Build thread White '99

Huh. I didn't realize there was a rare 7 cylinder motor out there. Seriously though, what the hell is that off of?

Boostwerks.com said:

Huh. I didn't realize there was a rare 7 cylinder motor out there. Seriously though, what the hell is that off of?

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That's exactly what i thought hahaha

Apparently, later model 4.0s in the WJs and TJs have a fuel damper in that position. Never seen one before, but from what I've read on them, they are a huge pain, and cause fuel leaks right on the exhaust manifold. Also nicknamed "flame throwers". Learned something new

FWIW, My 99 Fuel rail looks just like yours. No injector is there. However, there is a device there that might be a fuel pressure damper or ?? The device does not have any wires or vacuum lines connected to it.

Maybe somebody else knows what it is. Sorry I can't be more help.

The fuel rail shown above I got out of the junk yard from an 01 GC. But you are correct, there is a fuel dampener in that position that looks like a little top hat. According to the internet searches I've done, its supposed to smooth out turbulence in the rail from the injectors opening and closing. Supposedly making the injectors more efficient.

That being said, I have also been reading that they cause a lot of fuel leaks, and are not replaceable. If they leak, you need a new fuel rail, and possibly a new jeep after it burns to the ground. Several people have stated that it caused engine fires from leaking fuel right on the exhaust rail.

So, I decided against getting a rail with the dampener on it, and went back to the junk yard and found a rail out of a 98 ZJ. Cleaned it all up and installed the rail and injectors. I also installed the adapters, again, mine doesn't need them as I already have EV6 connectors. However I am debating on cutting and splicing in these new connectors because some of mine have broken tabs and what not.

Also, spoke with the machine shop today, and they said all of my parts have arrived and the block and head are all finished up. Just need to balance the rotating assembly and she should be good to pick up tomorrow. I also ordered some Comp Cams Break in oil with ZDDP to help protect the cam and a new water pump from summit. Hopefully those will be here early next week.

One thing I should mention is my OE cam was a retainer plate style, and the new comp cams apparently needs the thrust spring bolt kit Mopar PN# 83502890. So im hoping that the dealer will have this.

Still on my To-Do list is:
Gasket match the head and intake manifold
CC the head to finalize CR calculations
Clean and paint random engine parts and brackets
Order Brown Dog mounts. (just haven't pulled the trigger yet)
clean engine bay (dreading this part)

Once I get the block and parts, I'll hopefully be able to start assembling the block.

With a flat tappet cam, I recommend you use oils with an adequate amount of ZDDP always not just for break in!

bwinter1946 said:

With a flat tappet cam, I recommend you use oils with an adequate amount of ZDDP always not just for break in!

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That seems to be what everyone recommends. I would like to find an off the shelf oil that i can use after break in. From what I've read I should wait for 3000 miles before i switch over to synthetic oil. I normally run Mobil 1 10w30 Full syn.

Speaking of cams

Just for kicks, (and wanted to try out the new Dial indicator) I pulled out my old cam and wanted to measure the "lift" of each lobe.

From what I measured, .243-.245" on each lobe. Which is weird, the paperwork i have says I should be at .405-.408". Is my cam really that worn down?

I seem to have answered my own question.

I take the rocker ratio X lobe lift to get the valve lift?

If so, my rockers are 1.6:1 (stock)
1.6x.245= .392

1.6/.408 = .255 (what my lobe should be)

still shy of stock spec, but closer. Looks like my lobes have worn about .010"

Did I do that right?

yep. Valve lift depends on both the lobe height and the ratio of the rocker arm.

Finally got the block and head back from the machine shop. As well as a bunch of parts.

Comp Cams 10w30 Break in oil
GMB water pump with new tubing
180* thermostat
Melling Oil pump
Clevite bearing set Mains, Rods
Engine pro timing set
Comp cams 68-232-4
LIfters
Hastings Piston ring set
KB 421 .030 pistons
FelPro Full gasket kit
Sealed Power Freeze plug kit
Brown Dog Flex motor mounts

Random consumables, gasket maker, shellac ect.

Spent Some time cleaning the engine bay, But its not up to my liking. Ideally I want to rip out as much as I can, deep clean, then paint to make it look new. However, I'm ready to get this motor built and done so I can get back on the road. since now my wife and I are sitting at over a month with only one car. So we'll see how deep into the engine bay I get.





Once I got all my junk into the Garage I started prepping the block for paint. Pushed in the freeze plugs and oil galley plugs and started taping the block up.














After couple thick coats of engine paint, I think it turned out pretty good




More to come :us:

Worked on assembling the bottom end of the motor.

Installed the new clevite bearings in the mains, and checked with plastigauge. Right in spec, between .015 and .02.



Then moved on to installing the pistons. checked all my rings in the jug and on the piston, everything checks out good. Installed all six, and checked rod bearing with plastigauge, also good, .015 right in spec.





Installed the new Melling oil pump, with the stock pick up tube. I just went with a stock displacement pump, as I've heard of high flow pumps ripping up distributor gears.

Flipped the block over and installed the Cam, and new lifters. I don't have a pic of it installed, but I had to go to the dealer and get the cam bolt for a pre '98 cams with the preload spring in the head. For those looking to install a comp cam in a 99+ you'll need this bolt. later models used a retaining plate to hold the cam in instead of a spring load on the cover. 27$ from the dealer. ouch. Mopar P/N 83502890.





