Trucky-chan KA-T 620 project

[76Lil Hustler]

well I wouldn't complain with 400whp...one day. I'll be able to do this build eventually. just gotta get welding equipment and practice tig welding now. (thats what welding pipes is right?) but definitely going for a basic KA swap for starters. stage one, update L20B with electric ignition, intercooler and tuning and ride around on that while I gather KA parts. found two engines for 200 bucks I may just start there and give it all new gaskets and valve seals with a decent cleaning. still doesn't even come close to what your doing but this certainly helps to be able to follow this process. I like your placement of your inter cooler just wondering what kinda angle you had to achieve and the size is it? saw some folks putting them in their truck beds and that makes no sense to me unless you have a externally water cooled inter cooler.

[UnderControl]

I like TIG for pipe, but you most certainly can weld up an exhaust with MIG. The first exhaust I made when I did the swap initially was done with MIG.

 

Intercooler on your L20B?

 

$200 for a KA with harness and ECU is an ok price, but I'd be a little leery unless it is known to be a good running engine. I got mine for $100 but was known to have spun a bearing and since I was planning to build it anyway that was fine for me. I'd hate to see you get an engine, slap some new gaskets on and get it in only to find out it had other issues.

 

My IC is 24x8x2.5 and the angle is whatever it took to fit. I almost wish I had gone the route of the Aussie SR 620 on the forum which was narrower and taller. As it sits it is rather difficult to get the coupler on the in side of the IC.

[76Lil Hustler]

Couldn't I hook an inter-cooler up to my automatic transmission? The one I had selected is shorter than yours and should fit angled under the radiator just fine. regardless I was just wondering your dimensions for placement options of my own, be it on this engine or the upgrade.

 

The KA has a stuck valve but there's two included in the sale so I will definitely have one working just fine if I got em.

[UnderControl]

Oh, you're after a fluid/oil cooler, lots of room for those up front. An intercooler is for cooling down air after the turbo heats it up and before forcing it in the engine.

 

If you can budget for a full rebuild on one of those. A stuck valve leads me to suspect something is bent.

 

Figured out my electrical problems. It helps to connect the coil (key power) wire to the CanAm box... As for the gauges only working in the start position it turns out to be a matter of a mismatch between how the datsun switch works and what the new harness assumes it should. Both are 5 pin however the Datto switch seems to be setup with 1 power in, 1 Acc, 1 Run and 2 Start. Where as the new harness expects 1 power in, 1 Acc, 2 Run and 1 start. Basically what that means is that I'll need jump the Run wire on the new harness to either the coil wire or the Acc wire.

 

Pics all fixed now too.

[76Lil Hustler]

yeeeaah that thing. I even had the right type selected just typed inter cooler for some reason. stuck valve doesn't matter much with two engines. I'll just replace the whole top half and new valves out of the secondary engine. i like challenges and rebuilding an engine sure sounds like it will keep me busy for awhile.

 

how does one  "jump" a wire? getting into a lot of electrical myself. and could use a few tricks.

[UnderControl]

In this case "jump" is more of a splice. I'll be cutting off two wires and connecting them into a single wire.

 

Here's a pic I borrowed from the internet.

[76Lil Hustler]

Now that looks very cleanly done but I have been led to understand that overworks the single wire end and makes it hot. anyway to avoid this?

[Lockleaf]

If it does then the OE manufacturers are screwed. They do it all the time. But yes, use heavier gauge wiring than strictly necessary will eliminate that possibility

[76Lil Hustler]

If it does then the OE manufacturers are screwed. They do it all the time. But yes, use heavier gauge wiring than strictly necessary will eliminate that possibility

I had an electrician tell me otherwise buts that's what made sense to me. for instance when pairing 14 gauge you would use 12 as what they tie into granted this is for two into one if more I would say tie into 10 gauge.

[UnderControl]

It's admittedly not the ideal solution, but I don't feel like finding another ignition switch to suit the new harness. For some peace of mind I busted out the multimeter to measure the amp draw. These wires appear to be 12ga which is rated to 20A, but to err on the side of caution we can call them 14ga rated to 15A. Between the two I'm pulling ~4A so all good.  Of course I did notice in testing this that I have a leaky injector oring so the rail will need to come off briefly so I can replace that.

