'99 MJ 4.7L Build

[go4lo]

I've been researching and asking questions on here for a few months and I've finally started collecting parts and moving closer to a finish date for my MJ project so I thought I would start a build thread to document the 4.7L build going into my '99 MJ project. I will preface by saying I'm by no means an expert on jeep strokers but I have owned and built several 4.0L powered Jeeps over the past 10 years. This will be my first stroker project and the most indepth I've been on a custom engine build so please forgive me if I ask any "dumb" questions.

That being said below is a current pic of my project MJ and what parts I've collected for the stroker as well as my reciepe.

The engine I'm using is from a '99 XJ with 173K. The truck will end up being on 35s. Both the HP30 and Dana44 are built with 4.88s and Detroit Lockers and Alloy shafts. I plan to drive the truck a few days a week to work and use it on the weekends for wheeling and camping trips.



Receipe:
4.2L 12cwt Crankshaft w/Engine Tech Bearings(have)
4.0L Piston Rods (have)
KB IC944 .060 Pistons w/Moly Rings (have)
ARP Bolts (have)
CompCams 68-231-4 (have)
CompCams Lifters (have)
JP Double Roller Timing Set (have)
'99 Intake (have)
Mopar Perf Springs, Locks and Retainers (have)
Elgin Brass Freeze Plugs
Victor Reinz Upper and Lower gasket sets
Clevite Cam Bearings

I plan to have .0200 milled off the block deck to give me approx .0095 deck height, hopefully with this combination and the .044 HG I'll end up with a SCR of ~ 9.66, DCR of ~ 8.43 and quench of .0535. Also I am considering the YT and Harland Sharp Roller rockers as well as a DIY Port/Polish.

I was surprised to find that the VR uppder gasket set included the MLS thin HG, Part #54249S. I had planned to order the MP version but I don't see a reason to now.

[gradon]

Nice truck! It looks like a good recipe to me.

[go4lo]

The valves in my 0630 head have 173K on them so while I'm having the head work done what are you guys thoughts on replacing the existing valves or just reusing what I've got? If I decide to go the replacement route what valves would you guys recommend as a replacement to use with my combo that won't require machine work?

[gradon]

You might want to ask your machinist to check them out in order to get the clean bill of health. I like the tulip swirl polished ss mopar valves, but $12-15X12 adds up. I believe any new or used valve you use will need to be lapped/meshed with the seats to make sure they seal correctly.

[SilverXJ]

Definitely ask the machinist to check the valves. No reason to replace them if they aren't bad. Check the freeze plugs and make sure they match the block. The ones i got didn't and were missing a few. If you are debating which roller rockers to go with I highly recommend harland sharp adjustable. First, they are adjustable which makes getting the perfect preload easy, and second their support is some of the best I have used.

[go4lo]

I've been working on my head over the weekend and have a couple of questions. I ordered the Mopar Performance valve locks, but they are a single lock and my valves have a 3 ring lock. Which ones should I use? Will the Mopar Performance locks even work with the 3 ring locks?

Second question, probably a really dumb question , but why do the Mopar Peformance Valve springs have an inner spring? Are these to be used or removed?


BTW I tried to order the Harland Sharp roller rockers on Friday and they are out of stock for at least 2 weeks on either set....

[Bodo]

Going to have to use earlier model valves (single groove) with those locks. Anything HO before 99 should be OK.

Use the springs as they are. The inner spring is a dampener I believe. Good thing to have!

[go4lo]

Going to have to use earlier model valves (single groove) with those locks. Anything HO before 99 should be OK.

Use the springs as they are. The inner spring is a dampener I believe. Good thing to have!

OR - can I not just reuse my 3 ring locks?

[lafrad]

The 3 ring locks will not work with the "after-market" "Mopar Performance" Retainers. The 3 ring locks are MUCH smaller in diameter, and the valve tip ends up hiding below the top of the retainer. You MUST get different retainers, or swap valves and use the single groove locks. do NOT use single groove locks on 3 groove valves.

That is the secondary reason I have not used the Mopar Performance springs/locks/retainers (I have a '99 with triple groove valves too). For me, the primary reason was a desire to keep the spring pressures down. When I found the retainers didn't work, I finally found a different setup to go with. I'm happy I did, it runs very well, and I'm not nearly as worried about buttering the cam out.

