ISL33P

**enjoy** http://www.skylinesaustralia.com/forums/Co...fo-t210411.html

How to make a complete inlet manifold and plenum from scratch. Pictures tell a thousand words. The end plenum is exactly the same, just the base is a little simple. All hand made, no cnc machine just a milling machine and a lot of patience and measurements as you can see. Piece of 10mm aluminium plate A lot of time measuring and drawing and then approximately 4 hours on a milling machine. Not electronic aids, just by hand Base and bellmouths cut and ready to go All in place and tacked together Sheet of 3mm aluminium Sheet cut up and engraved Might as well throw in a throttle body since I have a few "lying" around And the end result. Polished and blasted ready to deliver. Obviously there is a lot more to it, but you get the idea. For example designing of plenum to not only fit but do the job.....runner size, diameter, dimensions, length, plenum taper etc etc matching round bellmouth to a square port final matching of runners & base once complete welded machining the base to ensure a perfectly flat finish polishing fitment of vacuum fittings throttle cable bracket on the bottom of the plenum make and mount fuel rail most circumstances, mounting of injector bosses Your looking at approximately 3-4 days works from design to end product you see above. More than anything, this will give you an idea of why custom parts (that have been proven) cost so much....and to tell you the thruth my costs are nowhere near what I have seen charged out there. End hourly rate is approx $40 per hour usually less, compared to some workshops charging from $80-120+ per hour it isn't really that bad. Any questions, please feel free to ask. Thanks, Ariel

Mat, thanks for the gaskets. Absolute pleasure to deal with AA++ Ariel

Hi Manoj, Still waiting on my $200...it has been 2+ months !!!!! Ariel

what do you want to know specifically ?

thanks for reassurance ill put something together over the next couple of days for a 4G63. is a complete inlet manifold/plenum chamber from scratch. no standard parts were used. sure am on CT

plazmaman do mandrel bent aluminium and maybe stainless but not sure

who me ?

simply draw the plenum on a flat sheet and have it pressed, this is how i do mine.....i am happy to help with the pressing if you like

try buying a collector from a local manufacturer, they are around the same if not a little more....just depends what you are after

sorry my edit didnt work http://www.burnsstainless.com/MergeCollect...collectors.html

i'll pay that one....i just do it for my own benefit hence im building my own flow bench

looking at around $100 to get it flow tested. any local machine shop/engine builder should have one. Ariel

something like this ? its a 14mm conversion for rb25, but something similar would be on the cards i'd say.

try this link...i have ordered bits and pieces from these guys before, very nice work to say the least

anytime you like

lol Lorg...your a classic...and there are more coming

flow from cyl 1 - 6 271 276 300 307 275 276 difference between 4 & 1 is 13.28% these figures are at 28". i have a print out from the flow tester in 25". the conversion is x1.06. Ariel

ps.....from memory you have previously placed much emphasis on that variance being due to water temps between the front and rear of the head, but now its the plenum ???

not a problem. More than happy to help anyone who is a DIY'er.....its the only way to really learn anything i can show you the flow results if you like

considering the standard plenum has a 12+% varaince from the lowest to highest flowing runner, 5% isnt too bad....oh yeh thats right the standard one is good for 300rwkw lol

Hi Joe, Just some tips. - From my own experience, plenum volume is not directly related to engine capacity, but more the port size. Try about half the volume that has been mentioned above. - Always use bellmouths as these are what you would use to even out the different lengths in runners, probably one of the most important factors in building a plenum. - The taper is something i wont disclose for some very good reasons, but have a look at all the top mount ones available and you would get the idea. Ariel

Manoj, I am still waiting on a rely to my pm's. Please get back to me ASAP. Thanks, Ariel

www.customplenums.com

thanks 2GU UP price are $900 + delivery with exchange runners required. see sig for some of my work