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98xj 5.3 swap (the poverty method).

Holy crap. Just took a trailer to the dump and the scale on the way out measured me at 5700lbs. I can't imagine that's right. Trailer is probably 300, I'm 200 and the GF is 100. Full size spare and bumpers/winch/roof rack and 200lbs of gear... That still means I'm WAY heavier than I thought I was. Either their scale is way off, or I've somehow added almost 1500lbs to my Jeep...
So that got me thinking, maybe I should weight the Jeep before ordering springs :)
 
yossarian19 said:
Coilovers at all four corners. Screwit. Get corner weights & go.
Click to expand...

I really want to, but that 4 link just won't fit while also retaining the exhaust. If someone can come up with a REASONABLE routing option, I'm all ears. Realistically, a 4-link isn't much more work than a ladder bar, with the exception of the exhaust routing.

I'll get some under-body shots tomorrow.
 
Was thinking about leaf options and decided if I'm going to pay anything to get this done, it should be an upgrade. As I mentioned, my leafs are old, beat, and bastardized.

Stuff I'd like to "upgrade".
1. Rear up travel. It ... does make it to full stuff, but only barely, with the opposite end of the truck flexed the other direction. Makes the Jeep rather tippy when the rear doesn't want to articulate. Would like to get smoother and lighter up travel and make use of bump stops ... ever. I don't think I've ever come close to hitting mine. I've already got the shocks (through floor) setup for another 3" up and 2" down.
2. Ride quality. It sucks. Rear end rides super harsh due to the 6 leaf bastard pack and that shackle relocation doesn't help. Would like to smooth things out a bit.
3. Rear steer. Shackle being mounted so much lower than the front eye causes horrible rear steer both on road and on the trail. Need to get the leaf eyes at the same height. Only reason I did the shackle drop is to lift the rear to match the front.
4. Axle wrap. All the extra weight from plating, bumpers, full size spare, gear, plating and reinforcement, combined with the weak and raked back leafs, combined with the 35" shoes/4.56 gears/300hp, causes my Jeep to eat u-joints and rear drive shafts all day.
5. I don't like the shackle sitting as low as it does. Gets hung up on rocks.
6. Move the axle back 2".

So I was looking at leaf options, and leaf + ladder bar options, and it occurred to me that I might as well get some longer leafs (better ride and articulation), with the correct spring rate (so I can throw out the shackle drop), and more torsional stiffness (to combat the wrap). My buddies k1500 we lifted recently, weighs a bit over a tonne more than the XJ, but the rear leafs aren't really dealing with any more weight than my Jeep's got at this point (maybe another 500-600lbs over my Jeep). His leafs are 63" eye to eye, 200lb/in spring rate, and 10" high, in a 5 leaf pack.
I figure the ass end of my Jeep probably weighs around 1600-1800lbs.
Take one leaf out of that 63" pack, for an effective spring rate of around 160lbs/in. Both leafs combined would have an effective spring rate of 320lbs/in. They height from the stock leaf mount to the top of the axle is around 5 inches, so I'd need to weigh those leafs down by 5 inches (their arc is 10") to maintain my ride height. 1600lbs would push those leafs down by 5 inches perfectly. 1800lbs might need the one leaf removed and replaced with an XJ leaf perhaps.

The 63" leaf is not offset, so that gives me 31.5" center. Just measuring around my Jeep, I found that if I measure from between my bumper and the body (pictured below), I've got 33.5". If I mounted the rear spring eye right between the bumper and body, that'd locate my axle 2" back from where it sits now (just enough room to clear the fuel tank), and then I'd just need to fab up a new front spring mount. This would pretty much answer all my above issues. Shackle would be sitting several inches higher than it is now without losing any lift, the longer leafs should flex better, but as the spring rate is higher and they're built for a bigger truck, they shouldn't wrap nearly as bad as I'm getting now. Leafs would sit level which deals with all the suspension oddities.

