'99 MJ 4.7L Build

[gradon]

You're doing fine.

[SilverXJ]

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?

That fine, You are suppose to do that.

They still need to be polished to a mirror finish but the cross buffs won't work....any ideas?

You can't jump from 80 grit to the cross buffs. You need to use the flapper discs and work up in grit number. Also, use some WD40 with the cross buffs.

[go4lo]

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?

That fine, You are suppose to do that.

They still need to be polished to a mirror finish but the cross buffs won't work....any ideas?

You can't jump from 80 grit to the cross buffs. You need to use the flapper discs and work up in grit number. Also, use some WD40 with the cross buffs.

Your right I forgot to mentionthe flapper disc step. Hopefully I'll finish up today...thanks for the help!

[go4lo]

Finally finished up late Saturday after spending a total of 12hrs grinding and polishing Not a fun job at all and not one I hope to have to repeat anytime soon.

I didn't go extreme on any of the ports or the chambers but I'm happy with the outcome and I think the head will flow better than stock.

Polished exhaust ports


Polished combustion chambers


Head Gasket check

[SilverXJ]

Looks good but I would spent a bit more time on polishing the exhaust Get rid as much of the casting grain as possible.

[gradon]

I actually enjoy the p&p process even though it takes a chunk of time(20+ hours on these iron heads until I'm satisfied).

[go4lo]

Looks good but I would spent a bit more time on polishing the exhaust Get rid as much of the casting grain as possible.

I tried to focus on the smoothing/polishing the short side radii of the exhaust ports the most. You can't see them in my pics but they are smoothed an polished and yes I could have probably spent more time on the exhaust ports but I'm not worried about it.

I feel like I need to measure the volume of the chambers to make sure they are all close to have a more precise figure when using the calculator. What's the easiest way to measure the volume of the chambers now that they are polished? I don't have any fancy measuring beakers or guages.

[go4lo]

I actually enjoy the p&p process even though it takes a chunk of time(20+ hours on these iron heads until I'm satisfied).

I'd be pulling my hair out if I spent that much time on them I really feel that the head flows well from the factory and the basic clean up will serve my needs well. I'm not building a race engine and will rarely need to take my engine to redline. Is this the best for every application, by no means, but hopefully it will fit mine.

[gradon]

Like I said before, you did fine and it's better than it was before you started. You want a small piece of plexiglass with a hole drilled in it. Use vaseline on the head face to seal the plexi, and a tad on the valve/seat mating surface to make sure they don't leak if the springs aren't installed, place the plexi over the combustion chamber, and use a syringe and oil and start measuring.

[go4lo]

Like I said before, you did fine and it's better than it was before you started. You want a small piece of plexiglass with a hole drilled in it. Use vaseline on the head face to seal the plexi, and a tad on the valve/seat mating surface to make sure they don't leak if the springs aren't installed, place the plexi over the combustion chamber, and use a syringe and oil and start measuring.

Great...thanks for the help. I'll try to round up the stuff to take the measurements tonight.

[go4lo]

I was able to measure the volume of the chambers last night and all came in just over 58cc. I'm sure my head will have at least a minimal decking done at the machine shop so the 58cc is problem not 100% accurate.

[go4lo]

The brown truck guy left me some much anticipated packages today....needless to say I'm stoked!!

Various small parts along with a set new Sealed Power Valves with single locks, the IC944 pistons and rings

New Valves


New vs. Old




Pistons...they sure are sexy

[go4lo]

Hey guys it's been a few weeks since I've posted any updates. I took a break from the engine to focus on the suspension build of the truck. My goal is to have the truck rolling prior to getting the engine back from the machine shop so that it doesn't sit too long before break in. The rear suspension is fininshed and the front should be finished up this week with the truck sitting on all 4 tires.

A few pics...




Now it's time to focus all attention to the engine build. I have 90% of my parts collected but I do have few specific questions that hopefully you guys can help with.

Question 1:
As stated before my block is '99 XJ block, I have the Comp Cams 68-231-4 cam and JP 5629 double roller set. Will I need any other parts to make this cam/timing set work in the '99 block? I thought I read somewhere that the bolt/retainer set up was different in the earlier years?

Question 2:
I don't have all the tools or confidence to assemble the short block myself so I'm paying the machine shop to do this as well; should I ask the machine shop to degree the cam? Also the JP set has advance and retard settings on it but I assume those will be ingorned and it's installed dot to dot? The Comp Cam 231 has a 4* advance? Sorry I'm confused on the timing?

Question 3:
The IC944s have an arrow indicating the install direction, is this the correct orientation or is KB wrong? What piston wall clearance would you guys recommend, my instructions are wrong(blue border)?

[SilverXJ]

Question 1:
As stated before my block is '99 XJ block, I have the Comp Cams 68-231-4 cam and JP 5629 double roller set. Will I need any other parts to make this cam/timing set work in the '99 block? I thought I read somewhere that the bolt/retainer set up was different in the earlier years?

You will need the cam washer, bolt, spring and pin. The part number is in the FAQ section under misc parts

Question 2:
I don't have all the tools or confidence to assemble the short block myself so I'm paying the machine shop to do this as well; should I ask the machine shop to degree the cam? Also the JP set has advance and retard settings on it but I assume those will be ingorned and it's installed dot to dot? The Comp Cam 231 has a 4* advance? Sorry I'm confused on the timing?

If you aren't going to install the timing your self and degree it then have the shop do it. The advance or retard settings are used if you want to advance or retard the cam, or if the cam grind is slightly off.

Question 3:
The IC944s have an arrow indicating the install direction, is this the correct orientation or is KB wrong? What piston wall clearance would you guys recommend, my instructions are wrong(blue border)?

The arrow is in the correct direction. The large quench pad goes on the engine opposite the cam, the manifold side. I would ask KB about the clearance.

[go4lo]

You will need the cam washer, bolt, spring and pin. The part number is in the FAQ section under misc parts

Thanks....I assume - '98 and earlier cam bolt kit: Jeep #83502890, washer: #J3173284. I guess I'll have to go to local JY or to the stearlership to pick up both? I can't find them aftermarket.

If you aren't going to install the timing your self and degree it then have the shop do it. The advance or retard settings are used if you want to advance or retard the cam, or if the cam grind is slightly off.

IF a cam has a built in advance or retard should the timing gears be set up to match the advance built into the cam or will that double the advance/retard? Example, cam has 4* advance built in, should the timing set be set to 4* as well or set to 0?