brought home some S5 manifolds yesterday for my upcoming intake swap.. took a closer look at them today while scrubbing them down and i noticed these gashes in the UIM. what could have caused this? and is there any way to smooth it out throughout the runners? you cant tell in the picture but there is actually a noticable groove/indent in the aluminum.. im sure this would adversly affect airflow.. suggestions?

 

Those markings are from the mold that the intake was made in.

 

casting lines, won't affect flow much but if porting those lines are smoothed out.

 

those marks are normal. get a dremel and port that **** while it's off the car

 

have fun getting that gasket off btw

I used a razor blade + 2 hours for all my intake flange gaskets, and DAMN my thumb is sore from the scraping. If your lucky, you'll get the blade under the gasket and areas will just peel off exposing the bare metal. Unfortunatley, no matter how hard you try, there will be areas that you cannot do this, and you'll just have to shave it off.

damn I need air tools..

 

casting lines eh? i was hoping you guys had some cool theory involving the intense heat of the rotary lighting an ebay filter on fire, resulting in molten metal flying through the manifolds cutting into the aluminum all the way, eventually completely destroying the motor.. but no. i get "casting lines." weak.

but yeah, i keep hearing how enjoyable its going to be getting those gaskets off.. luckily i have a friend 40 minutes away who happens to have a compressor and tools.. i might just purchase myself one of those 3M gasket remover atachments and get to work! i have plenty of time, though.. still have to buy new gaskets, injector orings and grommets, an rpm switch, a little airpump, vacuum line, fuel line, etc.. plenty of time to port + polish!

 

and then you get to make it idle, lol. i wish you better luck than i had on my intake swap

 

you cant say **** like that and not explain yourself mint87rx7. its illegal. tips man, tips!!

 

make sure you know exactly where each and every vaccum line needs to go. if i did it over again i would have just done the general swap and thats all. then once it was running i would go back and do all the porting and emissions removal. i wish i would have done it one step at a time because when it didnt run i had a hole list of things that i changed that could have caused it. take a lot of pictures before you take it apart because your going to wonder what it looked like before you touched it after its done.
if you have any problems remember my name and pm me, I will help you as much as i can.
also read the carl davis writeup, I dont have the link but just search and its easy to find

 

hmm.. you saying that makes me reconsider my plan. i was basing my swap off of the carl davis write-up but i also wanted to see if i could adapt the S4 LIM to the s5 UIM and dynamic chamber. also, while everything was off, i wanted to see if i could remove the vacuum spider and get rid of as much of the emissions as possible, as well as doing a partial throttle body mod. as for all the vacuum hoses, i still dont really understand how the whole vacuum system works, and planned to get some assistance with that.. maybe i should put a little more effort into learning about it first.

i would appreciate it if you could detail all the things you wish you didnt do during the swap.. what emissions stuff did you mess with? what problems did you encounter afterwards and how did you deal with them? again, i appreciate your help!

i am also looking for other opinions on mating the s4 LIM with the S5 UIM.. i have only seen in mentioned and heard that it "is better." not something i want to base my swap on. i believe one of icemarks posts said that.. anyone know the reasoning behind it? wow, ive effectively jacked my own thread..

 

lol, i found a thread where icemark and some other guy were arguing about whether or not the s4 lim flowed better but i didnt feel very strongly about either ones arguments. i dont have a link but i think i found it when i searched for "s4 s5 intake manifold difference". hope that helps.

btw, take pictures when u r done please! im porting my manifolds right now too so it would be kool to compare afterwards.

im actually thinking of shortening and heavily changing the whole upper intake manifold and TB assembly but well see if that ever happens....

 

How much did all the manifolds run? I'm running out of things to do to my FC and was going to pull the spider next since my ACV melted down and I pulled it anyways.

I was also planning on banjo-bolting the FPD, cleaning my injectors again, and removing the OMP system. It would be the perfect time to change out intakes.

Oh, to make those gasket removals easier, just pick up a gasket scraper from your nearest automotive store. Here's what one looks like.

 

im porting me upper lower and plenum right now so ill post some pics too

 

koooooooooooool

 

heres the upper

 

heres the lower. an old friend of mine that used to dragrace in the 60's told me to just leave it smooth not polished from the injectors down because otherwise the gas will bead and go in as drips rather than a spray does anyone have any input on this ? also as you can see in the pic i removed that bump where the rear 6 port rod goes through and smoothed it out toofor less restriction. also removed were the copper 6 port rod sleeves that go through the intake they come out easy with a hammer and a big punch or something also removed is the bump at the top of the small front port (second one back from the front of the intake) just be careful with this one you'll see what i mean

 

niiiiiiiiiiiiice. i love the polished uim. hey, i bought a flex shaft for the dremel today for $45. it lets u go about 2 inches deeper into the lim!!! u should grabv one of those man! then u can reach some more of the crap in the ports pne the lim:P:P looks good man. i will buy some batteries for my camera tomorrow and take some pics of my progress so far.

as for the fuel atomization, i totally agree with your friend but this only applies to the secondary ports on the lim. everything else should be polished sincve there is not air/fuel mixture those parts.

 

scrap fc posted a GREAT idea for sanding down and finishing the manifold https://www.rx7club.com/2nd-generation-specific-1986-1992-17/porting-intake-manifold-questions-searched-404013/

 

wow, that polished UIM looks great! when do you plan to install it? let us know what your results are..

 

alright but i bet i wont notice anything because i havent driven the car in 15 months (lost my licence) but i'll still let ya know anyways while i have the whole intake setup off i'm blocking off all of the emissions and im gonna try those pineapple racing 6 port sleeves and see how they are (anyone have any input on them)?

 

cool. i plan on doing the same thing, except i drove my car today so ill be able to tell, i think. id like some input on those pinnapple sleeves too, im getting some for cheap

 

Umm...what's the point of polishing just the intake opening?

 

increase air velocity.

 

But your only polishing the openings, not the entire inside. Wouldn't the roughness of the rest of the intake negate what little gains there would be from polishing the openings?

 

this it the first rx7 intake i've ported and i dont know how the rest are but mine was pretty damn smooth inside