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Blown 45 build

357K views 2K replies 127 participants last post by  Elffors 
#1 · (Edited)
Hello!
The build season is comming up here in sweden and my 45 is up for an overhaul again. I built it from an pile of parts from what must have been an seventies chopper.

View attachment 80272

After the first winter it looked like this
rather bobbish

View attachment 80273
Now i been drawn to more of a dragrace style.
The idea for now is to make it blown but maybe i go for a more radical N/A engine. Time will tell.
Hopefully i will have enough time and money to make this happen til next summer.
 
#6 ·
Re: Swedish 45 build

I hope the first picture is what you started with, & the second is the out come !!! That is sweet !!! Me personaly would not change a thing, it suits my taste as is !!!!
 
#15 ·
Re: Swedish 45 build

I'm with these guys^^^ leave it alone!
This is not a vote thread about leaving this bike alone or not.

no matter what you do ,make lots of pics and post them ;)

i've been thinking of building a blown /compressed "45 ...but i think it will break into pieces
that's why i decided to build "45 engines with matchless G3 cilinders and heads instead

(you can do a search here on cees fick /kees fick and you will find a thread and pics !)

but hey be my guest > i like special "45's and builders who think out of the box when building something redicule and fun !!!
So it was your bike in 45pic thread with matchless cylinders!?
Thats radical! Hats of to you.
I've thinking of such radical mods my self but doing some serious stuff in the past i know it doesn't work with small children and house restoration's.
it simply takes too much time.
But then i grow up to be an greybearded old bugger i will have an fully equipped machine shop in the garage and all time in the world. then!!!

look up the brew dude's 45 turbo flat out flattie, might give you some ideas good luck and keep us in the loop this oughta be good
That i must check out.
I've been doing an tuboconversion of a japanese fourbanger bike before.
It took me 2years to get it all right. But man, that thing is ludicrus fast.

This will be more of an show off bike at the local hot dog stand. (swedish expression)
More show than go, to keep the engine together

Maybe the blower generates to much heat so the bikes overheats and seizes. Thats my biggest concern, or the cylinderwalls are to thin, so the cylinders cracks.

Blown 45? Hell yes! I'll take two, sign me up...!
Naa.. sorry will only make one:D
 
#12 ·
Re: Swedish 45 build

no matter what you do ,make lots of pics and post them ;)

i've been thinking of building a blown /compressed "45 ...but i think it will break into pieces
that's why i decided to build "45 engines with matchless G3 cilinders and heads instead

(you can do a search here on cees fick /kees fick and you will find a thread and pics !)

but hey be my guest > i like special "45's and builders who think out of the box when building something redicule and fun !!!
 
#18 · (Edited)
Re: Swedish 45 build

This weekend the projekt was to shortened the snout. I got half way through this projekt then i realized that my work only had the inserts for the internal groovetool not the actual tool.:eek:
Well, i finished turning the new bearing surfaces which where the hardest part. Hopefully i can finish this by next weekend.

Keep the boost low or run lower compression. As long as the mixture is correct and air moving over the fins, it should live.
Lower? Im already down til 6:25 comp ratio.
But i am a bit anal about afr ratio's.
I'ts stupid to build an engine for a lot of $ and then seize it beacause you run a lean mixture.

Thank's for sharing. How did it end?
 
#21 · (Edited)
Re: Swedish 45 build

So i finally got around to work on this again.
The snout is done, and shortened 40mm (1.57 inches)
Next thing is to get sprockets, bearings and seal for the drive and machine a new shaft for the shortened snout.
 
#22 · (Edited)
Re: Swedish 45 build

This is a slow moving build..
Anyway, at last i got something done. I made an new shaft fore the snout fitted bearings and seals, and found out to my suprise that the shaft is'nt straight by 0.02-0.03mm and the darn thing is turning backwards..
With a little tinkering the internals could be turned upside down som now it turns the right way again!
Here's an mock up picture

I think this is gonna be great!
 
#26 · (Edited)
Re: Swedish 45 build

I must ask a stupid question...
Since we here in sweden have silly national sports like soccer and such and the americans have supercharging chevy smallblocks as theirs, i wonder do i go up in carburator size then i build a drawtrough set up or does the carburetor compensate for the added sucktion from the supercharger?

Lookin real good, man.
Thanks!
 
#28 ·
Re: Swedish 45 build

It isn't a stupid question. Now that you have asked it, I want to know the answer too.

One would think you would have to increase the size of the carb at least a small amount to allow the compressor to do its job and not be straining to breathe.

