Aircooled to EJ25 Swap

[Somethin2do]

Hi All,

I am attempting an Ej25 swap in my 1980 aircooled Vanagon and am currently in the process of pulling the ej25 / harness.

I found a water cooled bus to source a lot of parts from and am trying to decide between the aircooled transmission or water cooled.

Wanted to get some opinions from people here that have done similar swaps.

1) aircooled transmission on 1980 vanagon or water cooled from 1985?
2) I'll be sourcing the water cooled parts from the bus (fan, shroud, radiator and pipes)
3) anything else I might want from a water cooled bus for this swap?

Thanks!

Jeremy

[Heli-mech]

I am running a 2001 EJ25 in my 1981 air-cooled van. Its been on the road now for 2 years and works great.

I used the air-cooled DK trans which has a 4.57 ring and pinion .... compared to the 4.83 R&P found in the water boxer trans .... I find the DK air-cooled gearing to be pretty decent stock when matted to a EJ25. The van is very quick off the line and I run larger tire to drop my highway cruising RPMS a bit as well.

The downfall of running the air-cooled DK trans is that they are getting very very hard to find. So if you need to replace it down the line it will be difficult to find a overhauled DK trans to buy off the shelf. Also if/when you swap to the newer style waterboxer trans you need to change all the shift linkage as well since they are different.

As far as water cooling system donor parts go. Grab the .....

- radiator and mounting brackets/hardware
- fan
- shroud
- wiring and plugs
- main underbody cooling tubes and hoses to the rad
- Heater core hoses and T-fittings
- Front heater box (heater core & blower motor) control levers, cables and switches
- Rear heater box (Core, blower motor, valve) dash mounted switch and the harness that runs from dash to underseat.

I built my own harness, used a RMW plate, small car mount & small car header and a tom sheils reversed manifold.

I used the Subaru ecu to control the radiator fan, also have a fan bypass switch on the dash as well .... just incase.

I use a scangauge 2 on the dash for my primary gauges with a 20ft LAN cable running back to the ecu to link the two together.

I also run a triple gauge pod mid dash as a back up to the scanguage. Digital volt/oil press and coolant temp.

[markswagen]

I would sell the aircooled trans, and use the late trans, if the van is a keeper, and the linkage is not already worn out, it will.
They are very expensive parts if you can find them, the ball link on the side of the transmission I think is close to $100 or more, you can rebuild almost all the late linkage for that, for that reason alone, I would swap it out.
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markswagen {mobile mechanic} san diego area all early VW's cared for.

619 201 0310

[danfromsyr]

I'm not sure I agree with swapping out the transaxle for the later style.
but I do agree that you have to R&R the shift linkage anyways.
and you can sell which ever extra transaxle you have to fund the R&R of the one you end up keeping. you'll need the entire shifting linkages and shifter from the 85 if you are going to swap. the AC trans has a higher R&P which provides lower RPMs on the highway. but the Subie is fine either way and mpgs are based more upon the vehicle (weight and profile) than the gearing (rpms).

the aircooled transaxle mounts ~2in closer to the firewall, this will cause some space issues for the Subaru throttle body intake boot you'll have to work thru.

if your 85 donor has plastic water pipes you'll need to open up the hose in the aircooled frame outrigger, it's not a big deal, be sure they can't chaff on the sharp edge. rivet the metal internal collars in the pipes and they'll last a long time.
if your 85 has metal lines they'll fit thru the frame, but inspect them VERY thoroughly, as they rust from the inside out.. any blisters need to be scraped and can be potential ruptures.

or buy stainless/aluminum replacements. your call.

you want to keep the fan & shroud, and it's wiring if you can. there are multiple ways to go on that, so it's a personal choice based on skills and parts available.
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[connor_warren59]

I'm starting down this road as well, just FYI KEP has an aircooled specific carrier bar and intake so you don't have to cut any sheet metal during your install to make it fit since the aircooled trans sits forward about an inch and a half.

I'm going to be following this (and the other aircooled to subie) threads very closely. Good luck with your conversion! I'm excited to see others giving some love to the old aircooled Vanagons! ✌️

[Heli-mech]

This link has some great info and pics detailing a Subaru swap into a aircooled vanagon.

http://forum.club8090.co.uk/viewtopic.php?f=12&t=140429

[outside.the.9to5]

I am just almost done converting my 82 aircooled to EJ22.

To answer your questions:

I decided to keep the aircooled transmission for now as mine is in decent shape. The gearing is slightly better for highway RPMS as well.
I am going to modify the front transmission mount to move the transmission back a couple inches (to deal with firewall interference and RMW carrier bar mounting location).
I will probably pickup a watercooled trans. with all the linkages at some point as a backup.

