My 2F to 1HZ-T swap thread (1 Viewer)

[crushers]

i would say the 4.11 if you keep your cruising speed down... if you like 75 mph then the 33s would be better

 

[HZJ60 Guy]

My truck has 37's. Decided on 4.56 gears.

 

[kevinmrowland]

Well, I guess the test drive is unfortunately over, about 7,000 miles of it. Had a great time, engine runs great, same old truck and yet completely different. Passing up hill, no trouble keeping up with the 75mph traffic and yet being able to basically stall the engine off road, without actually staling are all fun new things. And even though I hope for improvement, all this on 17-20mpg is pretty satisfying. Got to drive and even wheel the hell out of it and it is a whole new truck.

Since I have 3.7s sitting on the shelf I am going to swap them in, I will miss the speedo reading correctly, but I think the rpms will be closer to where they should be.
Currently with the 4.11s, 55mph=2000rpm, 65-2400, 75-2800. The gas milage drastically improves the lower the rpms are kept and the motor sounds and feels like it wants to shift at around 2000rpm, lower than the 2F. I will switch the gears and see how it runs. the fiddling never ends...........

 

[roscoFJ73]

Well, I guess the test drive is unfortunately over, about 7,000 miles of it. Had a great time, engine runs great, same old truck and yet completely different. Passing up hill, no trouble keeping up with the 75mph traffic and yet being able to basically stall the engine off road, without actually staling are all fun new things. And even though I hope for improvement, all this on 17-20mpg is pretty satisfying. Got to drive and even wheel the hell out of it and it is a whole new truck.

Since I have 3.7s sitting on the shelf I am going to swap them in, I will miss the speedo reading correctly, but I think the rpms will be closer to where they should be.
Currently with the 4.11s, 55mph=2000rpm, 65-2400, 75-2800. The gas milage drastically improves the lower the rpms are kept and the motor sounds and feels like it wants to shift at around 2000rpm, lower than the 2F. I will switch the gears and see how it runs. the fiddling never ends...........

Its rare for the 1HZ not to make friends.

 

[JPHockerAZ]

Kevin,

Glad you got home safe and that you had fun driving the journey down here. Your truck is amazing and fun to drive, keep us posted on the future progress.



Joel

 

[60/40GUY]

Kevin,

Glad to hear you had a great trip. Sounds like a successful first run.

I cannot wait to hear your evaluation of the 3:73. I have both sets of axels sitting on the floor and am still on the fence as to which one to mate to the HZ. Right now I am leaning toward the 3:73 for the HZ and the 4:11 for the 2F. But the HZ will have the lockers.

Thanks for keeping us up to date. This thread is going to save me a lot of head ach down the road.


Frank

 

[kevinmrowland]

Spent a little more time fiddling this evening and
I FINALY seem to have gotten the tach to work properly!
So nice to see the little needle move like it is supposed to again. I verified the rpms with the Tiny Tac and it seems to read true across the band.

The translator from Dakota Digital is not set anything like the instructions say it should be, but it works. I am attaching a pic of the settings that eventually worked out, the only switch that is "on" is #3 And if anyone really wants I can count out what the course and fine settings are.
I installed the VDO sensor (part#340-020) on the bellhousing. It was a real bitch to get it forward enough to register off the flywheel teeth.

 

[kevinmrowland]

I plan to make use of the holiday weekend to swap the 3.7 gears in tomorrow. I hope I like the way they run.

Milage on the 4.11s over 7009miles worked out to be 18.4mpg (US) with a considerable amount of highway speeds and wheeling, fully loaded, running the AC. We will see if the 3.7s make much of a difference.

 

[kevinmrowland]

The 3.7 are swapped back in, initially I though it was a good compromise but over the last weekend I went on a 947mile road trip. And milage concerns aside, it is just not as fun to drive. Still a bit peppier than the 2F, but not nearly as quick as with the 4.11s.

And while it does not compare to the 7000 mile milage test above, the average for the weekend was 18.5mpg. A one tenth improvement. This is only over three fillups at:
17.47mpg
19.83mpg
18.21mpg

Not a definitive test, the first tank was a lot of idling, the second tank was highway, third tank was highway with a heavy load and all the milage numbers reflect the AC running all the time.
If I drove for gas milage with the 3.7s in, took my time accelerating, did not pass uphill on the highway, ect.ect. I am sure that the milage would jump significantly. But I drive the truck like I want to and the 3.7 numbers reflect me trying to drive it like it still had the 4.11s in.