[2wheel-lee]

I had an electrician tell me otherwise buts that's what made sense to me. for instance when pairing 14 gauge you would use 12 as what they tie into granted this is for two into one if more I would say tie into 10 gauge.

 

It entirely depends on the situation. 

[UnderControl]

I didn't take any video so y'all gonna just have to take my word on it for now. She lives again. My biggest question mark for this was if the coils were going to work right off and sure enough they're working like a charm. No fluid leaks other than from the coolant overflow tube because someone forgot to put the bottle back on. I do have massive(ish) air leaks at the base of the injectors so I picked up some new injector seals to see if I can get that sorted. I also noticed that the spring in the bov is way too soft so I'll have to swap that out with one of the other 3 springs that came with it.  Video to come once all that's sorted.

[2wheel-lee]

I once had an engine fire from a leaking fuel injector o-ring (rail to injector). I was very lucky that I had a jet ski in the bed with a fire extinguisher. Put the fire out and towed the truck home. Easy fix, but still sucked. Now I'm paranoid about injector o-rings. Now I consider them a must replace item any time an injector comes out with used o-rings.  

[UnderControl]

I did have one of those leaking as well, but caught that well before I actually started it and had spares laying around. This is sucking air in at the intake. Hopefully these seals I picked up at lunch fit. I want to drive this thing already. 

[UnderControl]

Leaks appear to be fixed and bov is staying closed at idle. Now I can start actually idle tuning. I still have lots of other little things to button up but none of them should prevent me from driving around come early next week.

[UnderControl]

I took a video, and now my video editor is throwing an error on start up so I'll have to find my install disc and do a good old fashioned uninstall/reinstall.

 

In the process of idle tuning this evening I did develop a rather inconvenient coolant leak at the fitting in the intake that feeds the turbo. On the plus side it idles nicely at about 600 rpm and I've gotten some of the surrounding cells pretty well dialed. New goal is to take it for a maiden voyage on Monday.

[76Lil Hustler]

how fast do you think you can get it once its done?

[UnderControl]

Based on gearing it should do somewhere around 150. Having driven this thing on the highway I'll stick with ~80, but I'll get there real quick.

[UnderControl]

 

Edited August 5, 2020 by UnderControl

[76Lil Hustler]

I skimmed through and didn't see so quick question. throttle body injection or port injected on your build? since its so close to done maybe just specs spread and build outline? please?

[UnderControl]

So far as I know all twin cam KAs are multi port, with the exception of the two guys on here that thought it would be a good idea to carb them.

[76Lil Hustler]

So far as I know all twin cam KAs are multi port,

 that's exactly what I need. lots of room for cranking up the HP on a setup like that.

[Charlie69]

In this case "jump" is more of a splice. I'll be cutting off two wires and connecting them into a single wire.

 

Here's a pic I borrowed from the internet.

 

 

Now that looks very cleanly done but I have been led to understand that overworks the single wire end and makes it hot. anyway to avoid this?

 

 

If it does then the OE manufacturers are screwed. They do it all the time. But yes, use heavier gauge wiring than strictly necessary will eliminate that possibility

 This is a lot of the reason IMO that our 30 to 50 year old harnesses have burnt wire/wires in the looms.  These multi wire splices work great when new but after years of corrosion the amperage draw goes up and people keep burning fuses so they either wrap the burnt fuse/fuses in tinfoil or put larger amp fuses in to keep driving the vehicle.  This will eventually lead to melting the insulation off a the wire and cause a direct short.

[76Lil Hustler]

when I have to splice I would update it as often as every 5 yrs maybe sooner depending on readouts every once in awhile. and move two gauges down (ie. tie two 14 gauges into a 10) from what I'm splicing off of so I have ample room for fluctuations/adjustments over time.

[UnderControl]

Redoing wiring every 5 years sounds terrible. Just so you know the KA engine harness has about a million splices from the factory. ~20 yo harness still working just fine.

 

In other news, nothing like going backwards to go forward.

 

 

So, I got my leaking fitting off and ptfe taped the shit out of it, but as I was putting it back in it occurred to me that  it felt awfully stripped out and sure enough it leaked even worse than before. While in the process of removing the fitting again.

 

 

Yeah, not supposed to look like that, but I was going to be re-drilling/tapping it anyway so not a big deal. I am glad that AN threads are standard SAE so at least I don't have to buy another tap and I happen to have a -6 to -6 fitting laying around.