my 250 picks

[DYNOED250]

ill post some decent picks guys, the motors just in a shit spot in the shed..
its the motor ive been craping on about for ages :>:>:>:>:>
still isnt back in the car , been competed for 2 mounths now

the sexi balancer is a romac item :> desnt look like theres 290 hp there heya

this is a quick shot of the car its going into just back from the spray shop.
well by just back i mean its been sitting there for 3 mounths.. not enuf time in the day, this is about the best shot i have as the rest of the car is still very much in pieces

 

[TCSTEVE]

sweet! couldn't of chosen a better donor car for 290 hp than that!
Peel hard!

 

[alloydave]

looking good , nice balancers alright but alas they lose there shine quite quickly .The clear cote protector stuff they put on them seems to come off
and then you get a small surface discolouration ,im trying to figure out what to put on it to stop this happening .Was that a 4 barrel redline manifold i see in your other thread ?
well it looks like youll be busy getting it up and going for the xmas crusing.
GO THE FORDS!
cheers dave

 

[DYNOED250]

this is how you have to port them to fit a quadrajet on because the back butterflys hit .
but i dont know what im doing with it now, my mate has an ultraflow limited sprint for sale 2 , what would that be worth, i was thinking around 300 ? + since they r worth so much new, any one interested just ask,

 

[Anonymous]

nice te im jealous

 

[Anonymous]

Pfffffft... It's a piece of shit!!!

LOL, nah, just kiddin mate... It's hell sexy
And 290 HP huh?? That's 216 kw!!!
...Is that at the wheels? Or flywheel readings?

So... u wanna tell me ur secrect to obtaining 290 HP?

 

[addo]

Is that a clear-over-blue-over-silver CAB or metallic blue with clearcoat?

There seem to be more Corties around again now. Where were they all hiding?

 

[DYNOED250]

today i spent it at my local engine shop, and a 250 was getting dynoed, its a spead way engine.

with a 350 holley, milled choke and 500 base plate
standard 84 da manifold
pace maker pipes
secerate cam grind
rollers
13.7 :1 comp
and methanol

this engine made 305hp and 340 fp

thats some crazy figures and the dyno its on is known for reading heavy. that out of a 350 holley is a made effort
cam specks i dont know what they are but i want. head has standard valves.

MY engine is 11.7 i think or 11.2 some where round there, pump fuel, wade flat tappet cam, rollers, springs retainers, and after market fuel injection. 290 hp and 320 fp i think long time sine we ran it, not sure on torque.
theres no secret to these engines, there is just mismatched parts. one thing that showed up on the dyno, is that longer primarys on the extractors is a good 20 hp upgrade.

 

[Anonymous]

Hmmm, I think Im gonna learn alot about the x-flows talkin to u. lol
Thanks for tha info man, every lil thing helps

...By the way, how much did you spend on your engine? Not including dyno tuning etc... just the engine alone?

 

[DYNOED250]

theres lots of smart people on here who know lots more than me, this is my 4th engine ive built, all i know is that on a dyno the old 250 is just as good or better than an ohc motor in a worked form. from the two methanol motors ive seen the 250 with a 350 holley made 305 hp and 340 fp, the ohc 4lt made 250 hp, and 325fp with a 500, the 4lt had a hi perforamce manifold as well the 250 had the standard manifold just ported. the 4lt with an 850 dp, made the same hp as the 250 with a 350 holley, if only we hada tried the bigger carb on the 250

mate honestly ive lost track of what ive spent its just been over such a long period

heres a guestamate

it would b 4500+ which isnt much but it is thats including clutch set up, efi set up the works

 

[Anonymous]

theyre any disadvantages in having the compression ratio so high?

 

[DYNOED250]

these other engines are methanol motors 13 :1 and above is common.
my motor only has so much because we went to 200 rods, with a nearly flat top piston, in my old motor i had dished jobs. im running a decomp plate and 2 head haskets, so there is a hp lose there and its still 11.7 or 11 .2 it was one of them, without it it was 16:1, the head is basickly stuffed its good for methanol use now, or on a motor with dished pistions. ive invested to much into it now, so the decomp plate was the cheap way out. the ideal would b 10.5 ish mabie a tad less, and no decomp plate, i might see the mighty 300 hp on unleaded. but ive still got dev work yet on my intake so i might get there yet.

main prob ive found with to much comp, u have to run less advance less timing , which kills power two, theres a match between the two u just gota find it

 

[Anonymous]

doesnt it start detonating/pinging over 11:something? or is that further up in the CR?

