Im building the header for my all motor car and i im stuck between having them collect together or just seperate runners that do not merge together. similar to the RB road race headers...

Whats the advantages/disadavantages for collected Vs. uncollected?

from a fabricating simple point of view, uncollected seems the way to go since the runners would not have any hard bends to meet up together at any point. but whats the proven/engineering side of it?

just to add, this will be a open header design. no exhaust or mufflers will be used.

 

what's the port type you plan to run?

 

this is actually for a renesis motor im building. 6 port bridgeport...

 

Since a bridgeported Renesis isn't going to make any more power than a stock ported Renesis due to the exhaust ports, may as well keep it simple. Buy a cheap header for it and run a single exaust out.

 

what do you mean a single exhaust? my mech says i should install a borla mufflr, right now im open header myself on a drag racing application...

 

if you remove the exhaust sleeves you can port the opening edge on the renesis much further down. letting it move enough exhaust to let the bridge actually make some power. i might have a new sleeve machined to fit to match this, or just leave it out. i havnt decided just yet...

im not really into buying parts anymore. i have more fun making my own stuff these days. this is still a hobby for me, so i like to enjoy it as much as possible.

 

he means collect it and be done with it.

that sounds a lot like you're simply adding a bit of volume to the runner. maybe i'm not understanding what you're trying to describe. from all i've read (pretty much rotarygod's and guitarjunkie28's assessments) if you try to make significant alterations to the aperture and bowl, you'll hit the water jacket.

 

Try it. You'll hit the water jacket and ruin your housings! You can't even port out to the size of the exhaust sleeve. You can't really do much of anything and don't even think about trying to bridge it. Besides the fact that you'll hit the water jacket if you do, it wouldn't live with the high heat of the exhaust and would break anyways. You are stuck with very few options on the exhaust ports. When I ported Ray's (Charles R. Hill) motor, I found out exactly where the water jackets were. I now have a scrap Renesis housing lying around while he has a new one in his motor!

 

i did the same thing kinda. but i had a spare one. so i just ported it until i ruined it on purpose to find out where i can and cant port.

so back to my original question, collected Vs. uncollected...? differences?

 

collect it. for these side port motors, i haven't seen anything yet to convince me that trying to keep all pulses separate will yield gains. also, as you well know, the center port is shared. if i were you and i had the skills to fabricate, the only thing i'd probably play with would be how long the pipes should go before converging.