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jagman

Rebuild begins!

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I have been told that the machining on my engine is done and that the rebuild kit has been ordered.  I plan to get the truck into my shop this week to pull the existing engine.  I will be posting questions as I go along so be kind!  Any suggestions on the process will be welcome.

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What parts are in the rebuild kit ? cylinders should not be bored/honed until the machinist has  pistons.

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My machinist told me he has overbored the block 20 thou  with pistons to match.  The rest of the kit is on order which I assume is comprized of the valve guides and valves. I am waiting for him to let me know how extensive the kit is.

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Got the engine block and head back today and have the block on the engine stand.  Reassembly will begin shortly.  I noticed that the pistons are dished but I will check them against the originals before I install them.  The head  and block were shaved  25 thou,  and block bored 20 over,  the crank is polished not ground so is original spec. No new cam but the original is within spec.  He tried to get me a new one but they are not available thru his parts sources.  Other parts like the timing stuff is part of the kit as are the gaskets. Oddly enough it also comes with a new oil pump.

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I don't mean to assume how experienced you are but just make sure the block and head are spotlessly clean, hot soapy water, long gun bore brushes, compressed air. When your done white cotton rags should come away just as clean as before you used them.

The same thing for the pistons, rods and crank then lightly oil everything.  Assembling the engine is the most enjoyable part for me.

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Hi Grannyknot, I usually use brakeclean to remove the machining oil and 170 lbs of air to blow out all the oil and water passages.  I have found that the brakeclean gives me a good surface for repainting the block and head.  I don't do many engines and if this is not good practice  let me know. I also use a 15w-40 oil for assy lube when I install the pistons and con rods.  I am thinking of using 15w-40 Rotella oil for the running engine. Do you have another oil you have found to work? 

Edited by jagman
Ignorance
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Dont use that oil pump.  Get one for a Ka. Bolts right up, pumps more oil and gives a higher pressure.

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23 hours ago, jagman said:

Hi Grannyknot, I usually use brakeclean to remove the machining oil and 170 lbs of air to blow out all the oil and water passages.  I have found that the brakeclean gives me a good surface for repainting the block and head.  I don't do many engines and if this is not good practice  let me know. I also use a 15w-40 oil for assy lube when I install the pistons and con rods.  I am thinking of using 15w-40 Rotella oil for the running engine. Do you have another oil you have found to work? 

That all sounds good too, but brake cleaning fluids are specialized for certain kinds of contaminants, they don't get everything.  That's why a good detergent helps get other kinds of dirt off. Methyl Hydrate (wood alcohol) is also a good final wipe cleaner, it's inexpensive and doesn't shrink your brain every time you get a whiff of it.

15w40 works fine as assembly lube as long as you're going to start that engine fairly soon after putting it all back together, all engine oils are made to drip off and get back to the pan, assembly lube is the opposite, stays put.

Redline makes an assembly paste that I really like, you can put your engine back together and leave it in the corner for 5 yrs and not worry when startup comes.

Rotella is a great oil but  I still break in my engines with straight 30w, not too slippery so it allows the rings to get intimate with the cylinder walls.

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8 hours ago, bottomwatcher said:

Dont use that oil pump.  Get one for a Ka. Bolts right up, pumps more oil and gives a higher pressure.

 

Just to be clear, it pumps more volume so it reaches a higher pressure at the same RPM as the regular one, but top pressures are about the same about 55-60 PSI. For example my well used L20B hot idled at 17 PSI and just changing to a KA pump it jumped to 29 PSI. If you run a spray bar or turbo the KA pump will supply that extra oil easily.

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Where do I get a KA pump and does it have part number?  I am also sending the alternator and starter out for a refresh.

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I am getting mine from rock auto myself.  They have a hitachi for 52.99.  1501040F00A is the part number, I looked up 96 Hardbody to find it.

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OK!  I ordered the oil pump today.  As of now I have the old engine disassembled for removal from the truck.  I hope to pull it this weekend and begin assembly of the "new"  engine.

I will undoubtedly have more questions as I get farther along. 

One I have now is the hose mounted from the water pump outlet to the intake manifold and the heater.  Can this be disconnected and the heater hose run from the block line without causing a problem?  If not, does anyone have a single outlet fitting to replace the multi outlet?

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18 hours ago, jagman said:

Where do I get a KA pump and does it have part number?  I am also sending the alternator and starter out for a refresh.

 

15010-40F00 all KA24E D21 Hardbody

15010-86G00*  all KA24E D21 Hardbody '94 and on.

 

15010-3S500 '98-'01 KA24DE

15010-F4500* '01 and up KA24DE

 

* Unisia Mexicana made... probably a Mexican auto parts supplier making the pump for Nissan. I know some of the Hardbodies were assembled down Mexico way.

 

I would look for the Hitachi? symbol on the outer case.

YEnaZpJ.jpg

 

 

 

Looking down into the large hole you can just see the top of the rotor on a regular L series pump.

V2fckkS.jpg

 

 

In comparison the KA pump has the rotor much higher and you can see the rounded side. THIS is what to look for.

