Author Topic: Drag Bike / The Big 4 Express. (Read 65886 times)

SOHC4 Cafe Racer Fan · « **Reply #500 on:** September 01, 2022, 10:22:44 AM »

Quote from: Don R on August 31, 2022, 08:15:42 PM

I drug the "other egli" frame off the shelf tonight and began to mockup the turbo bike. I want to see how the rake affects the ride height and how low I can get it since the exhaust doesn't go under it. Steve told me they added 10* to the neck but as it sits it's about 4 or 5* different than stock fork tube angle.
I went with the +3" box tube swingarm and the 750A axle, the A spacers don't work out due to the inside width of the swingarm. The tire is a 16x5" M&H slick. I'll likely cut off the wheelie bar mounts and weld on new ones that fit these bars. I think I can design in some adjustment.
The front end has cb550 #341 forks right now, if I use them, I'll order some new tubes, maybe lower them a bit more and probably go with K double discs on my A front wheel. It has a fork dampener and the front fender is fiberglass.
I made a fork brace for a cb900 once out of carbon fiber sheet and Kevlar composite from a funny car roll bar shield, I wish I had access to those scraps again. I don't know how rigid it was but it looked cool as heck.

That looks cool!

Don R · « **Reply #501 on:** September 03, 2022, 04:12:49 AM »

I'm thinking an F2 engine would work well with the turbo kit. The engine that was in it has flat top 836 pistons and the rings are so stuck I can't get them loose.
The ATP exhaust would look better ceramic coated, even though it's stainless, it is pretty blue.
I started building a low mile K6 engine case with an F2 backcut APE transmission, it has MTC steel rods which I prefer over the new but not in box MTC aluminum rods that came along with the purchase. The other choices of engine are a 77F or the 77K engine in the F'nK, it has 12,000 miles and tranny trouble, maybe a bent shift fork or slipped snap rings.
Just spitballing a little, sometimes when I type it and read it, decisions become more obvious.

Don R · « **Reply #502 on:** September 09, 2022, 02:31:44 PM »

I've seen some wonky sissy bars before but this one is really out there.

RAFster122s · « **Reply #503 on:** September 09, 2022, 03:54:36 PM »

If you wheelie that high, time to roll off and leave the bike...

Don R · « **Reply #504 on:** September 09, 2022, 05:44:59 PM »

Wheelie bars down, they tend to hang to the left a bit. I extended the right bar 1.5 turns to level them out. The existing top holes are an eighth of an inch off. I guess that's where it is. I'm measuring from the flats on the swingarm bolt and nut.
I added a pair of aluminum wedges under the safety bar on the lift in case it bleeds down since I'm higher than the bar.

Don R · « **Reply #505 on:** September 10, 2022, 11:26:45 AM »

The rear fender mount appears to have factory welds, but it's an 1/8" higher on one side than the other. I may be glad to have the frame jig still intact so I can check the axles and the motor mount bolts to be sure this thing hasn't taken a tumble. I'm not sure what it had for a back fender when it was assembled, after checking pics, there wasn't one on it.
This fender was mangled before I cut it up, the jury is still out on whether it's usable. Not my best work.

You build one wrecked bike and then you get gun shy. L0L!

Don R · « **Reply #506 on:** September 11, 2022, 02:40:23 PM »

I stretched a string to check centerline of slicks to the frame. I was able to adjust the axle side to side and change the shims. A 3/16" washer on the left and a thinner spacer made the wheel centered. I'm not sure about the sprocket yet since the engine isn't in it yet. I tightened the axle and swingarm.
The wheel was off center in the swingarm and not aimed properly, the wheelie bars aren't aimed properly although the distance from the wheels to the swingarm is good they are hanging to the left side. I believe the upper mounts are off an eighth or so front to back .

Edit; I used a crescent wrench on a pipe and bent the wheelie bar tabs straight, cut off one side of the seat hoop and welded it back on within a degree of level, when I moved it closer to perfect, the fender looked wrong, so I compromised. It now is pleasing to the eye and the tape measure agrees.

Next up, I'm going to put an empty engine case in it with an output shaft for sprocket alignment, then stack a cylinder and head so I can mockup the turbocharger.

Don R · « **Reply #507 on:** September 11, 2022, 04:05:18 PM »

I noticed the shocks are on the wrong sides, they have offset spacers to get chain clearance.

Don R · « **Reply #508 on:** October 09, 2022, 07:36:58 PM »

I dropped in a bare case, cylinder and head and located the engine bolts that I wanted. The head didn't have any exhaust studs so I need to swap it out and put in a cylinder stud or two. As I was told, I can assemble the engine in the frame. I'm not sure what the flat spots in the tubes are for unless a turbo support hanger was planned for it.

