Need advice modifying 250

[Trent250 21]

Hi all, I'm new here..

I'm planning some modifications to my 250 crossflow..

Here's the plan so far

10.1+ comp, 650dp carb, 14650 crow cam, el crank, 200 rods, 5 speed with 3.45 diff..

How does this sound to everyone?

What are other people running?

I'm open to knowledge and suggestions..

Cheers blokes

[78xcgxl 241]

For the trouble it's worth, i'd drop in a 4.0L, cheaper, more power, great on fuel and just all-round shit loads better. Just my 5 cents.

[slydog 7,873]

Seen this post on the other forum.What do you really want and how much do you want to spend?

 

For me first thing is no hyd cammed 6cyl needs a 4 barrel.I would be more concerned converting to msd and tfi or est dizzy, ewp and a good cyl head design, exhaust and fuel system first.

[nos2 751]

4.0, 12+ comp, e85.. Just sayin

[Banno 479]

As Slydog  said 'how much to you want spend'. Probably the most important up graded decision you will make on a build. Money spent=power and the more money spent the more power gained. 

[Trent250 21]

Wanting to spend around $3000

Looking for a good combo..

[slydog 7,873]

Then I would suggest a 4.0l as well.My FG XR6 couldnt catch Glenns XE with a stock eb-ed ohc driveline.

 

Ignition,good pipes,mods or complete diff eat half of that and are needed for that combo imo.

[78xcgxl 241]

If your not a fan of fuel injection or the wiring side of things you could always run a carby set up on a 4.0l. A mate of mine runs a EL tickford motor with a EA CFI intake with a Weber carby and he reckons it goes harder than in fuel injection form but however fuel consumption is much higher.  4.0l with a T5 and 3.45 diff makes for one quick car.

[matt_lamb_160 252]

Sorry, but half of these comments are not helpful. 78xcgxl, everyone is well aware that you would put in a 4L. You say it in every crossflow rebuild thread and it is annoying. If you don't like crossflows, don't read about them.

 

I'd prefer to rebuild a crossflow than install a 4L, but that was not the question.

 

No reason not to use a 4brl with a hyd. cam (sorry Sly), perhaps not a 650dp though. An engine with that cam will not see more than 5,500rpm and a 465 will be enough. A 500 2brl. will start to limit the engine after 4,500 and won't be as friendly as the 4brl below 2,500rpm. Cost difference isn't great as you wouldn't use a stock mani and carb.

 

What are you going to do with the car and what rev range do you intend to use mate?

 

You don't need 200 rods with that sized cam and pistons to suit are $$$ and hard to get.

[slydog 7,873]

Belive me I LOVE xflows but a maybe budget of $3000 plus do you have to pay people to do it for you smashes $3000 in no time.Perhaps buying a used speedway engine like what ducky had for sale is the smarter xflow option.

[matt_lamb_160 252]

Perhaps. But an engine at this level will work with basic ignition, second hand off the shelf pipes and you would need all the same driveline components for a 4L. The money all goes into the engine, intake mani and semi decent balancer.

[slydog 7,873]

Sorry, but half of these comments are not helpful. 78xcgxl, everyone is well aware that you would put in a 4L. You say it in every crossflow rebuild thread and it is annoying. If you don't like crossflows, don't read about them.

 

I'd prefer to rebuild a crossflow than install a 4L, but that was not the question.

 

No reason not to use a 4brl with a hyd. cam (sorry Sly), perhaps not a 650dp though. An engine with that cam will not see more than 5,500rpm and a 465 will be enough. A 500 2brl. will start to limit the engine after 4,500 and won't be as friendly as the 4brl below 2,500rpm. Cost difference isn't great as you wouldn't use a stock mani and carb.

 

What are you going to do with the car and what rev range do you intend to use mate?

 

You don't need 200 rods with that sized cam and pistons to suit are $$$ and hard to get.

 

Don't be sorry have your say by all means...doesn't mean your right,doesn't mean any of us are for old mate either.

 

I never found a hyd cammed 4 barrel xflow car to be any good unless you jammed it full of comp and camshaft at which point it is a solid cammed or even better roller cammed engine.4 barrel manifold on a daily xflow car are not fun as I can attest too and they will never be ideal...where as a 2 barrel doesn't seem to be as affected for some reason IMO.

 

As we can see old mate has read Glenn's combo list and has stary eye's now but as we know it doesn't need most of what is up there but we do need to draw a line somewhere and TBH I will have to agree with Nos and 78 on this one as the suggested budget is not going to cover what he wants if we are honest.Glenns car Heather truly did hold gap on me and I was full tilt into my FG.His car gets similar economy and for all intents and purposes wins more than it looses on the street without drawing attention to it's self. 

 

Like stated above though a 2nd hand speedway engine would be fine and you COULD use a 4 barrel on it but really again on a daily I wouldn't recommend it from experience.Q's xflow powered XF beat alot of cars it shouldn't have down @ Heathcoate last year and is a back yard build but it is all done by him and with a 2nd hand engine as the base and him doing all the xflow EFI and tuning.

