3100 and 3400 intakes

[beretta]

wanted to continue a post from a different topic i started. most of you probably know all the answers already but im still new in the intake swapping category.

So my gf's 99 lumina car has the good old 3100 and i have a 3400 top intake manifold i wanted to put on.
Are all 3400 large port ? and only 3100 are large port 02+ ? i thought in the same years the 3100 and 3400 would be the same thing.

So now to put this on i will have to change the lower intake manifold as well, just wondering what the performance increase will be on a stock engine. the car has been parked for just over a year now , my gf lost her licence for 6 months for having an outstanding fine and was suspended and didnt know and got stopped and charged driving under suspension witch is automatic 6 months with no licence, just recently got it back so the car will be going again soon.

Been a while since i even looked at it lol, im pretty sure it has around 340,000 KM on it, which is probably due to change the LIM anyways. it runs mint and passes pollution test with ease so would like to get more out of this engine until it decides not to run anymore.

I had all kinds of complete top ends heads and everything for various 3x00 engines planned on putting on the beretta but decided to go turbo and scraped everything not even thinking i could have put it on her car.

I have the top intake and TB already complete with egr and everything, the lower intake manifold will be cheap for me to buy from the JY 15 or 20 bucks probably for the whole top end so this will be something i can do for pretty cheap, and just want to do it for the sake of messing around with it. eventually later on maybe do a complete 3400 swap in it but probably try to get a couple more years out of this 3100.

What do you guys think about swapping the larger 3400 uppers and lowers on the 3100, will i get a decent amount of extra power considering the cheap amount its going to cost me to do this. is it worth while. im sure alot of you have already done this just wanted some suggestions. Probably a good idea to change the LIM gaskets anyways considering the amount of KM on the engine.

[Money pit Beretta]

Big ports are big ports. The 99 3100 is the same as the 2000 3400. The 99 upper has a wall in it by the EGR port and doesn't flow as well.

[beretta]

No they wont be the same... 3100's did not go to large port till 2000 all 99's were the same small port design that the beretta originally came with. Just look at it, they look nothing alike and the 3400 is missing 4 bolt holes to even bolt up.

94-99 3100


See how there are two bolts per port... Now look at the 00+ 3100



The same design as the 3400's... These are the 3100 large port engine, the intakes and runners changed drastically.

So really if your current engine has the 3100 with the lines on the upper intake then you can not use the plenum your starting to polish.

[beretta]

this is the 3400 top manifold i have.. i was told its from a 99 but maybe that is wrong.

[DTMAce]

Yep, that looks like the black 3100 above, and that won't mount on your engine if you have the 3100 with the lines in the upper intake like the first pic does. I mean just look at the bolt holes.

Now if your 3100 looks like the second pic above with the same bolt pattern, then yeah, it should fit.

Good luck.

[Money pit Beretta]

Got me, I was thinking of the Venture Van. The 3400 with the blank upper is a 99 and has the wall inside. That intake in your photo should be fine. Sorry, when I was looking for the 3400 intakes I got a few offers on the blank ones(always kind of fall back on that). Not something I wanted. The 99 van lowers are ok, it's the uppers that are bad.

[beretta]

so what is this one i have ? i know 3400. im not sure what it came off, i got it along with a box of stuff and side skirts to finish my z26 kit.

I was told its off a 99 but dont know what vehicle. and its the large port apparently so it must be 00+ ? i dont know LOL. and when i go looking for t a lower i want to get it off the same year if it will all bolt onto a 99 3100

[DTMAce]

I'm not an expert by any means, but I can tell just by looking at the pics above, that the intake you are working on is the same style as the black 3100 intake, but neither of them match the other 3100 intake with the lines in the top. The bolt holes alone just will not match up.

As to whether you can get by with just changing the upper and lowers, I have no idea. I would assume yes, but then again?

I can say that there is no way the newer 3400 intake you have there will mount on that older intake if it has the older style of 3100 already. Just won't happen.

Sometimes you are simply better off leaving it the hell alone.

[beretta]

Sometimes you are simply better off leaving it the hell alone.

I cant leave anything alone LOL. i know its different. i know i have to change the lower end, but i want to know what year the 3400 intake i have would be from.

228 or 238,000 KM on the engine now i looked today. so probably good idea to change the LIM gaskets anyways

[3X00-Modified]

You can use any 3400 lower intake... or any 2000+ 3100 lower intake.

[beretta]

You can use any 3400 lower intake... or any 2000+ 3100 lower intake.

Thanks, was waiting for you to chime in on this lol you seem to know alot about the 3400's

the upper i have then is what year ? i am confused on what years they were the same or different. are any 3400 uppers the same as a 99 and older 3100 ?

I was told this one is from a 99 but could be wrong, i dont know but i was assuming it would have been the same as a 99 3100 but obviously the 3100 is way different with the 2 bolt holes per runner.

Next thing.. if there is a 3400 upper that is the same, would i be better off getting that upper and bolting right onto the 3100 lower, or get the lower to match the one i have, if they are different the one i have will flow better or worse ?

sorry for being a knob lol

[3X00-Modified]

Ok...

all 3400's were the large port design 6 bolts total to hold it on the lower.

3100's were small port up to 99 and then in 2000 when they ran out of small port castings they switched to the 3400 style runners probably to save money and lessen the amount of design's, so its the same 3.1 block with 3400 parts on top and is tagged 3100. All the lower intakes are pretty much the same if they are large port. I do not think they had ones specific to 3100's or 3400's The only thing I remember is some have a 99 or blank casting on them and those were the 96-99 3400's, and others are tagged with a 00 the 3100 and 3400 being alike, and I think the latest casting was 03. So it's safe to say it doesn't matter which lower you run as long as it's the matching large port design.

so 94-99 3100's were all small port design.

96-05 3400's were all large port, 96-99 3400's had a big groove in the underside of the upper intake and you can see this big bump inside the intake in the neck area after the TB... the 00-05 ones are all the same and smoothed out more. Also the 96-99 3400's are the ones that had the better looking 4 as well in 3400 and some even came with a blank top specific to Aztek or something IIRC.... For example, the first 3400 I built, shows the lettering difference.

Look near the Fuel pressure regulator, you can barely see the outlines of a 00 casting, thats where the Lowers were tagged.



One other huge difference is the EGR... pre 2000 egr's had a horizontal flat mounting surface, the 2000+ ones were a vertical flat surface and the 00+ egr's are interchangeable all the way up to the 3500 style motor.

Any motor that is OBD1.5 that uses the three solenoid EGR will need an adapter. I have one of the 99 ones lying around and IIRC TCE still makes ones for the 00+ intakes.

BTW yours is a 2000+ one. The 4 has a very small center and you have the vertical style mount EGR.

[Styluss]

He has spoken...

[3X00-Modified]

LMAO... Way too much useless information in my head.

[beretta]

thanks,

That engine bay looks awesome too, is the TB just painted or is that aftermarket ?