Engine Differences.

[Marks95GAGT]

I have been checking out 60degreeV6.com. They talk about the 3100 and the 3.1L engines as if they are different. I know the diplacement is the same, but what about the rest of the engine. I also want to see what parts are interchangable if any. Any one have an idea what is up with the different engine listing?

Mark

[HondaCivicsSuck]

well,

to start off with the 3100 makes more hp like 25 more i think. 3100 has a better cam, liffters...... so really most of the internal things in the 3100 are improved :)

[Jason Lesbirel]

The fuel injection system is different (Multi-Port Fuel Injection vs. Sequential Fuel injection), and the heads between the two are quite different.

Also, the crankshaft was redesigned to correct a problem with older 2.8s and 3.1s. The 3100 has a digital EGR valve, which is not so much maintenance-free as just unserviceable.

The 3100 is significantly different compared to the old 3.1 liter V6, so much so that it is in essence a "new" engine.

[CDR Speed]

I think the differences have been pretty well covered here, but there's still a few. The MPFI had flat lifters, SFI had rollers, the SFI has an intake that is about 7,605,044,322 x better than the MPFI intake, the heads have bigger valves in the SFI, they have larger ports, a thicker mounting deck (to avoid warping/cracking), the SFI got guide plates to avoid the valvetrain clatter that some of the MPFI's were known for, the SFI got a different timing cover and cam design, higher compression, and a bigger throttle body. I'm sure i missed something, so feel free to add whatever you think of. They're basically different engines that are the same size.

[Marks95GAGT]

Thanks. Now I know what to look for. The guy that told me he had an intake for my car had a 3.4 mpfi intake. I didn't buy it of course, but now I have to do some serious work on my car. As for the lifters, that is a huge help, I think I need to replace one. Should I replace them? I have one that is collapsed and ticks when it is cold. Thanks, Mark

[CDR Speed]

Listen, if you're gonna be in there right next to the liftersm and have a few extra $$$ with wich to work, then go ahead and replace all of em.

[Marks95GAGT]

That is what I was thinking....and since I already have that side of the whole engine tore off, I am thinking cam....but how to get it out with the engine still in the bay. I am working on that one......lol :D

Check out the thread I started my leaking intake. I am gasketing matching the ports and doing a mild polish. I didn't realize they were so messed up until I saw how out of round they are.....

:)