TheSamba.com :: View topic - T4 into a T3

Mon Mar 02, 2020 10:34 am

So I'm working on my conversion from T1 style motor over to T4 power and I'm trying to document it for others, as well as refresh some of the old information that was out there but now has dead links and missing photos. I currently have quite a few tabs open on my computer trying to keep track of all the different threads I've been pulling info from so hopefully this will help to consolidate it with more links in one place.

My thread over on STF
https://shoptalkforums.com/viewtopic.php?f=1&t=151375&p=1277690#p1277690

I figured that since we get a bit more traffic over here on the Samba it may be helpful for people looking if I had a link to it here. Hopefully that's okay with everyone.

I am at the time of this post in the cleanup and asses phase. Going to take the heads up to a shop in Chico soon that has a lot of VW and T4 experience. And I'm collecting the last of parts I'll be needing (flywheel and gaskets etc etc) shooting to be running in time for the invasion this year.

--Reference List--
(Ongoing, please PM or post on the thread if you have some useful tips or photos that should be shared here.)

https://shoptalkforums.com/viewtopic.php?f=1&t=116220&hilit=conversion (Old conversion thread missing some photos)

https://www.thesamba.com/vw/forum/viewtopic.php?t=581759 (Black Fastback thread from Clatter)

http://pws.cablespeed.com/~danielzink/notchback.htm (Daniel's Notch photos)

https://www.thesamba.com/vw/forum/viewtopic.php?p=7106953&highlight=stf#7106953 (Specific T3 Boot photos from Clatter)

https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0 (Thread with some good photos in it)

https://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight= (More helpful photos)

https://www.thesamba.com/vw/forum/viewtopic.php?p=9353440#9353440 (Carb Manifold Mod)

https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0 (Another reference thread)

https://shoptalkforums.com/viewtopic.php?f=1&t=145853 (Cheap Junk Rebuild Thread)

https://shoptalkforums.com/viewtopic.php?f=34&t=151136 (1.7 Rebuild Thread)

https://www.thesamba.com/vw/forum/viewtopic.php?t=596485 (Notch with IRS conversion and T4 swap.)

-Individual Photos-

https://www.thesamba.com/vw/gallery/pix/1648951.jpg (Bobnotch photos)
https://www.thesamba.com/vw/gallery/pix/1489634.jpg
https://www.thesamba.com/vw/gallery/pix/1489631.jpg
https://www.thesamba.com/vw/gallery/pix/1489632.jpg

Mon Mar 02, 2020 11:35 am

I think I've got some pics of a t-4 into a t-3 in my gallery. There might be some pics of a conversion in my son's thread too. I know he took a bunch of pics, although most of them went on his Facebook page. I know there are others on here who have done the conversion as well. Maybe they'll share. :wink:

Mon Mar 02, 2020 11:49 am

Bobnotch wrote: I think I've got some pics of a t-4 into a t-3 in my gallery. There might be some pics of a conversion in my son's thread too. I know he took a bunch of pics, although most of them went on his Facebook page. I know there are others on here who have done the conversion as well. Maybe they'll share. :wink:

Thanks Bob! I added a reference list to the first post in these two threads (STF and Samba) including the threads I've been using and some photos from your gallery. Do you have some links to the rest on his Facebook that I could link to?

Anyone else with input or something I've missed let me know!

Mon Mar 02, 2020 11:54 am

I would have to tow my square & Type 4 engine to the Chico VW Shop if I wanted to drive it to the 2020 Invasion! :lol:

Mon Mar 02, 2020 12:04 pm

nogoodwithusernames wrote: Bobnotch wrote: I think I've got some pics of a t-4 into a t-3 in my gallery. There might be some pics of a conversion in my son's thread too. I know he took a bunch of pics, although most of them went on his Facebook page. I know there are others on here who have done the conversion as well. Maybe they'll share. :wink:

Thanks Bob! I added a reference list to the first post in these two threads (STF and Samba) including the threads I've been using and some photos from your gallery. Do you have some links to the rest on his Facebook that I could link to?

