prick tease....








;D

 

[andycafe]

.

 

[neevo]

If you don't know what you are doing when it comes to porting you are making another wise decision not too. Most people who attempt this usually end up destroying a head and end up with something that makes less power. It is almost rocket science doing porting and polishing.

What are people's thoughts on port matching the inlets to the carb boots as a minimum?

 

[o1marc]

What are people's thoughts on port matching the inlets to the carb boots as a minimum?

If the inlet of the port is smaller than the carb boots and there is a lip that the intake charge would create turbulence I would port match. I doubt this is the case though.

 

[neevo]

If the inlet of the port is smaller than the carb boots and there is a lip that the intake charge would create turbulence I would port match. I doubt this is the case though.

Thanks... as always

Will check out the transition and fix up if required.