Moved and and installed the head. New feel-pro gasket .051 and new feel-pro head bolts.

Started checking lifter preload, and I'm way out of spec. Stock push rod is 9.641", I need between .030"- .040" of preload on the lifters and right now I'm at .123. Way out. I need a shorter push rod by a minimum of .093".



I found a sealed power push rod p/n PR-3197. Its a 5/16' push rod with an OAL of 9.546". If i use this rod that should put me at exactly .030" preload. bottom end of spec, but that's the best I could find that I could actually buy.

So while I wait for that, I need to figure out washers for the main bearing girdle, and Im also waiting on a spacer for the harmonic balancer that I had the machine shop make up for me.

More to come :us:

I was going to ask earlier about the pushrods with a .020" cut on the block? Did you take anything off the head? I'm going to be doing mine in the couple weeks and these are the things I'd like to hear about!
You also didn't mention anything about your deck height?

I should add that shims under the rockers is cheaper than pushrods!

RCP Phx said:

I was going to ask earlier about the pushrods with a .020" cut on the block? Did you take anything off the head? I'm going to be doing mine in the couple weeks and these are the things I'd like to hear about!
You also didn't mention anything about your deck height?

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Yeah, I was anticipating buying new pushrods, it turned into a pain, more than I thought it would. My head was just resurfaced, the machine shop said maybe .001-.003 thou.

The first mistake I made was assuming the stock rod length. Manual said 9.4-9.5" OAL. So I ordered rods based on that measurement. But my actual rod length was 9.65" so the rods I bought are too short. But now I have an adjustable pushrod and I was able to dial in the correct length.

I never had the deck height checked, but I did do the math and had to wait until I assembled the lower end of the block. So with the stock 4.0 rods and the KB421 Pistons I would be sitting at about .0315 Deck clearance, figuring using the stock deck height (9.455)

D=[(X/2)+Y+Z]-W

(W) deck height 9.455
(X) Stroke with 4.2 crank 3.895"
(Y) Stock 4.0 rods 6.123"
(Z) Kb421 compression height 1.353"

(D) deck clearance

1.9475+6.123+1.353=9.4235

9.4235-9.455= .0315

Based on this math I decided to deck the block .020 to bring my deck clearance down and my CR up. So on paper my deck clearance should be .0115. After I got the block together I measured it an it was (to my surprise) right on!

With this set up I'm sitting right st 9.0:1 CR. Should still be able to run 87 octane in it.

Anyway, I ordered the correct pushrods, should be here tomorrow, and after that the engine is complete. Just need to gasket match the intake manifold and we'll be good to run!!

updates:

Got my throttle body back from my buddy. He bored it out to 62mm, added a new butterfly, and a fresh coat of paint. couldn't be happier with the way it turned out.






I was really struggling measuring my pushrods. I got the ones I ordered from the shop, but my methods of measuring preload gave me inconsistent readings and I spent waaaaaaayy too much time figuring it out. So as a last ditch method tp ensure my push rods where correct, I took the whole engine to the machine shop. The guy came out and measure the rods and 5 seconds later he was done, and the ones I had were within spec.



Long story short, I way over complicated it.

Anyway, I continued on installing the engine into the jeep. went pretty smooth. everything bolted right up.








Once I had the engine installed, I tried firing it up, and to my dismay I wouldn't start.

My mistake though, I had the rotor in the distributor one cylinder off. Once I corrected that, It fired right up


During the Cam break in, the oil pan seems to have sprung a leak, around the rear main seal area. Which is frustrating, I really don't want to pull that pan again.

Another thing that is on my nerves, is this manifold. Cheap? Yes. Worth it? NO. First off, fitment was less than stellar. Its pushing my downpipe hard up on the oil pan, and second, It has an exhaust leak on it somewhere already. I'm going to take it to an exhaust shop, and have them figure it out.

took the jeep for a spin. Engine runs good, however its running hot. 215-220ish driving around. So, Im thinking part of the reason is the exhaust touching the oil pan is heating up the oil, and my radiator is the stock single core. so next on the list is figuring out how to keep this engine cool.

More to come :us:

Have you done any tuning on the computer? That's the next thing I'm looking into for my build.
What did you do about the cam timing?

RCP Phx said:

Have you done any tuning on the computer? That's the next thing I'm looking into for my build.
What did you do about the cam timing?

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Not sure what you mean about cam timing?

I installed the cam the OEM way, by just aligning the dots on the cam and crank sprockets.

No tune on the engine though. Seems to be running smooth, no jolts and rattles so I think its doing a good job running the motor right now. Not that that really means anything. I would be interesting in putting a wide band O2 in and see really where my AFRs are at.

From what I've been reading, Its like a 50/50 split between people that go through and get a tune. Some say it isn't really necessary and the engine will run fine with out one, and others say its the only way to get power out of the block. Either way, Mine seems to be running fine right now, but I am not opposed to looking into a tune. Its just some more $$ that I really don't have at the moment.

You degree a cam because most manufacturer's don't use straight up timing. In the case of your Comp cam, it is suggested to run 3* advanced!