gerald m

Been thinking about this vacuum leak I had . and little did I realize that the front two intake runners are independent to the rear 2 runners . even with the open plate gasket under the carb my vacuum gauge showed pretty fair vacuum ( 15 inches at idle )on the front two runners ( where I had my gauge ) but the rear two runners were low and didn't show me so . Even with a T connector it might show lower than normal vacuum but not which rotor might be suffering . I am going to buy two little vacuum gauges one for each set of runners and keep an eye on them just for curiosity. Or am I thinking to far out of the box ? . I think it would be easier to tune the 500 if I could monitor each rotor separate at the same time .

locism

very cool build!

gerald m

Few more pics of the bike build, Found something pretty different for this country today. I will make another post about it .

gerald m

Steve Whitham's methanol burning turbo charged 13b broke his chain close to the end of his run ripping of the chain guard which bounced across the track and hit his opponent Don Irvine in the head knocking him unconscious. ( concussion , bruises, minor injuries )

Steve totally built this machine from parts that he gathered together . He calls himself a rank amateur but I think he will have to give up that title soon. I have had many conservations with Steve and have watched his build from scratch . He is running a reworked 2 speed chevy trans off the front of the 13b engine . Steve has had over 50 successful runs in the 8's and 9's without mishap

Just a freak accident ..

.http://www.google.com/url?sa=t&rct=j...BD6kwdxtecJ2bw

bumpstart

updates gerald !!!.. had a chuckle just now at a custom bike TV show
.. three top $$ drag oriented hogs on a dyno.. fist two get 110 ish rwhp and show stupid lean on the AFR

other runs clean and makes 130 ish rwhp.. then spits the bottom end and all the oil onto the dyno

gerald's dragon is capable in the right tune of making closer to 170 rwhp .. and will do it all day

gerald m

An update ? well not much to share with the dragon right now .

I have ordered 2 vacuum gauges for the bike so I can watch both rotors at the same time when I am fooling with the timing and carb adjustments . I will run them on the center iron intake runners where there are already 2 nipples for the vacuum hoses .

I am still trying to get it in my head why it is necessary to mod the spark advance on the first gen dizzy . Is the vacuum advance to aggressive for the engine and making it prone to pre ignition or what is the reason for doing this ? I certainly don't have a problem doing what ever is necessary to make things work proper but I need to know why ?? Is it because as soon as the throttle plates open it sends the dizzy to full advance or just what is the story here ? I also read somewhere that the old style 4 prong GM modules do advance the ignition a small amount .

Changed the belt drive a tad , wider thicker belt with 3 teeth less on my primary sprocket on the final drive seemed to relieve the pressure on the belt and stopped it from slipping at bottom torque with all kinds of top end left .

The bike really isn't far off from being street legal . Lighting , signals ,, The front brake can be installed in half hour as I have modified the front mag to fit the original front end so all is needed is to pull front axle install stock front wheel and brake calipers with a restrictor so both brakes will work from my hand control with less pressure being applied to front . and of course the big one to muffle the ( EXHAUST ) . It's not hard to get inspected here mainly they are concerned about serial #'s etc . lighting and all ( I still have the original # from the 82 Honda saber which would qualify for vintage motorcycle and make for cheap insurance . ) not that I want to ride a rigid frame bike anymore but it would be great just to slip down the street once in a while and maybe try out a Harley or two , that would make the old heart pump . Just one trip up through Saskatoon would make the whole build worth while to me.

Yea lots of guys are building bikes with 100-110 HP now . The thing that makes me smile is like you said the dragon has the potential to produce 160-170 HP and that is bare stock without any engine work done to it. I cant imagine what it would be like to put out say 300 hp. But that will need to be a totally different build as the belt drive would blow up immediately .