 

[DYNOED250]

true, it does but..... the chambers is a c2... but its not a c2 chamber any more looks like an early c series or a no letter head, nice open no sharp edges, we used optimax, and i think still 30 odd degers of advance, with injection i think u can go a bit more because its easy to make sure the a/f ratio is spot on to ensure its not lean which will ignite fast, hence detonation, if it is detonation richen up a bity, harder to burn slower flame front., and weather 200 rods with the different pistion spead make a difference who knows

 

[Anonymous]

Interesting...

My XF's a 200, but i was gonna stick a 250 crank using the 200 rods (i know... its becomming really common!) and the dished acl pistons (race series of course ) ...i was told 2 use the flat top acl pistons, but i reccon the dished ones would give a better CR - not too high. Whats ur opinion?

 

[xctasy]

Except for me and Whitey. I'm not trying to be a smart a$$, but the longer rods reduce effective compression, and make it cary less compression. With the camshaft you have, the effective compression isn't much higher than a stock 4.1 EFI.

Some people argue that the increased dwel time form the longer rods creates a hotter piston, but I don't aggree.

Here's a link to mess you up real good

http://fordsix.com/forum/viewtopic.php?t=5518&start=0&postdays=0&postorder=asc&highlight=

All I can say is you are on the right track. Unless you are running a top fueler, were a long ignition advance threashold before detonation is important, I'm certain you'll find a moderate total advance of 32 to 36 degrees is all you'll need. People think lots of advance spells a healthy engine, but it just means the spark is having to torch up a less than ideal chamber. Keneath Duckworth found this years ago with Cosworth engines. They couldn't carry a lot of advance either.

 

[DYNOED250]

but as long as u dont have a head with a heap off it . the race series come in a few types dished and flat, the dished RACE SERIES ones have bugger all of a dish there the ones i have, its only a few cc , they may as well be flat tops, all i can say is cc ya head first, this is after its ready to go, u know all machined and re-surfaced, then see what cc the race series r, run 0 deck hight, then allow a feww cc for ya head gasket, and going of how many cc ya head gets is a way of finding out if u will run into comp probs

you have to remember with bigger cams to it turfs all this comp shit out the window two, because of the way cylinders fill.
like u can get to motors with the same 11:1 comp, one can have a wild cam one a stockey and with a comp guage the stocky will get a higher reading than the hottie cam

 

[Anonymous]

Jeebus... It's all so confusing... Just when you think ur onto something, or understand something, something changes and rewrites what you though! LOL, oh well, live and learn

So, you reckon that the flat top acl pistons would give a better cr in a 250 with the 200 rods then?

 

[DYNOED250]

just meassure every thing first. id be going for the dished acl rave series, mabie even steping to just the acl standard 200 rod job, they have a bit less comp 2 i think.


heres a question for a few of the more knoledgle ones out there

do less cammed motors need less comp beccause theres less overlap in the valve ti ming so the cylider gets filled better down low.
and a highly cammed motor needs more comp because the overlap effect of the cam, isnt working yet. so u get shit cylinder filling and less comp

 

[xctasy]

Yeah, I see your point. But you can run a 11:1 Super Cobra Jet 427 FE with its stock 290 degree cam and a 6/71 super charger at 1:1 with just a brew of octane boosted petrol.

This is what they call a Millers cycle, where the exhast bleads off the excessive combustion pressure.

Being an egg head, I just find that closing event, and I can predict the cranking pressure just off that for any engine, any cam. If its advanced or retraded off the straight up installation, you can calc the combustion pressure. The yanks, in a Hot Rod article, found that you could predict how an engine was going to run by getting its warmed cranking compression ratio, and if its over 200 advance it, under 200, retard it on the cam. Or something like that. Then optimise the igntion. Suddenly, bad combos can work like rocket ships, with less need for the hi-grade ore in the tank!