Project CA20DETT

Post by **pnblight** » Mon Nov 27, 2006 9:17 pm

Hi Guys, My goal is simple but road to that goal maybe not so simple. I plan to build a CA20DET(T) in next few months. I had originaly plan to use a CA20s bottom end and modify 4g63 rods and custom forged piston with a ca18 head and main cap girdle(brace) fitted using the ca18 main bolts and drilling and fitting the larger ca18 head studs(bolts). But i think i may have found a better plan to achieve such a goal. As most of you CA lover know Tomei do a 2 litre kit for the Ca18 with 88mm stroke(std83.6mm) and 84mm bore (1950cc) using the orginal rod size. Well the CA20s has the same stroke 88mm so the conrod bigend will swing with the CA18 bottom end and it runs the same main and bigend journal sizes. To test this theory i bought a ca20s bottom end($100AU) removed the crank and drop it in to the ca18 block i had spare in the shed and it fits BUT the block might need a tiny bit of cleaning up around the webs to allow the slightly large counter weight to swing but all the journals and spacing are sweet. What this means is i can run the std stronger CA18 block with std size CA18 rods and head BUT all i need to do is reduce the piston height to allow for the exact stroke length which i could do a number of ways1/buy the Tomei Ca20 pistons(with the rised pin position for the 88mm stroke)there 84mm bore2/get custom pistons made buy CP Pistons or the like (not hard either) and i could get them 84.5mm to give a true 2litre capicaty3/Use a custom head gasket 3.2mm thick (to allow for the extra 2.2mm)4/Combination buy std forged oversized ca18 piston skim 1mm or 1.5mm off the top and use a tomei 2mm head gasket.

there are a few other small items that have come to light1/CA20S crank only runs a 6 bolt configuration on the flywheel instead of 8 as the CA18 runs(i can just run ca20 flywheel which i dont see as being a problem)2/CA20S crank runs a smaller nose on the crank for the oil pump and harmonic balancer(again the CA20s oil pump and balance fit) but the oil pump has me a little concerned as i have no idea on the spec of the two different pump i plan to strip both and compare and to compare oil pressure relief springs which could be swooped if needed. And if i had to could build up the nose of the crank to run the CA18 oil pump.

I know there are few guys on here who have already build different versions of CA20DET and was wondering if there are any major whole in my plan to build a engine in this fashion.

peteps i will try to keep in touch as it all comes together, just got to get in to the new house and hugh shed first

Post by **themadscientist** » Mon Nov 27, 2006 9:33 pm

You could have just asked and somebody would have told you that! Now, with the shorter deck on the original 1.8 liter block you will have to make up the difference with the piston's pin height as you said. This means decreasing the space you have for your ring pack making them more succeptable to ring land failure and possibly inducing more piston rock incraesing your skirt wear.The main reason I would go with the taller deck CA20 block with custom rods is to avoid these problems and get the longer rods.Your way will get you the displacement you desire as well of course.

Post by **pnblight** » Mon Nov 27, 2006 9:58 pm

On inspecting the CA20s block it's not as strong (as well webbed) as the CA18 and if i can keep the conversion to as many std parts(Off the shelf) as possible it make it easier to rebuild and build more.

As you mentioned the pin high issue i dont believe this to be a problem as i have seen to many motor use custom pistons like this for to long the most common i can think of is when guys fit 302 cleverland rods to a 351 and use custom pistons to allow for the extra rod length.These motors run hard and for ages with no real issues, so i cant see 2mm off the top of the piston with no ring position change being a problem.

The Oil pump is the only real issue i think i have yet to fully research. And i think i will trying to get a good flywheel for the stroker as i have seen the after marth of exploding CA18 flywheel at rev limiter, Basically nearly cut the s13 in half (nasty) right off. I dont intend on reving the CA20det(t) to hard as i hope to tune for more torque than anything.pete

Post by **rexhunta** » Mon Nov 27, 2006 11:46 pm

Finally Petes let his idea loose on Nico !

Watch this Fella guys, this is going to be one awesome motor when he's finished..

