98ZJ 4.6L Stroker Build

[purple_jeep]

Painting!

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Cheers

Chris

[purple_jeep]

Finally got my .001 undersized bearings today! Going to be a busy weekend!

Cheers

Chris

[purple_jeep]

Well finally able to start assembling the engine since my .001" undersized bearings arrived on friday!

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Started off by cleaning all the threaded holes in the block with taps I borrowed from work

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Switched out the Clevite standard bearings and re plastigauged all the mains. With the .001" undersized I ended up with all clearances between .0015" and .0020" so I am much happier with that! Removed the crank, put assembly lube on all bearings and reinstalled the main caps torquing to 40, 70 and finally 80ft.lbs on 1,2,4,5,6 and 7. Pushed the crank back and forth and torqued 3 to 40,70 and finally 80ft.lbs. Once 3 was torqued I measured end play at .0025" so that's good!

As part of installing number 7 I installed the rear main seal with Loctite 518 anerobic sealant.

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Then I installed all the pistons with Moly rings checking the clearances on the bearings with plastigauge with assembly lube on the top bearing but dry on the lower bearing. They all measured between .0010" and .0015" so thats on the tighter end of tolerance but should be no issue. After measuring I put assembly lube on the lower bearing and finished torquing them all to spec (ARP calls for 45ftlbs on their rod bolts).

Continued due to only 3 pictures per post limit??

[purple_jeep]

Bottom end mostly complete!

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Once done with the crankshaft I installed the Cam shaft making sure to use Comp Cams Cam and Lifter installation Lube on all lobes and assembly lube on the bearings after cleaning with break cleaner.

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Then I installed the awesome Timing set I copied from SilverXJ's thread. I really do like the quality of this and that its made in Australia (as was I ).

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That was about it for today other than installing the bearing brace with 2 3/8" grade 8 washers on each stud to help it clear the longer stroke. Also I was going to install the Oil pump but I cant work out how to install the pickup tube thoughts??

Tomorrow is degree the cam shaft and install the head with lifters etc.

Cheers

Chris

[SilverXJ]

When cleaning threads it is best to use a thread chaser, not a tap. You don't want to cut any threads, just clean them.

Bearing clearances are best measured dry, with no lube. You results may be a bit off.

There is a special tool used to install the oil pickup tube into the pump. It wraps around the tube right before the collar and is driven into the pump with a hammer on the tool. There are other ways as well. Some put a tight fitting wrench on the tube and drive it in that way. Some just hammer with a dead blow directly on the tube. Which ever way you go make sure the fit is tight and you want it as close to its final orientation during assembly as possible. Some like the tube brazed or welded to the pump after orientation is set. By orientation I mean you need to check the clearance from the bottom of the pan to the pick up.

[purple_jeep]

I measured the main bearings dry but the service manual said to lube the upper rod bearings when measuring them with plastigauge. Ah well I am on the lower end of spec so minus the lube I should be closer to the middle of spec.

Wonder if the local auto parts store has that tool. Where did you get yours?

Cheers

Chris

[SilverXJ]

Wonder if the local auto parts store has that tool. Where did you get yours?

LOL. I didn't. I use the wrench method.

[purple_jeep]

Wonder if the local auto parts store has that tool. Where did you get yours?

LOL. I didn't. I use the wrench method.

Thats What I am doing! Pain to get it seated all the way!!!

Next up is to buy a pushrod cut it in half and make an adjustable pushrod :p

Cheers

Chris

[purple_jeep]

Well another busy day! Why is it that everything takes so much longer than you expect :p

Lifters were soaked in oil overnight ready for installation today (Comp Cams installation instructions say it is recommended to soak but not required, also not to pump them up with oil.)

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Also found TDC for the #1 piston and installed the degree wheel and pointer. I found a printable degree wheel and just printed it on thick card stock, the pointer is just a wire.

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Once the Degree wheel was located with TDC marked I CC'ed the head so I could install it. This took a bit of work and I am not sure I trust my numbers very much. I got ~62cc for the head (no porting work).

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To do this I used green rubbing alcohol as the liquid and petroleum jelly to seal the perspex sheet to the head.

Continued due to 3 images...

[purple_jeep]

Continued....

Once I was done CC'ing the head I installed the lifters into their bores making sure to use plenty of Comp Cams Cam and Lifter installation Lube on the bases of the lifters and oil on the sides.

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Then I cleaned the block and head gasket surface one more time and installed the gasket and head on the block. I used new ARP head bolts which require their lubricant on threads, head base and washers except for bolt 11 which needs Loctite 592 on the threads (Permatex makes a competing product with part number 59214 which i was able to find at the local parts shop). These bolts were then torqued down in stages per the service manual to 110ft.lbs except 11 which is torqued to 100ft.lbs.

