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frenkienstien l18? is there a way?


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can you make a frenkienstien l18? what all parts would you suggest to get the most power out of my engine? i perfer to be old school, i dont want a turbo. i have a a87 closed chamber peanut head. my l 18 is bored .50 over has a l7 cam...the pictons are dished...maybe my motor is a stroker...idk i got the truck from my uncle and he didnt know much about it

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Frankenstein. You can stroke out an L16 with an L18 crank and rods. That way it's original, but more power. Good for stock classes where you only need to retain the stock block. Some are displacement limited though.

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What Matt said. If you are building an L18 motor, rings, bearings etc. it will cost the same to do it to an L20B. Instant 10 more hp. If you can find an old block for the $50 core charge and stick your A-87 head on it. Or even better get a Z22 block as well. Re-build it and put the L20B cam timing and an L20B head on and you would have an LZ 22 Frankenstein. About 20 more hp than the L18.

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Frankenstein motors:

Collect all the parts at pick-n-pull JY and buy it as a rebuildable $50 short block



Medium block 2.4 Liter


Stuff a Z24 crank and pistons into NAPS-Z or L20B block bored to 89mm by cutting down crank counterweights and clearance grinding block as per Ben Pila. This gives you a 2389cc L-series motor that doesnt require using defective (crack prone) Z24 block, fabricating timing cover, lengthening timing chain or modification to close hood. Z24 piston tops will need to be milled down slightly. Fedral-Mogul 33.8mm pin height pistons might not need milling?

Compression ratio with Z24 pistons and open chambered head is 10.25:1 before pistons milled.

parts: : modified Z22 block, modified Z24 crank, modified Z24 pistons, Z22S/ L20B rods

s/2+r+p: 227.7

piston deck height: 0.45 (above deck)



Stroker 2.3 Liter


Stuff a Z24 crank into a modified Z20/Z22/L20B block by cutting down counterweights as above. No piston modification or block boring needed for 2283cc L series.

see http://hobbslaw.nissanpower.com/custom2.html for an example

Russ noted that his deck height measured -1.77mm with the Z22E pistons that he first tried using, he eventually used milled Z22S pistons to achieve a higher compression ratio.

Parts: Z24 crank, Z22E pistons, Z22S/ L20B rods in a Z22 block or +2mm bored Z20/L20B block.

s/2+r+p= 96/2+145.9+32.1= 226.0 mm

piston deck height: -1.45mm below deck



Big Bore 2.3L


KA24 pistons into a bored Z20/Z22/L20B block. The small 2.8cc dish area of the KA24 pistons helps to preserve compression ratio even with the low piston deck height. Compression ratio with a open chambered U67 head is 9.9:1 or use dished Z24 pistons and peanut chambered head for 8.9:1 compression ratio.

Parts: Z22 crank, KA24 pistons, Z22S/ L20B rods in a +2mm bored Z22 block or +4mm Z20/L20B block.

s/2+r+p= 92/2+145.9+34.0= 225.9 mm

piston deck height: -1.55mm below deck



Longrod 2.19L/2.24L


Start with VG30E pistons and have the tops milled by 2.7mm to produce 29mm pin height. Custom pistons of similar specifications would also be recommended. Using the long Z20E connecting rods gives this engine a better rod/stroke ratio of 1.66:1. (stock Z22 rod/stroke ratio is 1.59:1). Start with +1mm VG30E pistons and bore the block +1mm to 88mm to gain a bit more displacement (2238cc). This engine with custom 89mm pistons is rumored to be the basis for the "rebello 2.3L".

parts: Z22 crankshaft, Z22 block, Z20E rods, milled VG30E pistons.

s/2+r+p: 227.5mm

piston deck height: +0.05mm (above block)



Long rod 2.1 L


I really like the possibilities for this 2.1L longrod motor.

