elaborated engines

well, seems to me that there is not such treath in this forum, so i post it now.
How did you elaborated your xj engine and what are the new performance?

 

Hello Luxio, I think there is a translational error in your post so I'll ask for some additional information. I'm assuming that by elaborating on an engine, you mean to ask about performance enhancements. Is this correct?
If it is, there are relatively few options for performance enhancements.

You can put Air Filter Pods in along with a 4 into 1 exhaust and then have to re-jet the carburetors, a long and involved process to get right.
Change out the stock coils for units from Dyna or Accell.
Install NGK Iridium plugs.
Then there is a very time intensive process called porting and polishing your intake and exhaust chambers located in the cylinder head. This is not something just anyone should jump into because there is an opportunity to mess up the head in the process.
I hope I gave you an answer to your question and I expect others will respond with opinions. Best of luck to you!

 

yes may be you are right. in italian language "to elaborate an engine" means change some parts to increase performance.

 

First thing is what bike do you currently have? Options are almost endless depending on your budget and what you want to do. You could rebuild the engine with better parts (higher compression pistons, better rods, ported heads, larger cams, ect...). You can swap to a larger engine (probably cheaper and easier depending on what you have already). You could turbo the engine or add Nitrous to it.

Of course the simple changes would be a header and jet kit.

Sean Morley

 

is there a company that makes streetable cams for these engines?

 

Iskenderian Racing Cams
Gardenia, California.

They don't make Cams.
They take yours and redo them with a different grind.
Adding lift and duration to the stock Cams YOU send them.

You need the tech info from the Data Pages out of the Workshop Manual.
I wouldn't think that the Yamaha Cams would benefit from too much Lift.
However, a little move duration of Intake is going to add some ponies to the stock configuration.

http://www.iskycams.com/askisky.php?email_mode=2

 

I am setup with Megacycle cams and they have a number of different grinds available (on your cams). I may have some cores I could send in for you to save you downtime. I can even probably get the head ported for you too. Problem you have is shipping. Those parts are do-able but will still add up quickly.

http://www.megacyclecams.com/catalog/catalog.pdf

 

Megacycle cams too, same principle, ship them your stockers and they build up the lobes and regrind them megacycle PDF they offer everything from mild to wild, best bet would be cam grind 256-30. Also remember that depending on the model, there might be a small benefit using a different models cams. The XJ650 in 1982 had .03 millimeters more lift and 4 degrees more duration than the Maxim engines. The XJ750 Seca motor had 4 degrees more duration than the 650 and 14 degrees more overlap. Something to consider on the cheap. cruzerjd

 

in italy this is not possible due to the italian laws.
i have an xj650 seca of 1982. i am thinking about change carbs block and changing the air filters.
can the xj900 carbs block fit in my bike? can differents sized pistons fit with the same crank case?

 

would they know if you changed the engine? are you allowed to bore out the stock engine?

 

If you put the 750 crank, rods, pistons, cylinder block and head on the 650 crank case, you would keep your engine # and the inspectors / authorities / cops would never know. Sounds like alot of work for 15 HP.

900 carbs on a 650 isn't the answer.

 

I agree with timetoride. Switch upper cylinder and then get custom pistons, cams and ported heads. It's expensive to do that though!. You could put lower compression pistons in it (or double up the base gaskets) then buy all the seca turbo components and turbo charge it!

Sean

 

Turrbboooooo!

Add the 750 head, a jet kit, racing pipe, oil cooler. You can also throw a turbo on anything, a fellow on Sport-touring.net put a turbo on a DRZ 400. This is much more involved and likely requires some cutting, welding, and a fat wallet.

Turbo DRZ 400 Linky



I love this little turbo!

 

this means that i can add the turbo in my bikes? wow :twisted:
there is some thread that explain this?

 

Just Say No.

 

drz400 NICE! i race an ltz, wich is the quad with a drz engine. MANY people out in the dune areas have turbo'd the quads, these engines hold up great with them!

i bet a nice set of cams and higher compression/larger displacement top end would be a lot easier and more reliable than trying to make your bike a turbo. it could be done though!

 

I see no reason why you can't. I have been using 750 Maxims in my 650 Turbo Chassis. I am planning on installing a 900 Seca engine into it when I get a chance (I have the engine already but will be rebuilding it).

The problem with simply bolting one on a stock engine is that the existing compression ratio will make it harder on the engine overall. Lowering compression by raising the jugs up can be done by shimming the base gasket with either a custom base gasket or by using 2 stock gaskets stacked on each other. This will help lower compression a little and leave a better ratio for boosting. The ideal way would be to have custom pistons made (which we can get) but that's fairly expensive. I have not lowered the compression on any of the engines I have used and they all have transmission failures well before any other parts fail.

If you can get a complete turbo parts bike you would have most of the stuff you need for the conversion, Of course you can custom make a system to it too. None of these options are cheap but I have no idea of your budget either.

Many years ago there actually were bolt on turbo kits sold for the regular maxims. I have only ever seen one in person.

There is probably not a thread in here but there is a lot of useful info on the in's and outs of turbo seca's.

 

so the better is 900 case + turbo?

 

Probably from max power standpoint you would get a 900 engine and perform your mods to it. The regular 900 ran very good to begin with. Once turboed it will be a monster!

Sean

 

Don't be a a pessimist, a boy can dream!