New 4.6L stroker build

[SilverXJ]

so now that you can do this in your sleep how much do you charge for a built motor

While you are correct, I could probably assemble and install a stroker or 4.0l with my eyes closed, doing everything 100% to spec, would you really want some that can't keep one running doing the job? lol

Anyhow... its still running.. about 80 miles. Oil pressure at hot idle is still 20psi.. still no odd lifter noise. When I change the oil I will do at my machine shop which has a bore-oscope. Shove it up the oil pan hole and inspect the cam bearings. I think I have a small oil leak form the RMS or pan gasket... or possibly just some run off from when I was priming it with the valve cover off. Also, a small leak in a tranny cooler line at an AN coupler. Cold start idle is a bit rough... probably because it is running lean according to my wideband... probably due to decreased idle vacuum. I'll take care of that eventually maybe. I'm liking the Hesco cam. Missing a bit of torque, but after 2000 RPM it just screams. Nice. The Brown Dog bushings are settling in nicely. I feel more connected to the engine with out and annoying vibes. Feels a bit more responsive as well. Feels very solid. Overall, compared to the 95 ZJ with pretty much stock everything except the OME shocks and a K&N cai it feels so new and firm and well sorted. Still, the suspension is stiffer in the XJ and will take some getting use to again. I've been hoping for the broad in the Volvo XC90 that kept trying to beat the ZJ out (never actually got ahead... i might be old and the transmission is shite, but it still can move) to try one on the XJ.

The knock is still ever present... I'm at the point where I will just live with it. It has never gotten worse yet. If it does i'll drive it till what ever it is fails so I know what the hell it is finally. Could perhaps be the header's harmonics of sorts. That is pretty much the only thing that was never changed.

I tried to fix the exhaust leak.. complete failure... while the gasket I was using works when you can pound it into the exhaust header while the head is off, its a bit hard to install while the exhaust is in the way. Kept slipping out. I think I ended up mutilating it to get it seated correctly. Two Thorley gaskets are on the way, which should just slip in.

Got my new alarm remote today. Its nice having keyless entry again.. especially since ZJ doesn't have keyless (sister lost remote when she was driving it.. nice) and the XJ door locks operate in the opposite direction.

I've noticed my rear brakes over heating so I ordered new rotors and Hawk HPS pads to hopefully fix that. Don't understand why unless the front brakes need more fluid, but it still stops well and shifts weight front. I'll see.

Volant is sending me the correct sleeve so I can get rid of the old and dirty k&n and Rusty's tube and use the Amsoil filter and shield it.

Nothing else appears to have failed over its long sleep.

[SilverXJ]

At this point I would just like to scream and throttle someone. But I don't know who.

Pulled apart the oil filter I used for break in last night. Little shinny metal shavings. Great. Went tot he machine shop, drained the oil and borrowed his boroscope. Found one cam bearing though the oil drain and sure enough, the bearings are dead again. It looks like that lose pick up was only causing the noisy lifters, not the cam bearing failure.

Oil pressure started out good then before I pulled it in the storage unit today after a long drive in hot weather it dipped to 18 psi. Cold start was always around 60 psi or so.

The constants in the equation have been the block, pushrods, head, timing set, connecting rods and rockers. The bearings have always been the same name brand. Clevite for the rods and mains and Durabond for the cam bearings.

I used Joe Gibbs 30wt break in the first time, 50wt the second time and this time I used Brad Penn 30wt breakin oil. All oil pumps have been new Melling standard pumps. New oil pickup this time. I used Royal Purple assembly lube, and primed the engine for 30 minutes before start. All push rods had oil before firing. No binding in the valve train. Had the cam bore checked by two people prior on this block and the cam spun easily when I installed it. Crank and rod bearings show dirt, but nothing that would suggest they were low on oil pressure.

