Boosted Ca18 Vs Boosted K Motor

[SLW42]

Hi guys, i know the general answer to this question is it's an engine conversion it's gonna cost money, i'm aware of this but what i'm trying to ask would it be more cost worthwhile to just add boost to a 3/4k or 5k, or drop the ca18det into the car, re wire the harness? Make a gearbox crossmember up, custom tailshaft and make a fuel system up, or just put a 5speed in behind the boosted motor? And spend the money on custom manifold for the turbo and get an exhaust made up?

[B.L.Z.BUB]

+1 I love my 4k and wanna keep it semi stock.

[Dropz]

I'm a real efi guy, unless its an old school v8 of some sort.

 

therefore I'd say the CA18det. also I do love my nissans lol.

 

The ca18det i think would handle the power alot better, and therefore be more reliable, as well as make a good project for the track.

 

but with all that said if its in a daily the 4k would be a better choice as it wont be as much of an issue with the uniforms if you ever get pulled over. unless you do the ca conversion 100% legal of course..

 

EDIT: also the ca conversion will take alot longer to complete and potentially have more issues like missing wires or things not fitting right. to begin with, but that wouldnt be too hard to overcome.

 

really it just depends what your after. cheap fun daily. or something a bit more serious for the track.

Edited June 10, 2010 by Dropz

[SLW42]

Both daily and track hack when i feel the need for it, yeah i'm mid ca conversion in my ke but i was thinking would it be to much for a street car???, i understand the pro's and cons of owning a boosted car they need tuning almost as often as you do a service, if not before, it just depends how much you thrash it. I just like the idea of a 1.3l k motor with boost and an external gate and screamer aswell as dosing people and then have them ask whats under the bonnet i think a boosted k motor would have more people say wow you can do that??, but i think i'll finish the ca conversion then buy another 70 and boost the k motor after i've had enough fun with the ca motor i just would like to know people's opinion on which would be more worth while due to 4k's liking to pop headgaskets quite frequently, and it would have to run next to no boost at all either wouldn't it?? Like 6 pound max?. but yes the ca conversion will be done by the books and hopefully hit the streets once again

[jason12]

If your already halfway through then go the ca. Will make more power more reliably and sound a lot better too :)

[SLW42]

Yeah i'm already half way through it, but this is kinda a future knowledge thing too ask questions now, finish one car start another! isn't that how we corolla drivers do it?? Oh btw TAZ_RX if you read this could you please pm me your cam specs for your old boosted 4k motor pretty please with a cherry ontop

[Karllos]

Really when you look at core motors, theres the K which is simple in design push rod single cam, carby yada yada

 

On the other hand theres the CA, Twincam, EFI, larger capacity =more torque, factory turbo engine (stronger), more refined, more aftermarket support, better choice of turbos, easier custom work.... i could go on but i think you get my point.

 

If you have 2 70's then go one with a boosted K motor and keep that mildly more legal and then use the CA 70 for the track/occasional street.... that way you have a back up car if one fails due to varying circumstances.

 

Karl.

[mungi mods]

rather than building a boosted k motor , just do a 4age/ze conversion

its relatively easy and cheap , easy to legalise and then can be boosted later

it wouldnt be that different in cost plus a stock smallport would probably make the same hp anyway + REVS

[Taz_Rx]

rather than building a boosted k motor , just do a 4age/ze conversion

 

No offence mate, but thats probably half the reason he's considering a boosted K. Every man and his dog has a 4age/ze/te KE these days. I have nothing against 4a's at all, they're a good motor, there's just too many of them about.

 

The cam I was using in the 4k was just a normal camtech 609. Specs can be found on there website. The 5k I'm using currently had a cam in it when I bought it so all I know about it is its a Cosworth cam. I'm going to get another cam ground soon to my desired specs and it'll also be a proper turbo cam with enough valve seperation. If you want a cam for a turbo K i'd reccomend doing the same. Just tell them something like "I want the same specs as a 609 (for example) but with 12-14* seperation for a turbo application". :)

 

To answer the other Q in your PM - There's a bolt in the #1 runner in most stock K inlet manifolds, I removed that and replaced it with a vac fitting. That one did the boost guage, vac advance on the dizzy and BOV. The only other line I needed to run was to the RRFPR which was just easiest to do off the brake boost line. It doesn't really matter what goes where as long as its "post butterfly".

 

As for the discussion in this thread, I probably can't offer too much without being biased. I would see your main savings (both in real money, and time/frustration) in the K being: The actual purchase price of the CA, engine and GB mount work, diff upgrade (get away with stock diff for XktX) ECU (depending if you want a Xkte) and engineering etc for legallities (depending on state Xktc/e may just need a mod plate).

 

 

Oh and your 4k will happily take more than 6psi. I've boosted an internally stock 4k to around 20psi before and didn't break anything. Headgaskets only blow if you don't do something about the timing. For piece of mind I'd reccomend using a genuine toyota HG and some ARP head studs and then you'd be fine with around say 15psi. I currently have my 5k set on 18psi, and thats seen 22psi before. :(

Edited June 11, 2010 by Taz_Rx

[SLW42]

Yeah Nah no efi on the k motor as i have a webber which has been jetted for boost and what not, it should handle it fine due to my mate having a to4 from a vl turbo on a stock 2t and it went like a shower of shit, sweet well it's sorted now i'm gonna finish the ca conversion and then either sell it and buy another ke with a stock k series engine and probably just put a thick headgasket into the motor and head studs as you suggested and one day you shall see a build thread for my boosted k motor :), yeah every one is doing a 4age conversion nowadays and thats another reason why i stopped mine not just that i saw a couple of 70's with bigport and smallport's in them and they drifted pox mind you they were basically stock, but i've seen a 3k with an exhaust and a cam do exactly the same so k motors might be the way of the future :(

[Sloth]

rather than building a boosted k motor , just do a 4age/ze conversion

its relatively easy and cheap , easy to legalise and then can be boosted later

it wouldnt be that different in cost plus a stock smallport would probably make the same hp anyway + REVS

 

As for the boosting later, you will need to do a bit of work to the engine to make sure it can handle the boost (eg if you have a 20v you have to mix black and silvertop bits and change the compression etc), I guess that's true of pretty much every engine though. Just thought I'd say it just so people don't think they can just buy a turbo one arvo and bolt it on :) (without damaging the engine).

[SLW42]

Yeah i was aware you can't just buy a turbo and bolt it onto the car and go for gold there is a process for it, which i'm also aware of, rising rate fuel pressure reg, custom turbo mani, custom exhaust, build carby for boost, and so on and so on

[Taz_Rx]

Don't need a thick headgasket, just a stock toyota one. Playing with the timing will stop you blowing HG's. :P

[SLW42]

Retarded timing or advanced? I'd imagine retarded for the increase in compression inside the cylinder chambers? Am i right? TAZ when i under take this thing man i will have a million questions for you bud, just letting you know in advance too dude, oh another thing too man is there anyway to get a de comp plate or something like that put in between the head and block like they do with the 4age's and fords n/a 4l's from e series to help not break anything as fast?

[Evan G]

4kc auto - 8.5:1

4kc manual 9:1

 

pretty low comp standard