Pete is the guy whose helped me with most of my CA bolt-ons. Knows his ****, and his GTR backs it up to prove it

Pete

Post by **tyrannix** » Tue Nov 28, 2006 6:37 am

im one of the other ca20 nerds

funny, im also waiting on getting into a new house so projects are mostly on pause

my ca20 bottom end is at the machine shop right now, (getting threads tapped for the head bolts and idler pulley) have you compared the timing belt cog from the 20 and the 18? i didnt count the teeth before i dropped it off there is also the possibility that a ca16de timing cog might work, i would think it would have the thinner nose like the ca20, but the right number of teeth (if the ca20 one doesnt)

and the crank pulley depends on how you set up your alt and stuff. the rear (alt/w pump) pulley *looks* about the same, but i didnt measure it yet

CJ

BTW, any of you know fraz? he dropped off the face of the planet (i think he lives in NZ tho)

Post by **rexhunta** » Tue Nov 28, 2006 12:52 pm

the bottom cog is different.. the teeth were wider.

Nah dunno Fraz sorry, NZ is like a another world away to us, we're on the opposite side of Aus.

Pete

Post by **Bwana** » Tue Nov 28, 2006 1:24 pm

Can't have too many Petes from down under I guess! Welcome!

Post by **pnblight** » Tue Nov 28, 2006 1:34 pm

yeah i'm awhere of the timing belt cog is different(forgot to mention it) type of teeth but same diameter which if i get the CA18 cog sleeved or custom made, it will fit with in the CA20 oil pump. The pulleys seem the same.pete

Post by **float_6969** » Tue Nov 28, 2006 2:50 pm

I would think sleeving the CA20 crank would be the eaisest/safest thing to do. As long as it's an interference fit, you should be fine.

Post by **pnblight** » Wed Nov 29, 2006 2:52 pm

I will have to have a look into the Ca16de timing belt cog as it been a dual over head cam it will hopefully be the same belt type as the ca18 and one can only hope it has the small hosed crank. If you find out Tyrannix first please let me know cheers CA20DETT bring on the torque hehe

Post by **float_6969** » Wed Nov 29, 2006 6:35 pm

Can I ask what your logic is behind a twin turbo setup on a 2L 4 cyl? I'm not saying it can't be done, but I just wonder what is to be gained from it?

Post by **themadscientist** » Wed Nov 29, 2006 7:26 pm

If he tries to use a logical argument I will laugh. If he says "cause it's f-in cool"! I will support him.

Post by **float_6969** » Thu Nov 30, 2006 3:55 am

LOL, my sentiments exactly!

Post by **tyrannix** » Thu Nov 30, 2006 6:35 am

ive been planning to use a single t3 flanged tubrbo\ (after dynoing with an sr t25 ) on the ca20

but the only/best single way i can see a TT setup working on a small engine like this is 2 different sized turbos.

a big one right on the manifold like normal, screamer pipe or not. then the larger exhaust flow pipe going back to a rear mounted small turbo(even the stock CA t25)

that way the big turbo will be the pirimary concern, and all its exhaust wil travel together, and the wastegated exhaust wont matter, it will be plenty to drive the smaller turbo

the trick would be to have the chargepipe from the rear turbo join right after the intercooler from the big turbo (the long distance under the car acts like an intercooler...thats the theory for rear ounted turbos anyway)

you could run both turbos well inside their efficiency range

and the small turbo will start producing boost at what? 2500? then that will only help spool the bigger turbo faster.... you could even go with a turbo thats not efficient for a 2 liter... as the small turbo running ~10 PSI will bump it up to a little over 3 liters

unless you want to try and do twin uber-small turbos, each running off 2 cylinders ?

but yeah, its just f'in cool

Post by **Kouks** » Thu Nov 30, 2006 9:32 am

Rexhunta, i have an off topic question for you...is your name R-Ex-hunta as in rx7, crx, or wrx.....

Twin turbo is f'n cool....back to regular scheduled entertainment.....

Post by **pnblight** » Sun Dec 03, 2006 6:37 pm

Ok well there is a number of reasons why i want a twin turbo CA20

Impulse clariaty (of the exhaust signal) for optimin spool efficienceBASICALLY the clearer the pulse signal (less cylinder per turbo) the better the turbo will spool. This is not my option but published fact. For example the same turbo fitted to a SR20 (4cyclinder 2 litre) will spool better than if fitted to a RB20 (6cylinder 2 litre). Most tuner will tell you this is true form real life testing.

