CA18ET Performance cross reference

Well, even though my Toad is broken and sleeping, I've been mulling over numbers over and over, trying to figure out a cost effective way of making a strong ca18et.

Custom parts are pretty much out of the question. Sure, you can get rods, pistons etc etc custom made, but if you can afford that, you wouldn't be reading this post.

So armed with some #s I've made some interesting discoveries.

90 - 93 VW 2.0 9A 16v engines use the same bore piston as the ca18et

the rod length is wrong though, 5.669" to the ca18et's 5.234"

BUT

1.8L Mazda engines (think Miata) have the same bore (83mm) different stroke (83.6mm for the CA to 85mm) but the rod length is the same (132.8mm)

So, in theory, we could use good Miata rods with VW or Miata pistons.

Hmm ... I'm interested

There's much more to it than just the bore or the stroke though. Different pistons will have different pin sizes, pin heights, crown shapes, etc. and the rods have to have the same diameter crankshaft journal and a shape to the bottom half that won't interfere with the engine block as it rotates.

But even IF all those were true, ABA block Volkswagens and the Mazda 1.8 aren't incredibly strong engines stock. They both take boost well, but only as much as we are already pushing with our stock CA18ET components. Seems like a lot of work for something that won't improve reliabilty one bit. Unless you mean buying forged internals for those two engines and using them in our engines. But then, why not just have forged internals that are specifically made for our engine and save the grief?

I personally think that our best bet will be stock CA18DE rods with Race Engineering forged CA18DET pistons. So long as the CA18DE rods are identical to the CA18DET rods which I think they are.

because the cost of having one-off parts made is astronomical compared to parts that have already been made.

There is a finite number of engine combinations. I'm well aware of the differences between rods and pistons manufacturer to manufacturer. I have also seen hundreds of Chev motors running mopar cams and con rods, as well as KA24Es running chev con rods.

I was trying to see what would work for us. I didn't say it would, or that I'd found the magical combination. I was hoping someone else could fill in the blanks.

I would also rather avoid the 500-2000% markup typically hung on any "JDM" parts. I can a set of 8 forged I beam rods for about $400 ... pistons for way cheaper - about $60 for the last set of 8

I've been talking to a guy who runs our local Miata club, and campaigns a turbo 1.8 Miata running a T3/04 on factory internals.

Dynoed at 326 crank HP and runs low 12s. Has over 170,000km on that engine.

I'd say that's more than 100hp over our stock limitations.

Hey, I think you're on to something with the Miata rods. Length is the same, AND the crank pin diameter is only off about .001 (no problem there). The small end is .788, but I'm not sure what the CA18's is. Now the big deal is the deck height. The deck height of the CA18 is 8.26, compared to the Miata, which is 8.720. So, even though their the same bore and same rod length, the piston qould stick up almost a half inch out of the block. But, now you know that you need a piston with a compression height of 1.373. Well, actually a little shorter than that, since that would put you at theoretical zero deck. So I'd look for something in the 1.350 range, with a pin diameter of .788 (20 mm). Look through the Wiseco website (or piston manufacturer of choice), and they should give you the compression height and pin diameter information. Also, if you find one with a 21 mm pin, it would work to, you'd just have to enlarge the small end of the rod.

Hope that all made a little bit of sense. Looks like you're on to something! :evillaug:

In case you can't tell already, I love finding stuff for these little cars! To me, this is more fun than building anything else. You have to either make or use your brain to do anything with these motors, kinda makes me feel like I'm back in the old days of hot rodding where they use what they could and MADE it work.

{edit}

Forgot to mention, I don't have any info on rod lengths, so that could be the downfall to this. If the Miata rod is wider, than no problem. The CA18 (as long as it's the same as the CA20) is .968.

Another thing to keep in mind is the Honda B18A (LS non-vtec) rod, which has a length of 5.394, which would make you need a compression height of about 1.190 with a pin diameter of 21mm. And we all know how easy Honda rods are to find...

:honda:

Whooops, scratch that idea, just found out the Hondas are .935 wide, so their too narrow.

But I need to check my calculations again, because the Wiseco book lists the Miata 1.8 as a 5.228" rod length, and a 1.201 compression height, which would put it around a 8.220-8.240 deck height... So something's wrong somewhere...

