Flash 5 Rises Like a Phoenix from the Ashes of F3

[bakaracer]

You want a pipe that makes peak power near where the bore does or adjust the bore to make power near where the pipe does to get the best performance. If not you will loise torque. Port out the exhaust only on the bore will make you loose torque. Remember the exhaust port is tuned to a certain tone. Your exhaust is the tuning horn for your cylinder. Ifyou open up the exhaust port, the intake ports will need to be adjusted too. They work together. There are certain angles too the ports has to face. If you make an adjustment, you need to correct the angle. If not you will disrupt flow and loose power. That's why i always say if you don't know what your doing porting wise. Leave it alone. All the companies put a lot of R&D into it to make them work.

[Wheelman-111]

Greetings:

Wise is Baka-san. I'll stick to removing some casting ridges and smooth it out as it lies.

Back to work last night, Pulling on Mighty Malossi crank:

F5CrankPull.jpg (144.72 KiB) Viewed 5490 times

The seam between the case halves is pretty critical. I worked carefully to clean off all the old HondaBond and wiped down the mating surfaces with my favorite solvent:

F5AcetoneCaseClean.jpg (149.07 KiB) Viewed 5490 times

My vision is starting to come back, thanks.
Next with a fresh tube of HondaBond, it's important to paint up the mating surfaces Completely with the Bond before pressing the cases together. Look, really LOOK all around inside and out for a small but reassuring seam of the stuff oozing out with no skips.

F5HondaBondOoze.jpg (158.08 KiB) Viewed 5490 times

Have a look on the inside, too. With a good light and rotating the crankpin out of the way, you can see all the way around. BTW this is how my Boost port turned out:

F5BoostFinalHondabond.jpg (162.68 KiB) Viewed 5490 times

I did not think it wise to cut into the little scrapers that hug the flywheels. I did this on Flash 4.2, and it may have been one source of lube issues contributing to failure. I angled my cut to preserve them. The area of the resultant trapezoid is still much larger than the cylinder boost port.

Only one problem: After I got the halves seated and bolted down - even installed the alternator - Prodigious Wheel-Thumb Strength proved too much for the left crank seal. Yup, I pushed it in too far - all the way to the pump drive. So I got to do it all ... Twice. Ran out of time to install the bore and finish up. More to come.

[LMH]

I pray for your bearing to stay in the case.

[Wheelman-111]

Greetings:

Thanks for your prayer. Actually, yes the bearings slipped off the crank for a change. They were still fully seated in the cases. After re-cleaning and Honda-Bond, I Pre-installed the seals and carefully slipped the crank through them. Now I KNOW they're in the right spot. Still lost an hour having to do it twice. One day I'll own a set of proper seal-pushers.

[bonesv]

Greetings:

One day I'll own a set of proper seal-pushers.

You could make your own using some correctly sized pvc pipe.

[deuce217]

Very nice thread. I look forward to seeing a video in the future of it running. When I get back from my vacation next year, I am hopefully able to purchase a stuffer crank.

[bradthreee]

I'm pretty dissapointed that you are no longer using your sticks and stones tool kit anymore

[kauaianman]

one thing i noticed about my malossi build is that the piston skirt hit the case on the rear transfer port/ stator side. i had to pull everything... sucked..

only noticed it after i started it up and heard the tapping sound

have fun. build looks good.

[kauaianman]

You want a pipe that makes peak power near where the bore does or adjust the bore to make power near where the pipe does to get the best performance. If not you will loise torque. Port out the exhaust only on the bore will make you loose torque. Remember the exhaust port is tuned to a certain tone. Your exhaust is the tuning horn for your cylinder. Ifyou open up the exhaust port, the intake ports will need to be adjusted too. They work together. There are certain angles too the ports has to face. If you make an adjustment, you need to correct the angle. If not you will disrupt flow and loose power. That's why i always say if you don't know what your doing porting wise. Leave it alone. All the companies put a lot of R&D into it to make them work.

what if you don't increase the exhaust port size, just take out meat after the port opening and match to exhaust?

or no good either?

[Wheelman-111]

Greetings:

TrippppleBrad, I represent that remark. My tool kit IS SO composed of rocks and sticks. How'd ya think I ported? Rocks. Spinning at 16,000 RPM, but still Rocks.

Kauai, thanks for the props and advice. How did you correct the piston/case clearance? Did it work out?
As for the exhaust port; the difference between the 23mm port diameter and the 29mm pipe diameter (or the 30mm step for the gasket...) is - let's see - a hollow Cast Iron cylinder with walls 3 (or 4)mm thick and extending back to a total height of an inch or so - from the gasket back to the outside wall of the cylinder. That is a TON of material to remove. Might wear out several of my Rocks before I'm done, give me some sort of Ferrous Respiratory Disease, and not sure what I would gain if I don't change the dimensions of the port where it exits the bore. As Baka-san insensitively pointed out (*Sniff*) I don't know what I'm doing too much.