IMG_20150510_161120.jpg


So, the million dollar question... Who thinks a set of 63"x10" arc, 200lbs/in leafs (minus one leaf) will do the job I'm hoping for? The math says they should give me the ride height I want, I know on my buddies truck, they ride much smoother than mine and he's got substantially less axle wrap than I have, and he's got 37" shoes and a tonne of extra mass to move. He also seems to flex out pretty well (better than me for sure).
I COULD just rip them off his truck at some point to give'm a try, but damn that's a lot of work that I'd just have to put them back on his truck by the end of the day :). Anyone else running 63" chev springs or have good input on leafs?
 
Last edited:
Well, the 63" leafs are in and they definitely perform substantially better on the trail, and with the front sway bar connected, they're actually slightly better on the street. Axle wrap has been reduced quite a bit as well, but not quite enough so I'll be adding an XJ main leaf above the 63" pack to see if that doesn't solve it.

Next on the agenda though is heat (again).
I'm running a Griffin CU-28182-TS - http://www.griffinrad.com/load_details11.php?PartID=194&id=CU-28182-TS&key_id=1-28182-TS&year=All&make=Chevy,%20Dodge&model=Racer


Top of Details Box
Griffin High Performance Universal Fit ComboUnit Radiator
PART NUMBER: CU-28182-TS
For ALL: Chevy, Dodge Racer
Overall Size (in): 22x19x3
Core Size (in): 17x19x2.25
Row Quantity: 2
Tube Size: 1(in)
Radiator Material: Lightweight Aluminum
Inlet Location: TR
Outlet Location: BR
Inlet Size: 1.5(in)
Outlet Size: 1.75(in)
Transmission Cooler: Yes
NPT: 1/4 (in)
TOC On Center: 8.00 (in)
Notes: Straight Lower Fitting
Overall Size: 22x19x3
Description: ComboUnit 22" x 19", 2 Rows of 1.00" ClassicCool Tube Dual Pass Right (Passenger), with Transmission Cooler, Straight Outlet ---- Includes: Radiator, Aluminum Shroud, Electric Fan(s) Optional Wiring Harness (PF-91CH) and Secondary Relay (PF-FRHCH) Sold Separately
Combo Thickness:5.3125 (in)
Fan Information: Single 16 (in) 1298cfm
Shipping Info: Weight-35.00(lbs), Length-25.00(in), Width-10.00(in), Height-38.00(in)


According to Griffin, this is rated to 450hp, and according to other guys with similar setups and similar size cores, this should be more than sufficient for my setup. When I first installed, I had issues with the built in trans cooler not doing enough, so I added a small trans cooler in-line as well. Now the trans temp is good, but now that summer is finally (almost) here and it's 15C out, I'm having issues keeping the motor cool. Fan is set for 94/92C which I keep hearing is too low and that I should bump it up to 98/96 or even as high as 100/96.

Driving around town in 15C, the fans are on almost constantly. On the highway, my average temp at cruise on flat ground is about 97C so the fan is on full time.
Whenever I'm out wheeling, or any time I need to climb a longish but mild slope, I hit 105C on a regular basis, before shutting it down to let it cool.
WTF?

Discussed with Griffin and all they can come up with is that my water pump must be performing poorly. That's entirely possible I suppose, and would explain the lack of cooling, but can these pumps (in the 5.3) really go bad in a way that they just decrease throughput?
Griffin techs recommended getting a higher output water pump. Has anyone else had to do that with a stock 5.3 (my XJ is 5100lbs loaded, running 35" shoes).
 
what do your radiator hoses look like? There's not really a good reason to assume the pump is weak unless it is making weird sounds or you think it was poorly maintained, pump impellers aren't exactly wear items. The pump moves a ton of water do a little degradation would be pretty much meaningless. It would be a lot more likely that the hoses are causing a restriction and low flow.

what cfm is the fan rated at? Is it dual speed or single?

how it's the tune? If you're running lean or rich it's a lot more likely to run hot.

your cowl is probably hurting your cooling on the freeway. Is going to promote positive pressure in the engine bay which is the opposite of what you want if you want air moving over the radiator. The license plate right on the grille also looks like it's in the way.
 