Once the head was on the pushrods and rockers were installed with plenty of installation lube.

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Next I measured the pre load on the pushrods per the instructions which came with the camshaft. Looks like I need a shorter pushrod as the marks are about 0.150" apart instead of 0.020"-0.040" Does that seem like a lot to be reducing the pushrods by?

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Can I degree in the cam like this or do I need to wait for the correct length push rods?

Also anyone know where I can get the header to down pipe gasket for a Thorley Header?

Cheers

Chris

[SilverXJ]

That does seem like a bit too much extra preload. Do you know the amount removed from the deck to get your 0 clearance? IIRC its around .030". It could be just a combination of tolerances of after market parts combined with machine work. Also, milling the deck will increase preload as will a valve job.

How did you measure the preload? Tighten bolt until 0 play, scribe, then tighten down all the way, wait then scribe again and measure? Also, make sure you are on the base circle of the cam and not going into lift.

You can go ahead and degree the cam before you get new pushrods.

As for the Thorley gasket I haven't found one other than Thorley's gasket that works well. There was one from a Chevy that sort of fit but it was a bit to tight going into the header.

[purple_jeep]

Ahh I was wondering if there was more to measuring the preload then what Comp Cams says in their instructions. I did pretty much exactly what you said (well in reverse) Torqued to spec, made a mark from a reference surface, released the bolts but made sure the rocker still held the pushrod in the right place and made another mark using the same reference surface and measured the distance between marks. What I did not do and Comp Cams instructions does not say anything about is the location on the lobe for that pushrod.

Block was decked 0.022" I believe, valve job was done so I guess these could all contribute.

Non-Adjustable Rocker Arms: A different procedure is required to set hydraulic lifter pre-load on
engines with nonadjustable rocker arms. After applying lube, install the pushrods and torque all rocker
arm bolts down in the proper sequence and torque specification. Rotate the engine by hand in the
normal direction of engine rotation until both the exhaust and intake valves have opened and closed
completely. Allow a couple of minutes for the lifters to bleed down.
Using the valve cover gasket surface on the head as a reference point, place a mark on the pushrod.
The smaller more defined the mark, the more accurate the measurement. Be sure the reference point
you choose for the first mark is easily accessible and easy to duplicate. The pushrod will be marked
twice. It must be from the same reference point and angle for the measurement to be accurate.
Loosen the rocker or rocker shaft bolts. Leave the rockers on the head so that they will support the
pushrods. Be sure the pushrods are standing free in the lifters, and do not have any pre-load. Using the
same reference point, place a second mark on the pushrod. Make sure the angle and reference point are
the same as the first mark.
You now have two marks on the pushrod; one with the assembly bolted into place as the engine will
run, and the second mark with the lifter unloaded. The distance between these two points will represent
the amount of lifter pre-load. If the pre-load is not within .020” to .040,” adjustment is necessary. The
simplest way to accomplish this is by using different length pushrods. When measuring to find the
correct length needed, be sure to include .030” pre-load that the lifter requires. If the engine uses
pedestal mount rockers, shims can be placed under the pedestal to reduce the pre-load. The stands on
shaft mounted rockers can also be shimmed in this manner. Longer pushrods will be needed for
insufficient pre-load.
In most cases, only one intake and one exhaust pushrod will need to be checked. If the valve stem
heights are not equal, then pre-load will have to be checked on each valve. If you do need custom
length pushrods, call CAM HELP at 1-800-999-0853. COMP Cams offers a variety of pushrods in
most lengths.

Hmm have to contact Kolak about a gasket then.

Cheers

Chris

[SilverXJ]

What I did not do and Comp Cams instructions does not say anything about is the location on the lobe for that pushrod.

Yes, you have to make sure its on the heel/base circle of the lobe. If the oil pan is still off you can take a peek in the crank case and see exactly where the lifter is on the lobe.

[purple_jeep]

I made sure the cam was on the base circle and repeated the measurement but got the same answer. Looks like I need 9.500" pushrods.

Trend has quoted me $6.57ea for 5/16" or $7.19ea for 3/8".

Smith Brothers has quoted me $8.00ea for 5/16" or $9.92 for 3/8".

Any reason to go up in diameter? Thoughts on those two brands?

Cheers

Chris

[SilverXJ]

I would ask for more details on the pushrods from both companies. What the shaft is made out of, how the ends are attached, etc. I see no reason to go up in size and I might be concerned that the larger ones would hit the holes on the head. Probably not though. I would actually pose that question to the push rod companies with your spring loads and see what they recommend.

As for companies I've used Smith Brothers several times in the past and they have always treated me well and have an excellent product. I'm not saying Trend is worse as they are both good companies. I had found that Smith had a better price when I compared them to Trend so I would question the differences between pushrods.