New 4.6L stroker build

[Muad'Dib]

Did you say if you decked the block or not? I dont remember reading about that...

Do you feel after even having the cam nitrided that you needed to groove the lifter bores??

[SilverXJ]

Did you say if you decked the block or not? I dont remember reading about that...

Do you feel after even having the cam nitrided that you needed to groove the lifter bores??

Yes, the block was decked. There was surface rust ont he deck and also the deck needed to be brought down to get the quench I wanted.

I can't really answer the question on the cam. ideally one would need two identical engines with one nitrided and one grooved and then see how long they last. I just wanted to do as much as possible to make the cam last. If I had to choose between one I would go with the grooving because more oil on the cam surface would be better than just treating the cam, especially at low RPMs where the cam isn't getting splashed by the crank.

[SilverXJ]

It looks like the crank thrust surface was too rough and work the front side of the thrust bearing. I sanded it ans smoothed out both my hand and using the engine starter to rotate the crank. A new bearing is on the way. In my opinion the machine shop should have caught this, but oh well. If my work fixed the surface fine.. it I need to pull the engine and have the crank serviced I won't be paying for that. Hopefully that won't happen. Any how I don't think that is the source of the noise. I can under stand the cranks lapping back and forth due to the wear on the bearing, but not the rhythmic sound. Something would have to be slapping the crank around at each revolution at that time. I'm going to replace the bearing and go from there. I found nothing else wrong with the engine, and I checked all the bearings and clearances.

[Muad'Dib]

I think you just have bad stroker luck!

Id be pissed.

[the_wrench116]

I think you just have bad stroker luck!

Id be pissed.

what grit paper did you use? 400 500 1000 not 80 grit right.

[SilverXJ]

I started with 400 and ended with 600.

[SilverXJ]

I think you just have bad stroker luck!

Id be pissed.

I'm not happy about it. The crank shaft was one of the few parts they obtained and it should have been checked over better and cleaned up before it was put into my engine.

I went back over the thrust surfaces on the crank yesterday with 1500 grit. Both Lowed and Home Depot didn't have sand paper over 600 and neither had an aluminum cotter pin. So I went about 15 miles out of my way to a real hardware store. Just for a sheet of sand paper and a cotter pin. The crank surface looks good and my starter and battery in the XJ hate me.

[SilverXJ]

Installed the new thrust bearing and oil pan after work today. Crank end play is at .004" dry. I just hope I cleaned the crank up enough so it won't happen again. I'm going to finish buttoning it up tomorrow and drive it again.

[SilverXJ]

Got it buttoned up today. Started up fine with a little of lifter noise from the engine being rotated so much that they bled down..cleared up in about a minute. Haven't driven it much thought yet as a new problem showed up.

Off idle it wants to stall out.. both coming from idle and going back to it. After that its fine. For instance, if you blip the throttle a bit it stumbles, the rpms increase then it drops back down and stumbles and will stall sometimes. I had the cam sensor out to prime the engine so I checked that... its where it should be. Checked all the connections and all is good. I also had the spark plugs removed during the repair.. didn't get a change to check those. So I am going to check the plugs, re check the cam sensor. Although it seems like an IAC issue. I have a spare I can replace it with if I find nothing else. Any ideas?


And I need to reconnect the antisway bar... wow that feels weird in a bad way...

[SilverXJ]

I'm not sure I actually fixed the thrust bearing issue. After my fix and fresh installation of the thrust bearing crank end play was .004". Now, after a bunch of idling and about 60 miles on the road it is at .0052". It might stop at this as it seems I didn't clean up the inside diameter of the flange surface well enough.. or it might not. I'm thinking about pulling the engine and getting this problem fixed. In my opinion I don't think it can be cleaned up by a simple machining or grinding or sanding as it is already .004" with a new bearing. It will be most likely on the high side of stock spec if it is cleaned up by a simple machining or polishing. My thoughts are to get just the thrust surfaces on the crank welded then machined to spec.

Thoughts on this? Let it go and see where it goes or get it fixed?

I did talk to the machine shop about this today. And they said that they would take care of it for me with no cost to myself aside from my labor.

[the_wrench116]

id drive it for a few days/weeks but if it starts sounding bad get it fixed. and make sure that they put it under warranty in writing.

[brendanbreen]

any good news??

[SilverXJ]

Nothing good... If you followed other threads on here you would see what I have been dealing with. First I had a thrust bearing go bad. So I looked into that and the crank surface for the thrust bearing was rough. I attempted to fix that with 400 to 600 to 1000 grit sand paper. Then I buttoned it up. Immediately after that I had a hesitation/ stalling issue and an extremely loud valve train. That turned out to be a damaged cam with the noses beginning to be worn off on the cam. So I need new cam and lifters. I talked to Isky and I am having a custom cam ground that will provide a bit less torque then the comp cam 68-231-4, more high end, and a quieter valve train. That should be arriving soon. I also sent the crank out to be fixed by the company that sold it to the machine shop. They polished it up and it should be returned soon. I purchased some Lunati Microtrol lifters that are suppose to provide better oil control, and require less preload. There was a bit of concern that they were really only .903" when stock is .904". However they measured .9036-.9038" as do all the other various lifters I have measure. So I am going to run those. The Comp Cam and lifters were sent back to Comp for diagnosis and refund and they could not explain what happened. I think perhaps the cam wasn't hardened correctly. I personally talked to the RMA diagnosis guy and had no insite into what happened. The break in was correct, the spring pressure was good and the oil was good. So I don't know otehr than teh hardening theory. I went with the Isky for the replacement cam because they a) they listened and talked to me (a few other companies didn't) b) they did dual pattern c) they recommended a decent custom grind and d) their ramp rates weren't as fast as the Comp cam.. while Lunati's were faster.. I didn't want a noisy valve train again.

So besides those problems I still had that knock coming from the transmission. Despite replacing the torque converter and flex plate it was still present. I purchased a used AW4 for $250 with 89,000 miles and will be installing that.

Since the hesitation issue was at idle and off idle, while diagnosing it was mostly at idle, replicating the problem. I think that is what saved me having to do a complete tear down and rebuild as the oil filter wasn't in by pass and filtering all the oil. The only metal particles I found were on the side of the oil pan. None in the oil when I drained it and none on the oil pan plug magnet. I'm going to replace the bearings and clean it out as best as I can with out taking it completely apart. The bearings looked good with no signs of contamination as well. The machinist recommended reusing the old bearings but I decided on new ones. The machine shop is paying for the bearing. There is no scuffing on the pistons either.

So that is where it is. Engine out, waiting the crank and cam. Transmission soon to come out.

[YJason]

I hope my Comp cam 68-231-4 doesn't do the same as yours. My valve train is a little niosy as well. Hopefully the crower cam saver lifters will save my cam??

I'm in the same boat as you with the AW4, mine is getting hot and I think I cooked it this past Sunday. It goes from outside temp to 150-160* in about 5 miles. It shifts and locks up like it suppose too but if I'm not careful it will go to 240* in no time. I'll probably be swapping in a used trans also in the near future.

Good luck with the rebuild and trans swap.

[SilverXJ]

I don't think any amount of extra oil on the cam would have helped my problem. I already had the lifter bores grooved. What ever went wrong went wrong quick. The 68-231-4 will be a bit noisy due to their ramp rate, same for all the CompCam eXtreme Energy cams. I just don't want that anymore. I have enough noises as it is.

What do you think is causing your tranny to over heat? Do you have an aux cooler? Larger tire with stock gears?