Ambitious project - CA20S to CA20DET conversation

[Spawn_CA18]

hello there my friends ,

I have a all-engine fully build ca18det on my S13 now , car is in mint condition so i just can't remove my door cards or rear seat etc. and i'm using it on drift days & small competitions.

now ,

I'm planing to build another car for drift usage. sure it's going to be a Nissan . My project car is going to be a 1992 nissan laurel altima (aka cefiro) with badass! carburated CA20s 105hp. Car is not bought yet , but i think i will buy it next month.

My plan is open-up the engine and rebuild it with CA18DET 4 port head .

So,

i made a lot of research on forums , and i found some finished projects about it , but there is no solid guide to how prepare this conversion.

Basicly my notes are ,

- Full CA18Det 44F1R head with plenum , exhaust manifold, injectors and sensors etc.
- Oil jets( squirters ) from ca18det
- Crank girdle from ca18det
- piston rods from 1.gen 4G63 and machine it to CA20 dimensions.
- custom piston wirsts (can found with search from other Japanese engines)
-fully programmable ECU and CA18det harness.


after all of this , i need all of your advices . other details on this head swap .

-which head gasket to use
-what type of rods and pistons to use.


my goal is 250-280whp or so . not more.

let's do this thread like Encyclopedia about this conversation...

i will share all photos on here when i start my project.

[biosehnsucht]

The CA20 block probably lacks the fittings for oil squirters, even if you drill in the same place to tap them there's no guarantee there's an oil galley there. Will be interesting to find out though! I believe the CA18DE block lacked them ... just the DET blocks had them.

IIRC stock CA piston is 83mm, what size CA20 ? the 4G63?

[Spawn_CA18]

i can get a X-Ray photo of block to find where is oil lines on block . it can be helpfull.

CA20S is 84.5 x 88

we order 84.5 CA18det piston from wiseco with extra 50USD for my friends CA18det. after open up block measurements will set part setup i think .

by the way , i can't find any service manual for CA20S

[TheMAN]

the CA20 was found in the S12 Silvia/200SX and various other cars... if you look for a S12 manual, you'll find what you need

[themadscientist]

The oil gallery is ion the same place. That's the main gallery that feeds the mains so it's there. You would have to drill into it and machine the block around the hole flat so the squirter bodies could seal and tap the holes for the banjo bolts.

You would need to locate the right spot on the block to mount the idler pulley for the DE head. It is there, there is enough meat in the block and it can be done. I have done it.

You will need to drill and retap the head bolt holes in the block. The CA20 uses an M10, the CA18DET an M11. BE AWARE! The holes are not as deep on the 20 block and you will need to cut down the 18 head bolts because they will bottom before they seal the head. I also know this from experience. I drilled, tapped, and bolted a DE head on and torqued to spec only to be able to wiggle the head around. Learn from my mistake.

The drive eccentric on the crank is different as is the cog for the belt. The tooth profile on the E belt its very blocky where the DE belt has a trapezoidal one. A cog the fits the smaller diameter crank snout on the 20 can be made. You will see what must be done when you hold the two in your hand. The belt will be some strange length and you will need to figure out the tooth count and special order it.

These are some of the hurdles before you.

[TheMAN]

wouldn't it be a better idea to use aftermarket head studs instead of cutting the factory head bolts (and possibly compromising their strength)?
what about drilling the holes deeper in the CA20 block and installing M11 timeserts so that CA18DE(T) head bolts/studs can be used?

[themadscientist]

Either would be worth looking into. I am not sure if the block has meat under the bolt holes to accept a deeper hole. It wouldn't take much to get the clearance. Additionally, the DE block holes are drilled oversize near the top and the threads don't start until a little ways down the hole. The E block is threaded up to the deck.

[Spawn_CA18]

Finally i get the engine . Still didn't take the photo

I get my DET head and oil jets also . This week i will tear apart the engine and start to do the measurements.

About bolts; It's better to shorten the head bolt than drilling the block . I will expand the threads to M11 on block and use shortened DET ARP studs on it .


When i take photos , i will post them here .

By the way , i'm planning to go 86x88mm to get a little more displacement. First i try to finish it with NA without turbo with 9.0-9.5CR pistons . After al done i will switch it to turbo .


Next weekend i will put the photos.

BTW engine came from a A31 Cefiro (Laurel Altima) with 470.000km on odo

[float_6969]

Whoa, 2 year project back from the dead. The only way this will truly survive is with some pics!

[Spawn_CA18]

[float_6969]

Looking... cobweby, LOL! Needs moar DOHC!

[Spawn_CA18]

i'm sorry to say that , but project is delayed to a future date again F*ck economic crisis . i sold the engine...

[float_6969]

That sucks