3500 plenum swap check list.

[IsaacHayes]

Bump.... Info please... I'm lost as to where to get the connector/s.

[PCGUY112887]

I thought you could get an adapter from a 98+ish (somethin like that) cavi?
I remember reading something like that from 3400swap.com, I may be wrong though.

[IsaacHayes]

No, it was Phil's thread on here about 3500 top end swap (heads up). But the thing is, no junkyards around here have any new cavi's. So I'm wondering how to go about getting it.... Don't want to slap my old one on there when this one fits so nice..

[IsaacHayes]

Got in my 3400 Lower today. Tapped for my coolant line (97 venture van). Went to junkyard and they actually had a sunfire in that had the MAP connector (no motor, but the new style map was hanging there!). I checked some saturns too as I know they might have it, but they were all old style square box MAP sensors. So I got that done. Got my 3.1L mpfi EGR tube/plate. And a nasty flat tire. I put 2 plugs in the hole!!!

Ben: I'm off to NAPA now to find those bolts. I'll let you know if I figure out the thread pitch.

Questions if anyone cares/reads this thread anymore.
1) whats the best way besides welding to join my EGR tube and the 3.1L'ers? I think burn (who wrote the article on here for $5 egr adapter) said his muffler cement/tape started to leak after a while.

2) Will the IAC hole provide enough vacuum T'ed off for both the FPR and Trans Modulator for proper operation? Or should I go with a large vacuum tube to each to ensure this.

[IsaacHayes]

Anyone on the above questions?

Sappy: Bolt size is M8, 1.25 tp. You said 2.565" long, which equals 65.15mm. Only sizes I could find were 60mm or 70mm long, at 3 stores. NAPA was closed, so I'll try there tommorow, but I doubt they have that odd size.

Can you confirm if it is indeed a 65mm long bolt, or if 60mm would work???
Is 65mm from top of head to tip? That would possibly explain the extra 5mm, as bolts are measured from under the bolt head, to the tip...

Also, I take it a regular bolt would work, it doesn't have to flange type bolt right?
I might go with some swell looking hex head like the ones you supply with the 3500 TB adapter. I'll need a hex bit socket though so I can use a torque wrench. BTW there is a guy selling stainless steel M8 1.25x60mm bolts on ebay for 28 cents a peice in qty of 35.

[tejohnson]

I would like the bolt length myself

Just got mine ready to go this past weekend:

http://groomlakelabs.com/?q=gallery&g2_view=core.ShowItem&g2_itemId=2221

[SappySE107]

Its 2.565 from the bottom of the head to the tip. 2.764" over all length. I need to find some steel (stainless is a bitch if you drop one cause a magnet is worthless) bolts that look nice for my swap kit. mcmaster.com might have them as well though I dunno as I haven't tried to do a search on their site. That is where I got the other bolts though (i don't use stainless bolts anymore on the TBs either because the magnet thing).

[IsaacHayes]

Hah, nice! I like how you tapped the bolt hole that holds the MAP bracket into another vacuum port. Cleaned up nicely without the EGR/IAC stuff. I think me and you will have the best looking 3500 plenums when ours are done. I'll be sure to have pics when I'm done. I see you took the side tab off too that I'm going to do by the powersteering/alternator. I also see you took that square tab thing off on the right side by the throttle body. Did you have to tig that closed, or am I safe to cut that off and not have to weld it???

BTW, There are such thing as 65mm long M8 1.25 bolts, but they are very uncommon/rare/special order. (plug for firefox, I hit delete and it took me back a page, I went forward and my reply was gone. I though oh crap. But then I clicked the quick reply, and firefox rememeberd all the fields. Try that with internet exploiter! woo hoo!)

[IsaacHayes]

NAPA didn't have them. I went to "Fastenal" and ordered them. Only .47cents each! wow that's about a dollar cheaper than hardware stores. Should be in friday or tuesday. M8 1.25mm thread pitch, 65mm length.

EDIT: picked up the bolts today. They chaged to have them come in shipping of $3.00. Was still under $6 for 6 bolts. I should of ordered the black ones too that had the inner hex drive head, but I don't have a hex bit to tighten them with and that would cost more money. But I bet that would look slick with the black manifold. Oh well I'll just paint these standard bolts. I got ones with only partial thread. I need to verify they work but they should.

[Rhedalert]

I just installed my 3500 manifold onto my 3400. I used flanged metric bolts from Sears hardware M8x1.25x60mm I don't see 65mm as necessary. If anything, the 60mm bolts were close to bottoming out on my lower manifold. I also tried that cheap EGR trick, I don't know what car it was initially installed into but my w-car does NOT have that kind of room for something like that. So at the moment I'm at a loss and I'm running with the manifold hole plated off and the exhaust mount plugged. Also I have to do something about the MAP sensor, either extend the factory wires or do something else, it really looks half assed. Runs good though!

[IsaacHayes]

Thanks for the info. I still haven't tested out my bolts yet that I got. Do you have a picture of your engine bay/egr space issue? I *have* to get the EGR to work on mine, it's impossible to turn it off on my car.

Did you notice a decent improvement? You already had a 3400, so the change isn't going to be as big as it will be on my car.

[Superdave]

No offence guys but man that 3500 plenum is fugly... lol


i'll stick to my ported 3400 plenum, hehe

[IsaacHayes]

And we'll make more power than your ported 3400!!!! hahaha Just gasket matching the 3500 it will outflow your 3400 and also has other benefits (larger area, shorted runners, equal flow, etc).

But seriously, what do you think of my avatar? That's how my engine will look when it's installed. Wait till you see the pictures of the finished product. It will be one of the best looking 3500 setups you've seen!

[Rhedalert]

I'll get some pics soon. I did notice a difference in where the power is. More to be had off the line, plus at around 3500 rpm it moves well. I'll G-tech it just for kicks. I also might have a fueling issue holding me back, as I'm using a set of injectors off a 3300 and I don't know if they flow more or less than stock 3400.

I like the manifold in black actually. My whole engine is painted black (except the upper intake) but I haven't touched the new upper intake yet, I may do it though.

[IsaacHayes]

Awesome. It's always good to hear it from each person that did the swap. Everyone says low end got a boost, so the more I hear the more it confirms it. EXCELLENT. I want more off the line power!!! That's the only place I'm lacking. 3300 flow less than 3400 injectors. You should run your stock 3100 injectors and FPR, because the computer is designed to control those. Also you should be using a new O2 sensor if you haven't changed that. It leaned me back out and I picked up a lot of power from it. (was runing rich). I think you replaced yours recently though right?

Going downstairs to start preping everything. Got my die grinder in yesterday!