Smallport intake cut and shut...?

[JDMBenji]

Hello everyone,

My names Ben.

I have a few issues at the moment, I've broken my bigport engine. The keyway broke that the crank pulley sits on and it's wobeling all over the place which in turn caused my battery to run low and discontinue the circulation of water through my block...:right:

So I bought a smallport engine off a mate for $100 =D. The only difficulty is the intake manifold everything else still looks like it is much the same but I'll find out how difficult it actually is soon enough.

But I was wondering if anyone on her had a cut and shut smallport manifold or knows how to do it? Would be able to lend me a hand.

PS - it's for an 86 that had the JDM bigport.

Has anyone heard of any cheap engine stands going as of late?

Cheers guys

[Nikkojoe]

You can try and get a T3 smallport to bigport adaptor plate to use your old bigport intake manifold (you dont run tvis as the adaptor goes in it's place).

Otherwise someone that can weld alloy can modify your intake. Try a few engine builders or fabrication places.

[timbo]

my advice is go for whats cheaper. i have a cut and shut manifold on my smallport and i've never had a problem with it, looks like a fairly good welding job. check out my members ride thread for a picture.

[Tim.duncan]

im also intrested in as much info as possible!

i am under the impressions that if you just hack the front and back off and weld them up it affects the way the oil breather set up works. now this is an issue with the smallports as they run a Manifold Air Pressure sensor for the ecu.

so do you need to cut threw the runners and turn the whole plenum around to avoid this???

can some one shed some light?

[Nikkojoe]

The Map port is not affected by the cut and shut. The oil breather is, so what i would do is get a fitting put onto the intake pipe (or get a rubber intake pipe with one) and run the breather to that port.

[Tim.duncan]

ahhh simple an easy, cheers mate dident think about that at all

[sun_moon]

You can try and get a T3 smallport to bigport adaptor plate to use your old bigport intake manifold (you dont run tvis as the adaptor goes in it's place).

please do not do this. smallport manifold is a FAR better design... there is a video on youtube showing when they cut the manifold at the runners, it shows how restricted they are compared to a smallport manifold.

the beauty of using a smallport engine is u have an engine with a DECENT port size and also u get a better manifold.

[timbo]

DO NOT run the oil breather into the intake pipe, ie before the throttle. i bought my car with this setup and the throttle and manifold were clogged with residue and gunk (plus the original bigport pipe now has a hole in it...). i highly recommend running a catch can to avoid cleaning your throttle every week!

[Nikkojoe]

please do not do this. smallport manifold is a FAR better design... there is a video on youtube showing when they cut the manifold at the runners, it shows how restricted they are compared to a smallport manifold.

the beauty of using a smallport engine is u have an engine with a DECENT port size and also u get a better manifold.

Didn't say it was better, i said it's easier.... (assuming he already had a rwd bigport manifold - of which then he would probably have a rwd throttle body so he could run the oil breather to the intake without drama).

[Nikkojoe]

DO NOT run the oil breather into the intake pipe, ie before the throttle. i bought my car with this setup and the throttle and manifold were clogged with residue and gunk (plus the original bigport pipe now has a hole in it...). i highly recommend running a catch can to avoid cleaning your throttle every week!

If you have seen a factory manifold this is how it's done. If your motor is in shit condition it's gonna push a lot of oil and shit into your intake having it hooked up like factory. I've never had a problem with this and this is how it's always been done for me.

I've seen a rebuilt engine where the cylinder bores were too big that it pushed oil into the intake at idle....

[timbo]

If you have seen a factory manifold this is how it's done.

really?

i found this pic of a smallport still FWD:

http://upload.wikimedia.org/wikipedia/commons/thumb/1/14/4A-GE_redtop.jpg/800px-4A-GE_redtop.jpg

oil breather into the plenum... more smallporst;

http://img457.imageshack.us/img457/3497/4agcomparisonte5.jpg

http://img166.imageshack.us/img166/9073/25042008892hb0.jpg

http://i272.photobucket.com/albums/jj200/TylerRoozen/1008072317.jpg

[Nikkojoe]

Do you actually know that it doesnt just GO into the plenum? It goes through a port, to the throttle body BEFORE the butterfly....

