ET to DET head??

Hi all,

I was wondering what is needed to change the ET head to a DET head, or would it be cheaper and easier to do a complete motor change

cheaper and easier to get the motor swap.

To integrate the DE/DET cylinder head onto the ET block you'll need

full head (duh!)
DE or DET ECU (DET ECU would work better)
the cam angle sensor on the head
DE or DET engine harness
wiring diagram
DE intake maifold for N/A or DET intake manifold for turbo. THERE IS A DIFFERENCE!!! the DET one (except the one from the 88-89 S12) will not have NICS while the US market (and surely others) DE will have it.
DET exhaust manifold (if you're going turbo) or DE exhaust manifold for N/A
DET injectors for turbo DE ones for non turbo.
DE or DET coil packs
DE or DET power transistor (you better find one in the junkyard or bend over to get it from NISSAN this is a VERY expensive part)
DE or DET fuel rail
DE or DET......... so on so on and so forth

Mind you it is much more complicated than what anyone could possibly lead you to believe. By the time you total up the work you need to do you might as well just swap motors cuz I think the only step you wouldn't need to do is take the engine out and swap the blocks and internals).

thanks for that info, I might as well get the motor swap then too save in hassels

It would be better, easier, and cheaper to do the opposite................DET bottom, with ET head. I've heard they bolt right up.
You get the strength of the DET bottom end, and no wiring issues with the ET head.

what about those cam and crankshaft sprockets.....forgot about how they DONT MATCH !

You will need the head. You can find these on eBay all the time. The 1.8L DOHC Pulsar head is the same as what you would find off an S13, and would probably be a little cheaper. The 1.6L head works as well I believe.

You will need to machine a cam gear to accept your distributor (once this is done you can just use the stock computer and ignition system).

You will need an exhaust manifold, these are on eBay all the time. If you are going turbo then you will want one with a t3 flange, anything less is a waste of money.

You will need an intake manifold. There are 8 port versions and 4 port versions. I think the 4 port versions were only in the UK and they are not very common. With the 8 port version I imagine the computer tries to shut down the secondary set of runners at lower RPMs for better torque and fuel mileage. You could just wire these open or if you want to use the feature, build an RPM activated switch for about $5. If you can't do that, you could probably buy a VTEC controller for $200 that will do the same thing.

If your manifold comes with a fuel rail, use you S12 injectors (as long as you don't make too much power). If you want to make power, buy a fuel controller and use whatever injectors you need to handle your power output.

If your manifold doesn't come with a fuel rail, build your own. It's not expensive and not hard. You get parts from Summit Racing.

You will need the timing gears from a DOHC car. You can find these in a junkyard or from someone parting out a car. Most people parting a car have these since they don't really break and most people just buy the whole engine outright. If you don't trust used equipment, you can probably get them from your Nissan dealer at a reasonable price.

If you want to rev the engine to it's 7500 RPM redline, I would suggest different rods. The SOHC rods are only designed to handle 6k rpms. I don't have faith that they could repeatedly take 7500 rpms. You can use rods out of the DOHC or you can get some forged rods and not have to worry about breaking them ever (as long as your aren't retarded when setting up fuel curves).

You could just purchase the whole CA18DET engine off of eBay for $1800 and have an engine that is capable of 250HP or so.

Or you can buy (prices I've paid so far or estimated from ebay and forums):
a head, $150
an S-AFC: $275
Forged rods and pistons ($1100, I haven't bought this, but it's about what it will cost)
Exhaust manifold, $300 or less depending on how pretty you want it
Turbo, $75-300. (my t3 cost me $300, my buddies t04 cost $75).
Intake manifold $75 or so
Timing equipment and covers for cams, $50
Gaskets and other stuff, $100-$200
Fuel injectors, $50 (mine were for free, but you find big ones on eBay for about $50)
and for $1875-$2200 you will have an engine that is more than capable of 300+HP.

Head flow will be your only limit at this point and the DOHC head flows really really well. Don't sell youself short by buying a little turbo. Anything smaller than a .63 A/R t3 will hurt you on top end pretty bad. Little Honda 1.6L b16s spool up t3/t4 hybrinds by 4k rpms. With good valve springs the DOHC CA will do 8500rpm without much trouble, so if you put on a smaller t04 you could flow air to provide 400HP and have an awesome top end. If you want a good bottom end for more streetable performance then a t3 will be good, just don't get a really small one. If you want your turbo to be completely spooled by 2k rpm like Nissan likes to do, then you would be better off with a small block v8. You would make more power for less money than any Nissan engine would do for you. I'm awaiting a few more misc bits and rods and pistons before I put the DOHC head on my car. Another guy tried putting the DOHC on the 2.0 block and had some trouble, but the 2.0L block is slightly taller too. He did get it on however. It would not be a project for someone that wasn't comforatable with machining parts and really if you have to ask how hard is the swap, then that would probably include you. If I ever get the money for those rods and pistons (hopefully by Spring), then I'll make a nice little write up on it.

