Novak Conversions Jeep Wrangler TJ engine mounts

A lesson learned—keep it light and nimble!

Irun said:
I want more time, but also take a small measure of pride in saying all the work was done by me. If I order one I'll not be able to say that. There are several folks here that can relate. Although I'm not in their class, conquering another small build objective helps keep my own mind sharp. As I've said before, the real challenge is in maintaining overall balance. I'm still struggling and learning there!
Click to expand...
I don't see a HP 44 as anything but a mistake even if it was lower cost. If you think you had a fun time cycling for clearances before, toss one of those pieces of shit under there and then make everyone who recommended it come over and make it fit. They are a few and I mean a scant few rat turds within the same difficulty as getting a Currie HP 60 under there.

That and they would be ridiculous overkill for 35's and not enough for 37's which makes them a stupid choice for much of anything.

If I had a stock Rubicon 44 out of a TJ laying there on the ground ready to bolt in, I'd still buy and build a HP 30 non disconnect housing and use that with a Super 30 locker. The only bracket work I would do is replace the lower control arm mounts with the ones from IRO. Not because I should but because I can. If fact, that is exactly what I did with the Rubi 44 for mine. (there again though, my build is not based on wise choices)

That and at the end of the day, this isn't really a numbers build, it is a what works best for what I need it to do build and that answer is now and will remain the HP 30.
 
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Irun said:
Interestingly, I talked to a buddy of mine this evening about what I want to do. It turns out he has a bare HP 30 housing he said I can have. I'm going to go take a look at it next week. If it looks okay, I'll bring it home and do a closer inspection. Going this route would mean I'd spend time on it, but I could work at it a little at a time.

Also, I checked inventory this evening and I already have:
- small hub kit
- ball joints
- a master rebuild kit
- a pair of 5-760x u joints
- knuckles that Blaine did inserts on for the tie rod flip, and
- mini skids from @Wildman

That means I'll need gears, a 1330 yoke, 30 spline inner shafts, a 30 spline ELocker, and some additional shims.
Click to expand...
What gear ratio do you need? That and don't do the 1330 if you can find a 1310. More clearance at the exhaust and you'll need that.
 
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mrblaine said:
I don't see a HP 44 as anything but a mistake even if it was lower cost. If you think you had a fun time cycling for clearances before, toss one of those pieces of shit under there and then make everyone who recommended it come over and make it fit. They are a few and I mean a scant few rat turds within the same difficulty as getting a Currie HP 60 under there.

That and they would be ridiculous overkill for 35's and not enough for 37's which makes them a stupid choice for much of anything.

If I had a stock Rubicon 44 out of a TJ laying there on the ground ready to bolt in, I'd still buy and build a HP 30 non disconnect housing and use that with a Super 30 locker. The only bracket work I would do is replace the lower control arm mounts with the ones from IRO. Not because I should but because I can. If fact, that is exactly what I did with the Rubi 44 for mine. (there again though, my build is not based on wise choices)

That and at the end of the day, this isn't really a numbers build, it is a what works best for what I need it to do build and that answer is now and will remain the HP 30.
Click to expand...

Blaine, can you get deep enough gears (5.38) for the HP30 fronts like you can for the Rubicon D44s? I understand the benefits of the HP30 in terms of the ring and pinion strength and the driveshaft clearance.
 
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mrblaine said:
What gear ratio do you need? That and don't do the 1330 if you can find a 1310. More clearance at the exhaust and you'll need that.
Click to expand...

Great point on the 1330. I didn't even think about the exhaust clearance issue! (y)

I'm trying to decide on gears now. I ran two sets of numbers on Grimm Jeepers, to get a ballpark estimate. My focus was on actual tire size, figuring if the tire size is slightly larger, my RPMs will go down and not up. Also, I tried to factor in the loss/failure of the miserable .69 overdrive (i.e. if I had to run in 3rd on the highway).

Based on that, I leaning heavily in the direction of 5.13. With my current 31" tires this gives me approximately 3088 RPMs in 3rd (@ 55MPH) and 2712 RPMs in 4th (@ 70 MPH).

Eventually I could see a max tire size of 33", which puts me at 2899 RPMs in 3rd (@ 55MPH) and 2546 RPMs in 4th (@ 70 MPH).

It does sound a little weird to be at 5.13 gears with a 31" tire, but the numbers seem to work with the 42RLE.

