250-300hp Crossflow

[SPArKy_Dave 8,871]

You would get more torque/power economically, by adding a low boost turbocharger.

 

But even that is expensive unless you're on straight gas, or EFI.

[slydog 7,873]

I hear ya bro...in a xflow RPM cost $$$ but they make torque in spades which in street cars means faster acceleration!Just got to mold em right...It's not super difficult just harder than and engine swap with zero add on's as you need a package.

 

I took my ute to Winton last year while it only revved to 6700 at the time it won all bar 1 of 12 races and only lost to a blown XR8 FG ute by less than a fender in the top end.It's all in the combination brah...that motor on street tyres in any gear would smoke the tyres till you got out of the throttle.Crazy tractor engine it was but while I short shifted in low gears I revved it out in top which shows RPM isn't everything but it also isn't cheap.  

[mcfly94 169]

You would get more torque/power economically, by adding a low boost turbocharger.

 

But even that is expensive unless you're on straight gas, or EFI.

yeah not going down turbo avenue, it almost sounds like the cheapest and most reliable option is a standard fresh au motor?

[SPArKy_Dave 8,871]

For a mild crossy, you're really limited by the following - extractors/exhaust, intake manifold/carby, High torque cam, and reducing engine load by removing clutch fan, and adding thermo's instead.

 

After that, start looking at things like torque converter, diff gearing, etc. 

(but you'll use more fuel)

 

Following that, it's headwork to improve breathing. Larger valves, and HD valve gear.

 

On from that, is balancing the rotating assembly, stronger rods, forged pistons, ARP fasteners, grouting the block, crank girdle, etc.

[mcfly94 169]

For a mild crossy, you're really limited by the following - extractors, intake manifold, High torque cam, and reducing engine load by removing clutch fan, and adding thermo's instead.

 

After that, start looking at things like torque converter, diff gearing, etc. 

(but you'll use more fuel)

 

Following that, it's headwork to improve breathing. Larger valves, and HD valve gear.

 

On from that, is balancing the rotating assembly, stronger rods, forged pistons, ARP fasteners, grouting the block, crank girdle, etc.

Ive done extractors and full 2.5" exhaust and running twin el thermo fans.

 

Ive got an eb2 3.27 lsd diff, and c10 with std converter.

 

Head has been fully recond with new springs std. and larger inlet and oulet valves, not too big but bigger than standard.

[SPArKy_Dave 8,871]

Also remember, that a crossy won't like a large diameter freeflowing exhaust system either.

 

If you've got no backpressure, you'll lose alot of lowdown torque.

[mcfly94 169]

Also remember, that a crossy won't like a large diameter freeflowing exhaust system either.

 

If you've got no backpressure, you'll lose alot of lowdown torque.

owwww, yeah its pretty damn free flowing, full 2.5" with hooker aerochamber and resonator.

[slydog 7,873]

Cheap and performance are not in the same sentence or you are asking the wrong question.Budget is the key,make a HONEST budget and plan on that.If it works out go for it if not alter/change thoughts,standards,expectations and see what you end up with then see if you would be happy or not.

 

Nothing is ever as easy as it is written so don't think a fresh AU engine and conversion would be cheaper either.  

[SPArKy_Dave 8,871]

What carb/intake setup do you have?

[slydog 7,873]

Also remember, that a crossy won't like a large diameter freeflowing exhaust system either.

 

If you've got no backpressure, you'll lose alot of lowdown torque.

 

I'm going to a twin 2.5 with my new combo...LOL But the single 3" works great as is but it STUPID loud!

[mcfly94 169]

Cheap and performance are not in the same sentence or you are asking the wrong question.Budget is the key,make a HONEST budget and plan on that.If it works out go for it if not alter/change thoughts,standards,expectations and see what you end up with then see if you would be happy or not.

 

Nothing is ever as easy as it is written so don't think a fresh AU engine and conversion would be cheaper either.  

yeah nothings seeming easy at the moment! -__-, id say my budget would be 2k over the next 6/7 months, to build up parts to do the mods, really wouldnt want to spend more than that.

[mcfly94 169]

What carb/intake setup do you have?

all the shitty standard crap.

[SPArKy_Dave 8,871]

After all, speed is just a question of money................ how fast do you want to go?

[SPArKy_Dave 8,871]

I'm going to a twin 2.5 with my new combo...LOL But the single 3" works great as is but it STUPID loud!

 

LOL!

[mcfly94 169]

After all, speed is just a question of money................ how fast do you want to go?

i want it to pull as hard as my mates ecotec, thats got like 160kw, and thats hell of alot nicer to drive and pulls way harder. and his is standard except 2 1/4" exhaust and still has standard 3,08 ratio

[SPArKy_Dave 8,871]

all the shitty standard crap.

 

You'd be suprised how good the weber carby can be.

If it's rebuilt, rejetted and tuned correctly.

 

They're an overcomplicated thing, but good when working well.