The 10K mouse motor written on the rocker cover refers to the 750 K5 bike that was wrecked, it had 10,000 miles and 10 oil changes then the PO took the carbs off and left the bike in a barn with the intakes open.

Don R · « **Reply #509 on:** October 09, 2022, 08:37:21 PM »

Somewhere I need to mount the fuel pump, I noticed an enterprising seller has cheap facet fuel pumps with ATP turbo pak decals on them for a cool hundred dollars. Or you can buy the decal for $14 shiped from england.
I also need to find a spot for the ARD CDI remote magneto coil and capacitor but it will get tested first. I did find the mark II instructions, it is self generating and does not get any outside voltage.

Don R · « **Reply #510 on:** October 09, 2022, 08:45:51 PM »

http://www.hondachopper.com/garage/ard_magneto_manual/ard_magneto_manual.pdf

Terry in Australia · « **Reply #511 on:** October 10, 2022, 02:19:53 AM »

Have you got a pic of your ARD Don? I've got a couple here, but don't know if they're type 2, 3 or 4.

Don R · « **Reply #512 on:** October 10, 2022, 02:44:13 PM »

I didn't know they went past type 2. I'll get a pic. tonight. The turbo test fit appears to be challenging too.
I want to test run the ARD by putting a crank and a couple oiled bearings in an empty case and spinning it as fast as possible, if it appears to work then toss it on a known good running bike.

I think that cap is for some kind of Fiat, maybe the Abarth? Bobina and the rotor says W. Germany.

Terry in Australia · « **Reply #513 on:** October 10, 2022, 04:19:36 PM »

Thanks Don, mine don’t have the original tractor magnetos, I haven’t looked at them for awhile but from memory they have a similar magneto to a 2 stroke dirt bike and the belt only turns a shaft with a rotor button in a distributor cap. I know that one of the later versions had a round manhole cover on the outer casing to check and clean the points and at least one had an electronic ignition that required a special coil and black box as well.

Don R · « **Reply #514 on:** October 10, 2022, 04:23:23 PM »

I also have one of the FM tractor mags, I like the start retard on these but am not committed to running either. Jaguar sold me some of his last FM parts and it throws a spark but the stroker engine had sunken sleeves.

Terry in Australia · « **Reply #515 on:** October 10, 2022, 06:19:06 PM »

Quote from: Don R on October 10, 2022, 02:44:13 PM

I didn't know they went past type 2. I'll get a pic. tonight. The turbo test fit appears to be challenging too.
I want to test run the ARD by putting a crank and a couple oiled bearings in an empty case and spinning it as fast as possible, if it appears to work then toss it on a known good running bike.

I think that cap is for some kind of Fiat, maybe the Abarth? Bobina and the rotor says W. Germany.

Thanks Don, yep I had one of those ones as well but sold it to a Cafe Racer guy in the US (might have been a member here, I don’t remember) I’ll drag one of mine out when I get home and take a pic to show you the difference. Mine are for Z1/KZ900/1000’s, and getting popular again so I might sell them to finance another Dyna 2000 for my 1428cc bike.

Don R · « **Reply #516 on:** October 10, 2022, 06:59:24 PM »

https://www.ebay.com/itm/185439461217?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=56PkeSqTTnC&sssrc=2349624&ssuid=sLFMhkXMQBO&var=&widget_ver=artemis&media=FB_MSG&fbclid=IwAR3H6-4_MvDHcxQ0d9kgM4X3XFQoniuMmmp8JCtfO7fTu9CJ1GdVj9U5xIU

I think this is the cap and rotor, if it works, I'll buy new ones. Fiat X19 maybe.

Terry in Australia · « **Reply #517 on:** October 11, 2022, 12:15:19 AM »

Here you go Don, here's the ARD Mk 2, or 3, or 4:

ARD Tuesday by Terry Prendergast, on Flickr

ARD Tuesday 1 by Terry Prendergast, on Flickr

ARD Tuesday 2 by Terry Prendergast, on Flickr

ARD Tuesday 3 by Terry Prendergast, on Flickr

I wondered if they were possibly an ARD that was modified by an owner and not by the company, you and I know how agricultural ARD stuff was but a lot of guys aren't familiar with them, but the two I bought came from 2 different sellers, one here in Oz and one in the US, so I'm sure they're an actual model. They look very simple, and the benefit with these is that they don't need an external coil or black box. It kind of makes me wonder why ARD bothered to then make an electronic version with lots of external parts.

Oh, and yes, that cap looks right, I can take a look at mine for a part number if you'd like, have you found a rotor button for it?

