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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.
 
#719 ·
Pressurized system today.
I turned out not so good. it leaked enough for 14psi through a 4mm hose for a 0 psi reading at the boost gauge!
it was a porus on the charger outlet but mainly it leaked at the Y-manifold. i made that my self cause the stock wouldn't fit because of my stroker plates.
I'll have to do it properly this time around.
There are some 15ish horses escaping here!!!





Easy tiger, Guy at work said i could loan the gopro. Weather should be bad until the weekend so have patience
 
#723 ·
Now i have welded up some leaks and reworked the Y-manifold.
Turned down the small legs of the y on my lathe to make them round and smooth again and made some custom manifold bushings out of aluminium.

A lot better but i had to use loctites hydralic thread sealant to make it leak proof. I know it can't handle alot of heat, but it's proof for now.

The pressure release valve opened at 12psi so i will have to adress that. 20psi would be better.
 
#725 ·
A-Bombers Brother - sooo good, see you there nxt year, AND I really LOVE your Scoot....
 
#726 ·
I've been chasing leaks. When i started i fed the machine 14psi and got a zero reading, now i get a 12-13psi reading. Left is a leak at a really hard to get place and i think i can live with it.

Got myself a dyno appointment at september the 1st. If afr is decent then we can get some numbers out of it:D



Where you there? I looked for you but i didn't see you.
 
#727 ·
Where is the leak? Im having a hard time believing you can live with a leak that you know about.....

So you havent riden it with it producing boost?!


Im really looking forward to a video of this dyno run and of a real first ride and dont forget the happy dance.
 
#729 · (Edited)
I'd recommend a gage right on the adapter plate at the carb flange. I wouldn't trust what the losses might be through that hose.

On second thought, if you can plug all (or most) of the holes and it can equalize at 20, with no flow through the small hose, then yeah, it'll read ok...

Please 'scuse the brainfart....
 
#731 ·
The skies had finally cleared up.
Did buy an cheap action cam to a make vid for Mr brant & co. Test filmed in the garage to see if it catched what i looked at.It did.
so i started the vid and vent riding. I had a blast! 2 times deers jumped in front of me, Bike started to misfire/backfire and when start to fix it a guy pushing a praam asked me if i was out shooting unemploies.
-yeah i heard they pay 10$ a scalp.

I meet the strangest people riding this thing.


The misfire was a easy fix, it was spark jumping to boostgauge hose, again..
After that i wanted to see how much boost i was getting. This thing rips!
Sadly i was not getting any higher boost rating(???)

But it felt like a new machine, way more power on the butt dyno. Maybe it's because the mixture is forced into the engine instead of out through the pop up valve.

..Ohh you wanna see the vid??
Sadly the battery died 5 seconds after i put the helmet on. moahaha!
 
#733 ·
It was a slow day at work and i couldn't stop thinking of why my boost wasn't as high as i had expected. Googled for some m45 flowmaps and Did some calculations again and my conclution was that my boost rating was reasonable. So i had calculated wrong before so now i have geared my charger to low.

Googled some more.. but WTF1!

I have always belived and made my calculation based on the fact that i bought a eaton m45 charger but now i have realised that it is infact a eaton m24!

Have calculated it all wrong again?
Nah, my m24 are from a vw passat and they have internal gear ratio of 1.93 so for every revolution the pulley does the lobes turn 1.93 times which infact makes the anabola m24 a "m46" .

I can't find any flow maps for this thing. But a anabolic m24 is sufficient for my horse goal of some 50ish horses.
And what am i gonna do with this dynosession?
i want to swap to a smaller pulley and a bigger carb before i strap her down on the rollers. If i dyno now that aint gonna tell me anything if i swap pulley and carb.

I think i am in the 40 horses zone as is
 
#734 · (Edited)
I was looking at some blower boost charts at Blower Drive Service's website, and ran across this info. Probably old news to you, but it was a "refresher course" for me, got me thinking about what I'm doing with my blower project on pump gas:

" Final compression ratios in excess of 12.4:1 are not recommended for use with "pump gas." The higher the final compression ratio, the higher the octane rating of the fuel must be in order to help prevent detonation and serious engine damage.
The formula for calculating your exact final compression ratio is as follows:
Final Compression Ratio (FCR) = [ (Boost÷14.7) + 1 ] x CR
Boost = Maximum blower boost
14.7 = psi at sea level
CR = engine compression ratio
Altitude plays an important role in determining compression ratios. If the altitude in the area where you normally drive is significantly higher than sea level, then your compression ratios will also vary. To determine the effects of the altitude on a calculated compression ratio, use the following formula:
Corrected Compression Ratio = FCR - [ (altitude÷1000) x 0.2 ] "

For my project their chart says I should be seeing 14 lbs boost but I am only seeing 7 lbs boost, and I'm positive I don't have any leaks, so I don't know why I'm getting so much less.

Another chart says with 14 lbs boost and 8:1 pistons I should be getting about 15:1 FCR, and should not be running pump gas, but I am and am having no problems. So, are their charts wrong or am I doing something wrong???

Since you are aiming for a whole lot of boost with pump gas (or are you running race gas??), how do you avoid detonation and damage to the motor?

If you can pull it off, I'd run on the dyno with both setups and see what the diff is...