But also let me ask why do you think a 4cylinder 2000cc is to small for twin turbo when a 6 cylinder 2568cc(RB26dett) is fine (toyota did a twin 2litre 6 cylinder also which would be worse).When you take into account that 2cylinders will be more efficience to spool then 3 cylinder how much better i cant tell you. So there are real reasons behind my choose.

The other reason that lead me down this path was my success building a kick *** R33 GTR Rb26dett using the garret GT2860R 707160-5 turbo rated at 320hp a piece so a 640hp to 2568cc (1:40125)ratio and when i had the std GTR turbos left over i check the ratio for them on the Ca20 std gtr turbo ~240hp each so 480hp to 2000cc (1:4.166)ratio. So using the rb26 as a template these turbos should be better the my current responce i'm getting from the after market turbo on the GTR, IF i use same cams and cam timming and have similar port design etc etc. And the GTR has no lag to speak of and makes 530rwhp@20psi on pump fuel.

So the plan was to retirer alot of my old GTR gear on to the S13 silvia CA20DETT and i have already installed the R33 intercooler and built a custom rb26 style plenum and done exstensive manifold and porting work to the head ready for the 260deg tomei cams. Also got R34 GTR fuel pump and injectors installed with a Apexi PFC running the show. Also got custom intake piping and turbo back 3" exhaust to let the baby breath well.

PLUS AS THE MAN SAID I THINK THE IDEA OF A CA20DETT WILL BE F__KING COOL HEHEHEHE .

I hope the long stroke of 88m will give good torque, the twin turbos good responce for the power level and the over all package will be light and powerfull and keep the s13 well balanced weight wise as the Ca is the lightest of the motors for the S13.

Pete

Post by **float_6969** » Sun Dec 03, 2006 7:17 pm

Christmas smiley's rule...

Post by **rexhunta** » Mon Dec 04, 2006 2:31 am

Kouks wrote:Rexhunta, i have an off topic question for you...is your name R-Ex-hunta as in rx7, crx, or wrx.....

Twin turbo is f'n cool....back to regular scheduled entertainment.....

wrx hunter

Pete, with the manifold design, going by memory, you'll run each turbo on 1-3 and 2-4 ?

Would you consider going something liek a sr turbo, but steel wheeled ? I think they looks slightly bigger then rorys 400r gtr turbos.

Pete

Post by **pnblight** » Mon Dec 04, 2006 12:23 pm

rexhunta wrote:
wrx hunter

Pete, with the manifold design, going by memory, you'll run each turbo on 1-3 and 2-4 ?

Would you consider going something liek a sr turbo, but steel wheeled ? I think they looks slightly bigger then rorys 400r gtr turbos.

Pete

The manifolds will be 1 & 4, 2 & 3 to keep an even pulse signal to each turbo.(an even 360deg rotation between pulses in each manifold)No you don’t want to run a turbo designed for a 2 litre on a 1 litre capacity as it is design very differently even if the hp rating aren’t that different the (exhaust housing) The GTR turbos are designed to spool off 1284cc capacity and to drop to 1000cc is nothing especially when you are going to 2 cylinder impulse signal.

To explain why, if you had two turbos rated at the same hp.One designed for a 2 litre motor and the other for a 3 litre motor, even tho the hp rating are the same they will be different turbos. Why to get good response on the small engine they run traditionally a small exhaust housing and wheel to use the limited gas flow that is there to gas the turbo turning quicker where on the bigger motor where gas flow isn't an item and the turbo's spools well they will tend to have a freer flowing exhaust housing and wheel, so not to as restrict the motor performance to much in the high rpm range. (I hope that makes sense very hard to explain)

Post by **rexhunta** » Tue Dec 05, 2006 1:36 am

hot about the little c12s from a 1jay ?

i mean they're around 1.25l per turbo, Patto uses them on his Ducati Motorbikes cause they spool extremly fast on a 1100cc bike ?

Pete

Post by **Kouks** » Tue Dec 05, 2006 7:37 am

1jay as in........1jzgte--supra TT Mk3?

NVm of course, 1.25X2=2.5. c12's is what they use huh.......

Post by **rexhunta** » Tue Dec 05, 2006 11:54 am

Kouks wrote:1jay as in........1jzgte--supra TT Mk3?

NVm of course, 1.25X2=2.5. c12's is what they use huh.......