I agree with your statement about it being stupid to run one lean too. I have watched far too many guys ruin a perfectly good engine trying to suck that last 0.5hp out of it by running it just a touch leaner, and leaner, and leaner.....till they find the lockup point....
 
#29 ·
Re: Swedish 45 build

Good question, but the looks of the pullies you are running close to 1:1 ratio.

Here's the deal, the blower is 45 cubic inches in displacement and is only about 65-70% efficient and that's at 4-8K rpm range.

The effective cubes is around 76".
That at 100% volumetric efficiency cause it's huffed makes a needed 111 cfm @ 5000 rpm.

Now what rpm is that 45 gonna be at most of the time? That is what you carb it to.

I suspect the carb you have now will be fine to start with if it was setup for a higher compression NA 45. Less cfm will limit max rpm, jets will determine fuel.

Best is to get it to idle and use a vacuum gauge at the carb base. Set it accordingly at that range. Move on to the next rpm range out of the idle circuit and jet it there. I would suggest an O2 sensor in the exhaust on each hole for best results. Maybe with another set of test purpose exhaust headers just to set it up, then when it's dialed in you can put the intended pipes on it.
 
#30 · (Edited)
Re: Swedish 45 build

Finally i got the thumb out of my arse and actually did something with this build!

I laced up my backwheel with a 15" dropcenter rim and mounted my new tire.
I know it's probebly rubbish but this is more show than go. A flathead 45 is never ever gonna go as fast as this is gonna look:D

Good question, but the looks of the pullies you are running close to 1:1 ratio.

Here's the deal, the blower is 45 cubic inches in displacement and is only about 65-70% efficient and that's at 4-8K rpm range.

The effective cubes is around 76".
That at 100% volumetric efficiency cause it's huffed makes a needed 111 cfm @ 5000 rpm.

Now what rpm is that 45 gonna be at most of the time? That is what you carb it to.

I suspect the carb you have now will be fine to start with if it was setup for a higher compression NA 45. Less cfm will limit max rpm, jets will determine fuel.

Best is to get it to idle and use a vacuum gauge at the carb base. Set it accordingly at that range. Move on to the next rpm range out of the idle circuit and jet it there. I would suggest an O2 sensor in the exhaust on each hole for best results. Maybe with another set of test purpose exhaust headers just to set it up, then when it's dialed in you can put the intended pipes on it.
Thats right. ratio is 1:1.
Having done some calculations with the corky bell supercharger book, i found out thats going to be about 0.69bar boost which would result in a 50bhp+ range.
But i've learned that expectations should be set looow, because you can't bench race the dyno. it never lies and never live up to wild expectations...

I've got myself an used SU HS4 1½" inch carburator. it's about what i think is the right size.
 
#31 ·
Re: Swedish 45 build

Hell yeah, that will work just fine. Get her to idle and then I would get a tuning set of pipes. Maybe some purpose built ugly ones with bungs for each hole so you can stick an O2 in there and really see, not guess what's happening. You only need one of those generic digital gauges and O2 kits.

50 hp is gonna make that little monster move out good. You're not gonna spin it high enough to make enough boost to hurt it......now change the ratio on the pullies and get the huffer spinning earlier....:0
 
#34 ·
Re: Swedish 45 build

Hell yeah, that will work just fine. Get her to idle and then I would get a tuning set of pipes. Maybe some purpose built ugly ones with bungs for each hole so you can stick an O2 in there and really see, not guess what's happening. You only need one of those generic digital gauges and O2 kits.

50 hp is gonna make that little monster move out good. You're not gonna spin it high enough to make enough boost to hurt it......now change the ratio on the pullies and get the huffer spinning earlier....:0
I've got one of those innovate lc1 things since my turbocharging days.

Have you ever held an japanese sportbike with 14PSI+ boost wide open on the public road, and trying to read those little afr gauges and trying to remember the reading at a certain rpm?
At the higher rpm you will be carrying the front wheel high, going at an ridiculus amount of speed............
I had enough of that, i leave the fine tuning to my dyno operator friend. Then i get my Afr on paper.
Rejet my Su, dynopull, rejet, dynopull, and so on. Til i get it just right.

Looks awesome with that HOOSIER on there. I'm running an SU on my servicar that was supposed to be good for a paperweight when it was given to me. Post up a video when you get it going, can't wait to see and hear it. keep up the good work. George
thanks! Su's can carry a lot of attitude, with their slight angle.
Uppkaftigt is the correct swedish word..
 
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