Don R · « **Reply #518 on:** October 11, 2022, 08:16:23 AM »

I can only assume the rotor matches the cap. I won't replace either until this thing throws a lightning bolt or two.

Don R · « **Reply #519 on:** October 12, 2022, 09:27:58 AM »

Hey Terry, if you are able to get the cap and rotor button parts from the guy on facebook could you shoot me the numbers?
I'd like to see an ARD info sticky somewhere and an ATP info thread too.

Terry in Australia · « **Reply #520 on:** October 12, 2022, 04:43:24 PM »

No worries Don, will do. I just checked FB and he hasn't replied as yet.

Don R · « **Reply #521 on:** October 19, 2022, 12:51:39 PM »

I've been polishing and cleaning the extra turbo parts and working on the wastegate, the valve seems to be stuck. I got it to move back and forth with some help but it appears to be pretty stuck. Makes me wonder if it was operating the last time the bike ran.
It needs to come apart to clean and polish everything. It looks like an exhaust valve with a stop bolt above it, pressure from the intake seems to operate it so there must be a diaphragm of some sort in the top section.
The unit came apart fairly easily, the diaphragm is now cleaned out and moves, the valve itself didn't come apart easily so I left it in and cleaned the stem in place.
Several really short stem valves came with the parts totes. After seeing the wastegate I'm guessing Steve was rebuilding or modifying them.

Terry in Australia · « **Reply #522 on:** October 19, 2022, 03:55:02 PM »

I love my twin turbo Subaru that, due to the magic of ECU’s and modern injection can run high compression with no ill effects.

One of the biggest issues with turbocharging CB750’s back in the day was that you had to run low compression pistons so as not the blow head gaskets, if the bikes were street ridden they were always struggling with low power off boost, and an over rich mixture, needed so the bike didn’t run too lean when on boost, with the very real possibility of melting pistons in the process.

There were no intercoolers to feed cool air into the intake, so hot air was being pushed back into the engine (not ideal) and most of the turbos available at the time were too big for a CB750 so exacerbated the problem by adding massive turbo lag to the equation. I take it that your intention is to take this old drag bike back to the track Don, where none of the above issues will be a problem for 1/4 mile runs?

I rode a turbo Kawasaki Z1 in 1978, I remember that it was a real pig in city streets and I struggled to keep up with the Kaw’s owner (who was riding my shiny new CB750F) until I hit the Eastern Freeway on a Saturday afternoon when traffic was very light, and the Kawasaki transformed itself into a wicked, wicked beast, when on boost.

Don R · « **Reply #523 on:** October 19, 2022, 05:12:02 PM »

My thought is moderate compression on E85 (mixed by me or bought from VP fuels) a small amount of street riding, bike/car shows and maybe a trip or two down the track. That will help with detonation, cooling and give me a broader safety margin for AFR. I already have an o2 sensor with data recording and a pyrometer.

The induction is still up in the air, a friend has learned the microsquirt EFI and another is a VP at Holley in charge of EFI and racing. My buddy with the Harley shop behind his house is up to speed on anything designed to fit where this old Ironhead carb bolts on. I've been watching the George Bryce from Star racing videos, he says an EFI can run a hugely oversized throttle body with few ill effects. Engine masters TV showed how E85 can be used with a turbo/blower and no intercooler.

I'm thinking a lightened rotor and 750 A charging system that is on the shelf to keep it in voltage. Maybe I can live with a partial loss charging system head and taillights with LED's and an Oddysey battery that I also have. It's heavy though.

My plan is for it to be more of a street freak than an actual drag bike or cruiser. I'll likely try out the Bendix/zenith with an added powerjet.

Don R · « **Reply #524 on:** October 20, 2022, 01:17:10 PM »

I chose the turbo intake that's not chromed, of course it had some nasty casting flash inside. I spent a couple hours smoothing and porting the inside. There is now an edge on the center divider where it was blunt and now the inside is relatively "chunk of junk" free.
I wire wheeled and sanded the nasty black coating of wrinkle finish off the outside. I'd like to get a cerakote kit and do all of these headers and manifolds.
The band saw made short work of cutting the 2 1/4 X 4" long silicone turbo hose into 2 pieces. That leaves a spare if anyone needs one.
I've been thinking of how to do a timing retard for boost, it might be as simple as a boost referenced switch tied into the start toggle on the gen2 ARD mag. An MSD would be ideal though, hotter spark and availability of any rpm/timing controls needed.
I also found a video of guy running a gas carb on E85 with the use of a thunder-jet/power jet additional fuel circuit added to the carb. It would be interesting having three knob adjustable fuel circuits in a single carb.

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Author Topic: Drag Bike / The Big 4 Express. (Read 65886 times)