NAPZ motor...

[RatsunRailer67]

So i have had this truck for a few months now and im totatlly not into the slodat thing... I want something with some power. I have owned a few toyota and i love the power of a 22r... The Napz motor seems to be a lot like it and i just wanted to get some ideas from you guys. I know where i can get a motor for really cheap and i was gonna build it pretty nasty, well as much as i can get nasty with an all motor unit... Any other ideas motor wise that i can do for cheap? I have seen a lot of L motor rebuilds on here, but my buddy has a L16 and it just seems like a nowhere game for power. Im tired of the J13...

[datsunon40s]

I have been dabbling it this as well what I have forund if you want high rpms go with an SR20det if you want torque go with a KA24DE or a VG30 dont mess with the napsZ I have had a few with webbers and there DOGS my :D.02 Good luck:confused:

[datzenmike]

The Z22 with an L head and front timing cover will wake up some ponys. Guy on the Realm has an Z22 with L head/cam/side draught carbs and just over 130 RWHP. All nissan spare parts. The compression is up there due to the smaller chamber L head too.

[fiveNdime]

Depending on the year of your motor, I say keep it and do it just like datzenmike said. I have the same setup in my 521 and it goes pretty good but nothing like a SR or KA would obviously. I can still bark 4th gear with 245 rubber on the back, and thats with a 5 spd thought. I have roadster SU's matchbox ignition, big cam and some other stuff done. I love the way mines setup. I definitely wouldn't mess with the original head setup though.

[RatsunRailer67]

anyone know of any threads i can look at?:D

[ppeters914]

Don't forget to sell the J13 after you do the swap. Some folks still want 'em.

[fiveNdime]

anyone know of any threads i can look at?:D

 

:confused: for the motor build :confused:

[datzenmike]

anyone know of any threads i can look at?:D

 

Here's some reading to get you started. It's for an LZ for a 510 so ignore anything that does not apply to you. Thanks to Jason Grey:

 

How to put an L-series head on a Z block

 

To use the NAPS-Z block with an L series head, you need to use all the parts foreward of the block from an L20B. Use the front timing cover to match the L series head pattern as the NAPS-Z is slightly different shape where it seals to head around the timing chain. You also need the longer L20B timing chain and matching gears, guides, tensioner and longer L series distributrer drive spindle. The NAPS-Z blocks lack a chain oiler peg. You could drill the block and add a chain oiler peg but this is probably unnecessary since L series front cam tower and the chain tensioner both oil the chain. Im told the L28 6 cylinders didn't even use a oiler peg. Drill a dipstick hole on appropriate boss on right side of block and plug the left side dipstick hole since it will now be covered by exhust manifold. Use an L series dipstick and tube in the new hole, the NAPS-Z dipstick wrong length. Use an original 510 L16 oil pan and oil pickup, NAPS-Z or L20B oil pan wont clear the 510 crossmemember and steering. You will need a headgasket with larger bore if cylinders are over 86mm. The cheap but difficult solution is to use a NAPS-Z headgasket. The shape of the timing cover to cylinder head gasket surface is different between L series and NAPS-Z, headgasket modifications are necessary to seal front cover section if using the larger bore NAPS-Z head gasket (use an entire NAPS-Z gasket and seal the front cover with silicon or cut and splice the front segment of a L series gasket onto a cut NAPS-Z gasket.) The NAPS-Z gasket lacks the valve "eyebrows" so the gasket bore is a true circle, this would prohibit beneficial grinding of the head chamber and block to unshroud the valves, probably best to use the 89mm Z24 gasket even if on a 87mm Z22 block since it will allow the most unshrouding within cirular bore. The NAPS-Z block has all the water passages of the L series (plus a few extra) however the NAPS-Z gasket covers some of these coolant passages that should be open for an L series head, drill holes in the NAPS-Z gasket to match an L series gasket for correct coolant circulation. Even easier to assemble, buy the expensive Nissan Motorsports 88mm big bore L-series gasket. The opening of the cylinder head oil passage at the headgasket should be elongated to better match to the oil passage of NAPS-Z block.

 

The NAPS-Z20E block that I checked had headbolt threads same as L20B block but I have heard that some NAPS-Z blocks have the headbolts threads deeper in the block hole, you can obtain more clamping force for headbolt by using all long length headbolts (turbo 280zx headbolts part #11059-P7600). Countersink or mill down the upper face of cam tower by 0.5" where headbolt contacts camtower so the headbolt sits 0.5" lower into block. For headbolts that do not thread through camtowers, use .350" thick washers below the longer headbolts to keep them from bottoming out in hole.