Crossflow Build Advice

[Nath 1,975]

Horses for courses I guess guys. Realistically unless I drive like a proper P plater all the time I can't see it spending huge amounts of time above 4500 on the way to work...

 

In the end I chose the 4 barrel though because with that manifold I have options to change to something bigger later on if I decide to do more work on it. Besides that, it's gonna see a bit of track anyway so it makes sense to pay some attention to the top end figures.

 

I'm sure either one will light up street tyres anyway so I can't see a small difference in 60ft time on drag slicks really mattering that much at the end of the day, I guess all that it changes is the amount of smoke coming from the rear end if I launch it at the lights

[broken-wheel 659]

on the street the 465 on the aussie speed would be king, add 3:27 on the rear out of a E series lane and you'd have a ball until valve bounce or the cam falls over, it will embarrass all non V8 holders out there and some LS1's too

 

with the programable MSD you won't see a difference on the 60 foot, dial in your launch limit and launch! no wheel spin? add 200rpm until you spin them, once you got the sweet spot add another 200RPM and remove 2 degrees of timing and for the next 500RPM retard 5 degrees with a slew rate of 1.4 sec, this will get you close to the ball park of 1.7 1.8 sec 60 foot every fucking time pending the track stays the same, this is regardless of 2 barrel 500 or 4 barrel carb, the 4 barrel will walk away mid track 

[wagoon 2,429]

Nath if you are planning on racing you either need to start collecting T5's or have another plan when you start breaking them.

Going the 4 barrel is a smart choice so you can easily upgrade to a 600 later, as unfortunately we all have budgets that we have to fit within. Will be really interesting to see what gains you get when you do step up to the 600.

[Nath 1,975]

T5s are cheap but I see the problem...

 

What would the alternative be?

[TF_250 398]

on the street the 465 on the aussie speed would be king, add 3:27 on the rear out of a E series lane and you'd have a ball until valve bounce or the cam falls over, it will embarrass all non V8 holders out there and some LS1's too

 

with the programable MSD you won't see a difference on the 60 foot, dial in your launch limit and launch! no wheel spin? add 200rpm until you spin them, once you got the sweet spot add another 200RPM and remove 2 degrees of timing and for the next 500RPM retard 5 degrees with a slew rate of 1.4 sec, this will get you close to the ball park of 1.7 1.8 sec 60 foot every fucking time pending the track stays the same, this is regardless of 2 barrel 500 or 4 barrel carb, the 4 barrel will walk away mid track

 

Very complicated traction control, not needed or practical on a car running said 60' times, Bolt on a set on mt radials and you won't break traction at all.

 

As for the op engine I'd go for a 600 vac carb will do the job fine, imo the 465 is a little small for this engine combo. I've tried both carbs and the 600 was better then the 465 both cruising and at wot. Just my opinion though.

[broken-wheel 659]

i'd stick with a single rail, much cheaper, stronger and plentiful, make sure you get the falcon one, the others fit but are not as strong, others: sigma/valiant, use the 30w straight oil and you'll be ok, you will not have the overdrive of the T5 but the chance of breaking it will be quite slim, not with 300hp

 

what size MT won't break traction?

[wagoon 2,429]

Nath as I have said before your only real option it to run a single rail, if it's good enough for the speedway boys that run meth powered roller cams then it's good enough for us. The good thing is I am 99.99% sure the T5 clutch is the same as a single rail so when the one you have blows you don't have to replace the clutch as well.

I paid $200 for an xf complete box with bellhousing, shifter housing and shifter, crossmember and clutch cable. Inside was stupid clean with the only damage being a tiny chip on 1 tooth on reverse, I could have sworn the guy I bought it off wanted to add $100 to the price once I lifted the top plate to check inside and he saw how clean it was.

With the amount of torque your setup will produce you can run taller gearing then adjust with tyre size and you will never miss the 5 speed. That is until your flying down conrod straight full boar trying to pass the car in front into the kink.

 

Broken-wheel it's cool that you know all this technical stuff and I for one would love to hear the details and see pics of the setups you have run. But this thread is about a motor that is capable of mid-low 13 seconds at the very best with a well setup car and a good driver. A crossflow with this sort of horsepower on a decent prep'd track could not spin a warm soft compound street tyres of the line let alone any sort of drag tyre, and I am yet to see a crossflow that needs a transbrake and 2 step setup and is capable of running easy single digits unless it has a large compressor hanging off the side.