Good luck with the dyno, wish we had one over here....
This is still my favorite project here on JJ....
Willy



 
#736 ·
I was looking at some blower boost charts at Blower Drive Service's website, and ran across this info. Probably old news to you, but it was a "refresher course" for me, got me thinking about what I'm doing with my blower project on pump gas:

" Final compression ratios in excess of 12.4:1 are not recommended for use with "pump gas." The higher the final compression ratio, the higher the octane rating of the fuel must be in order to help prevent detonation and serious engine damage.
The formula for calculating your exact final compression ratio is as follows:
Final Compression Ratio (FCR) = [ (Boost÷14.7) + 1 ] x CR
Boost = Maximum blower boost
14.7 = psi at sea level
CR = engine compression ratio
Altitude plays an important role in determining compression ratios. If the altitude in the area where you normally drive is significantly higher than sea level, then your compression ratios will also vary. To determine the effects of the altitude on a calculated compression ratio, use the following formula:
Corrected Compression Ratio = FCR - [ (altitude÷1000) x 0.2 ] "

For my project their chart says I should be seeing 14 lbs boost but I am only seeing 7 lbs boost, and I'm positive I don't have any leaks, so I don't know why I'm getting so much less.

Another chart says with 14 lbs boost and 8:1 pistons I should be getting about 15:1 FCR, and should not be running pump gas, but I am and am having no problems. So, are their charts wrong or am I doing something wrong???

Since you are aiming for a whole lot of boost with pump gas (or are you running race gas??), how do you avoid detonation and damage to the motor?

If you can pull it off, I'd run on the dyno with both setups and see what the diff is...

Good luck with the dyno, wish we had one over here....
This is still my favorite project here on JJ....
Willy



Ok, my boost is 4-6psi (boost needle is shaky) and my CR is 6.5. That leaves me with an FCR of 8.25-9.15.
Our highest octan rating on pumpgas is 98 for gasoline, but the enviromentalist partie forced all gascompanies to offer ethanol at 104 octane at the gasstations.

Soo i don't expect detonation until some 20psi or something.
But i have no idea how detonation prone the flattie combustion chamber is.

Dyno it the way it is and then change ever thang. Don't forget bore size and cam profile. All of which change what the huffer is stuffing air into.

Bigger bore = less boost

blah blah blah
You are probably right guy's i dyno as is, but i will order a smaller pulley today
 
#737 ·
The best gas we can get here is 92 octane, but it has 10% ethanol, so that enhances the boost capability without detonation somewhat...
 
#738 ·
I bought another tach from the nameless auctionsite.
This one has the same font as my boostgauge and is mechanical drive and reads twice the turn of the cable.



I will have the off season to figure out where to put it and how to drive it.

I have an 26 tooth pulley and 4-6psi boost.
now i have ordered an 20 tooth pulley and what do i get then?
Supercharger will spin 30% faster.
I guess 9psi.



I made an adapter for my compression tester today since you brought the subject up. I had 7.5bar at the rear and 7bar at the front
 
#740 ·
Or 7-7.5CR. I will have do those compression tests again cause i forgot to disconnect the charger when i kicked the bike. It could have affected the reading.

I slided the su's jetneedle further into the alupiston, but it's been raining very heavy for 5days now so there have been no testing or filming.
wednesday we 4inches of rain in 24 hours
 
#741 ·
I couldn't keep my fingers out of the cookie jar.
I just had to put the smaller pulley sprocket on!
After a couple of early mornings at work i had this:


Tried heat shrink it on the sprocket shaft. Of course it seized and had to be knocked into place by a mallet.
That busted the bearing house circlip and its groove inside the charger, which set me back a couple of nights.
When it was finally fitted, it was to small cause the chain rode on the snout.


That made for some intresting lathe work to make clearance for tha chain



After that it was just plain wrenching.

hopefully there can be a testride tomorrow!!
 
#751 · (Edited)
That is some beautiful Country you have there My Friend. Do you have Elk (we call them Moose, we also have Elk here that are like Huge Deer ) there? Bike sounds great! What does the boost feel like now?
There is an earl in big mansion near by. he kept deers and wild boers on his land for hunting. Guess what?
They escaped!
very horny creatures them deers.
At dusk and at dawn they are everywere. Mooses are in more normal numbers, at least i see a couple every week.

I have nothing to compare the feeling with.
This is the only harley i have ridden. it's 210 horses short of my last bike.

Last time i rode it N/A was 2years ago so it's even hard to compare to that.
But it just feels like a bigger engine. I haven't met a hill that required a downshift yet. and when shifter thingy broke down i have ridden al the way home in third gear through intersections and all. twice.
I guess i have 50 horses here, give or take 5 horses.
But on monday the bullshit stops at the dyno.

Bike sounds great! The country side looks great! More importantly the bike sounds great!
The sound is heavily muffled.
The cam is in a waterproof box on the helmet.
Not a single word of what i said was recorded and the bike actually sound twice as much. i really got to do something about that.

I don't know what to say.

Fuck that was good. Imma re watch it.
There will be better ones my friend

Right now its set up for 5 pounds boost. Small steps. I'm figuring to lose a bit through cam overlap. But at the moment its run with what I got. If it works I'll go up.
What are you aiming for in terms of speed?
This landracing thing really appeals to me.
 
#747 ·
Bike sounds great! The country side looks great! More importantly the bike sounds great!
 
#750 ·
Right now its set up for 5 pounds boost. Small steps. I'm figuring to lose a bit through cam overlap. But at the moment its run with what I got. If it works I'll go up.
 
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