The best 3100/3400 engines to look for?

[Monzsta]

So after lurking for years, I find myself driving a '97 Lumina with a 3100. After wearing out the search bar, I need a few questions answered.

1. What are the best years for the 3100 and 3400, respectively?

2. What would be the best bolt on parts from other cars? (i.e. 3500 uim/lim, cam from 3100 Montana, manifolds from 3400 Grand Am, ect, ect)

Just looking for a quick rundown on the "sweet" engines of the bunch for junkyard scrounging. Found a 99 3400 and a 00 3100. wondering which to grab.

Thanks in advance
Scott

[Monzsta]

Don't use a 3500 lower. I don't even think the bolt holes are the same...


You got 3400 heads, good. You need 96+ 3400 LIM, OR a 2000+ 3100 LIM.

The 94-99 3100 stuff is small port. Avoid that as the ports/casting is tiny and can't be ported to even 3400 stock.

Check for Vans for the early 3400's if no late model cars are available there.

3100's to avoid will have more than 6 bolt holes on the top of the LIM, and the small port 3100's can be identified easily as they have lines on the top of the plenum. If you see those motors keep walking.

More info like this, consolidated in one thread would be wonderful.

[IsaacHayes]

Once I have time I will make something in the wiki that shows what you can swap on to what.

3400 - newer/less miles is better. In 2000 they made the upper intake flow a little better.
3100 2000+ got the same top end as the 2000+ 3400.

Cams are all the same.

3500 upper can be put on the large port 3100/3400's.

3500 heads, LIM, and upper can be put on a 3400. But won't fit a 3100 bore.

Impala 3400 2005 exhaust manifolds are the cross over log type but the ports are huge like the 3500 style size, so it should flow better. 3500 "shorty header" style from a malibu might fit some cars, with 2 front exhaust manifolds used on both sides for most older cars seems to fit... Then you run the pipes into a Y somewhere then to the rest of the exhaust system.

[Monzsta]

Thanks a bunch. The 3400 I was looking at was in a '99 grand am, and had the smooth manifold/6 bolt/large lettering like the '00 3100 did. Is this a good engine, or are the 2000 and up differences internal, and not seen from the outside, like a small port/large port 3100?

[IsaacHayes]

2000+ had a better transition on the upper intake's neck. As far as that there isn't any big difference really. The 2003+ heads went to 8mm bolts on the rockers and some have troubles with those I've learned with pulling out for some reason.

The 99 will do you just fine as long as it's been taken good care of. Be sure to change the LIM gasket with a metal felpro before running it though to take care of that for once and all.

[Monzsta]

Okay, I'm going to see if I can land the 3400 tomorrow. The accompanying trans is an extra $20.00, but I can't remember if it's a 4t60e or a 4t65e. I'm going to grab them both. Any wiring or ends/brackets, pcm, ect I should snag while I can?

[IsaacHayes]

If it's a 99 I think it might be a 4T45-E. I would guess when they went to 3400 and new body style is when they went to that trans.

[85_Olds_Ciera]

Once I have time I will make something in the wiki that shows what you can swap on to what.

That would be nice...to also include 2.8Ls....if possible...

[IsaacHayes]

I don't know enough about the mpfi motors, other than you can do a top end swap on them to gen3 stuff and get custom push rods. All the little other details with that would have to be figured out by the user (powersteering etc). www.domesticcrew.com had a guide on this I believe though.

[85_Olds_Ciera]

I don't know enough about the mpfi motors, other than you can do a top end swap on them to gen3 stuff and get custom push rods.

Even tidbits like that would be appreciated...I realize there are computer and mechanical details...but small tidbits can be quite helpful.

I've switched heads...oil pumps...etc.etc...but knowing what can be done is helpful. For SBC, there were not that many considerations needed...but these newer motors, they seem to be changing more often.

thx

[geldartb]

If it's a 99 I think it might be a 4T45-E. I would guess when they went to 3400 and new body style is when they went to that trans.

yes that would be the 4t45-e for the new body style.

[85_Olds_Ciera]

I don't know enough about the mpfi motors...

GM has some tidbits here...

First generation V6/60-degrees have cast iron cylinder heads with inline valves; second generation engines have aluminum cylinder heads with splayed valves. First generation engines V6/60-degrees are produced for front-wheel-drive and rear-wheel-drive vehicles exclusively. Parts are interchangeable between the two versions except as noted in the part descriptions below. Chevy V6/60-degree engines are available with 2.8-liter (173 cubic inch) and 3.1-liter (189ci) and 3.4-liter (207ci) displacements. 1985 and later V6/60-degree blocks have larger main bearings than pre-l985 engines; these late-model blocks are recommended for high-performance and competition applications. All Chevy V6/60-degree engines use metric fasteners exclusively.

[bszopi]

I don't think that wording has changed at all in almost 15 years. Unfortunately, that catalog is very out of date for the 60V6 engines, and I don't see that changing any time soon.

[Monzsta]

Okay, got the 3400 home, ($180, Pull -A- Part) left the trans at the yard. Tore the engine down to find a decent engine. Almost no sludge, no coolant in the oil, and no metal in the oil. The cylinders have no ridge, and the cross hatch is still visible. The plugs and chambers were oil encrusted, probably due to the original intake gasket on it's way out. A full port job on the heads, a fresh load of gaskets and it'll be in the Lumina with a FAFB 2980 stall torque converter ($70 + $25 core, Whatever It Takes Transmission Parts) and the DHP tuner's on the way. How much will I hate myself for not putting a cam in it now, while it's apart, and what's a decent cam for it?

My neighbor's got a '99 4 door sunfire with a bad trans. I'm hoping to score that car for the final home of the 3400/4T60E, but the Lumina will do for now.

Off topic... but it's my thread.. I did manage to sorta shim the accumulators in the trans.. I used some 5.7l Hemi valve springs and 2" washers (2 in each accumulator) with a load of type F trans fluid, now the trans has the firm shift I like, with a good chirp WOT 1-2. The transmission was like brand new on the inside, so I was comfortable doing this. Can't wait to feel what the 3400 will be like.

[3400-95-Modified]

5.7L HEMI valve springs... YIKES... I've never heard of going that crazy with shimming the accumulators... What works works though...

Any idea on the spring pressure change from the stock springs to the Hemi ones??? I would assume it was a huge jump. those stock accumulator springs aren't that heavy.