 

Really there's 2 options 2nd hand speedway xflow or OHC and OHC is my first choice this time as it needs less to go faster really.    

[BBS XE 160]

I'd say $3k would only cover it if you do most if not all of it yourself, farming out any machine work you can't do at home. 650dp would drown it wouldn't it?

[matt_lamb_160 252]

I am sure all of our alternative options are wrong because none of us know what he wants, we need to hear from him. Not much point offering other options before then.

 

Too many of these threads focus on what other people would do rather than supporting and helping the original person with what they want to do. Perhaps I should just stop reading these types of threads and just focus on builds I like and stop crying about it lol.

 

I'd build a 300 with LS heads, 4.125" stroke and bore and run metho injection, but nobody cares. Plus it can't be done for $3k haha.

[78xcgxl 241]

Oh dear I’ve offended a crossflow purist, my bad. Sorry I’ll won’t voice my opinion and share my ideas then, thought that‘s what the forum is about, but okay.

[matt_lamb_160 252]

Forums are to help people with their questions and to share what you are doing. You didn't offend me. You annoyed me and what you added was hardly an idea, but I am over it.

[nos2 751]

Lol

[GspecZL 979]

I think everyone is entitled to there opinion that is what the forum is for. I tend to agree at that budget I would look at a 4 litre.

 

Trent250's name leads me to believe he like 250 crossflows. so if he can do the work himself I think $3000 could go a fair way.

[gerg 10,871]

$3000 can get you 200 reliable hp from a crossy, will be as quick as a stock V8 and you won't break the bank running it. Money is best spent on balancing, porting and blueprinting rather than splashing out on name brand bits.

 

650DP is too much carby for many V8s, let alone a 6. A 390 would do nicely, but I agree that a 465 would be best.

 

You're not exactly spoiled for choice with manifolds and pricing, so you're basically stuck with Redline or Aussiespeed. I like what one bloke did and cut and shut an EA single-point manifold onto a crossy flange. A popular speedway trick I believe. Much more even length runners than on the aftermarket ones, but this will only allow a 2-barrel carby.

 

Stock valve springs are shit, but everything else is pretty tough. Get roller rockers if going above 0.500" lift, and don't go crazy with the compression. Might be an idea to look into an EF crank if you want to rev it.

 

3.45 diff will shit you to tears after only a short time driving. You'll get sick of changing gears all the time and besides, the engine will use too much power accelerating itself off the mark. I put a 3.27 in my wagon and next time I have to open up my diff I'll seriously think about swapping back to 2.92s. I also find that you lose too much time between gearchanges when accelerating. Taller gearing allows you to keep on the gas longer while your mate next to you is going backwards reaching for yet another gear. A torquey engine like a 250 will love it.

 

My old man had a warmed over XF EFI 4-speed and when the box got done up, they put a V8 gearset in with taller ratios. That plus the 2.92 diff meant that 1st could pull 80 kays but because the engine had great torque, it would go hard getting there too. He shamed some V8 dunnydores in its short life (before his wife wrote it off).

[slydog 7,873]

How about this...there are ALOT of threads on peoples builds and alot of researching old mate can do as he has found Glenn's combo anyway and asked the same question on 2 forums.Let him do some of his own research and advise of what he can can't and is willing to do before everyone has a 4-5 page argument over what can and can't happen...in the real world.

[ando76 4,354]

I have a suggestion for old mate - Have a look at what Clevo 120Y has achieved with WOMBAT's speedway car.  Now there is a combo that is punching way above its weight with mostly stock components.  WHY - because it is a well researched package using mostly stock components. 

 

Another option is find a low K x-flow (I have two, one with 115 and one with 190K's so they are around) and stick a hydraulic cam in it with a set of roller rockers, new lifters, timing chain.  gumtree sourced extractors and inlet manifold and go and have some fun. 

 

The strength of these engines is the torque they develop.  Torque is king on the street so a short rod, stock crank combo kept to below 5000 will last forever, win heaps and will fall within the budget. 

[PRO250 1,506]

Come here with 3k you can have the 200rod engine out of my yellow car ill never use it im blown now  

specs 200rod crossy, 10.5 comp, 218@ cam, basic head and springs,  ballanced, 4barrel and 465 holley, stock grafhed dissy and steel gear, engines got less then 4000kn on it can see running and drive. burns tyres easy but will not turn past 5500 the cams to small. would be making 170 200rwhp at a guess does need a much bigger cam but its low end power is brutal

not looking for offers cause its a turn key engine with all the sorting done for you  

[Trent250 21]

Pro250 Where u located?

I think I will go for a 465 carb now

I want to rev it max 5500 so would I need el crank and 200 rods?

Might go for taller diff.. would u notice much power difference?

Cheers everyone for your suggestions..

[Trent250 21]

The parts I already have are a 4 barrel intake manifold and a cylinder head which hasnt been ran before and don't know mods on it.. but looks shallow chamber..

[Trent250 21]

Cheers