The feel is a bit heavy on the handle bars when sitting with the 50 degree rake but lightens up almost immediately when the bike starts to roll out and stays very stable right to the top. No fishtailing on dirt or grass , it just digs a 2 or three inch rut and goes perfectly straight , any more traction and the front would be lifting . Don't know how one is suppose to break in an engine on a bike like this I guess just take it a tad easy for a run or two but at least now I have a back up engine sitting that could be up and running in a few hours if need be .

Still thinking of buying the 82 12a ,it is complete and comes with everything as it comes out of the car for 150.00 heck a used starter and dizzy is worth that much . By the way I took your advice and am running a second belt for water pump back up ( not really a belt it's a 3/8 O Ring ) takes a pretty good stretch to get the thing on but I think it will work , I guess I will know after a couple of 8000 rpm rips weather it will stay together or not .

Right now there is an unbelievable amount of snow here , more than I ever remember seeing in this area so I have another 3 or 4 weeks before I can take him out and try things so for now I am just tinkering with things like some descent looking rad hoses to hook all the solid piping together .

Any comments or suggestions are always welcome Thanks for your interest Bumpstart take care and be safe . Gerald m.

bumpstart

basically.. the extend or all open 6port likes more timing down low and thus will be happier with the base plate set somewhere from 5-10 BTDC than to the stock 5 ATDC

this .. if allowed to rev to full curve mechanical advance will take timing under load ( no vac advance at full load ) to closer to 35 BTDC than the stock 25 BTDC

obviously too much timing is also counter productive to power .. and brings detonation risk in some engines

by taking 1/3 to 1/2 off the centripetal advance slot slot length then you can tailor the end point to be closer to stock full load timing
.. whilst keeping aggressive base timing that will give back some power losses under 2500 rpm lost to the large ports and poor inlet airspeeds

the situation is a little bit further accentuated with a weber IDA carb,, not having the proper ported vac point for vac advance
..then it is common to see mild port engines with as much as 10 BTDC base timing to make up the difference to off idle power

if your holley has the correct port and its hooked up.. all good,, you can set for best idle vacuum somewhere between 5BTDC and TDC

if closer to TDC then you dont really have to mod the mech curve.. but from 5 BTDC,, yes you possibly will


the stock curve ( mechanical ) is 5 ATDC ( -5 ) to 25 BTDC ( +25 ) = 30 degrees at the crank
if you was to put the dizzy to 10 BTDC.. it will range 10 - 40 BTDC .. 15 degress ( half the mech curve ) too far

be aware that 1/2 to 1/3 off the slot is ambigous enough to encompass a dizzy that likes 5 ,, and one that likes 10
.. its up to you to tweak it up and down to get best idle vacs ,, whilst being sure no more than about 25-28 BTDC is happening at revs beyond 4000
be also aware that the slot length relationship to rotation angle isnt 100% linear and so its all done by set and suck with a timing light for idle,, and a check at 4000 rpm
( use calipers o n the stock pulley,, set at the factory split gap ( 15 degrees ) and project that clockwise,, twice.. marking as you go.. this give 10 BTDC and 25 BTDC marks )

also bending the posts that retain the tension springs for the mech advance will reduce the tension and get the max mech advance in faster.. usually timed for 3500- 4000 rpm .. some ported engines will like it all in at 2500- 3000 rpm

the trick with the mech advance slots is to cut a washer into moons,, and tack over the end of the slot.. be aware to dissemble the dizzy there is a screw down the centre shaft

gerald m

So the mod I did is a little different than most guys are doing but I think with the vac advance on the Holley I should get a fairly smooth advance and on the right port on the carb it should loose vacuum advance and let the frozen mechanical advance take over . If it doesn't work the way I think it might then I will switch it and close of most of the slot and let the pins float a bit .

No offense Bumpstart I just have this idea in my head and want to see what happens , If it doesn't work out I will do it the way you suggest .