 7jkQ4Im.jpg

 

 

The high volume pump has rotors that are 13% longer.

sBzw2v1.jpg

 

Oil pressure at lower speeds is dependent on how fast the pump can replace all the oil that bleeds past all the bearings and jets. Bearing clearances and oil jets do not change size with RPMs so the leakage past them remains constant. On a very worn engine with loose bearings, rods, main, cam, or and engine with a cam spray bar or an oil feed for a turbo the oil pressure will be lower than when they are new and tight. At idle the oil pump is working against a large 'leak'. A high volume KA oil pump can replace the oil faster at the same RPMs and the pressure has to back up and be higher. The relief spring and valve on the pump is set for around 55-60 PSI.

 

You can experiment with washers under the spring to increase the pressure but it's not revving 7-8K so not really needed. The rule of thumb is 10 PSI per 1,000 expected RPM. Keep this in mind.... I had a piece of grit or casting flash jam my L16 oil pump relief valve in my 521 in the 80s. It split the oil filter from it's screw on base so I wouldn't go crazy turning the pressure up..

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I bought the Haynes manual for the 720 and finding that the torque specs are not easy to find and in some cases are confusing.  I cannot find the torque settings for the cam tower bolts anywhere.  The book has an entry for cam nuts?  Does anyone have a definitive listing of torque specs for the KA 24?  Thanks!

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PER FSM:

Cam Cap Bolts:
1.Tighten to 17 INCH LBS first in sequence.
2. Tighten 80-104 INCH LBS

Cam Sprocket Bolts:
123-130 FOOT LBS

Idler Sprocket:
48-61 FOOT LBS

Crank Pulley:
105-112 FOOT LBS

Timing chain tensioners TOP & BOTTOM:
56-66 INCH LBS

Lower timing chain guides:
9-14 INCH LBS

 

Be aware of Inch Lbs and foot pounds.  Always chase and clean threads before assembly.

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41 minutes ago, jagman said:

I bought the Haynes manual for the 720 and finding that the torque specs are not easy to find and in some cases are confusing.  I cannot find the torque settings for the cam tower bolts anywhere.  The book has an entry for cam nuts?  Does anyone have a definitive listing of torque specs for the KA 24?  Thanks!

 

 There are no KA engines in the 720, so???? The 720 has Z series engines with 8 spark plugs. The KA24E and DE have 4. In addition they (KA) are TTY bolts so have to be replaced. Did you mean a Z engine?

 

 

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Yes. I misspoke It has 8 plugs  and is a z24.  You have now an indication that I don"t multi-process or have a memory worth a s--t!

However, I have sent my starter and alternator to the rebuilder for an update since I have no idea how many miles/hours are on them.

I will need some info on the bypass hose that goes to the carb from the thermostat housing. The autoparts stores here have a hose that they say fits but is a 1/4" too large.

Rock Auto has a hose they say is 1" in diameter but is this the right hose?

Thanks Steve

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It's OK.

 

The thermostat is mounted inside the intake. It does have a cover over the thermostat but I don't know of a hose from it to the carburetor. Got a picture? I'm guessing  T V V Thermal Vacuum Valve with 3 small hoses?

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So these KA pumps are better than stock L-6 oil pumps ? Might need to get one for the Z .

 

Priming oil system is best for a new engine

 

4-B793383-2272-4-C31-8009-02-E2-EEE516-F

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Not better exactly, they just move more oil volume. I have always replaced my stock pump with one from a KA. Just insurance.

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Again I misspoke . The hose goes  from the thermostat housing to a fitting on the intake manifold beneath the carb  and from there has a hose going to the block and the heater.

The hitachi oil pump arrived today.  Charlie69 sent me the torque specs I needed so I will spend some quality time in the shop tomorrow. 

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That's the heater return hose.

 

Hot water exits the block goes by hose into the cab heater, exits the heater goes back to the underside of the intake manifold fitting where coolant flowing along the underside of each runner from the head joins it and then flows down to the the lower radiator hose fitting on the timing cover, and back into the water pump. Coolant in the intake manifold warms the cold air and helps vaporize the fuel droplets. These are just water hoses, what ever will fit, will do.

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14 hours ago, jagman said:

Again I misspoke . The hose goes  from the thermostat housing to a fitting on the intake manifold beneath the carb  and from there has a hose going to the block and the heater.

The hitachi oil pump arrived today.  Charlie69 sent me the torque specs I needed so I will spend some quality time in the shop tomorrow. 

I think you're talking about part number I had an issue with here. I believe it is 92422M in the diagram within that post. My solution was to about ten inches of 7/8ths hose, because it is mostly a straight shot from the water outlet to the bottom of the carb. 

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Thanks for the torq specs and the info on the oil pump. I have the new engine partially assembled.  I will torq the pan bolts and install the oil pump and distributor soon.  As with all my projects some bolts seem to have wandered off so I need to find them before I complete the install of the timing  (or is it timming) cover.

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Datzenmike  I seem to have misplaced your description of the oil pump shaft position to set the distributor. I remember the 11:00 oclock but don't remember which halfmoon is to the right.

Please tell this dummy one mo time?   Thanks

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