Ive got no problem with working on or altering:twisted: engines, Im just sick of the engine thats in the car at the mo (getting sick of getting pisssed on by toymotas etc).

Ive got a CA18ET just sitting in the shed and was thinking of rebuilding it and was wanting some better proformance from it, so I started thinking about replacing the head for a DET, and was wondering if there was any pitfalls in doing the change.

I was wanting some nice power from it but good fuel econ seeing that it will be used everyday (at the mo im only getting 5km\L :x )

I was hoping to get around 250-300hp

I can pick up a complete eng, ecu and loom for around $1200

Ok, the intake manifold 8 runner thing ... it's just a butterfly inside the manifold. It can be removed easily, you just have to fill a couple holes. Makes a difference in high boosted engines only, as you have to give up some bottom end.

Now, the one problem I have with this equation ... compression ratio.

I was told (and told it had been confirmed) that the compression difference between DE and DET is entirely in the head.

Now, we really need to know. If bolting up a Pulsar head will send your compression up to 10.5:1 ... bolting a turbo manifold onto it will be a bad thing.

I was also told the Pulsar head will have everything facing the wrong way.

I want the opposite ... forget the DOHC.

So you seem to have done your homework, what's the difference between the ca18et and the DE/DET pistons.

I know the DE and DET have floating wrist pins, but for $10 I can have my ca18et's set up on DE rods.

I'm going to grab an entire Pulsar engine when I have somewhere to put it. Now, the ca16de has the same rods and crank girdle as the ca18det. And they're everywhere. The only reason I'd want the ca18de is if the pistons can be used too.

Any ideas?

I'll get back to you on that...8)

I was thinking the same thing Matt about using the pulsar parts. First one who finds out more about this will be a great help to the club.

The compression ratio difference between the DE and DET is entirely in the pistons, just like the CA20E and CA18ET. Many of the CA18DET guys use the DE pistons to raise their compression ratio. http://www.nissaninfiniticlub.com/forums/showthread.php?threadid=5733&highlight=compression

The pulsar head will have everything facing the wrong way? I don't even have the slightest idea what could be backwards. If you are refering to the fact that the engine sits wrong ways in the FWD model, you do realize that if you rotate the head 90 degrees clockwise (or counter clockwise, depending on how it sits in the FWD car) it will suddenly face the right direction. A quick look on ebay gives us two auctions to compare heads.

FWD CA16DE out of a Pulsar: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7911026553&category=33615&sspagename=WDVW

RWD CA18DET: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7910702766&category=33615

Comparing the two, you will notice that the only difference is the red valve cover plates don't have identical vents. I don't know if that is a FWD difference or a 1.6L difference. Either way, it wouldn't be a big deal to do some hose routing to take care of that. The intake and exhaust ports are on the same side of each engine, the cam gears are at the front on both engines, I have no idea what would be backwards.

You could have your pistons machined to fit, but if your investing in forged rods, no point in being cheap and not having awesome pistons too. If you had both you would pretty much have a bullet proof engine (of course assuming proper fuel tuning). The difference I know of is the floating wrist pin vs the pressed style. I haven't looked into it much because I don't care to use them.

Only the CA18DET have the girdle I believe the DOHC engines may have a different crank as well. The reason I think this is because where our flywheel bolts to the crank, our SOHC engines have 6 bolts while the DOHC have 8. It could just be that Nissan decided to start putting two more bolt holes in the cranks, but I would doubt it. I don't know what the differences are between the SOHC and DOHC crank, if there are any differences other than that.

If you wanted to cut down on the build up price you could take rods from the CA18DE from a Pulsar, get pistons from someone parting a CA18DET and have an engine good for a pretty good amount of power for a lot cheaper. I believe the stock DE and DET rods are good to about 300HP (I would assume that's about 250 lb/ft).

On a side note, the CA16 valves might be a bit smaller than the CA18 valves. This could limit your power output if you are going for max power.

I think most of us interested in the pulsar engine parts are interested primarily in the the rods. Being that they are the same as the ones in the CA18DET. And yeah i was thinking about finding some DET pistons to match the pulsar rods but that gets pretty expensive again. We should have that importpeformanceparts.net make forged pistons for the CA18DET in different compression ratios. I can't seem to find any forged pistons for the CA18DET that aren't around 1000 us dollars from japan. That's just crazy. I'm thinkin the L16 and L24 parts are looking pretty promising so far.

And yeah i was thinking about finding some DET pistons to match the pulsar rods but that gets pretty expensive again. We should have that importpeformanceparts.net make forged pistons for the CA18DET in different compression ratios. I can't seem to find any forged pistons for the CA18DET that aren't around 1000 us dollars from japan. That's just crazy. I'm thinkin the L16 and L24 parts are looking pretty promising so far.http://www.nissaninfiniticlub.com/forums/showthread.php?threadid=49078

CP Pistons makes them.