Road RPMs at given speed in miles per hour10 MPH55 MPH70 MPH
Based on a 30.7" tire and 4.88 Gears
11517834310618
283946125870
353429383739
436920272580
5---
6---
7---
8---
9---
10---
R118064928262

Road RPMs at given speed in miles per hour10 MPH55 MPH70 MPH
Based on a 30.7" tire and 5.13 Gears
11595877011162
288148486170
356130883930
438721312712
5---
6---
7---
8---
9---
10---
R124168258686

———————————————————————————————————————————————————————————————————————————————————

Road RPMs at given speed in miles per hour
Based on a 32.7" tire and 4.88 Gears
1142478329968
278743305511
350127583510
434619032422
5---
6---
7---
8---
9---
10---
R110860957757

Road RPMs at given speed in miles per hour
Based on a 32.7" tire and 5.13 Gears
11497823410479
282845525793
352728993690
436420002546
5---
6---
7---
8---
9---
10---
R116564078155
 
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mrblaine said:
1. I don't see a HP 44 as anything but a mistake even if it was lower cost. If you think you had a fun time cycling for clearances before, toss one of those pieces of shit under there and then make everyone who recommended it come over and make it fit. They are a few and I mean a scant few rat turds within the same difficulty as getting a Currie HP 60 under there.

2. That and they would be ridiculous overkill for 35's and not enough for 37's which makes them a stupid choice for much of anything.

3. If I had a stock Rubicon 44 out of a TJ laying there on the ground ready to bolt in, I'd still buy and build a HP 30 non disconnect housing and use that with a Super 30 locker. The only bracket work I would do is replace the lower control arm mounts with the ones from IRO. Not because I should but because I can. If fact, that is exactly what I did with the Rubi 44 for mine. (there again though, my build is not based on wise choices)
Click to expand...
These three things pretty much summed up what I was thinking. I had to cycle the front suspension a dozen times or more to get it to barely work with a Dana 30. Given the much larger HP 44, I see this as being a major nightmare for a novice like myself.

Plus, as I noted before I've wheeled with heavy footed people who literally beat the crap out of their Cherokees, with HP30s. I rarely ever saw a failure that wasn't a snapped axle or twisted splines. Now that I've learned about the importance of tire placement and value of a 30 spline locker, I feel very confident in going the path of a HP30.

Lastly, I do have a front Rubicon 44, with the parts to make it work. However, based on past experiences I've learned that the Dana 30 is just a better choice for my build and needs. I really don't see a down side to going with a HP 30!
 
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Having only been around the Jeep world a little over a year you light and nimble build is has become kind of a blueprint for my own build. The high pinion 30 seems like a great option. I have thought about selling my Rubicon 44 and getting a a high pinion 30 myself. Knowing now that the 30 is just as strong and how little clearance the is my Currie track bar just barely scrubs past the stock diff cover
 
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I’ve always believed that an HP 30 with 30 splines is stronger than a LP 44 Up front. They are basically the same axle setup from the diff out, but even the smaller gearset in low pinion is stronger in the front than the larger HP 44 gearset. So stronger, lighter, and easier fitment.

Am I correct in my thinking?
 
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NashvilleTJ said:
I’ve always believed that an HP 30 with 30 splines is stronger than a LP 44 Up front. They are basically the same axle setup from the diff out, but even the smaller gearset in low pinion is stronger in the front than the larger HP 44 gearset. So stronger, lighter, and easier fitment.

Am I correct in my thinking?
Click to expand...
I don't know if there is an actual way to quantify that. What I do know is the folks that wheel with tire speed on slick rocks tend to blow up the smaller gear sets even in High Pinion and don't blow up as many of the larger 44 gear sets in Low Pinion.

The only HP 30 stuff we have ever had issues with can almost always be traced back to a poor set up. But we don't need wheel speed, just torque. We have a few locals running 37's on a HP 30 which I think is fully stupid. I also see a lot of Rubi 44's running 37's and that isn't any smarter.

I would with a reasonably educated guess surmise that the larger teeth withstand impact loads better and torque doesn't matter as much.
 
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I’m in the same boat. I’m going to build a HP 30 with 30 spline inners. I’ll most likely do a junkyard HP30 for cost reasons if I can get one cheap enough but @bobthetj03 has a great point that $1k more buys you piece of mind and lots of time. It will really just depend on what we can find and the duration of our patience.
 
