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mcfly94

250-300hp Crossflow

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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.

But 2 barrel holleys dont have secondarries?, yes it has 2 barrels but they open together

 

The seconderries on webbers there machanical you open them with your foot, so how are they progressive?. You stomp it to the floor they open

 

Webbers are shit id fit a holley at that power level with out a second thort, that and you dont have to go back to school for 4 years to learn how to tune them, and they work better at the power level he is talking about. youed max a webber out at 160kw for sure. i kick around with a few speedway guys making numbers with them but they all say theres a free 40+hp if they could just fit a holley. A big holley works better and feels better cause its bigger and big engine little carby is slow like trying to suck a cat thru a straw you fit a bigger one you can then try and suck a large dog thru so it will go harder even on a next to stock engine

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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.

 

He was and never prooved that single pattern cams worked better then a duel even thow he ran 12s on a avgas engine but yet theres a few now in the 11s with duel patterns

 

Theres a 1000 ways to skin a cat just cause he says its right does not make it so, the proof is in the pudding.

 

Glens 250hp and 300hp builds never made it to the testing stage (that i know of) so how do you know that his 14 second engines would go 13s? its talk thats it. My big engine would not go 13s in street trim it had big balls but would move a badley set up car

 

If this was mine i still do a little 214 214 engine and use what you have and no rollers it will push the car well but if you want it to drive like your mates stock commondore and still be as smooth as it fit a windmill  

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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.

 

He was and never prooved that single pattern cams worked better then a duel even thow he ran 12s on a avgas engine but yet theres a few now in the 11s with duel patterns

 

Theres a 1000 ways to skin a cat just cause he says its right does not make it so, the proof is in the pudding.

 

Glens 250hp and 300hp builds never made it to the testing stage (that i know of) so how do you know that his 14 second engines would go 13s? its talk thats it. My big engine would not go 13s in street trim it had big balls but would move a badley set up car

 

If this was mine i still do a little 214 214 engine and use what you have and no rollers it will push the car well but if you want it to drive like your mates stock commondore and still be as smooth as it fit a windmill

 

The 300hp one has been done to a tee by a guy over here for his daughters xf and it did work out well for them and on the money, thats the only one i know that is on the road.

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is it running 13s chris?

 

as for turbo there easy power but going by mine a bit harder to set up :( not that im rushing but the power they make is so diffrent like 3 times the TQs pushing it and you dont even have to rev it  

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is it running 13s chris?

 

as for turbo there easy power but going by mine a bit harder to set up :( not that im rushing but the power they make is so diffrent like 3 times the TQs pushing it and you dont even have to rev it  

yeah i was going to say, id say i could manage a decent 12psi setup on my bottom end? i think? or am i off?, as my cr is only around 8.97, with 22 dished pistons and the early open chamber head.

basic setup say:

  • full 3" exhaust $500 a couple straight throughs keep noise down
  • LPG system (GRA B2 converter, impco vff30 lockoff (with boost referencing), 3/8" lines, 225 or 425 or GRA480, i reckon 425 on 4barrel)
  • WB02 for tuning $300
  • Upgrade the ignition, and just use MS to control the ignition with tfi $600
  • 600x300 cooler $300
  • Cam with good torque band that will work with turbo, valve springs $400
  • Upgrade piston rings to moly.

Probably just a simple log manifold turbo setup with garret T04 0.84A/R turbine and 0.6A/R or 0.7A/R

 

And ive already got e-series 28 3.27 diff and C4.

 

I reckon i could get to around 200kw at the fly reliabliy and much easier than N/A.

 

definitely kick the vy ecotec.

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is it running 13s chris?