My machinist still is on the idea of the lifters/rockers allowing too much oil to the top end causing the pressure loss. I don't believe that. The cam and lifters are Hesco, and the rockers are Harland Sharp from Hesco. Many people use them. Plus they have been used by me on two other blocks with out issue.

Another mechanic that works at the machine shop thinks there could be a restriction to one of the bearings, causing that one cam bearing to fail and then transferring the load to the remains 3 bearings, causing them to fail in turn.

The last theory from my powder coater/welder that use to race open wheeled cars years ago, is that the bearings are just bad. That was one constant, the Durabond bearings. I can see a bearing being marginal anf dail maybe 60,000 miles down the road, but not on a cam break in.

I don't know. I have no more ideas of my own other than the bock maybe flawed in some way. Any ideas anyone else has I would be willing to entertain.

And the knock is still there. But I think that is something else as it has been present on 3 other blocks with cam failure or low oil pressure.

[dwg86]

I hate to hear that you are having more problems. Does this block have the lifter bores grooved? Are the cam bearings wearing on the bottom?

[SilverXJ]

No lifter bore grooves. And the bearings are worn toward the bottom.

Even though I measured the clearances and was safe I am going to put some checking valve springs in and see what happens in the valve train. Wouldn't make sense as the Comp Cam had more lift and never killed the cam bearings.

[4.whoa]

Is there any chance that the cam bearings spun a little ? Not like seizing and going along for the ride,but just reclocking to where the oil holes aren't lined up properly anymore?

Curious: why did you prime the engine for 30 min before firing? It needs to be primed, certainly, but once all the pushrods are pumping oil steadily, doesn't any more just "wash" the assembly lube off? I don't know if it does, just wondering.

[SilverXJ]

Did I say 30? should have been 20. I was trying to get oil everywhere and get all the air out. I think the minimum recommended is 5 minutes after oil gets to the push rods.

I went back and checked the retainer to seal clearances, really hoping that I screwed up some calculations, but using checking springs the retainers didn't come close to the seals. Plus the seals don't show any damage.

I didn't remove the cam yet, but I doubt the bearings spun. They didn't on the previous two failures.

One though I had was about the timing chain. With out the timing cover on, and the load side under tension I have 1/4" of play as measure off a strait edge. Could the rubber guide be pulling out that 1/4" of play and tightening the chain? I see no signs of rubbing on the cover other than on the guide. Then why didn't the Comp Cam kill the bearings?

[SilverXJ]

Got the cam out with some persuasion. #2 bearing was the worse, then #3, then #1 and the last had the least wear. Once again the thrust is showing wear with copper rubbing off. Maybe my machinist is right about the oil pressure being relieved through the top end. Oil does come up through the push rods rather quick when priming the pump and a lot of it at that.

Oil restictor pushrods maybe? But what size hole? .040", .030", .020"? Then will oil build up in the lifter causing it to pump up?

[Exos]

Got the cam out with some persuasion. #2 bearing was the worse, then #3, then #1 and the last had the least wear. Once again the thrust is showing wear with copper rubbing off. Maybe my machinist is right about the oil pressure being relieved through the top end. Oil does come up through the push rods rather quick when priming the pump and a lot of it at that.

Then wouldn't your main and rod bearins show wear too?

[SilverXJ]

Well.. the thing is that the crank thrust bearing is still showing wear... maybe the rods and mains are getting enough oil to lube them, but not enough to get oil out a whole lot.. plus the line to them is pretty straight form the main gallery.. where the cam bearing's line isn't exactly a straight shot....

It would explain the cam bearing failure though... I've heard of people bending rods and not killing the cam bearings.. i don't have a single bent rod and nothing is binding in the valve train.

[SilverXJ]

I think the plan is as follows:
1) Comp cam lifters as they were the last lifter used in the combo that that cam bearings didn't die
2) Restrictor push rods. Need to talk to my machinist about what size restrictor. .020", .030" or .040". The current push rods have an .080" hole, which basically has a direct line to air.
3) Try to find some aluminum cam bearings. Haven't had any luck yet.. ideas?
4) Thinking about a HV pump. Once the restrictor pushrods are in that would decrease the chance of oil getting out the top to begin with... not sure on the HV pump yet.