Since the prospect of opening up that much material is so daunting, I think I'll just knock down the casting flanges and smooth it out with wire brushes. If only MadDog would teach me the proper, Old School way to port this Arn block... (Jus' messin' wit ya, Dog!)

[bakaracer]

You want a pipe that makes peak power near where the bore does or adjust the bore to make power near where the pipe does to get the best performance. If not you will loise torque. Port out the exhaust only on the bore will make you loose torque. Remember the exhaust port is tuned to a certain tone. Your exhaust is the tuning horn for your cylinder. Ifyou open up the exhaust port, the intake ports will need to be adjusted too. They work together. There are certain angles too the ports has to face. If you make an adjustment, you need to correct the angle. If not you will disrupt flow and loose power. That's why i always say if you don't know what your doing porting wise. Leave it alone. All the companies put a lot of R&D into it to make them work.

what if you don't increase the exhaust port size, just take out meat after the port opening and match to exhaust?

or no good either?

If your opening the inside of the exhaust port and not adjusting the intake side, No!. You can't just do one side. The engineers designed the port diameter and shape for a reason performance wise. Its designed to make peak power at a certain rpm

[kauaianman]

baka, thanks for the reply.

wheelman, only way "I" got to fix it was shave the case where the poston hit... thats what sucked. i had to re-split the case and do everything all over again...

now when i setup malossi cast i make sure to check if the piston is tapping before pulling in the crank. (i use a set of dummy bearings, setup the piston and crank and check for clearance, then i shave whats needed and check again before pulling crank and sealing case together with new bearings).

just shaved the old bearings enough to slide in and out of the crankcase and crankshaft.

[bakaracer]

baka, thanks for the reply.

wheelman, only way "I" got to fix it was shave the case where the poston hit... thats what sucked. i had to re-split the case and do everything all over again...

now when i setup malossi cast i make sure to check if the piston is tapping before pulling in the crank. (i use a set of dummy bearings, setup the piston and crank and check for clearance, then i shave whats needed and check again before pulling crank and sealing case together with new bearings)
just shaved the old bearings enough to slide in and out of the crankcase and crankshaft.

You could have just shaved the corners on the skirt of the piston. Rounded them off. That's where they usually touch.

[Wheelman-111]

Greetings:

Thanks K&B! I would rather shave my eyebrows than split the case a THIRD time.
Here's the beautifully-finished machined head:

F5CylHead.jpg (180.96 KiB) Viewed 5469 times

Even port-happy Wheelman knows not to monkey with that. Here's the surprisingly rough cylinder exhaust port, collared down to 23mm:

F5ExhPortBefore.jpg (129.81 KiB) Viewed 5469 times

The blue is masking tape stuffed in to minimize shavings from going everywhere and to block my tool from messing up the cylinder side of the port. Note the outer circle where a gasket rests when using a stock pipe. The inner circle chokes the diameter of the port, and has hard edges that I felt would create turbulence to disrupt the returning pressure wave. Note the rough ridge on the floor of the port at center. There's another on the ceiling and the whole finish is rough as 150 grit sandpaper.

I took a chance and got to work using a carbide cutter to rough in, and a concave stone to blend the corner into a curve:

F5ExhPortMid.jpg (209.73 KiB) Viewed 5469 times

I took about an hour, and with some fine blending with a sanding drum it looked like this:

F5ExhPortFinalUp[No matches vd_4].jpg (126.04 KiB) Viewed 5469 times

And Upside-Down:

F5ExhPortFinalDown.jpg (148.78 KiB) Viewed 5469 times

I'll wire-brush to finish and get that mirror finish on the exhaust port, and it'll be time to assemble. Wheelboy my 8 year-old kid helped clean up the cylinder fins and clean up the outside. I'm hoping he'll help with Final Assembly tomorrow.

By the way, King, why did you say it needed an extra head gasket? Seems to me Malossi wouldn't make it that critical on a "Sport" cylinder. If you insist, how do you run a gasket with that O-Ring head? A gasket has to be compressed across its full width or it will leak The O-ring won't allow that even pressure distribution.

[kauaianman]

baka,

what wheelman did is what i was talking about by matching the exhaust port to the pipe. didn't make the port any bigger, just took out meat for better flow in/out of the exhaust?

ported a cylinder like this recently but didn't have a chance to test yet.

hope it works out wheelman.

nice polish finish!

and nice PG short