 

as for turbo there easy power but going by mine a bit harder to set up :( not that im rushing but the power they make is so diffrent like 3 times the TQs pushing it and you dont even have to rev it

 

No idea mate i only know thats it runs and made the power at kwinana performance :-)

I dont think it was built for the drags lol

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a stock engine will suport 12psi with a good tune and would make easy 200killer wasps at the motor  

 

id go the gra setup but there was a guy on the old forum making 185rwkw on a impco 225 carby im sure it was a stock engine to

 

you can do it cheapish to if your smart with your coin i will have mine done for less then 3k thats including timing retard and a 3inch stainless exhaust and a custom planum (got off a furn member cheap)

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a stock engine will suport 12psi with a good tune and would make easy 200killer wasps at the motor  

 

id go the gra setup but there was a guy on the old forum making 185rwkw on a impco 225 carby im sure it was a stock engine to

 

you can do it cheapish to if your smart with your coin i will have mine done for less then 3k thats including timing retard and a 3inch stainless exhaust and a custom planum (got off a furn member cheap)

yeah i thought so.

I got the idea of getting it all running at the engine, but i reckon my c10 wont like it.

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If u still wanna go N/A , jus use a stock as a rock bottom end , stock c2 head 110lb springs a 528 camtech and a 4brl carby . I used to smash 5lt commodores down the strip , even with 2.77 diff . Revved it to 5.5k rpm every chance I got and never had an issue . All you would need is a stall for the auto and your laughin .

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If u still wanna go N/A , jus use a stock as a rock bottom end , stock c2 head 110lb springs a 528 camtech and a 4brl carby . I used to smash 5lt commodores down the strip , even with 2.77 diff . Revved it to 5.5k rpm every chance I got and never had an issue . All you would need is a stall for the auto and your laughin .

 

Hey Grimmy you should really put some 3.45's in that diff and watch how it goe's then.Q has that cam in his sedan and pull VERY hard.Q runs 3.23 's and it makes it come on cam quicker. 

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I would but that poor old engine is cactus , poor maintenance and lack of oil saw it wipe a lobe or 3 . I've got the gears but with the engine I have now their really isn't much point .

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Dude I got a kick ass solid here that will turn a 250 into a tractor.I mean torque from zero and solid HP to 6700 easy with the right springs and SOLID bottom end.It will tear the manual apart though you will have fun till it did.

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Dude, if your going MS only for ignition you could have a bit of fun.

If your not revving more then 5700rpm you could have the MS and ign set simple style for under $400 easy i recon. over that rpm you'll likely be going CDI or wasted spark. I think rob might have a good CDI up for sale soon =P

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Is that the sure cam slydog ? I've got 250* at 050' atm , might have to build another bottom end for it !

I'll have to stick with the tfi dizzy and msd for now crazy , budget is a bit thin lately haha

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Nah a single pattern camtech unit 650 lift 270 duration on 106 lob sep with 104 ICL.It is soooooooo easy to drive around it's not funny but when you hit it it comes on soooooooo hard.Sounds super super cranky and rather choppy at idle but it has been the best so far by a long shot.

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Ive got some plans, and once ive sorted the car issues im going to be going for a TFI dizzy with hardened gear, MSD street fire ignition and coil, DC electric water pump, remove all the a/c gear. So first step should only be a few months away.

 

I want to stay standaard 250 crank and rods just have the whole bottom end rebuilt, fit some roller rockers (dont know to go adjustable or not?), fit some 302 ARP bolts to the rods, 308 head studs, heavy duty push rods.

 

Been through Cyco 250's threads, and noticed he spins his standard bottom end to 6100rpm and still made around 350hp, although he does have a serious balancer and obviously a fully balanced bottom end. I want to go for this balancer (yeah i know there $$$$$$$$$$), but does this require crank trigger? If so how hard is to setup crank trigger and could i run it with the TFI, msd street fire?

 

Things i have no idea about is what comp ratio should i be aiming for? what cam/lifters/locks/retainers? what head would be best? (any chance of me working my unmarked open chamber? just not to the limits like cyco did?), what type of spark plugs?, what type of igntion leads? (im running crane 8.5mm at the moment).

