leejoseph Posted January 18, 2015 Report Share Posted January 18, 2015 I'm working on a 97 Chevy Venture. I'm doing this for my neighbor who is absolutly poor. His 97 Venture Van died and someone gave him a engine for it. So I just assumed he knew if the engine was the same one but its not. Its a 3100 from a car. It appears almost the same besides just a few plug ins. It looks around the same year. Can anyone tell me if I can use the 3100 in place of the 3400 without spending much money. ? Quote Link to comment Share on other sites More sharing options...
l67ss Posted January 18, 2015 Report Share Posted January 18, 2015 I'm working on a 97 Chevy Venture. I'm doing this for my neighbor who is absolutly poor. His 97 Venture Van died and someone gave him a engine for it. So I just assumed he knew if the engine was the same one but its not. Its a 3100 from a car. It appears almost the same besides just a few plug ins. It looks around the same year. Can anyone tell me if I can use the 3100 in place of the 3400 without spending much money. ? If its a 96+ 3100 you can use it just by switching a few partsz Quote Link to comment Share on other sites More sharing options...
leejoseph Posted January 20, 2015 Author Report Share Posted January 20, 2015 If its a 96+ 3100 you can use it just by switching a few partsz Do u know how I can tell what year it is and what parts I may have to change ? Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted January 20, 2015 Report Share Posted January 20, 2015 There should be a VIN stamped on the engine somewhere. 10th digit is the year. http://en.wikibooks.org/wiki/Vehicle_Identification_Numbers_%28VIN_codes%29/Model_year PCM may not be completely happy with the new engine. I think it'll probably run, but not great. You may be able to switch the PCM or flash the software on the existing one if there are drivability issues. What's wrong with the 3400? Quote Link to comment Share on other sites More sharing options...
Leadfoot Posted January 20, 2015 Report Share Posted January 20, 2015 I had a 3400 swapped into my 94 Cutlass to replace my 3100. I don't recall every detail, but its basically the 3100 components on top of the 3400 long block and works just fine. I believe the wires for one or 2 of the sensors had to be extended because the location was different. Quote Link to comment Share on other sites More sharing options...
l67ss Posted January 20, 2015 Report Share Posted January 20, 2015 If it has a maf its 96+. If the lettering is small with lines on the intake its pre 99....large lettering with no lines its 99+. I previously ran a 2002 3400 in my monte first with a 97 pcm then witha 2000 lumina pcm.....both with 3100 programming. Had zero issues. Only a 30thousandths dif in bore between 3100 and 3400 Quote Link to comment Share on other sites More sharing options...
leejoseph Posted January 21, 2015 Author Report Share Posted January 21, 2015 There should be a VIN stamped on the engine somewhere. 10th digit is the year.http://en.wikibooks.org/wiki/Vehicle_Identification_Numbers_%28VIN_codes%29/Model_year PCM may not be completely happy with the new engine. I think it'll probably run, but not great. You may be able to switch the PCM or flash the software on the existing one if there are drivability issues. What's wrong with the 3400? He had overheated it and I think the head or the block is cracked. Quote Link to comment Share on other sites More sharing options...
leejoseph Posted January 21, 2015 Author Report Share Posted January 21, 2015 If it has a maf its 96+. If the lettering is small with lines on the intake its pre 99....large lettering with no lines its 99+. I previously ran a 2002 3400 in my monte first with a 97 pcm then witha 2000 lumina pcm.....both with 3100 programming. Had zero issues. Only a 30thousandths dif in bore between 3100 and 3400 The 3100 has small 3100 sfi with lines the van that has the 3400 is a 97 ? Quote Link to comment Share on other sites More sharing options...
l67ss Posted January 21, 2015 Report Share Posted January 21, 2015 The 3100 has small 3100 sfi with lines the van that has the 3400 is a 97 ? So its a small port 3100. Will still work just less power Quote Link to comment Share on other sites More sharing options...
DiscoStudd Posted February 1, 2015 Report Share Posted February 1, 2015 Just a little more fat to chew on: When I was in search of a 3400 for my Impala, I came across 2 different "types" of 3400. One "type" fit N-Bodies, the other type fit W-Bodies, U-Vans, and Aztek/Rendezvouses. The main differences were the motor mounts and the coolant piping, which I would wager a guess could be swapped out between the 2. I ended up buying an engine out of a same year Venture. The mounts were the same, however the pulleys mounted to the timing cover were in different locations. It was no big deal to swap over the original engine's pulleys, as the mounting bosses for said pulleys were identical on both motors. Also, the coolant pipes were the same, save for the connections to the heater hoses (U-Van had quick connect heater hoses, Impala had slip-on hoses.) Again, it was cake to swap over the originals. Another strong suggestion from me would be to replace the headgaskets, LIM gaskets, and timing cover seal on the donor motor before installing it in the van. Search Youtube for a video on how to replace the timing cover seal. Seeing as you'd have the motor torn down, go ahead and install the LIM and UIM from the old 3400 onto the donor motor (provided the donor is 96 or newer - the large port LIM won't work on 94-95 3100's) and you'll be in the ballpark... Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted February 1, 2015 Report Share Posted February 1, 2015 I thought the 95-99 3100s were different from the 2000-2005 ones. Quote Link to comment Share on other sites More sharing options...
DiscoStudd Posted February 1, 2015 Report Share Posted February 1, 2015 I thought the 95-99 3100s were different from the 2000-2005 ones. Well that's true for how they looked externally. The 94 to mid-99's had the small port intake. Internally, 94-95's had stamped rocker arms, which rub up against the large port intakes, so swapping over to a large port intake is out of the question unless you swap heads over to 96+. 96+ have roller fulcrum rocker arms that don't contact the large port LIM's. The 3100 switched to the large port intake like the 3400's in mid-99. Sounds confusing, I know. I remember 60degreev6.com having an article posted that explains the differences between small and large port intakes and what they fit... Quote Link to comment Share on other sites More sharing options...
DiscoStudd Posted February 1, 2015 Report Share Posted February 1, 2015 Almost forgot, I found a write-up on how to pull the engine on a U-Van through the top, negating the need to drop the cradle. http://www.dodgeintrepid.net/showthread.php?t=170909 Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted February 1, 2015 Report Share Posted February 1, 2015 On an Intrepid forum of all things... lmao Quote Link to comment Share on other sites More sharing options...
DiscoStudd Posted February 26, 2015 Report Share Posted February 26, 2015 http://wot-tech.com/index.php?page=small-port-vs-large-port-3100-manifolds Quote Link to comment Share on other sites More sharing options...
Crazy K Posted March 6, 2015 Report Share Posted March 6, 2015 can and will work. here are the issues you will run into: large port intake can fit onto a block with a small port head, if you either: 1: use small port lower intake gasket on engine, and large port upper intake gasket ( possible, just add $) 2: drill the pilot hole at the top center of the head for the single guide pin that GM relocated on the intake. The gaskets are otherwise completely identical. need a 1/4 inch drill and a dab of grease on the tip with rags surrounding the area to catch metal shavings (very easy, done this before) Old style rockers will not clear the large port intake. if 3100 has slots under the pedestals to use roller rockers, swap them from 3400 onto engine. if not, you can carefully clearance the intake. read: http://60degreev6.com/forum/showthread.php/43246-95-3100-to-3400-intake-swap slight clearancing of 3400 lower intake can be done. Quote Link to comment Share on other sites More sharing options...
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