big block XS250 (400) Turbocharged

[sprocket]

For the time and money or when I see someone with a 70hp xs400 I would just get a bigger bike

When I see a 70hp XS400, I wanna know how he made that much power!

I already have a few bigger bikes!

 

[xschris]

With time and money most anything can be done. I saw a guy put a 450cc engine in a vespa

 

[Pork Chop]

I want a flux capacitor on mine!

Only problem with a flux is that you can't do the ton as it tops out at 88mph.

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[Pork Chop]

With time and money most anything can be done. I saw a guy put a 450cc engine in a vespa

A bit off topic but this is one of my favourite engine conversions.

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[lcgtr]

For the time and money or when I see someone with a 70hp xs400 I would just get a bigger bike

Your right but remember at the start of this post why I brought this bike. I cant legally ride a larger bike on the road for 12 months, otherwise Id be putting the timae and effort into my XS650

Thanks for the info Drewpy

can I use DOHC rings in my SOHC?

 

[domains]

need a waste gate... how will you oil turbo?

 

[lcgtr]

Its internally wastegated.
Not sure where to pull the pressure from. I was thinking id tap the flow to the filter, use a conversion kit for a commando to adapt a spin on filter and then plumb to the turbo.

 

[drewpy]

Its internally wastegated.
Not sure where to pull the pressure from. I was thinking id tap the flow to the filter, use a conversion kit for a commando to adapt a spin on filter and then plumb to the turbo.

if your talking oil pressure, check out the xj600s as a few German guys have successfully used these adapters on the sohc.

its in my blog

 

[drewpy]

can I use DOHC rings in my SOHC?

no idea, you can tell us if you do it

 

[lcgtr]

this thing, the sandwich plate

thats a much better and cleaner method than I had in mind
Thanks mate, just have to track one down now

 

[drewpy]

that's the one

the bottom picture is a fabbed item

 

[lcgtr]

So the plan is to fit the top off an xs400.

I brought the barrel off an XS400 with pistons from the states for another previous project which I still had. It was supposed to be standard bore so I brought a set of NOS pistons cheap which were supposed to be 3rd oversize.
When I got it all here the bore was 2nd oversize and the NOS pistons were 2nd oversize as well........... unfortunately I never checked them properly when they arrived, I only discovered a month ago, lesson learned.
It shits me too because they both clearly have '.50' stamped on the pistons so the sellers should have known better.

Anyway when I pulled my new 250 apart I discovered the heads were different and also that the top ends were interchangeable as there was some talk on some forums that the gudgeon pins were different but I thought that was unlikely as all the rod lengths were the same and it doesn't make sense for Yamaha to make different conrods for the 3 versions.
Not that it wouldnt work with the 400 jug but the 400 has bigger valves and since I want more power I thought Id go the whole hog and luckily in my research I discovered Maddington MC Wreckers had a 400 they were breaking up (or they did as of late 2010)

250 head

400 head

so I found a complete 400 top end at Maddo wreckers which was an awesome pickup because Ive never seen a 400 over here in Perth before

Turns out now I have both the round cylinder jug ( .50 over) and the square jug (.25 over) for the 400. Ive read the square one is rare??? but Im not sure which Ill use atm

 

[lcgtr]

Now for the turbo I had planned to hack off the manifold and weld a flange to the exhaust housing. Its not easy to weld to cast iron but can be done. In fact where Ive seen it done they used old piston rings as a filler rod (as they are cast iron as well)

But I recently found out that the 1998 to 2001 fortwo smart car came out with a seperate casting

so if I wait I may be able to get one of these and Id like a spare as I can see the cartridge wearing out before I get the oiling requirements right

Also since now I know its now actually a Garrett turbo I will price up a new housing from a 1241 (I have a mate in auto parts whos a distributor)

Garrett GT12 - GT1241 - 130 HP ✈ Turbocharger Specs

Products | Turbochargers

Plus there is a Chinese company who appears to do a Vband housing which would be awesome but I need to buy 5...... anyone else interested ?
Turbocharger, GT1238 708837-0001 China Turbocharger supplier

 

[lcgtr]

Also I found out a cant take the turbo feed off the filter as once it goes through the filter it directly feeds the mains
The good old oil pressure switch is looking good, or the take off for the oil pressure gauge
Does anyone have a picture of how the oiling system runs from a factory manual??

 

[drewpy]

Lubrication chart - pressure feeds

oil pressure switch, oil main gallery, con rod, oil filter, piston cylinder, bypass valve, transmission main axle, clutch, cam shaft, oil pump, relief valve.

from Yam manual

 

[Drewcifer]

Hey mate, welcome to the forum if you're new (wasn't sure) and congrats on passing your test. Your 250 will seem easier and more fun even after you go bigger, trust me. My 360 is so light guys with bigger bikes love to ride it.

glad you are able to tune your 400. We all want to see what you can do!

Drewcifer

 

[lcgtr]

Thanks guys.

 

[lcgtr]

Im really chasing a diagram like this

obviously xs250, xs350 or xs400 will do

Anyone ever seen one?

 

[drewpy]

here's one

 

[xschris]

Nice one!!