Monster engine time

[sharky]

I want to build a good grunty motor and ad a sniff of NO2 for a little bit of drag oomph.

So a few questions...

Whats a good size ? I have been looking at the prices of wiseco 1260 +1314 kits....maybe find an xjr13 barrel/piston set.
Compression ratio ?

Cams...reprofile stock or aftermarket ?

Head job / oversize valves ??

Looking at a proper ram air system. Maybe FZR or R1 carbs etc

Last year at AFR i was chattin to Supercharger,i says "Why isn't Ozkat ridin the 1370 Gixxer down to Dubbo"?,Simple answer was"The more you modify an engine with high performance oversize bits,the less reliable it becomes as a general purpose bike".If your gunna pump $$$ into an engine for drag purposes ya gota go all the way,as 1 modification wont work without another.There's a joint in Brizzy that does nitrous kits for around $1200 ride in ride out. Personally i rekon you'd be well happy with that,rather than waste your money on something that will become impractical to use anywhere but at Willowbank.
There was a topic on [edit] www.dragbike.com.au about gas conversions at Ipswich way.Ozdragkat might be able to dig up a link,otherwise Abusa can give you the details.

I've heard that Yamy FJ/XJ donks are bullet proof.Yet to see one used for performance modification(but i dont get out much).I think Badvan was playin with an XJR13 for his new bike,but i'm usually always wrong.
cheers

[sharky]

So maybe just a mild 1260,clean up the head a little (stock valves), ram air and a good tune plus the gas....."plausible"...and cheaper.

Oh, and the reason for the ram air system......
...none other than 'why not' [}:)]
As I have said before these motors like fresh cool air so I'm taking it one stage further than my current (and previous) bike.
And I love the look of the ol' zxr750's with the air hoses through the tank...:D

[Tony Nitrous]

Do FJ / XJR motors have forged or cast pistons ?

Worth knowing if you looking into NOS.

Find as many folk, Willowbank, Dragbike.com, ASF,
etc etc and see what they're using.

I went for "NOS" Holley brand as it piss easy then to trade jets,
filters, Fuel pumps, and do re-fills when they are using the same
gear as you.

I keep getting told NOS kits are old hat, but they are simple,
reliable and a popular known product with history.

Dont bother with the stupid little bottles.
I ran a 2.5lb and it looked BIG on the bike, was OK for the drags,
but was never enough on the street.

I really should do it again....;)

[zx12argh]

How much attention from the plods do you get with a big blue bottle hanging off the side of the bike?

[ozkat]

The bottom end is where its all at. Its no good throwing money at the top end if down under isnt up to it. If you burn a piston or valve or even destroy a head you can fix or replace it alot of the time. You severely damage a crank or throw a rod your fucked, most likely your whole engine is destroyed. Do your research as well, alot of blokes were breaking cranks on oilcooled suzuki motors a few years ago at the drags before datalogging came in. The common thought was that oilcooled cranks were weak, not the case. They were starved of oil, an extra 500ml of oil cured the problem. Sharky build from the bottom up, dont add from the top unless you are 100% sure about the bottom. If the FJ engine has a roller bearing crank your off to a good start.

[Tony Nitrous]

quote:Originally posted by zx12argh

How much attention from the plods do you get with a big blue bottle hanging off the side of the bike?


Not a problem in UK, rode with mine on everyday for years,
even took it for the annual safety cert with it on.

Not sure they are quite so broad minded here,
might have to be under the seat or in the tail,
which brings up the problem of bottle size.

In the US you can buy a 2lb bottle with all the mountings
to sit it at the correct angle (important) with is sold
specificaly to fit under a Busa seat hump...[8D]

[xjrjack01]

what sort of times are hoping to get Russ?

[sharky]

Haven't a clue mate....first few runs will be done with an egg timer [:o)]

[Jockney Rebel]

..or a sundial.....:}

[Jockney Rebel]

btw dont the new xjr lumps have forged pistons? i think i read that on the blurb when i was lookin to buy one

[evad]

Hey Sharky, Have you had a look at this site?
http://www.fjmods.btinternet.co.uk/Shammas.htm

[Chris41]

Heres a link Sharky, I'm thinking first go aftermarket ignition and get stock or performance cams dialed in. anthing else is big dollars.
Chris

http://www.dynobike.com/xjr1300_hotup.htm

[xjrjack01]

quote:Originally posted by Jockney Rebel

btw dont the new xjr lumps have forged pistons? i think i read that on the blurb when i was lookin to buy one

Yep all the 1300's have forged pistons with carburised rods & electroplated bores. The last time I took my 1300 to the drags I was getting consistent 11.5-11.6 sec passes (no internal engine mods just timing bigger mains larger intake rubbers)I also tried a few runs with the silencers removed but my times were worse cause it was running to lean & wouldn't rev past 8000 rpm. Individual filters, bigger jets, decent exhaust & bigger rear sprocket would see those times improve a bit without spending to much cash, I recon yours would go quicker too cause it aint got half as much shit hangin of it as my old girl.