More so when you cut and shut, this port is lost and then you blow your dipstick out because your engine is in shit condition

[JDMBenji]

Like, I have a whole RWD bigport that I broke. So I can use the manifold off it? But would be the mot effective way to make power? Yet it would be much easier to buy that adaptor plate... But if a fair bit of power is gunna be lost I'd wanna keep the small port manifold.

Best way?

PS - anyone have a whole ae92 loom? And will it fit in the 86 properly?

Cheers, Benny

[Nikkojoe]

IMO being stock it wont be that bad. You do have more compression on the smallport.

You can still run your bigport management on it, as long as you use the bits for it (like dizzy). Although it wont be optimised for the engine, people still run it like this without drama.

[reecegze]

Smallport does flow more but most turbo 4a's are using the bigport manifold and it flows perfect to 200kw so I wouldn't bother with upgrading the inlet based on flow and port size. Just get an adaptor plate

[JDMBenji]

Cheers, mate thanks for the help =)

Much appreciated indeed.

[timbo]

Do you actually know that it doesnt just GO into the plenum? It goes through a port, to the throttle body BEFORE the butterfly....

More so when you cut and shut, this port is lost and then you blow your dipstick out because your engine is in shit condition

dude don't get on you high horse, im only able to tell from what i can see. where exactly is this port?

[sun_moon]

Smallport does flow more but most turbo 4a's are using the bigport manifold and it flows perfect to 200kw so I wouldn't bother with upgrading the inlet based on flow and port size. Just get an adaptor plate

reece remember that compressed air flows differently.

notice how ITBs are used to flow better on a NA engine, yet a turbo engine its not as critical.

[Nikkojoe]

dude don't get on you high horse, im only able to tell from what i can see. where exactly is this port?

sorry i can't get on my high horse unless ive got a ladder. I was merely replying in a way that you did to, but anyway...

I did take pictures of my spare smallport manifold just incase you wanted to see.

[Nikkojoe]

http://www.ae86drivingclub.com.au/dcimages/1/1/0/549142.jpg
http://www.ae86drivingclub.com.au/dcimages/1/1/0/38165.jpg

This manifold was removed from a 285,000km adm smallport, which had a let go bearing on no.4 and cracked piston, which pumped oil into the intake and exhaust.

[timbo]

righto, thanks man! mine doesn't shoot out oil but it does have a little bit of residue... might have to look into this.

[ditn]

Sorry for bumping such an old topic but i have a question and i cant find the answer
i have a ae101 engine at home.
I was planning on using the t3 plate with bigport but the t3 doenst match up 100% with the ports :s
So i was planning on buying a cut and shut manifold with my smallport but im concerned about the breather port like shown on page 2
If i run a catch can can i avoid the problem of the oil collecting,or would it be better to fix the adapter plate?

[tottacrolla]

The reason why people have oil problems with the small port cut and shut is because the stock breather pipe is connected internally via a small diameter cast in pipe to the throttle body, when they are cut and shut the cast in pipe gets cut and it now draws air directly from the vacuum in the plenum and in my case it was actually drawing oil up past the piston rings.
I resolved the problem by running the breather to a catch can, I also have a pipe going to the air filter from the catch can and this draws out any fumes from the catch can.

Be aware that some cut and shut manifolds are not angled down like the TVIS manifold is and you will likely have bonnet clearance issues with one of these manifolds.

[timbo]

This is mine, angled throttle body and I use a catch can. Don't run it straight into the manifold, it's oily, gunky and has bad fumes. Just plug the manifold with a nipple.

http://www.ae86drivingclub.com.au/dcimages/3/1/1/3/190056.jpg

http://www.ae86drivingclub.com.au/dcimages/3/1/1/3/190050.jpg

[ditn]

ty for the tips,hunting for a cut and shut one at the moment :)