[NZXD 2,328]

I'll have a completely rebuilt single rail up for grabs end of the year, if your t5 holds out until then.

 

I'm just sussing out a tremec 600 ft lb 5 speed.

[broken-wheel 659]

 

Broken-wheel it's cool that you know all this technical stuff and I for one would love to hear the details and see pics of the setups you have run. But this thread is about a motor that is capable of mid-low 13 seconds at the very best with a well setup car and a good driver. A crossflow with this sort of horsepower on a decent prep'd track could not spin a warm soft compound street tyres of the line let alone any sort of drag tyre, and I am yet to see a crossflow that needs a transbrake and 2 step setup and is capable of running easy single digits unless it has a large compressor hanging off the side.

 

 

well if he is going to get the MSD with 4bbl carb and aussie speed manifold with that cam he has in mind and can't light up 275's with a manual then I think he should rather clean up the stock manifold, rebuild the weber, add a tow cam, extractors and new hyd lifters and call it a day, he will enjoy it more and enjoy his wallet a lot more

[Jiminy Kriket 133]

The bell housing you got off me nath will accept the single rail straight onto the back of it. I modified the nose cone of the t5 gearbox to fit the standard single rail bell.

 

So, if you are planning on going to the drags and have an hour or so spare you could drop the t5 and bolt up a single rail just for the weekend use.

 

Same drive shaft as well, so no issues there. Just bolt the box up and go playing, then when you need the overdrive to make the work commute easier, bung the t5 back in.

[Nath 1,975]

Gonna play devils advocate here and ask what I can do to bring the build into the 12s...

 

Not that I have any plans, just curious what it'd take.

[wagoon 2,429]

Gonna play devils advocate here and ask what I can do to bring the build into the 12s...

 

Not that I have any plans, just curious what it'd take.

Lots of money, completely different setup suspension than you currently have/want and a bigger engine. Lots more horsepower and changing to auto would help as well as making the car lighter. If you still want to hit the twisties you are going to need twice as much horsepower (think turbo) so you don't have to change the suspension completely and still have a tight chassis for corners, but the car would more than likely be auto so twisties won't be anywhere near as fun. Sly is running 12.2 @112mph and while his car will run quicker when sorted you can see what needs to be done to get into the region.

[wagoon 2,429]

well if he is going to get the MSD with 4bbl carb and aussie speed manifold with that cam he has in mind and can't light up 275's with a manual then I think he should rather clean up the stock manifold, rebuild the weber, add a tow cam, extractors and new hyd lifters and call it a day, he will enjoy it more and enjoy his wallet a lot more

Well with that reasoning I think I better give away my useless engine that I'm putting in my sedan and just run a standard setup cause cause I' running an msd a 4 barrel and a slightly bigger cam.

[Nath 1,975]

Relax guys, everyone's got slightly different stuff that they find works.

 

Funnily enough I have been looking into some coilovers - mustang ones though, if they're not too expensive. Still not sure what I'm gonna do with the rear... maybe just some new leaf springs.

 

Wouldn't make it a dedicated drag car I was just curious - won't a stock BF Typhoon run high 12s-low 13s? Those aren't exactly slow. There's always the option of configuring it for boost later on if I want to.

 

Gearbox wise, I'll just use the T5 till it blows up then look for a Single Rail.

 

Aussiespeed manifold on the way, looking for a good Holley in Sydney now. Will order the cam soon.

[slydog 7,873]

Less talkey more buildey... 

[Nath 1,975]

Less talkey more buildey... 

Waiting for parts! Pretty keen to get some spanner time in.

 

https://www.youtube.com/results?search_query=homer+simpson+waiting

 

 

Think I might try and clean everything up tomorrow (especially the head) and get it all as spotless as I can. Not much but it has to be done eventually anyway.

[wagoon 2,429]

Nath its all good dude

 

As for going 12's the suspension and chassis setup has a lot to do with it. Because you have leafs so it makes it a bit harder to have 1 setup that covers all, nothing money cant over come though. You can have 2 different setup that you swap between but you have to be prepared to do that, which is not a 5 minute job. The newer cars running these times have the benefit of newer style suspension and a lot of power. It really all comes down to money these days as they can make just about anything now.