 

One of the main reasons Holly 350's feel faster, is because both primary and secondaries open at the same time.

 

With the weber's, the secondaries are progressive, to save on fuel.

[mcfly94 169]

You'd be suprised how good the weber carby can be.

If it's rebuilt, rejetted and tuned correctly.

 

They're an overcomplicated thing, but good when working well.

 

One of the main reasons Holly 350's feel faster, is because both primary and secondaries open at the same time.

 

With the weber's, the secondaries are progressive, to save on fuel.

i rebuilt all the diagraphms etc, hasnt been tuned properly or jetted

[SPArKy_Dave 8,871]

i want it to pull as hard as my mates ecotec, thats got like 160kw, and thats hell of alot nicer to drive and pulls way harder. and his is standard except 2 1/4" exhaust and still has standard 3,08 ratio

 

Sound's like you need to get in contact with XRGLEN..... he was a firm believer that a single pattern cam, gave the best outputs on these engines.

 

Where-ever he is now, he was definitely the Crossflow powermods guru.

[mcfly94 169]

Sound's like you need to get in contact with XRGLEN..... he was a firm believer that a single pattern cam, gave the best outputs on these engines.

 

Where-ever he is now, he was definitely the Crossflow powermods guru.

yeahh, i was hoping some of you guys would have some of his know how.

[SPArKy_Dave 8,871]

Have a read of XRGLEN's 300hp Crossflow build thread -

 

http://www.xfalcon.com/forums/index.php?/topic/11087-300hp-x-flow/page__hl__ 250hp  xflow

[slydog 7,873]

Sound's like you need to get in contact with XRGLEN..... he was a firm believer that a single pattern cam, gave the best outputs on these engines.

 

Where-ever he is now, he was definitely the Crossflow powermods guru.

 

Doesn't mean he was right either bro.No one I know who runs FAST uses a single pattern camshaft.The exhaust outflows the inlet and if the head is ported very well having extra exhaust duration helps pull the inlet charge into the cyl.But again each combo is different... 

 

yeahh, i was hoping some of you guys would have some of his know how.

 

He is over at hotsixes if you want to chase him up.Won't save you any money and you will not go faster but thats your choice.

[SPArKy_Dave 8,871]

 

the key to this motor will be the aussiespeed inlet and the crow 14650 cam.. i have seen many inlets for the x-flow over the years and none including the aussiespeed 4bl inlet are as good as this 2bl inlet.. the runners are excellent in design, size and flow and with other small bolt ons and tuning tricks, like a heat soak inlet spacer, properly graphed dizzy, carb spacer and a good cold air intake system, im sure this motor will crack the 300hp mark naturaly aspirated..i have used this crow cam more than any other cam in the x-flow and it is very good.. it has proven to be a great tow cam on low octane fuel and tall 2.77 diff gears as well as excellent in hi-comp 14 second street car combos.. it does not have to be used with roller rockers or low diff gears nor does it need 4bl carbs or a EF crank to keep it together.. the trick is it is a single patern cam with good lift and near perfect valve timing.. you dont even need to re-graph the dizzy unless your chasing every hp possible..as the motor will only rev to 5500rpm, it will only need off the shelf extractors and 2 1/2" single exhaust.. this cam pulls very hard from 2500rpm and is great on fuel on a long runs returning 10lt per 100km with a 650dp holley and 2.92 gears in my old XD ute.
i will have photos of the motor next month when it goes together.. then i will try for 13 second quarter mile times next race season and the kwinana motorplex....cheers

 

I think this is what you wanted to read -

[mcfly94 169]

Have a read of XRGLEN's 300hp Crossflow build thread -

 

http://www.xfalcon.com/forums/index.php?/topic/11087-300hp-x-flow/page__hl__ 250hp  xflow

yeah i already have, more work than i want to get involved with.

What if i went a more simple route.

Doing 2 barrel 500 and 2bbl aussie

reduces exhaust to 2 1/4

mild crow cam that hits the limits of the stock rockers, upgrade to double row chain.

regraph the dizzy to suit cam

master blaster coil for a bit stronger spark

shave the  head for more comp?

how would that go? surely id hit the 160kw mark? or little bit more involved?

[SPArKy_Dave 8,871]

Doesn't mean he was right either bro.No one I know who runs FAST uses a single pattern camshaft.The exhaust outflows the inlet and if the head is ported very well having extra exhaust duration helps pull the inlet charge into the cyl.But again each combo is different... 

 

Yeah I was meaning for a budget motor.

He seemed to be good at getting a lot out of the engines, for not much outlay.

[SPArKy_Dave 8,871]

I just realised your parts shopping list is from XRGLEN's thread....... my bad.

 

I spose you could fit that cam, and see what happens.

 

Maybe up the stall speed of the converter, to when the cam comes in.

Try advancing the cam if you're keen.

And make the exhaust a bit more restrictive.