Bottom line is that it is just not as much fun, so the 4.11s are going back in.
I want the hot-rod 60 back.

P.S. All milage numbers are GPS verified, the odometer reads 16% off with the 3.7s and BFG 33"

 

[hks3sgte]

Good thing you tried both ratios. Enjoy driving your hot rod. Slap those 4.11s back in!

 

[60/40GUY]

Kevin,

Great info to have. Thanks

Sounds like I'll be using the 4:11's

Thanks again. This is a great thread with a lot of usefull information.

Frank

 

[kevinmrowland]

Update:
Still love the new engine.
The 4.11s have been back in for awhile now, thankfully, the 3.7s were starting to really kill me. I have only been on one trip since then, 857 miles, two states, a variety of terrain including flat highway, hilly highway and dirt back roads in VT.
Three tanks of gas at:
17.15mpg
18.97mpg
19.19mpg

18.4mpg overall average.
This is compared to the, boring to drive, 3.7 gears that netted me 18.5mpg. All I did was back off the skinny pedal a bit and I got the same mileage out of the 4.11s as I did with the 3.7s but still had fun driving. No unnecessary hot rodding or quick starts, 70mph for 8+ hours on the highway, everything else was back roads, still had power to spare on the hills. Amazing the difference gearing makes.

 

[Dougal]

Update:
Still love the new engine.
The 4.11s have been back in for awhile now, thankfully, the 3.7s were starting to really kill me. I have only been on one trip since then, 857 miles, two states, a variety of terrain including flat highway, hilly highway and dirt back roads in VT.
Three tanks of gas at:
17.15mpg
18.97mpg
19.19mpg

18.4mpg overall average.
This is compared to the, boring to drive, 3.7 gears that netted me 18.5mpg. All I did was back off the skinny pedal a bit and I got the same mileage out of the 4.11s as I did with the 3.7s but still had fun driving. No unnecessary hot rodding or quick starts, 70mph for 8+ hours on the highway, everything else was back roads, still had power to spare on the hills. Amazing the difference gearing makes.

So for those too lazy to do the maths, what was your crusing rpm then and now?

 

[kevinmrowland]

Currently with the 4.11s, 55mph=2000rpm, 65-2400, 75-2800.

And the 3.7s basically lowered everything about 200rpm (of course it was a percentage, not even across the band, I have it written down somewhere) but the torque was just not there anymore which is what I think killed the mileage. While the lower rpms are more efficient, it does not do much good if the engine has to work harder to compensate for less available torque.

 

[Bryan062087]

Have your fuel economy #'s improved any from 19 mpg?

 

[kevinmrowland]

?from yesterday?
I haven't even driven since the last post.

 

[Bryan062087]

Ahh, didn't see the date.

 

[Ducks]

The peak torque of the 1HZ is supposed to be 2200 rpms. I don't know how the turbo would change that. Would you be getting your best fuel mileage if you were cruising at that rpm? I know with my 2F, I get my best gas mileage when I'm cruising at 1800 - 2000 rpms. The peak torque of the 2F is 1800 rpms.

Thanks for all the work you did on putting this thread together. It is extremely helpful.

Chad

 

[kevinmrowland]

It is hard to explain, that peak torque was the reason I tried the 3.7s in the first place, but it seems to be negated by how the different gear set equals less torque at the wheels, so in essence, even thought the cruising rpms were right where they should be, getting to those speeds took more energy since some of the torque was lost in the gears.
This is not based on any prevailing scientific principle other than how it felt to drive. The long and the short of it is that the 4.11s are WAY more fun to drive, and if I back off the skinny pedal a bit, I can get the same mileage that the, not fun at all to drive, 3.7s afforded. So I think it is a win, win.
Now if I could find a nice 6 speed to bolt behind the HZ.............

 

[86cruiser]

your 2f to 1hz

i have a 1986 landcruiser i am trying to put the 1 hz in. i have the 5 speed trans attatched. will the trans out of the gasser work or should i use the 5 speed. where can i get one those ac mountig brackets.