[go4lo]

The 3 ring locks will not work with the "after-market" "Mopar Performance" Retainers. The 3 ring locks are MUCH smaller in diameter, and the valve tip ends up hiding below the top of the retainer. You MUST get different retainers, or swap valves and use the single groove locks. do NOT use single groove locks on 3 groove valves.

That is the secondary reason I have not used the Mopar Performance springs/locks/retainers (I have a '99 with triple groove valves too). For me, the primary reason was a desire to keep the spring pressures down. When I found the retainers didn't work, I finally found a different setup to go with. I'm happy I did, it runs very well, and I'm not nearly as worried about buttering the cam out.

Wow...thanks for the explaination. Looks like I've got some more parts to collect..

Ok, so a few more questions: What set up are you running with "softer" springs? Will any year single groove valves work with my head? If so I assume I could just order up a new set of valves for a earlier, say '97 4.0L, to work OR pull a set of valves from a another head?

[Bodo]

I've got a 99 WJ head and am installing 96 valves in it. No issues.

[lafrad]

http://www.jeepstrokers.com/forum/viewt ... f=5&t=1433

That thread is where I shared everything I needed to do for the change in setup. The 'seat pressure' is VERY close to stock springs, and the 'max lift' pressure is just a smidge over stock pressure, at the increased lift. The weight of the spring is MUCH less than stock, the weight of the retainer is MUCH less than stock, and it has NO PROBLEMS revving to redline with no signs of float. It allowed me to run the stock pushrods and rocker arms, with the stock valve-cover.

[go4lo]

http://www.jeepstrokers.com/forum/viewt ... f=5&t=1433

That thread is where I shared everything I needed to do for the change in setup. The 'seat pressure' is VERY close to stock springs, and the 'max lift' pressure is just a smidge over stock pressure, at the increased lift. The weight of the spring is MUCH less than stock, the weight of the retainer is MUCH less than stock, and it has NO PROBLEMS revving to redline with no signs of float. It allowed me to run the stock pushrods and rocker arms, with the stock valve-cover.

Nice write up! I think I'm going to try to source some valves from a an older head or just order some new ones since I already have all the Mopar Performance parts.

[go4lo]

When looking at new intake valves Rock Auto lists 2 different stem diameters for a 1997 Cherokee head:

SEALED POWER Part # V2527
w/radius key groove; 1.91" Head Dia., 0.3265" Stem Dia., 4.911" O.A.L.
w/radius key groove, 1.91" Head Dia., 0.3115" Stem Dia., 4.911" O.A.L.

.03115" = 7.9121 millimeters
.03265" = 8.2931 millimeters

Any idea why there are both sizes? Other websites like O'Reilly Auto parts lists the SP V2527 with a stem diameter of .03115"?

[go4lo]

I had the day off work today so spent about 6 hours working on the head. Like most others on here I used the Standard Abrasives Deluxe P&P kit from Summit. After reading through countless hours of threads on here and the 21 page manual from Standard Abrasives I decided to "try" not to enlarge any of the ports and just do a polish/clean up the casting flash and any sharp angles. I really don't want to increase the top end power much at all since my truck will be used primarily in low end torque situations. My goal is to just create a little better flow without enlarging the ports.

This is is my first time so please review my work below so far and let me know what corrections I need to make.

FelPro Gasket for '98 and older 0630 head. With no porting the gasket is spot on the 2 sides and floor of the intake ports.


Started with the 40 grit and finished with the 80 grit rolls

First try next to stock port




More


Gasket test fit


After polishing the 6 intake ports I moved to the intake bowls per the SA manual. I was able to get them decently polished and the front edge of the stem boss rounded. I still need to work on the upper edge of the stem boss.

I did have one question, under the valve seats there is a machined section before the casting flash begins. I tried to blend these 2 areas together for smoother flow, I hope that was okay?






I gave up on theintake valve bowls for fear that I would go to far so I started on the exhaust ports. I was able to get 4 of the 6 down to the 80 grit. They still need to be polished to a mirror finish but the cross buffs won't work....any ideas?





Gastet test fit after polish



THanks for any help! I plan to polish the combustion chambers tomorrow and finish cleaning the bowls up.