Even with just a short start up I could tell immediately that the little engine runs much different than the #1 engine and both exhaust pipes were hot right away before with #1 the rear rotor never really fired hard until 1/3 to 1/2 throttle . # 2 engine is going to be much stronger , even the exhaust was much stronger sounding . I guess time will tell . gotta hode on .. http://youtu.be/hwe2Yrxbxdw Have a good one . Gerald m.

bumpstart

fixed the link


the method i described in the post above is "regraphing" and is used on milder engines for street use that are unsuited to the stock dizzy curve

the method you have done is the fully locked mod..
nothing wrong with this.. we do it for bridgies as its the same issue.. more extreme

for them a dizzy fully locked at max mech advance to suit best peak TQ is the method used
it will amount to a little too much timing down low
,, and this will cost a little bit of power under 2500 rpm and some idle quality,, and also pre-long the cranking

-- but be fine for everywhere else
it does fit in with the simplification of the ignition system you have been doing to guard against vibration issues
( IMO .. for your situ is much better to lose 5 hp or 5 Nm here and there but rule out totally issues with heavy vibration )

bumpstart

PS.. your filler neck needs to breathe
.. you need to uncap the vent hose and run the line to a catch bottle that is allowed to vent .. else motor will smoke on decel

another trick is to take the seal out of the cap .. but since it is so short it may be subject to surge that high and be messy onto engine

gerald m

Thanks for fixing my video Bumpstart my computer went to hell for a few hours and just wasn't working proper Yea i hear you about the vent tube , i have a vent hose on the other tube attached to the center iron right next to the filler going down under the engine . I did consider hooking up a pcv valve from that tube to the carb base but in the long run it would maybe cause more problems . I will try my mod if it gives me problems I will redo . Looking forward to spring so I can get the Dragon outside and give him a rip or two .

There are only three grass drag meets in Saskatchewan that I am aware of . Looks like I will need to travel out of province either Alberta or Manitoba there are a few I can catch up to there .

I would still like to run a little juice through the bike but decided to make sure everything is strong and stable before pushing things to far even a 70 HP shot would be nice . Take care man and have a good one .

gerald m

The little wagon looks like it is in pretty fair condition considering the vintage . twin dizzy, I presume a 10a but it doesn't say . Looks like the front bumper has had issues and front left fender , glass looks good rest of body looks pretty good looking at the pics very little rust . Apparently it has not ran for a very long time 4 speed standard. The dude wants 1000 bucks I imagine he will go down some . color is a light blue . just thought I would post , interested if this type of car is worth anything . 1000 mile or more trip to go get .

gerald m

finally got a few pics of the little Rx3 wagon has bias ply tires buy the look of it so I am sure it hasn't been driven for a long time ..

bumpstart

there is people in my country who would give eye/ teeth for that car
.... if its twin dizzie it wont share much for you to use but as a restored classic that is a uber desirable collectors vehicle

bumpstart

http://www.google.com.au/url?sa=t&rc...44990110,d.dGI

enjoy

gerald m

Wow that commercial brings back some memories .. Long before I was interested in the rotary but I remember that so well , it seems like a short time ago that commercial was on like many times a day . In 40 years they have went from hummm , hummm to zoom , zoom .

No I would never molest a nice old car like that for parts there can't be very many of them left in any kind of condition never mind in the condition that it is ,

If you notice in the back ground there are many mazda trucks and courier type of vehicles , I wouldn't be surprised if he has more Rx stuff .going to get in touch and find out just what he does have .

The rad on the dragon is from a courier and also getting very hard to find maybe I can figure out some kind of a plan to buy the little car and bring him home and pick up a spare rad or two at the same time , I sure I never find another at least not as complete as that one is .

bumpstart

thats if 100 bidders from aus/NZ havent climbed over the top of you to get it first...

gerald m

Not yet I just got a reply from the dude with his best price It's up to me , will PM you

gerald m

Well if I end up parting the little wagon out I will see if we can figure out a way to send you the cold start if you are interested NC ,It can't weigh much so shipping wouldn't be to bad . when I get it home and have a good look at things I will decide if I want to work on it or not . Biggest problem I don't have a shop and it won't fit in the living room . If I have a good summer maybe I will build a nice little shop . I don't even know how many miles are on it which I guess really don't make much difference . It is kind of a cute little **** . and I'm darn sure there aren't any in Saskatchewan .Your right One of the little pickups would be nice to have to pull the Dragon around with . As always thanks much for the input .