I found two articles on converting the sohc RB engines to dohc. Since the CA is essentually a 4 cylinder version of the RB, this should apply almost exactly to the CA18.

http://r31skylineclub.com/content/techinfo/twincam_conversion.pdf

http://users.esc.net.au/~cobra30/twincam.htm

Mmm ... guess I was typing faster than I was thinking.

The head won't be backwards, but everything that bolts to it will. The intake manifold and exhaust manifold specifically. Sure, people are selling them, but it's still more change. I've also heard the water necks are in different places, again this is only what I've been told.

See, this is the problem, is I've gotten my information from what should be reliable sources.

"Ask Sarah" from Nissan Performance Mag

The big difference between the DE and DET is compression ratio, 9.5:1 on the DE (10.0:1 on pre 1989 models) and a more turbo friendly 8.5:1 on the DET. Ignition timing is at 15 degrees for the DE and 10 degrees for the DET. The DE has 260cc injectors, 370ccc on the DET. There are some differences from year to year in the intake manifold and ports, cams, front wheel drive versus rear wheel drive but otherwise, the DE and DET have the same block the connecting rods are the same 133mm, same connecting rod bearings and main bearings, identical 83mm x 83.6mm bore and stroke, 1809cc displacement, cast iron with main bearing girdle, forged four counterweighted crank, 204.8 mm deck height, and 1.59:1 rod/stroke ratio.

Now, we knew about the crank differences, but that shouldn't be a problem. If nothing else, it would allow us to use a lightened ca18det flywheel.

Anyone will make us forged pistons. Although I think we'd all be more than happy with hypereutectic. I prefer tolerances to slop.

If people are serious about getting custom pistons made for the ET, I'll start sourcing it out.

I'm pretty sure I'll be happy with the stockers though.

Forged crank, happy bearings, good rods, total seals, ... good enough for me. Unless I need to bore it out *lol*

Gotta find me a Pulsar short block :twisted:

Hmm ... I wonder how much a ca16/18de rotating assembly or short block weighs ...

Free part day coming up, you only gotta be able to carry it 3 feet.

Matt will the stock CA18ET pistons fit the CA18DE rods? Or will the pistons have to be modified due to differences in the wrist pins? Also if you look at Barts comparison picture of the different CA rods and pistons you can see that the CA18DET has a shorter piston skirt than the CA18ET does. I'm wondering if they did that because the rods are a little wider. Would the stock CA18ET piston skirts hit these wider rods? If that is so we would surely need CA18DET pistons. Any ideas on this?

Free part day coming up, you only gotta be able to carry it 3 feet.
Really...when...I am so there. The bottom end of a pulsar can't weigh moch more than a complete triple snowmobile engine, and I can carry one of those...

There is no reason why you cant use CP Pistons forged pistons in the ET engine. The DET uses flattop pistons with 4 valve reliefs, just like the ET uses.

And a little piston slap never hurt anyone.;)

That's a good question. If Bart ever does resurface, since he has pistons and rods from every CA engine, he can check for us. I didn't really think of the width issue, but I'm still pretty confident.

Getting pistons fitted for full floating pins (I don't even know if the ca18et already uses them) costs $10 a piston at a machine shop.

I'm going to lean on my favorite parts guy and see what he can dig up for DET pistons. You never know what they can find. I'm sure OEM would do. I can get custom slugs made pretty easily, I'd just rather not have to.

Alex, I think it's august 8-9 at Standard.

$45 all you can carry. Bring some kind of blunt object to get people away from the car you're dissecting. Last time I went I had to chase a guy off the only S12 there. And you only have to carry it from one side of a white line to the other. I know I can bench press a 383 cylinder block once. I didn't move for a couple days after, but I can do it.

Hell, if it'll save me money, I can perform pretty amazing feats of strength.

Just have no idea how to get the bottom end out of a Pulsar motor in a wreckyard.

I'm still thinking about the DE pistons. Tha link was nice and all, but considering they still haven't figured out compression ratios and how they affect performance, I'm, not going to treat that as gospel. Since the DE head is a completely different design (small chamber?), I wonder what the combustion chamber volume is of the ca18et vs the de.

I put a set of small chamber heads on my Charger, and it sent the CR through the roof.

So if the head voilumes are indeed smaller we might end up with something like an 8.5:1 motor, which would be supreme.

And Nissan has the same pt # for the 87-88 ca18de pistons in the Pulsar, even though the C/R is different by almost a full point.

Time for more searching

A jack, and axle stands, then either disconnect or cut everything you don't want off, then get a few people to lift out of the engine bay...4 cylinders are not as heavy as you'd think...8)

I will have to leave my calendar open for that weekend...8)