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starkey480 said:
I’m in the same boat. I’m going to build a HP 30 with 30 spline inners. I’ll most likely do a junkyard HP30 for cost reasons if I can get one cheap enough but @bobthetj03 has a great point that $1k more buys you piece of mind and lots of time. It will really just depend on what we can find and the duration of our patience.
Click to expand...
I've got one. I removed it from my TJ-6 because it has a goofy truss on it over the pumpkin. Pretty sure it has a locker and 4.56's in it. Not sure what the spline count is. Interested?
 
mrblaine said:
I've got one. I removed it from my TJ-6 because it has a goofy truss on it over the pumpkin. Pretty sure it has a locker and 4.56's in it. Not sure what the spline count is. Interested?
Click to expand...
Absolutely. I’ll message you
 
NashvilleTJ said:
I’ve always believed that an HP 30 with 30 splines is stronger than a LP 44 Up front. They are basically the same axle setup from the diff out, but even the smaller gearset in low pinion is stronger in the front than the larger HP 44 gearset. So stronger, lighter, and easier fitment.

Am I correct in my thinking?
Click to expand...
All else being equal the two strength advantages I could see would be the 44s larger ring gear and axle shaft

Dana 30 Ring Gear Size = 7.125
Dana 44 Ring Gear Size = 8.5

Dana 30 Axle Diameter = 1.13"
Dana 44 Axle Diameter = 1.31"
 
Irun said:
Great point on the 1330. I didn't even think about the exhaust clearance issue! (y)

I'm trying to decide on gears now. I ran two sets of numbers on Grimm Jeepers, to get a ballpark estimate. My focus was on actual tire size, figuring if the tire size is slightly larger, my RPMs will go down and not up. Also, I tried to factor in the loss/failure of the miserable .69 overdrive (i.e. if I had to run in 3rd on the highway).

Based on that, I leaning heavily in the direction of 5.13. With my current 31" tires this gives me approximately 3088 RPMs in 3rd (@ 55MPH) and 2712 RPMs in 4th (@ 70 MPH).

Eventually I could see a max tire size of 33", which puts me at 2899 RPMs in 3rd (@ 55MPH) and 2546 RPMs in 4th (@ 70 MPH).

It does sound a little weird to be at 5.13 gears with a 31" tire, but the numbers seem to work with the 42RLE.

Road RPMs at given speed in miles per hour10 MPH55 MPH70 MPH
Based on a 30.7" tire and 4.88 Gears
11517834310618
283946125870
353429383739
436920272580
5---
6---
7---
8---
9---
10---
R118064928262

Road RPMs at given speed in miles per hour10 MPH55 MPH70 MPH
Based on a 30.7" tire and 5.13 Gears
11595877011162
288148486170
356130883930
438721312712
5---
6---
7---
8---
9---
10---
R124168258686

———————————————————————————————————————————————————————————————————————————————————

Road RPMs at given speed in miles per hour
Based on a 32.7" tire and 4.88 Gears
1142478329968
278743305511
350127583510
434619032422
5---
6---
7---
8---
9---
10---
R110860957757

Road RPMs at given speed in miles per hour
Based on a 32.7" tire and 5.13 Gears
11497823410479
282845525793
352728993690
436420002546
5---
6---
7---
8---
9---
10---
R116564078155
Click to expand...


I had 4.88s when I had 265/75/16s and it was barely good enough with the 42RLE. Mountain passes still sucked. Actual size of this tire is ~31.5. 5.13s would have been a better choice.

Currently have 5.38s with 33x10.5 and it's very good. Shoot for close to 3k rpm at 75mph like @jjvw always recommends.
 
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psrivats said:
I had 4.88s when I had 265/75/16s and it was barely good enough with the 42RLE. I would do 5.13s for sure.

Currently have 5.38s with 33x10.5 and it's very good. Shoot for close to 3k rpm at 75mph like @jjvw always recommends.
Click to expand...
My target was in the 3K range at 70 MPH, but we're close enough! (y)
 
If I didn’t have a rubicon with an already built stock front Dana 44 axle, I would totally be swapping on a HP30. They are just really worth the effort and like you said, I’ve seen pleantky of XJs on 35s getting bounced around the trails with no ring and pinion fails.

I did the swap on my 99 TJ that had a 32rh after I bought a rear Dana 44 with 3.73 gears. I was hoping to find a HP30 with factory 3.73s but had no luck, so I ended up installing new 3.73s with a Aussie locker. At the time I was running 33x10.50 tires and the 3.73 ratio was perfect for daily driving with the 3-speed auto.

I really do not understand why Jeep used the HP30 in the YJ and XJ and all the way to the 99 model year and the LP30 in everything else. You would have thought that when they did the switch to Quadra coil on the 97 wrangler, they would have carried over the high pinion.
 
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Novak Conversions Jeep Wrangler TJ engine mounts
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