Parts: L20B crank, Z22E pistons, Z20E rods in a Z22block or Z20/L20B block bored +2mm

s/2+r+p: 227.9mm

piston deck height: +0.05mm (above block)



Long rod L18


flattop Z20S pistons and peanut chamber head for 9.7:1 CR, better rod/stroke ratio for higher RPM.

Parts: L18 crank, L18 block, L16 rods, Z20S pistons

s/2+r+p: 207.66mm

piston deck height: -0.29 (below deck)



Low compression combinations for use with turbochargers



Turbo 2.2L


7.87:1 Compression ratio with 45.2cc open chambered head.

Parts: Z22 crank, 2.2E pistons, Z22S/L20B rods in Z22block or Z20/L20B block bored +2mm,

s/2+r+p: 224.4

piston deck height: -3.45 (below block)



Medium-Long Rod Turbo 2.05L


Use 32.1mm piston, 149.5mm rod from late Z22E. These rods are not as sturdy as onther L series rods.

Parts: L20B crank, Z2.2e pistons, Z22e rods, Z22 bock or Z20/L20B block bored +2mm over

s/2+r+p: 224.1

piston deck height: -2.85 (below block)



Short Rod L16


7.8:1 CR using 37cc cylinder head. Lowering compression of a L16 would be easier by just installing a open chambered L20B head and using stock bottom end.

parts: L16 crank, L18 rods, L24 (flattop) pistons, L16 block.

s/2+r+p: 205.2mm

piston deck height: -2.70mm (below deck)



Turbo L18


Use deep dished L20B pistons in a otherwize stock L18 for 7.63:1 compression ratio (using open chambered head) or bore +1mm and use dished 280Z pistons for 7.85:1 compression ratio.


Information Source: www.nissantech.com

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Ha ha I saw that. Didn't want to spoil the moment.


Only thing I disagree with is the combustion chamber size for the NAPS Z engine. Jason Gray quotes 45cc which I'm sure is correct but is likely from the '84-'86 720 'Mileage Option' Z20S (possibly the Z20S in the A10, haven't measured one of those) I have measured 2, Z20E (200sx) 2, Z22S (720) and several Z24s and all were 57cc.

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dam z, nice job one typein all that up, thats alot of cool info to know. thanks for taking the time



Damn! Mike beat me to it.I'm a lazy bastard.It was just click & paste.HOWEVER,i did tear up the 620 resource site for the motor info and could NOT find it.I know it WAS there.Anmyone know what happened to it?

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how much $$ you got?



i talked to guy this weekend that 'fit' a Z24 crank into an L18.

wasnt cheap, even for a race motor :o

said it was ~2100cc


get it on the road first!


i don't believe that one you cant safely do it. a friend of mine talked to a machinist about putting a l20 crank in an l16 and he wouldn't do it. The machinist said there would not be enough materiel left after milling and boring the mains and craank to fit

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Z24 crank and L18 block and L piston I get a rod/stroke ratio of 1.26!!!! 1.5 to 1.8 is fine and high revving bike motors go to 2.


With a 1.26 ratio, the piston is going to be low in the cylinder when the rod and crank throw form a 90 degree elbow. This means the piston is almost being pulled sideways against the cylinder wall! Probably do-able but this will accelerate cylinder wear and piston scuffing.

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Using only what you have ??????


If the L20B block WAS a good running motor, put the L18 head on it. You now have an L20B but only with an L18 head. Better would be an L20B head like a U67. But this will work.


I would say that if your L18 is a good runner why mess with an L20B. If you are absolutely sure the L20B block was a good running motor with good rings and bearings OR you plan to rebuild it, then go ahead but not really worth the bother unless the L18 is in poor shape.

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What is the cheapest way to make a frankenstein engine?

putting L motor parts together is not really changing anything.


"frankensteining" (<-- new word! :huh: ) involves 2 or more different motors parts...


cheap? :lol: find someone who wants to give it to you, otherwise drop it from your vocabulary.

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  • 9 years later...

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