Heli-mech nailed the parts you will need from a watercooled donor. Make sure you get the radiator mount clips that go in the frame. Also it would be wise to grab the water gauge from the dash cluster, especially if it has a tach! Might need the foil as well.

I bought my engine seals one by one which was annoying but I didn't know any better. I would buy the engine reseal kit at once - you should replace them all anyway. Did you compression test the motor? Might be worth doing head gaskets as well.

Timing belt kit I used was Continental kit with waterpump, idlers, seals etc.

Any other questions just let me know

[outside.the.9to5]

Also, just as a side note, I used the RMW complete kit. It has been a joy - it's basically just assembly - the fit and finish is great and the design is very well thought out.

[Heli-mech]

I forgot to to mention I welded a 3/16 plate to the stock mount and extended it aft & lengthened the rear shift linkage as well by the same amount.

I also trimmed up the firewall a bunch to give clearance and allow access to change/mess with the starter from above through the engine bay when required.

[Heli-mech]

I have a complete serviceable waterboxer trans and linkage in stock in the shop for when the DK trans fails. I like the stock 4.57 R&P gearing on the 091 DK trans .... so much so that I may get one for the 094.

[outside.the.9to5]

[Heli-mech]

I extended my trans mount by 1.75" to 2.00" .... I basically moved it aft by one bolt hole pitch.

/

I just mocked the engine/trans up in the engine bay using a engine crane and attached the moustache bar with clamps to the frame rail when I was happy with the clearance I had on the firewall for my OEM Subaru intake tube. It worked out so that I could almost pick up one bolt hole on the oem trans mount .... so cut/grind/drill/flip/drill/weld and it was done.

I then bolted in the trans mount and redrilled new holes in the frame rail for the moustache bar ... only applies to small car mount users ... then reinforced the the frame with a angle iron doubler and bolted it up.

The shift linkage I over sleeved it with a tube and mocked it up in the van ... tack welded it ... checked shift pattern engagement and throw and when happy removed it and fully welded it up.

[Heli-mech]

My setup is a little weird since my van is lowered due to garage door clearance issues. Currently sitting on weitec springs, 16" Merc rims and front delrin coil spring spacers ... so my tire size selection is based around the biggest/tallest rubber I can fit and still get into my garage for storage/van work.


I originally ran a 205/55R16 with the EJ25 & DK trans. These were very close to the stock 185/14R diameter and resulted in ...

100KPH @ 3400rpm
110kph @ 3775rpm
120KPH @ 4075rpm

My new tire setup is 225/60R16 102XL nokian entyes with the EJ25 & DK trans which gives me ...

100kph @ 3125rpm
110kph @ 3400rpm
120kph @ 3775rpm

The new tires did rub a little on the outer fender under bumps and hard lock steering input. This is due to the lowering springs giving the van a lot of "muscle car rake" and was fixed with some gentle mods to the fender lip and a machined delrin front coil spring spacer to level the ride height out.

All that said I am very happy with the EJ25/DK trans combo running the 26.50" tall tire. Its a nice sweet spot in the rpm range and the van pulls hard off the line and through all the gears.

[outside.the.9to5]

[outside.the.9to5]

[Somethin2do]

Thank you all for the suggestions! I ended up buying a 1983.5 vanagon that had cooling for $1000 from a local guy. The body is in excellent shape so will use it to take care of some of my rust problems. It also has the watercooled dash, long coolant pipes and almost everything else. It is missing the radiator and fan so will be buying those somewhere else.

Swapping sliding doors.. I thought this would be an easy task but got stuck fixing the spring and height for a while!

I have a huge dent on the driver door as well so will be swapping both driver and passenger doors.

I ordered all my parts from KEP and will be prepping the van over the next month or two to have it ready to put the ej25 in. Will keep you all updated as I go.

[danfromsyr]

shame to see a rust free 2tone tintop used for parts scavenging.
SHM..

but good on reviving the westy I guess.. go team..
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[mikemtnbike]

dan- you're mixing up your multiple threads- plans are changing for the OP.

https://www.thesamba.com/vw/forum/viewtopic.php?t=697985&highlight=rain+gutters
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1991 Vanagon GL 2.1 AT Westfauxlia. "Frankie" Totaled https://www.thesamba.com/vw/forum/viewtopic.php?t=764510&highlight=carnage
1995 Eurovan Camper "Marzivan"
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