CROSSFLOW extractors

[CHESTNUTXE 7,299]

After looking at a lot of different extractors i see some that have 2 sets of bolt holes on the top flange,can someone tell me why this is,or is it for pre-crossy,or f100,cortina fitment ? i see this a lot on headers ?.

[adrianphu123 73]

iron and alloy head have different bolt patterns

[CHESTNUTXE 7,299]

ok i didnt no that,cheers,what about if building a more powerful n/a  crossy,would you go for the average set of extractors or go straight for a nice set of pacemaker or aussie speed type ,at the moment i have a 2x1/4 o.d with std exhaust manifold,i was thinking of 2x1/2 or 3 inch single,i will be running a 600vac,aussie speed 4 barrel manifold,larger cam ect ect,

[gerg 10,871]

That combo will need a decent exhaust. Anything less will be strangling it. Pacies are good, get the 6-3-1s if you can stretch that far.

 

2-1/2" minimum system I reckon.

[CHESTNUTXE 7,299]

ok what is 6-3-1 ?

[Mr Polson 10,214]

6 individual pipes, into 3 individual pipes, into 1 individual pipe. At least that's how I've always understood it.

[gerg 10,871]

Inline 6s can have 2 types of groupings of extractor pipes.

 

On a 6-3-1 type: 1 & 6, 2 & 5, and 3 & 4 are each paired off into 3 pipes to create perfectly shared pulsing for each pair of cylinders. This is because the pairs fire directly opposite each other in the firing order. This promotes scavenging at higher rpm. Then they all join further down into a single outlet. Hence it starts at 6 pipes, joins into 3, then down to one.

 

6-2-1 type: 1,2,3 and 4,5,6 are grouped into two pipes that have thier respective cylinders pulsing 240 deg apart, but one cylinder ends up trying to scavenge the other two even though only one of them will benefit. They then join the two a bit further down but some choose to either extend this secondary section or keep them separate and have a true dual system. They are better at low-mid rpm, and aren't as good up top. Mind, it's only a matter of a few hp. There are space advantages of this type and are slightly cheaper. Some folks on here have built very powerful engines using them in modified form, so they're probably pretty good.

 

Either one is a vast improvement on a stock manifold but I just prefer the sound of 6-3-1s myself.

[CHESTNUTXE 7,299]

ok cheers,has anyone ever tried a dual exhaust on a 6cyl i have seen a few in the old days on xc's and others.

[ando76 4,354]

Yep - dual 2.5" with an X pipe.  sounds and works awesome.  There is a vid on here somewhere of it running.

 

Get yourself a set of Pacemakers - extend the secondaries if you are looking for every last bit of torque, and then big single - 3.5" minimum.  No exhaust shop will tell you this - they will all say that's way too big and yadda yadda yadda.  Trust me they are wrong.

 

When you mod these engines they need to get the bad stuff out. 

[Grimmy 312]

I've got the 6-3-1 on my xflow atm , they sound heaps different the the other type on a single system . Very smooth . I'm going to try and set up a dedicated twin system with the normal style headers and get some back to back numbers . But what works on my engine mightn't on a different combo . Time will tell

[CHESTNUTXE 7,299]

so the 6-3-1 extractors,3x1/2 exhaust, should be enough for a wild crossy build,what is the max these engines will put out once sorted,320-350hp ? i have read a lot on here the last few months,seems the go is a big crow or camtech,roller rockers,aussie speed manifold and 4 barrel 600 vac or pumper,and exhaust,i think i read somewhere a full street trim xe or xf runs a 11 sec quarter ? is this true.

[Grimmy 312]

11? Definitely not haha high 13's maybe . 300hp is pushing it , unless you invest big dollars . I doubt mine has 300 , but it still hauls arse

[CHESTNUTXE 7,299]

see the thing is i just spent 12 months building a 357 c.i cleveland for my xe and have a fmx as well to go in,i never thought i would get interested in the crossy thats in it,its a low km engine mid 82 alloy head 2 and it goes really well ,so when it comes out i plan to spend some bucks on it to hot it up for drags and fun,if i can find a corty or xd xe xf to play with thats the idea,i have a friend  who owns and runs a machine shop,and he is keen to help me do up this crossy,so all the info i can get is really appreciated guys,what flat tops are still available for the 4.1 all i have been able to find is keith black flat-tops,im sure the factory pistons will have some dish in them so i want to bump up the comp,zero deck it,mill the head and try for around 10.5.1. or more. i think i have the e2 head leaded 1982.