Block is going to be cleaned as if everything else. King main and rod bearings, cam bearings undecided. If I don't go with a HV pump I'm thinking of just cleaning the one I have now and reusing it. Don't know. Pistons and bores are fine. As for the cam I don't know. Maybe see if Clay Cams will take a look at it and re do the parkerizing.

[dwg86]

That makes sense about the pushrod holes being to large and letting too much oil go to the top end and lowering oil pressure. I used an HV pump, and no problems so far.

Give Trend pushrods a call. They are who I used and their prices are good. I think I paid $70.00 for a set of one piece chrome moly pushrods. I think that is the same company that Bulltear used to make thier pushrods with the smaller holes.

[SilverXJ]

I have emails to smith brothers, manton and trend pushrods. Its going to be around $130. But if it fixes my problem it will be money well spent.

Technically the lifter is suppose to meter the oil going to the top end. Well, it not doing it right then.

Also thinking about moving the stock oil sender to the rear of the oil galley where they are on the WJ and TJ.

[the_wrench116]

could you send some pics of the oil pressor sensor relocation afterwords?

[SilverXJ]

When primed oil comes up through the rockers quickly. And its not just a trickle. My machinist thinks that is where the problem lies. However, many people run this combo and don't have issues. I compared the stock pushrod and rocker combo's holes. The stock pushrod has a .095" hole, where the ones I am using have a .088" hole. The stock rocker has a .064" hole, where the Harland Sharps I am using have a .080" hole. Another difference is that the stock hole in the rocker is offset more to the pushrod side of the rocker. I have also been through 3 sets of lifters on the 3 cams. The comp cam had the comp lifters, the Isky cam had the Johnson lifters, and the Clay Smith cam had the generic lifters that I have seen marketed under different names.

Code: Select all

Lifter            Body inlet      Pushrod seat
Comp               .098"            .079"
Johnson            .089"            .078"
OEM                 .052"            .095"

My machinist recommends I go with the stock lifters. However i have a few problems with that. 1) cost, 2) where are they made, 3) it has a small hole into the body, but the hole going to the pushrod seat is the largest of the bunch. Wouldn't that have a tendency to bleed the lifter if more oil is going out through the larger pushrod hole than the lifter can refill through the body hole? I'm thinking of the comp cam lifters considering I didn't have this problem with them

I asked him about running a restrictor pushrod with a .040" restrictor and he agreed with that.

He also wants to groove the cam journals. However, two of the bearings already have a 360* groove in then on the ID. #1 and #3. He wants to groove all the journals, but I don't see the point if the two bearings already are grooved. Maye just groove the journals with out the groove in the bearings. Any down side to grooving the journals?

So:
1) Lifters. OEM? I don't know, maybe comp?
2) Pushrods with .040" restrictor
3) Groove all or just two of the cam journals?
4) HV oil pump... undecided about that.

[SilverXJ]

Oil sensor relocation:

On TJs and WJs the oil pressure sensor is at the rear of the main oil galley. I feel that this location gives a more accurate of true oil pressure than where it is located stock. I am relocating my sensor to this location. On my block there is already a boss there for the sensor, how ever it is not drilled. I don't know if it is like this on earlier blocks. The thread size for the sensor is 1/8" 27 NPT, so you will need a corresponding tap. I used a 5/16" drill bit to drill the hole. I don't like the fact that I didn't drill in the center of the boss, but oh well. The hole intersected the galley on the bottom. Looks like a 1/8" hole into the galley. Drilling was easy, and I stopped to check my depth several times.

The location:


View of the hole with light shone through rear oil plug location:



View from the rear oil plug with light shone through new hole:


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