Yeah, 1 JZ no **** ( oops, i think he says 2jz )

Yeah they run the smaller CT12as from memory, we've dropped a few off a mates JZX90 to go a big single. Think he actually may have them still laying around.

thier pretty much the same size as like a t12 turbo, one of them absolutely tiny t turbos..

Also, most came out with steel wheels. the 2jz used the CT12b, which are heaps larger, but being the effecincy of a 1.5x2 that'd suck.

Pete

Post by **pnblight** » Sat Dec 16, 2006 1:13 pm

I have my plan of action for the turbos sorted i will be trying to get the two r34gtr turbos reshafted with steel wheels (hopefully Turbo tec will be able to help) thay are the right size and suited to small displacement motors and are capiable of ~400rwhp on a rb26 which is good size for my goal of mid 300rwhp on the CA20 and the turbos are the bootle neck for the rb26 at the point.

Peteps hope to know if the rebuild of the turbos is possible early in the new year.

Post by **pnblight** » Sat Dec 16, 2006 1:16 pm

does anyone have or know much about the ca16de as i want to find out if it runs the same timing belt as the ca18det but if it has the small nose on the crank like the CA20s because the timing gear pulley and belt on the ca20 is different to the CA18det

Post by **pnblight** » Wed Jan 03, 2007 1:15 pm

Not sure if anyone interested but I have now sourced off the shelf

Forged Pauter Rods from the US

and i have been talking to CP Pistons about a custom CA18/20 pistonsend result 84.5mm piston with revised pin height and 5cc dished crown to reduce compression back to 8.5:1 or very close to.

look at ACL Race bearing Ceramic head gasket 1.2mmand new Nissan water pumpoil pumpgasket set

Cams i am still alittle undecided weather to go solid lifter and a 10.25mm 260deg set of tomei or stay hydraulic 8.8mm lash 260deg tomei.

Pete

Post by **float_6969** » Wed Jan 03, 2007 2:13 pm

LIFT FTW! But now you've got to figure in the price of not only the cams, but the lifters and springs as well.

Post by **sideways danny** » Wed Jan 03, 2007 4:41 pm

pnblight wrote:does anyone have or know much about the ca16de as i want to find out if it runs the same timing belt as the ca18det but if it has the small nose on the crank like the CA20s because the timing gear pulley and belt on the ca20 is different to the CA18det

the CA16DE uses the same crank as the 18DET. all 8v CA's use the small nose crank, all 16v CAs use the large nose crank

the way round the crank sprocket issue will be to have a piece of solid bar welded into the hole of the DET sprocket then have a new hole and keyway cut. it's that or have one made from scratch

Post by **pnblight** » Wed Jan 03, 2007 6:16 pm

yeah thats the problem waying the cost against posible performance gains between the two options. It basically boils down to a $950-1000AUD for the 10.25mm solid lift cams over the 8.8mm lash cams. But if the cams become the bottle neck in the system at the 8.8mm lift, the larger cams could unlock alot of performance. Will just have to see how the budget goes.

pete

Post by **pnblight** » Wed Jan 03, 2007 6:22 pm

thanks for that

i'm not sure if i like the sleeving idea as the key ways will be in line and would must likely have to be one big key. I guess i could weld it up and start again (would have to be carefull not to soften the cog tho).

I think my perferred option will be to see if i can buy a blank pulley/cog etc and get the hole and shaft cut into it.

pete

Post by **float_6969** » Wed Jan 03, 2007 7:17 pm

How hard would it be to just use the two pullies to make one? Ex; The ID of the CA20 pulley is correct, but lacks the correct diameter/number of teeth, whereas the CA18 pulley has the right number of teeth, but it's ID is too big, right? A little time on a lathe would easily solve this problem. Lathe down the outside of the CA20 pulley so that it's just a smooth circle on the outside, then bore out the CA18 pulley so that the ID just barely smaller that the OD of the lathed CA20 pulley. Make marks on both of them so that your timing teeth line up correctly. Then put the modified CA20 pulley in the freezer and heat up the modified CA18 pulley. Drop the chilled CA20 pulley into the heated CA18 pulley, line up the marks, and then let the assembly's temperature settle out. Since it was an interference fit, when they come down to the same temp as each other, they will be pressed together so tight that the chances of it slipping are slim-to-none.

If that doesn't make sense, lemme know and I'll try and draw a diagram.

Project CA20DETT

Project CA20DETT

Re: Project CA20DETT (pnblight)

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