CB performance billet velocity stacks.

[henk]

hallo,

i bought a set of the big alu velocity stacks from CB performance.
but if i mount them the gold color mesh that sits over the jets sits in the way.
do you have to adjust the stack a bit or do i have to change the mesh with something else?
also if you want the synchronise the carbs,how you do that as the snail almost fallls tru the stacks.
do you have to make an adapter or so?

henk!!!

[neil68]

I had the same problem with my Geers stacks...had to file them down slightly to gain clearance for the jet screens.

[henk]

ok,thank you gonna shave them done a bit so the fit good over the screens.
anybody who has an idea to synchronise them?

henk!!!

[richie]

ok,thank you gonna shave them done a bit so the fit good over the screens.
anybody who has an idea to synchronise them?

henk!!!

Maybe Sync them with 2 standard stacks on the 2&4 cylinders, then swap them back out for the CB version?

 I have synced them with the big stacks from Geers engineering using the snail, just drop it in and take a reading, it does just about seal even though it may not give you a 100% correct flow figure it will be the same both sides which is what matters

cheers Richie

[NoBars]

My snail works fine with the CB stacks. I don't run the screens because of jet extenders.

[henk]

OK thanks,gonna do the synch with the standard stacks then.

henk!!!

[Taylor]

Or you could take them off and run Weber stacks.  I just back to backed the two and saw zero or 2 HP less with the CB stacks.

[henk]

you should said that two weeks ago,before i bought them  

henk!!!

[DKK Ted]

Ok, the stacks in question are made by JC Ent. for CB. I'm running a set of shorts stacks my self. I also used Jack's jet covers that are clearanced for the stacks, and yes if you want to use the stock screens, you'll have to clearance them a little to fit. As far as syncing them in, I had bought a snail sync from Berg a few years back and had the bigger adapter to sync the bigger stacks, but you can use the smaller one as said, does work. As far as performance,, I noticed a little stronger bottom end. So like anything else, all motors are different, may work for some and not for other. Just my 2ct's.
I work for JC Ent. part time at night, and most motors I've seen on the dyno are high HP motors, and have the big tall stack's, they work. 

Ted

[Taylor]

I'm not saying they don't work exactly.  Does Jack back to back them on a dyno other than a hand brake dyno?   

[henk]

ok thanks guys,i have them now so i did put them on.
one more question,i seen with the big stacks that the auxiliary venturi is a bit more loose as the big stacks are a bit
shorter then the stock stacks.
the stock stacks seems to hold the auxiliary venturi in place.
can i lleave it like that or should i put sleeves between them to tighten it a bit more again?

henk!!!

[Taylor]

Standard procedure is to knock out the brass plugs and tap the Carb bodies for set screws.  If you can make a sleeve,  that will work too.

[henk]

ok thank you will go for the sleeves then.
i just made a little ride with it and for me it seems that the engine is picking up a bit better in the lower revs.
but as you said only when placed on the dyno you can be sure.

henk!!!

[Old Guy]

This is one area where the dyno doesn't give you the complete picture.  Every engine is different and things like fuel standoff, air over the carburetors during actual racing conditions, etc. all play a part in what stacks are best.  Our particular Pro Gas car ran the quickest with the CB stacks.  A dyno (especially one like Roger Crawford's) is an invaluable tool.  But it is just that, a tool.  Like a very wise dyno operator and top tuner once told me years ago "you don't race dynos son, you race race cars".