i will shortly be aquiring a rebuilt (but not assembled 250xflow
it has been bored out 30thou, port and polished etc etc

essentially i want to take it further with new pistons (flat tops?) and a new cam... it will be in front of a 5spd (either t5 or supra) and has a set of tuned extractors which run into a 2.5inch exhaust, on the inlet side is a redline torker manifold which cuerrently has the standard xf webber ontop..........

after completion the engine will be pput into my daily driver (xf falcon) and i therefor want it to be drivable down low and use a reasonable amount of fuel

the wuestion is.. what should i do.. are higher comp pistons worth it? and what cams do people recomend....


sorry for the long post

-mitch

A mate of mine had a High comp datsun 1600 and that thing had phenomenal amounts of torgue. Going around a corner in third and just 1 pump of the clutch and this thing would snap sideways at 80kmh+.

lol ok.. not sure how that helps but thanx for the reply

no good

wtf???? can sum1 help me out please? preferably with a sugestion?????

just wondering how much did you pay as i seen it on ebay and was thinking of buying it but forgot until about 5 hours afterit would have ended

lol, yeah this is the one from ebay, the auction ended at $306 or so.

As for post whores (EBGAS)... f**k off. you s**t me.

I think what xcabbi was trying to say is that hi compression can lead to phenomenal torque?

As for my 2 cents, the only problem you will see with hi comp is obviously pre detonation, if you go overbaord, a copmression of 10:1 or more will need premium fuel, and probably additives. as a comparison, the AU engine runs 9.6:1 compression, and drives on regular fuel without pinging.

So if you aren't going forced induction in the long run.. think long and hard about this one lol... raising your compression is the go.

Flat top pistons are not that expensive, $500ish for brand newies from ACL. After that, you might wanna have a look at the rods, and the crank, machinig/balancing of crank goes a long way. you won't whinge about revving out anymore. And as for the rods... I guess you can use the ones it comes with. If they are in good nick.

A cam for your car, Ive found for $200 from Crow Cams, and megatork or some brand after reading through some magazines. And I know you love your carby so, get at looking yours rejetted, or ofcourse a holley 350 should be enough. if not there's the 500
And if you actually plan on revving this engine, get a new harmonic balancer, one for your car isn't much, and would make a difference in revving, range, fuel economy, and mostly driveablibility.

As for driveline, the 5 speed definately, especially for efficieny, power, and fuel economy. And after that, whack in a 3.23 gear into the diff (they're not expensive) that'll solve you're take off issues. From there its.. umm.. traction lol.

Oh and almost forgot, you might wanna check out your cooling system before sticking this engine in, Id replace all the coolant lines, and probably even the radiator... or get it HIGH pressure flushed. You don't want your new engine getting rusty..lol. Im sure youve seen my donor engine

and YOU were appoligising for long post lol.... can't wait to see results by the way... Dyno day on 7th of July I think it is... ready by then? he he.


Cheers

XF 5 SPEED WHAT ARE U CRAZY, i would think twice before considering to put one of those behind a worked 250xflow. I've blown 3 of those boxes up in the time of owning my xf. 4 speed is way stronger. Better still get custom bell housing and stick a new model t5 in her. Cost a bit more but you'll get more than 5 minutes driving please, smoother gear changers, and thje ability to do a burnout or 2.

Muff

lol dima you give me de ja vue.... i will be doing some investigation into pistons and cams specifically.. as for crank balancing and the rest i dont want this engine to rev to 14k.. the diff can stay fro now, and the rest will happen as it happens.. i never ruled out a blower...

anyways wish me luck.. let the money wastage begin (well on friday anyway)


-mitch

Muffy - in the original post, he stated that it would be a T5 or a supra box. The borg warner 5 speeds used from the sigma's should be banned from all existance.

Mitch - you might not want her to rev to 14K, but smooth reving, no vibration and the ability to rev to atleast 6 is always good. Atleast get it reground to have a smoother crank, you might aswell while you're there... unless its already been done?

And if you are planning on forced induction( lol), then don't go flat tops.. stick with dished, best of both worlds.

Oh, and there's nothing wrong with de ja vue
Money wastage... no wonder you feel bad about it, lol. Think of it as money that will repay you in joy, bragging, and (hopefully) fuel economy.


Cheers

haha fuel economy... you make me laugh dima...

i have abandoned the flat top idea,, the block will be shaven instead,

and yes as stated earlier i will be putting a t5 (or maybe a supra) box behind this thing.. not a bs xf 5spd..


-mitch

and you reckon i know sfa about XF's????? f**k, if that's not the pot calling the kettle black, i'll give up now

granted the early 5 speed boxes from the sigmas arent worth a pinch of s**t, just like the sigma's they come from, but if you even pretended to know anything, you'd know that ford dropped the sigma 5 speed box early on for the T5

its true, they weren't even around for that long. All the very later '87 model XF's came with T5's, and from the EA onwards. Ford realised their mistake Im sure.


Cheers

are the T5 from late XF ('87) the exactly the same as EA/EB ?

the bellhousing is the only thing that differed between the late XF and the EA T5, mind you, the ratio was changed in the EBII models, with the addition of a reverse synchro. And a 6 bolt clutch.


Cheers