I personally think that our best bet will be stock CA18DE rods with Race Engineering forged CA18DET pistons. So long as the CA18DE rods are identical to the CA18DET rods which I think they are.I don't think this is going to work if you look at the forged JE pistons that the UK members are running they look a bit different than a forged det piston.
http://home.iprimus.com.au/xris5/parts/top.jpg
DET pistons
http://img.photobucket.com/albums/v210/30psi/PICT0021small.jpg
ET pistons. They do look very close but the valve reliefs look a little different to me. I think the are 7.8 to 1 compression.

Why wouldn't forged DET pistons work? Not quite sure what you mean. I was told that one could even use stock DET pistons? Check out this thread http://www.club-s12.org/board/showthread.php?t=6792&page=1

Why wouldn't forged DET pistons work? Not quite sure what you mean. I was told that one could even use stock DET pistons? Check out this thread http://www.club-s12.org/board/showthread.php?t=6792&page=1there could many reasons why they wouldn't work. The first reason would be the valve reliefs. If they are the same that would require both heads to have the valve that are the same size, same position in the head and the same lift and angle of lift of the valves. If all these aren't the same you may have piston to valve contact, it may also depend on what cam you will be using. Lets say that the valve reliefs are 1mm further to the edge of the piston on the ET over the DET. that alone will create a problem if you assemble your engine without checking this first. this is just something you have to keep in mind. Now I'm not saying the DET piston will not work for sure it's just there is things you need to consider before you lay your money out for a set of pistons that you don't know will work for sure. I also want to just buy some DET pistons and build my engine but I though why would Silvia engineering get custom pistons built by JE if they could have just used DET pistons that are already available.

Ok yeah I see your point. That is why we need some more research in this area. I definetly won't be buying anything until i know for sure so I hope people in the know will be able to tell us more.

Ross racing piston are about $400 to have made. I order a set for my ca18det. They are very good quality. If anybody wants i have a lot of ca18det parts like rod and piston and a ca18de head.

Well Bart just go back to me and here is what he had to say about all this.

Quote:
Originally Posted by ahoffman83
Bart I know you haven't been around the forum in a while but hoping you will be back soon. Do you know if the CA18DET rods will fit in the CA18ET with the stock CA18ET crank? If you can find this out this would be a great help to lots of us here. There is some uncertainty as to whether or not they fit the stock crank due to the width. Get back to me with any info you have. Thanks

Bart "yes they do i test one side by side with a stock et rod/piston and its all perfect fit with the det rod/piston combo"

Also check out my thread I listed above. Bart made some more posts to that one as well.

now is the bottom pic that you listed the forged det pistons or the et pistons cause if those are the et pistons then those are from the ca20e not the ca18et

Ross racing piston are about $400 to have made.

For a custom set?!?!?!

You can't barely get a set of off the shelf wiseco's for under $500!!

Man, if that's the case, screw trying to get a piston to work, get custom ones made! I sure thought they would be more than that though....

now is the bottom pic that you listed the forged det pistons or the et pistons cause if those are the et pistons then those are from the ca20e not the ca18etthe bottom picture is ET pistons from Silvia engineering that are 1mm overbore. Pictures are from 30PSI's engine.

well looks like silvia engineering used the design off the ca20e pistons cause of the dish, maybe to allow alot of boost..... stock et pistons are completly flat at least here in the states anyways

With their low compression, the stock ET's must be waaaay down in the hole if their flat... :dontknow:

Valve reliefs are very routinely cut into pistons. Some piston makers will even sell a blank sort of "universal" piston.

The set in my Charger had to be redone due to the new heads and valvetrain. I think it cost me about $30

that's why you use clay when building an engine ... cheaper than new valves/pistons

Where are you getting your pistons Joel?

Off the shelf Speed Pro forgies and Hypers are way way less.

Hell, there's a complete ca20e HP kit with Ross forgies for under $1000. Even cheaper if you go with the Wisecos, and that includes

Complete Gasket Set
Copper Performance Head Gasket
ROSS Forged Pistons
(84.5, 85, 85.5mm Bore) and
(8.5-1, 9.1, 10-1, 11-1 compression)
Performance Rings
Performance Wrist Pins
TOGA HP Main Bearings
TOGA HP Rod Bearings
Timing Belt

I've been leaning on them to make a ca18et kit for the same.

Hopefully I'm gonna use off the shelf wiseco's for a 4G63 with a stroker crank...

I looked through the Wiseco book, but the bore size of the CA18 isn't too common...

If this buildup of mine works, just get a CA20 block and build it up! :evillaug:

That's wierd that they make a HP kit for the CA20 but not the CA18. Seems like more people would be interested in hopping up the CA18...