[wagoon 2,429]

My solid roller cam crossflow made 350hp and ran 11.8 with a carby in a 1200+ kg cortina with the previous owner. I have rebuilt the engine using 29 cc dished pistons and a C2 cylinder head with 42cc combustion chamber and my CR is 10.3-10.5 Cant go flat top pistons as it will make the CR to high.

The same cortina as I mentioned before ran low 13's with a mild crossflow with a 2 barrel carby. Yes they can be made to go fast and like you said plenty of knowledge on here about that

[CHESTNUTXE 7,299]

ok so what cc would my stock pistons be ,i think i meant c2 head not e2.

[wagoon 2,429]

Wouldnt know what standard dish was but doesnt really matter. Get the head ported first(depending on how far you want to go with this) and shaved then cc the combustion chamber. Once you have the cc work out the piston dish required with zero dech height. Precision international have new hypertec pistons in 4 or 5 different dish sizes and oversize ( one may even be flat top I cant remember)

[ando76 4,354]

As Ryan said it is really easy to get comp into these things, even with stock pistons.

 

Wassy ran low 11's in his full weight XE sedan.  Awesome car, having seen it first hand at Glens, I can tell you it was very impressive.  I doubt you would get it registered in the form that it ran its quickest time (meth individual runner injection) but still a fast car.

 

Both Glen and Mossys cars are both showing well over 400 at the crank on the Moroso scale.  Power levels like that are achievable but cost serious $$$.

 

Spend your money on the cylinder head.  Get the best one you can afford and I would suggest sticking with the c2, D, c2a as you will be wanting comp.  The bottom end does not need flash, big dollar forged components.  Just balance the stock stuff and fit rod bolts as a bit of insurance.  Get a good sump and oil pump and that's the bottom end done.

 

With a really good cylinder head that flows over 220cfm, that bottom end and the right cam shaft you will be nudging 270+ hp if the ignition is good and the tune is right.  You will also be making a mountain of torque.

 

Is this going to be a cheap exercise - NO.  The cylinder head alone would be around $2500 without rockers.  But if you are chasing big numbers it costs.  simple as that. 

 

The good part about these engines is that they have been used in speedway, drags etc for a bloody long time.  This means bits for them come up all the time on Speedway swap and sell sites and the like.  With some judicious spending you can find good parts - dirt cheap (pun intended) and build fun engines for bugger all.

[CHESTNUTXE 7,299]

ok,where do you get this nice roller cam for the engine ? i have read somewhere that big block roller lifters will fit ?

[wagoon 2,429]

Cleveland rockers fit and you will have spares. You can get 6 cylinder sets which just have 4 less rockers but the actual rocker is the same

[CHESTNUTXE 7,299]

yes wagoon the crossy has the same rockers,i have built several clevelands including this pillow-block thats going into the xe soon.

[wagoon 2,429]

Sorry I miss read your previous post, missed that you were asking about roller cams. My solid roller cam is from tighe cams. I still have the box at home for the roller lifters and am using big block tie bars for the lifters.

[CHESTNUTXE 7,299]

ok why big block ? are they longer to sit in the lifter bore ? i just got on the tighe website wow some serious solids and the roller is semi finished to gring whatever your spec is,may i ask how much your cam was ?just had a look at the presecion pistons ,there are heaps of them from 5cc to 30cc,but some have the 1.547 pin and some have 1.478 are these the 200 rod pistons ?

[slydog 7,873]

You use big block cos no one makes any for a xflow thats why.

 

So you have to buy 16 not 12. Pricks...

[CHESTNUTXE 7,299]

what about cleveland or windsor ?

[gerg 10,871]

Wasn't it also big block Chev pushrods (the longer of the two)?