 

Along with this ill send my C10 to be built a bit more, but i want to stay with a semi auto stage 2 setup.

 

And what diff gears?

 

The car will be street driven, probably never get stripped, and probably get used daily.

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Hi boys. Grimmy your windage tray is almost complete. Just waiting on the Folder to be repaired. And i have a convertor of that exact same RPM(4600) for sale too if you like.
 
MCfly Crank trigger is very easy to set up. As long as your handy with the tools.
 
 
Cheers Wazzy

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Ive got some plans, and once ive sorted the car issues im going to be going for a TFI dizzy with hardened gear, MSD street fire ignition and coil, DC electric water pump, remove all the a/c gear. So first step should only be a few months away.

 

I want to stay standaard 250 crank and rods just have the whole bottom end rebuilt, fit some roller rockers (dont know to go adjustable or not?), fit some 302 ARP bolts to the rods, 308 head studs, heavy duty push rods.

 

Been through Cyco 250's threads, and noticed he spins his standard bottom end to 6100rpm and still made around 350hp, although he does have a serious balancer and obviously a fully balanced bottom end. I want to go for this balancer (yeah i know there $$$$$$$$$$), but does this require crank trigger? If so how hard is to setup crank trigger and could i run it with the TFI, msd street fire?

 

Things i have no idea about is what comp ratio should i be aiming for? what cam/lifters/locks/retainers? what head would be best? (any chance of me working my unmarked open chamber? just not to the limits like cyco did?), what type of spark plugs?, what type of igntion leads? (im running crane 8.5mm at the moment).

 

Along with this ill send my C10 to be built a bit more, but i want to stay with a semi auto stage 2 setup.

 

And what diff gears?

 

The car will be street driven, probably never get stripped, and probably get used daily.

Your on the right track there just a few things,

Rockers, if going soild cam you need adjustable if hyd you don't but if you dont have any just but adjustable, you never know what the future mods will be!

insted of 308 head studs performance wholesale does a 250xflow arp set.

you dont need a crank trigger with the ati balancer the dizzy will still work

if you go crank trigger you dont need the tfi, you could gut it out all you would need is the rotor button.

AS for comp the more the better but being daily street driven maybe shoot for 10:1 and could run on 95 ok

 

built stage 2 (autoshift) will be fine

 

You my need to find a happy meduim for gears being daily drivern and depending on cam and stall.

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Your on the right track there just a few things,

Rockers, if going soild cam you need adjustable if hyd you don't but if you dont have any just but adjustable, you never know what the future mods will be!

insted of 308 head studs performance wholesale does a 250xflow arp set.

you dont need a crank trigger with the ati balancer the dizzy will still work

if you go crank trigger you dont need the tfi, you could gut it out all you would need is the rotor button.

AS for comp the more the better but being daily street driven maybe shoot for 10:1 and could run on 95 ok

 

built stage 2 (autoshift) will be fine

 

You my need to find a happy meduim for gears being daily drivern and depending on cam and stall.

ill straight for adjustable then, i reckon id probably go solid cam anyway.

oh cool save money then! didnt know they made a set for the 250.

whats the benefits of crank trigger?

what comp would be the limits of the standard 250 crank and rods? im happy to run higher octane fuel.

 

ahkay cool, sort of comes down to cam.

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You can go up to around 11.5:1 Comp for 98RON pump fuel to be safe without detonation. A crank trigger takes away the electronics in your dizzzy. Basically like a Crank angle sensor in a new car. Everytime in goes past the magnet it triggers the pulse. The only thing left the distributor does is direct the spark to that cylinder. In saying that it depends on what revs you want. I didn't have any trouble with the stock Re Graphed dizzy untill about the 6300RPM mark.It helps at high RPM the dizzy getting "Scattered". I have seen this from Dyno graphs between a dizzzy and crank trigger.

 

Cheers Wazzy

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