Hoooper said:
what do your radiator hoses look like? There's not really a good reason to assume the pump is weak unless it is making weird sounds or you think it was poorly maintained, pump impellers aren't exactly wear items. The pump moves a ton of water do a little degradation would be pretty much meaningless. It would be a lot more likely that the hoses are causing a restriction and low flow.

what cfm is the fan rated at? Is it dual speed or single?

how it's the tune? If you're running lean or rich it's a lot more likely to run hot.

your cowl is probably hurting your cooling on the freeway. Is going to promote positive pressure in the engine bay which is the opposite of what you want if you want air moving over the radiator. The license plate right on the grille also looks like it's in the way.
Click to expand...

Fan is 1600CFM single speed. Tune is stock other than fan triggers set to 94/92 and having all the basic stuff removed.
At a cruise, FT = 0.0% and LTFT = ~13%+. IIRC, my headers are about the right temp.

I guess I'll try moving the plate, but I'm wondering if I've just got some air in there still. Is there a special trick to burping the 5.3? I have my throttle heater hose plugged.

*edit* durp. My plate is not in front of the rad. The winch control box however, is. Also, part of the rad is going to be partially blocked by the lower CM, but I just don't see that as being enough of a problem given this rad is rated to 450hp.
 
1600 cfm that's not very much, but on the freeway it shouldn't have anything to do with the issue. Burping the 5.3 depends on your setup. For me it's really tricky because I have a radiator hose that runs as high as the filter neck so it will never fill with water through the filler. I just fill it by disconnecting the hose and filing it, then letting it fill the rest of the way over a couple heading and cooling cycles. I guess these engines really prefer to have a surge tank so my long term solution might be to put a surge tank up high on the firewall for a fill point.
 
Hoooper said:
1600 cfm that's not very much, but on the freeway it shouldn't have anything to do with the issue. Burping the 5.3 depends on your setup. For me it's really tricky because I have a radiator hose that runs as high as the filter neck so it will never fill with water through the filler. I just fill it by disconnecting the hose and filing it, then letting it fill the rest of the way over a couple heading and cooling cycles. I guess these engines really prefer to have a surge tank so my long term solution might be to put a surge tank up high on the firewall for a fill point.
Click to expand...

I have to do this too, I can't get near enough water in without taking the hose off to fill.
 
Maybe run some kind of Tee filler in the upper hose so you do not have to remove it?
 
Boostwerks.com said:
FWIW, It's typical to leave a funnel in the filler neck and let the motor run for a bit to burp the system. The funnel allows the high point to be above the hose.
Click to expand...

I've actually got a valve on my rad cap that allows me to manually crack open the line to the reservoir. I'm thinking I could just get the motor toasty, park up a 60 degree incline (and keep my driver side higher than the passenger) and crack that line. That SHOULD make the rad cap my high point.

But, I threw out my back so I've been in bed all week. Probably another week at least before I can drive the Jeep again. What a kick in the nuts eh? 5.3 done, new chromoly rears so my seals aren't leaking finally, 63" leafs installed, and I can't drive it for several weeks.
 
What'd you do to your back?
Also - don't add a burn to your troubles. Park on an incline, crack the bleeder *then* idle the engine to warm it up.
 
Nah, the rad cap has the valve built in. You just pull the lever and it manually opens the pressure valve that exits to the overflow hose.
Back, no idea. Woke up last Monday, sat down at my desk to get started with the day, 5 minutes later it felt funny, and 5 minutes later much less funny. Still can't sit more than 10 minutes at a time, but today I'm at least able to stand up for 10-15 minutes without excruciating pain. Guessing I herniated a disc. That's what you get for working a wimpy office job and sitting most of the day. Sitting is pretty much the worst thing you can do to yourself.
 
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