bumpstart

no need for the cold start here !! coldest i see is 5 C on about 10 mornings of the year ..however it is an interesting feature that is hard to find .. if breaking it up you should offer it all complete and paletised up with everything from door cards /dash /steering wheel through to driveline and vin plates and i expect it will be snapped up to make a RHD equiv on other end of the peaceful pond .... however if its a good underlaying body and the coolant drained then im sure there would be many US byers very interested
.. it is certainly looks an excellent and not too hard resto project

gerald m

Here's how the gauges turned out . I think they will work just fine it;s not like I need to monitor them all the time but with the different colored zones on the gauges I can tell what vacuum I have without reading numbers , just a quick glance will tell the story . Now to find some nice silicone hose with real clamps to connect the coolant pipes to the rad and bike . Just can't take looking at the ones that are on it anymore . Also found an original stock chrome front fender for the Trac front end just finished making a deal with the dude he also thinks he might have a nice set of hand grips that clamp on , the push on ones are only good for one run and they are already sliding off and the home made metal mesh ones I had on it last year worked great but are very hard on the gloves .

As far as the 73 RX3 wagon goes it's a done deal I just need to go get it . I'm anxious to see what else he has . I may never do anything with the little wagon but it's mine

gerald m

searched for over a year now for a stock front fender for the 82 saber Trac front forks . Finally found a fender in reasonable condition couple small dings but me thinks it is as good as it will get .

gerald m

You right bumpstart not that I thought you were wrong. also besides maybe the BMW and only a few of those . Went to the bone yard wrecker today with my tape measure and did some measurements on just different stud spacing on vehicles and found that quite a few call them mid size I guess, from Ford and some Nissan and a few dodge and a few non R- model Mazdas have the 4x110 size wheels unless they don't fit over other things but it looks like there is lots of room . I just grabbed a couple hide away spares that had air ( it is just to load the little dude ) and for all I know there might be a wheel in the back of the car . I think thursday me go get the thing. I will post you a few pics when I get it home . I'll winch the little **** up the ramps on a plank if I have to.

I noticed the 82 RX7 has the 4x110 but it has bolts instead of nuts . Wish I was a bolt instead of a nut .

bumpstart

yeh the mazda rx7 up to 82 have the 4 x110 and all the earlier mazdas use wheel bolts
.. might need to pinch some of those from a yard
( or maybe one from each of the remaining three wheels )
the early mazda rx7 ( 79 -81 ish ) should also be 13 inch wheels like the rx3
.. some of the vans may be 14s but should still fit

gerald m

[QUOTE=bumpstart;11461857]yeh the mazda rx7 up to 82 have the 4 x110 and all the earlier mazdas use wheel bolts
.. might need to pinch some of those from a yard
( or maybe one from each of the remaining three wheels )
the early mazda rx7 ( 79 -81 ish ) should also be 13 inch wheels like the rx3
.. some of the vans may be 14s but should still fit[/QUOTE



Almost 1700 km. to go get the little **** but there seems to be a shortage of the little wagons so maybe it's a good way to preserve one even if I don't do much with it .. Twice on my way home after stopping for fuel and a scratch people ask ( what the hell is that thing .. twice ,, same words except 400 km. apart ) ..

The dude I bought the car from just sold it for another older guy but has one of the nicest car collections that I have ever seen for a private collection . no mazdas but when I get the pic downloaded and set up I will post some of them very nice down to earth guy ,, good contact to know .. I think almost anyone into cars will appreciate the types and quality of his collection .. ENJOY
Good news I found the elusive wheel bolts under the floor mat !! some might not consider it a big deal but me do .