[wagoon 2,429]

And to run boost later without changing pistons you need to run big dish pistons now. Just mill the head down to get the combustion chamber cc's low enough so you end up with 10:1CR that your looking for. Then when you switch to turbo just strip the NA head of its parts and get another head with plenty of combustion chamber cc all done.

[matt_lamb_160 252]

Performance below 2,500rpm is almost irrelevant for a strip car but not a street car, that is why I said the comparison is no good. The bottom end limitation of the 500 Holley is the issue here. For the strip, top end is the issue. The 500 will have a bottom-end comparable to a well setup 600 vac. Not all "real worlds" are the same.

[broken-wheel 659]

by 2500 my secondaries (mechanical dp) weren't even open, they started to come online at about 3200 so just under 110km/h on the highway, it's all in the tuning really, like I said before ... AFR and Vacuum gauge and a pocket full of jets, irbleeds and PV's and you're in business

 

the secret to the holley carb is not to listen to anyone! read the book and trust the numbers and  you can't go wrong, every engine is different and every torque converter is different too, what someone considers drivable someone else considers "fucking shit" also i like everything mechanical when it comes to carbs, I know what speed I'm doing on the highway so i'll read the vacuum it's pulling and set the PV on that, you should never be in the power valve circuit when cruising! then I adjust jets and airbleeds around that to get me 15:1, pump cams and shooters take care of the rest and the 2ndaries come open just above the rpm it takes to cruise on a very slight hill, up to that point set the timing to vacuum if you use the MSD, start plotting dots after that RPM where you'r secondaries start to crack open, this way you don't get 28 degree when you take off from the lights or bumper to bumper in traffic, makes the car much nicer to drive and you can retard 30 degrees above 70 vacuum under 3000 RPM to get that exhaust crackle*pop out the back which really makes the cross flow sound more like a Jag

 

my point is the 600 or 650 mechanical secondaries is just as good as a 500 down low if you only use the primaries down low....unless you're towing...then your wallet will burn a hole ...

[matt_lamb_160 252]

A lot of that is what I said (apart from the whole mech vs sec thing) and is why the small 4brl is better than the big 2brl (you can leave half of it closed until you need it and maintain good signal).

 

In the end 2brl will be ok (the cam is not really on before 2500 anyway), but the 4brl will be better.

 

Mech. Vs vac well... ...have it which way you like, but vac will be easier to get accustomed to for most (I do like what you are saying though broken-wheel)

[ando76 4,354]

Yeah Matt.  That's why I like the idea of the 465.  smaller primaries and then big secondaries when you need them.  Best of both worlds. 

 

I'm leaving the mechanical vs vacuum alone.  In this build I think the OP would be better with the vac secondaries and just go out and enjoy the engine.

[PRO250 1,506]

The carby just bolts on the engine just build the thing and try both the engine will tell you the one it likes

We run a 465 on beacons car with a camtech 237@50 cam we know the carbys to small cause it gets to 5500 and falls on it arse it would go harder with a 600 but its what he has and it is a streeter and spends most of its time under 2500rpm so it better for him

While where talking about it I run a 600 on a next to stock 250 engine and that thing is good on fuel and if you did not look you would think it has a stock webber till you put your foot into it the noise tells you theres a big hole over the manifold

Just build it, even a shit slap job 250 with a crap head and 230@50 cam will do 200rwhp im unsure what you want from it but 200hp crossy with push a big falcon well, a boost stock one much better just sticking that in there HAHA

You still running for forged pistons? or that ideas gone now?

[Nath 1,975]

I think it may be worth the extra stuff around of getting pistons to suit a boosted application and getting all of the compression from head work. That way later on if I decide to slap a turbo on it it's a head swap, cam change and turbo kit.

 

On the plus side... I start a new job on Monday. The money is pretty good so I might have some extra to blow on the engine.

[broken-wheel 659]

 

 

On the plus side... I start a new job on Monday. The money is pretty good so I might have some extra to blow on the engine.

Congrats! Don't look at it that way with the prices of these X series going up every 6 months I say it's money in the bank! (in my head anyway)