Have to Rebuild L20b, Want to make Big Bore 2.3

[510SSS]

Hey everyone I couldn't get my l20b working correctly, some lame mechanic built my lower end in his garage and it is making all kinds of noise and putting too much pressure on my valves. I think he screwed up the crosshatch on the cylinders causing them to glaze and therefore cause smoking and carbon buildup on the cylinder walls.

 

What I want to do now is I have torn down the motor and have taken the head off, a u67 ported and polished with oversized intake and exhaust valves. What I want to do is see if I can get a Z22e block from the junkyard and just use it to rebuild with the u67 head?

 

My local JY has a 1983 200sx, I have read that his block has longer rods. Would i be able to use these rods with KA24e pistons bored out to 89mm (which brand/part number should i get)? from a 240sx not a D21 truck right? (Can Z crank work with fully floating wrist pins? of the ka24e?)

 

Also I would have to get a modified headgasket would I not? What do you guys use? Nismo gasket is kinda pricey, can you just modify a Z Hg? I have read you have to drill 8 new holes in it.

 

Thanks for all your help guys, I hope I can finally get this engine built before I totally run out of money, I have gone too far to stop now.

[Tristin]

http://community.ratsun.net/topic/25497-sealiks-shit/

http://community.ratsun.net/topic/31213-waynos-lz22/

http://community.ratsun.net/topic/996-jason-grey-info/

[68Datsun510]

Hey everyone I couldn't get my l20b working correctly, some lame mechanic built my lower end in his garage and it is making all kinds of noise and putting too much pressure on my valves. I think he screwed up the crosshatch on the cylinders causing them to glaze and therefore cause smoking and carbon buildup on the cylinder walls.

 

 

 

 

wtf am i reading???

[Stoffregen Motorsports]

There's already a couple threads going about this.

 

I will say again that I am not a big fan of using the L20 block for a big bore motor. Use a Z20 block instead. You can use a L20 block if it's thick enough, but they generally are not, and you can use a Z22 block but you can accidentally bore into the steam ports between the 1-2 and 3-4 cylinders.

 

I know guys here will say you can bore all three blocks to 89mm, but I prefer the Z20 block.

[laotsu]

the 200sx in your local JY no longer has the motor in it.

I have a Z20 for sale...

[datzenmike]

Hey everyone I couldn't get my l20b working correctly, some lame mechanic built my lower end in his garage and it is making all kinds of noise and putting too much pressure on my valves. I think he screwed up the crosshatch on the cylinders causing them to glaze and therefore cause smoking and carbon buildup on the cylinder walls.

What you have said make little to no sense whatever. If you had built this motor yourself you would know. If your mechanic told you this stay away from him.

 

What I want to do is see if I can get a Z22e block from the junkyard and just use it to rebuild with the u67 head?

.

Yes you can rebuild it with stock Z22 block and internals and put a U67 head on it. You will need an L20B timing cover, oil pan, engine brackets and an L distributor. The compression will be about 9.84 to one.

.

My local JY has a 1983 200sx, I have read that his block has longer rods. Would i be able to use these rods with KA24e pistons bored out to 89mm (which brand/part number should i get)? from a 240sx not a D21 truck right? (Can Z crank work with fully floating wrist pins? of the ka24e?)

.

The rods have to be 145.9mm long (the same as all L20B rods) to work with KA24E pistons. Some Z22s have this length others do not so measure them or get L20B rods.

 

KA-E pistons and rods from the S13 are fully floating. The KA rods have a pressed in bushing to make them float while the Z22 or L20B rods do not. You can use the E pistons with normal rods and press in pins or have the L20B rods sent out to have them bushed and an oil hole drilled in them... but added expense, and this isn't a race motor. D-21 pistons will also work and are used with rods that have pressed in pins.

 

The floating or pressed in pins are at the other end of the rod from the crank. The crank doesn't know or care which kind you use so you decide.

.

Also I would have to get a modified headgasket would I not? What do you guys use? Nismo gasket is kinda pricey, can you just modify a Z Hg? I have read you have to drill 8 new holes in it.

.

Use a new Z22 gasket and trim the front part around the timing chain off. Graft an old L series h/g front onto it. Around the timing chain only has to seal oil and fumes in so it's not that critical. Look up Sealik's posts on the proper drilling of holes for an L head on a Z gasket.

[510SSS]

Idk how that dosent make sense I did rebuild the motor myself after this guy screwed it up I know what is wrong because I have troubleshooted the entire engine myself. I am just asking specific questions about a rebuild I dont need my explanation critiqued. Anyways thanks to mike for info I was really needing.

[Ratwagon1600]

 I dont need my explanation critiqued.

 

Im going to critique it.

 

Work on your grammer and sentence structure if you are genuine about wanting help. 

 

Mikes right, your first paragraph made no sense at all.

 

Whatever happens, good luck with getting it working properly.

[510SSS]

Guess you dont know much about engines if you think that improper crosshatching does not in some cases cause oil burning problems. I suggest u re-read and use your brain. If you can't understand it you need to up your IQ read some books aussie.

[Z-train]

"I think he screwed up the crosshatch on the cylinders causing them to glaze and therefore cause smoking and carbon buildup on the cylinder walls. "

 

screwing up the cross hatch is kinda damn near impossible to do.Glazed surfaces are smooth.Carbon doesn't stick to a smooth surface,which is why you polish EXHAUST ports and not INTAKE ports.

And like Mike said:If your wrench told you this,run away from him and run fast.Screaming is optional.

[Ratwagon1600]

Guess you dont know much about engines if you think that improper crosshatching does not in some cases cause oil burning problems. I suggest u re-read and use your brain. If you can't understand it you need to up your IQ read some books aussie.

Three people with more experience than you'll ever have with these cars posted a comment that they couldnt understand your question.

 

Go away, youve just consigned yourself to the "dont bother answering this person list".

[510SSS]

rude boy

[Ranman72]

I am not sure how your pistons can cause to much pressure on your valves

It is a COMBUSTION CHAMBER where gas compresses and explode into power

I am confused

[laotsu]

Popcorn time!

[wayno]

[uberkevin]

[Stoffregen Motorsports]

I'm not one to rubberneck, but ratwagon is right this time.

[510SSS]

cool does being right help your ego? I'm just here to try to get help to get my datsun running, not to divide ourselves over petty internet semantics.

[datzenmike]

[Stoffregen Motorsports]

I think if you poke around here in the engine section, just over the past couple weeks, you will find all the info you need. And that whole nitpick about your first paragraph, well it did not make a whole lot of sense. Maybe if you spoke to the mechanic who looked at it and got a clarification as to what he actually meant, in more specific terms, we might actually get to the root of your query.

 

Hang in there, it's all fun and games until someone loses an eye.

[Ratwagon1600]

I'm not one to rubberneck, but ratwagon is right this time.

Dammit dude, only this time :rofl:

[Stoffregen Motorsports]

Don't get used to it.

 

Cheers!!!