Inliners

[playinsafe44]

Is anyone still running the a 6? My '73 has 64,000 with a 3spd and 3.73 gears (used to be an old nursery truck). Im just wondering if anyone is keeping the 6 for the long haul and what you guys are doing to them. One of these days I want to put in an OD tranny. I was thinking about the NV3500 (heard it would work), megasquirt it, a split manifold and maybe an RV cam. My goal is mileage!!!!! Being able to use it as a truck is still important though!

[BIG10]

What kind of mileage do you get now?

[playinsafe44]

Last tank I got 14.5 mpg, and that wasn't a good baseline. I am filling up again tomorrow, and I will post what I got on it. I just want to build one of these old trucks to be a good daily driver with the best mileage I can squeeze out of it.

[BIG10]

Sounds like a good plan.

[playinsafe44]

Well I fueled up again today. It came out to 15 mpg even. That is all city driving. I don't think highway mileage would be much better though. With the 3.73 rearend and the 3 spd non-OD, the revs stay pretty high. I think low 20's should be acheivable. Any thoughts?

[BIG10]

I always thought it would be cool to swap in a 4.2 I6 from a Trailblazer. They put out some pretty good torque, but if I was doing that much work, I'd just drop in a LSx. Plus, my wife's TB only gets 15-16 in town. Sorry, I'm not much help with your question.

I don't know if an RV cam would help, but I would keep the 3.73's.

[playinsafe44]

Yea I think the 3.73's would be perfect with the OD I'm planning. It's funny you mention the 4.2. There is a guy over at the inliners.org site that is running one in an AD truck. I am planning the same thing except VERY mild compared to his (I have a '47 on an S10 frame). I'm addicted to trying to get better mpg, and inlines are just different.

[nekkidhillbilly]

i cant see it being any better than a v8 really

[BIG10]

I like the 4.2. I had a 2wd short wheelbase Trailblazer that did a little better than my wife's EXT. I got 21 mpg on a trip to Dallas once. I set the cruise at 65 and it did okay. The EXT 4wd is quite heavy for the I6, but it pulls well. Towed my mom's Venture home 300 miles flawlessly.

[BIG10]

Sorry if I highjacked your thread.

[nekkidhillbilly]

ive never got better than 16 out of the 4.2

my 4.8 truck would get way better

[playinsafe44]

I think the 4.2 has a lot of potential. First it started out in a really heavy vehicle to begin with, and then it has all the emissions equipment. I think with megasquirt, a leaner tune, less emissions junk, and possibly a 5 speed out of a colorado, it might do really well. When its all said and done, and the mileage is in the low 20's like a comparable LSx motor, I would still be happy because it's something different. All I need now is a decent '06+ 4.2 to pick up. Still trying to find a good deal on one in my area, but I don't really know where to look. I frequent craigslist and ebay.

[BIG10]

Originally Posted by playinsafe44

I think the 4.2 has a lot of potential. First it started out in a really heavy vehicle to begin with, and then it has all the emissions equipment. I think with megasquirt, a leaner tune, less emissions junk, and possibly a 5 speed out of a colorado, it might do really well. When its all said and done, and the mileage is in the low 20's like a comparable LSx motor, I would still be happy because it's something different. All I need now is a decent '06+ 4.2 to pick up. Still trying to find a good deal on one in my area, but I don't really know where to look. I frequent craigslist and ebay.

Why 06+? The 4.2 debuted in 02. What's the difference? Would a Colorado 5 spd bolt up? I've always wondered why they didn't put the 4.2 in the Colorado instead of the I5.

[playinsafe44]

I thought I read somewhere that the colorado 5 speed would bolt up (Atlas series engine). EFI DIY on inliners.org has done a lot of research on the 4.2's. I think he is where I read that the '06+ had a better flowing head on them. A significant power increase too.

[sierra4x4]

I put a 250 in my 86 3/4 ton 4x4 in place of a 350. I drive it every day to work in the winter. I havn't checked the mpg of it but it seens to be very good on fuel. I need a OD becouse she revs to high with 4.10's.

[bigblock73]

I am keeping the inline 6 in my 77...but will be replacing the 250 one day with a 292 I picked up recently. I am going to put a 200 beind it and TBI it.