1985 720 engine swap

[Crytek89]

Any thoughts on adjustable motor mounts to save time on fabbing them up?

 

Looking at these - link

 

@Shaker - what're your plans for engine mounts on your SR build?

[Shaker]

I used the ISR ones your looking at

[Datsun boi 720]

I just joined this forum today and i just started a 720 ka swap this week I don't know how to add pictures of it, so if someone could help me out with that. I got a lot of info out of reading the thread thank you so much and please keep us posted.

[datzenmike]

Hi Datsun boi and welcome to Ratsun. If you want to show your truck perhaps start a new topic in 720 or Project Datto so that any questions and answers are all your own.

 

 

Pictures...

http://community.ratsun.net/topic/54932-photobucket-ratsun/

[Datsun boi 720]

What did the transmission you are going to use come out of?

[datzenmike]

The KA will bolt right up to the 720 transmission.

[Crytek89]

Confirmed - Tranny will remain the same and probably for the best. Having to deal with an engine swap AND tranny mounts/gearshift relocate and driveshaft adjustment would be too much effort for myself personally unless I had a lot more free time.

The swap itself is fairly straight forward, some things will be changed of course for my own build and I chose to rebuild my KA.

 

But definitely start your own thread so we can follow the progress and offer advise should you require it :) 

[Crytek89]

Hey guys,

 

got the oil pan and rear sump off the D21, also picked up some new NRG spark plug wires.

I need some help picking out a frame mounted fuel pump though, I'm really in the dark as to what I should be looking for in terms of lph/psi - would just any universal one do?

 

Other than that and a few other parts (vacuum lines etc.) I think I'm probably going to look at trying to organize a swap for Easter long weekend..

[datzenmike]

3-3.5 PSI will work.

[Crytek89]

3-3.5 PSI will work.

For the Z24 yeah, for the KA I thought it was around 40psi?

 

I'm just wondering if this is something I have to look for when buying or are they adjustable either manually or through ECU?

[Lockleaf]

It is something to look at. Find out the KAs required pressure or ago guys with running KA swaps what pump they used. Doesnt matter what the ka is in.

[Crytek89]

yeah found out through a friend it's 43.5psi with vac line off.
Now just need to find a pump that I can adjust to that..

[Rjawm]

This is the external version of the pump, a Walbro 255, most 240sx owners upgrade to when their factory pump dies, they turbo their KA, or swap to a SR.  I see no reason it wouldn't work, and it's what I have on hand to use on my pending swap. 

 

 

http://www.highflowfuel.com/i-10383995-walbro-gsl392-255lph-inline-external-high-pressure-fuel-pump-w-400-939-install-kit.html?gclid=CP3VxKeb3tICFRBEfgodwJcCSA

 

 

 

 

BTW, on the oil pan, trucks DE's use a single cam block so that's why they still require so much modification to "fit" a 240sx DE block, which uses a totally specific block, and never had a rear sump option from the factory.  Also, be very careful in your front sump to rear sump modifications, I have yet to see a follow up post from anyone that has tried it that doesn't have some sort of starvation issue.  My personal choice has been leaning toward a custom dry sump setup when I get to that point, otherwise I'll take on the headache of making the front sump work.  Just haven't made that decision yet with 3 other projects in front of that one lol.

[bottomwatcher]

I just finished a ka swap using the walboro pump. I left the orinal pump to feed the walboro and it works fine. But I think the best solution is to find a gas tank with punmp and swap it in. The walboro is loud! The ka has a fuel pressure regulater in line so that is not an issue. B w

[datzenmike]

The regulator 'regulates' it to mid 30s so no need to be too specific on the pump pressure.

[Crytek89]

Update time!

-Motor mounts purchased from ]2eDeYe and should arrive soon.
-Oil pan is welded and good to go
-ACT clutch arrived
-Wiring box from Icehouse arrived
-Walbro fuel pump arrived
-New NRG spark plug wires arrived
-Flowmaster Cat arrived

Exhaust system is set to be installed this weekend with the Borla and new Cat

Only thing I need left is new vacuum lines and I'll pick those up this weekend.

 

Gonna finally swap the engine next weekend (May-long in BC)!!

Really excited, it's been a long time coming and I'm not gonna put it off any longer at this point - also because my Z24 is leaking oil and my strata hates me for it :P

[bottomwatcher]

There will be some tweaking with the exhuast. The ka manifold goes straight into your framerail. Some pie cuts and beating with hammer, weld and repeat until you get clearance. I had purchased a 720 exhaust although they look the same in pics the ka uses donut gaskets and the flange is a different size so you will need the downstream flange from the ka manifold. I also needed a 45 angle to connect that to the rest of the stock exhaust. Another simple issue that lasted 6 hours. Your going to need a little fortitude here and there. Keep posting progress.

[Blas671]

this is a really nice truck! i have same year sat for 23 years in old mans garage ..... runs like a champ ... swapped stock carb and deleted emissions

[Crytek89]

ARP hardware all installed - main/head studs.
Everything is all torqued down and timing is set.

Just have to throw the intake manifold back on and install the injectors and alternator.

Might take a half day on Friday and head back up to get an early start on it for Saturday/Sunday swap.

[Crytek89]

Well, spent all day in the shop today - engine is out. New engine going in tomorrow morning and hopefully have it running by end of day tomorrow. I'll have a few photos for ya once she's all done.

[Crytek89]

Well things didn't go exactly as planned.

 

Couldn't really do much without the engine mounts, oil pan I had a friend fabbed up didn't work and spent probably a bit too long on the oil sump relocate.

With that said, the oil pan is fixed and looking good - took the D21 pan and a 240sx pan and mashed 'em together - and for the oil sump relocate we basically had to eyeball it and weld that together and keep it below 2" height to clear the pan itself - not an easy task.

Engine is in however and sitting on some wooden blocks for the time being - going back up next weekend to finish the job - here's a few photos during it all though.

 

[Crytek89]

Evening 'gents.

 

I just got back in town from another weekend of working on the swap and I have a progress report and some feedback thus far.

 

1. If you are ever planning on doing this swap, don't. Go with the single cam KA out of the D21, it'll make you life a heck of a lot easier and a ton less frustrating.

2. You will need to do a full vacuum delete, the KA sits too close to the firewall in the rear to have the vacuum cluster in order to work, not to mention the line running from the exhaust manifold to the intake manifold.

3. The KA brackets that were made up from ]2eDeYe do work, kind of. You will need about 4 large washers under the mounts to have it sitting square and the drivers side mount needs to be heated and bent 1/2 down about 10 degrees to fit properly.

4. The 720 throttle cable does work, as previously mentioned by Bottomwatcher.

 

Other than that.. it's going to be about a month of weekends to get together or a solid week if you have time; however with the engine sitting in the bay, my god does it look good - photos from this weekend below.

[Crytek89]

 

Right side engine mount - again, had to be slightly modified to work.

 

 

 

 

This is how it's currently sitting now.. probably another weekend of work to get it running.

[bottomwatcher]

I bit my tongue when you said you would have running last weekend. This is not quite the drop in and go that others have parrot ed here and I think it probably contributes to some getting in over their head and not finishing the swap.Crytek89 you seem to have a handle on it and will see it through. I feel your pain. Keep at it!

[Crytek89]

I was feeling very optimistic haha

 

But yes, ultimately this swap is going to take a while to complete and not for the faint of heart. I'm just lucky enough to have access to my grandfather's shop with all the right tools at my disposal.