Need help with some details

[Piperpilot3tk]

Hello, my name is Mike and this my first post! About five years ago I owned a ZJ that I built up and I had a stroker kit custom put together to build a 4.6 to replace the high mileage stock engine. About a month later i found a like new 2006 LJ Rubicon for a steal and could not pass it up. I initially intended to build a stroker for the LJ but after doing a lot of reading and research I came to the consensus that the stock PCM could not be tuned for the stroker, so I put the parts away and kept them when I sold the ZJ. A few weeks ago I revisited the tuning issue and found that there is now support for tuning the 06 PCM and now I am ready to start putting together an engine for my LJ.

The parts I have are: 12 counterweight 258 crank, -.010 mains and rods. Eagle H-beam rods. Custom made Ross pistons with 19.5 cc dished domes. Total Seal gapless rings. Clevite bearings. New balancer. Assembly dynamically balanced.

I also have a 96 core engine, which I know will not work with my engine mounts in the LJ. I found a 03 model engine that I can get for $200 that was severely overheated I could use for the block, sheet metal and miscellaneous parts.

Now for the questions, I have misplaced all the figures I had regarding compression ratio and quench, and could use a refresher. I also have been reading for a week straight trying to decide on a cam, and I am still undecided, should I go the safe route and stick with the stock cam and lifters? As far as the tuning goes I read a lot of good reports about flyinryan and was considering using him for getting the tune straightened out. What are your thoughts.

Thanks, Mike H.

[SilverXJ]

there is now support for tuning the 06 PCM and now I am ready to start putting together an engine for my LJ.

Talk to [email protected] or [email protected] for a custom PCM tune. Also, consider the AEM FIC6 that you can tune yourself.

The parts I have are: 12 counterweight 258 crank, -.010 mains and rods. Eagle H-beam rods. Custom made Ross pistons with 19.5 cc dished domes. Total Seal gapless rings. Clevite bearings. New balancer. Assembly dynamically balanced.

Nice list. I wouldn't use the gapless rings as I have heard nothing good about them.

Now for the questions, I have misplaced all the figures I had regarding compression ratio and quench, and could use a refresher. I also have been reading for a week straight trying to decide on a cam, and I am still undecided, should I go the safe route and stick with the stock cam and lifters? As far as the tuning goes I read a lot of good reports about flyinryan and was considering using him for getting the tune straightened out. What are your thoughts.

For starters we have an excellent compression calc here http://www.jeepstrokers.com/calculator. You will need to know that length of your Eagle rods and the piston pin height. Usually these are some where on the part or the box. You already have a dish cc, so that is good. As for as a quench number you want to keep it between .040" and .050"

For the cam you can go with a JRC custom cam http://www.jonescams.com/ as he seems to be one of the few interested in helping to find the correct later cam blank and keep the retaining plate.

[Piperpilot3tk]

Rod length is 6.150. The pistons were made for a zero deck height if I remember correctly. According to the calculator if I use a stock cam and figure .043 quench, I should have a 9.85 SCR and 8.5 DCR. This should be good with 91 octane and maybe 87? What is the issue with the zero gap rings? What does it cost for the jones custom cam and what grind would you recommend?

[Piperpilot3tk]

The 03 core engine I found today was severely overheated and I am just about positive the head is cracked. Has anyone ever experienced deck warpage due to overheating? The reason I ask is my pistons are set up for zero deck height and if the block needs to be decked I don't want to have to machine the pistons. I have a almost new 0630 head I could use, but I would have to run some aftermarket coils and plug wires, anyone already do this?

Anyone bought a head from here? Looks pretty nice and the dished stainless SBC valves would add a couple of ccs to the chamber which may help.
http://www.ebay.com/itm/281016724115?ss ... 1423.l2649

[SilverXJ]

Rod length is 6.150. The pistons were made for a zero deck height if I remember correctly. According to the calculator if I use a stock cam and figure .043 quench, I should have a 9.85 SCR and 8.5 DCR. This should be good with 91 octane and maybe 87? What is the issue with the zero gap rings? What does it cost for the jones custom cam and what grind would you recommend?

91 octane, yes. 87, not likely. Perhaps midgrade based on the tune (AFR and timing). 8.5:1 DCR is the max you want to run on pump gas. As for zero gap rings I have heard of some failures due to the rings getting to tight, but more importantly I have heard of 0 gains from them. As for the Jones custom I recommend you talk to Mike Jones about what you want your vehicle to do and give him all the specs. And don't base your wants on the way you think the exhaust needs to sound.

The 03 core engine I found today was severely overheated and I am just about positive the head is cracked. Has anyone ever experienced deck warpage due to overheating? The reason I ask is my pistons are set up for zero deck height and if the block needs to be decked I don't want to have to machine the pistons. I have a almost new 0630 head I could use, but I would have to run some aftermarket coils and plug wires, anyone already do this?

I wouldn't use the 03 head anyhow unless it said "TUPY" under the valve cover, but then the flow still isn't that great and possibly warped from over heating. Personally I haven't seen a block deck warp from over heating, but its also a question of how hot it got. I wouldn't expect the pistons to be for a perfect 0 deck clearance without machining due to different production irregularities in rod length, crank shaft indexing and deck height. I would think they left the piston down in the hole a bit to account for those differences.

I would go with the 0630 head as it flows better. However, you don't need to change the coil rail, just add straps from the valve cover bolts with studs to the coil rail. There is also this : http://www.jeepstrokers.com/forum/viewt ... =26&t=2756 The other thing you have to consider with the 0630 head is that using the stock exhaust manifolds isn't optimal as they interfere with the head port and there isn't much room for the manifold to head seal. I would recommend an set of headers for your 06 TJ as they have bigger ports that will work.

Anyone bought a head from here? Looks pretty nice and the dished stainless SBC valves would add a couple of ccs to the chamber which may help.
http://www.ebay.com/itm/281016724115?ss ... 1423.l2649

Oldyeller is aka Titan. I recommend you doing a search for various opinions on them.

[Piperpilot3tk]

I would hope you can tell I would not select a cam because of the way it makes the exhaust sound! That coil mod looks great, but I wonder if the the exhaust ports would line up with a Banks header.

As far as the rings go if they are going to cause an issue I will not use them, but I have them already so whether they make difference or not is not an issue for me right now. Any place I should look to find a description of problems with these?

[SilverXJ]

Here is a good source for info on gapless rings http://ls1tech.com/forums/tags/gapless.html a google also would be good.

After market exhaust headers for the 99+ head typically have larger exhaust ports in the flange and will line be fine with either the 0331 or earlier heads.

[Piperpilot3tk]

Thanks for the links regarding the gapless rings. I think the set I have are the Sealed Power gapless top ring plasma moly type. I need to give it some thought and decide if I want to use these or go with conventional type rings. Any recommendation for conventional type rings?

I have used Borla and Thorley Jeep headers in the past that had much larger ports than the head casting. The new Banks headers are supposed to have almost perfect alignment to the year model specific castings, which leads me to wonder if a 6 int 3 type will lign up correctly with the older 0630 casting?