Anyone else with input or something I've missed let me know!

I could check with him later today, and see if he'll let you have some of his pics and a link to his facebook account. I don't know it's particulars, as I'm not on facebook.
Here's a link to a page he started on the Samba. https://www.thesamba.com/vw/forum/viewtopic.php?t=596485
In it, it shows some of the re-work to the body he was doing. Some of it was because he wanted to do an IRS conversion, and partly because while he fabbed up the rear portion, he really wanted a stock rear section in the car. At least there are pics of his t-4 conversion in it. 8) You can add it to your list if you want.

Tue Mar 03, 2020 10:04 am

Thanks Bob, I'll keep adding here and to the list on STF as people send more info.

And a shameless plug please go read through my thread (linked above) and give your input and answer my plethora of dumb questions! :wink:

Thu May 14, 2020 9:17 am

Posting this one here as well since I need extra help when it comes to wiring...

Those with conversions, how have you connected the T4 alternator? (a diagram or sketch would be awesome, I read one description somewhere and was lost almost immediately.)

Here's the T3 alternator kit which has 4 wires going to it so it should be a fairly simple process?

Thu Jun 04, 2020 2:49 pm

thank you nogood for the consolidated list

here is a small contribution

and a link to the pdf nate created lost to the interwebs that I've managed to dig up

Nate M. wrote: Heres a link to a full scale PDF file for an adapter that I made for my type4-type3 conversion. This allows you to use the standard type3 bellows. Simply print it out and cut the metal. Then graft the stock type3 bellows adapter to the new mount plate. Hope this helps. . .

https://drive.google.com/file/d/1GQApIrVWj15075jK_yltYyicoyQBVaA2/view?usp=sharing

and a link with some info and photos of the finished adapater I found helpful
https://www.thesamba.com/vw/forum/viewtopic.php?t=...pics+added

Thu Jun 04, 2020 2:56 pm

br0qn wrote: thank you nogood for the consolidated list

here is a small contribution

and a link to the pdf nate created lost to the interwebs that I've managed to dig up

Quote: Heres a link to a full scale PDF file for an adapter that I made for my type4-type3 conversion. This allows you to use the standard type3 bellows. Simply print it out and cut the metal. Then graft the stock type3 bellows adapter to the new mount plate. Hope this helps. . .

https://drive.google.com/file/d/1GQApIrVWj15075jK_yltYyicoyQBVaA2/viewusp=sharing

That is fantastic thank you! Do you have any photos of joining the adapter to the T3 tin piece?

Thu Jun 04, 2020 3:03 pm

Glad it helps !

Just edited the post to include a link to a thread with some photos that should also help though they are photobucket pics and subject to disappear at any moment.

ps if you get around to having one made and want to make an extra to sell me, you let me know =]

pps I'm in la, where in ca are you ? You're way ahead of me on your project and probably have a clue as to what you're doing...I do not ! Would be cool to see your progress and ask questions some time.

Fri Jun 05, 2020 4:46 am

nogoodwithusernames wrote: Posting this one here as well since I need extra help when it comes to wiring...

Those with conversions, how have you connected the T4 alternator? (a diagram or sketch would be awesome, I read one description somewhere and was lost almost immediately.)

Here's the T3 alternator kit which has 4 wires going to it so it should be a fairly simple process?

Keep in mind that most of the t-4 conversions use the t-4 Bosch alternator, which uses an external voltage regulator (slightly smaller than a pack of cigarettes). I know that's what we used on my son's car at least. We also used the harness for it as well, and only had to add 2 wires (mostly lengthened).
Plus we eliminated the t-3 under rear seat VR.
I don't know how the Denso alt will fit in the T-4 space, as we didn't have one to try while the engine was out. Also keep in mind that the alt shown is internally regulated.

Tue Oct 06, 2020 1:08 pm

Been running with the T4 motor for a bit now and been enjoying driving the car again. Drive it every chance I get around town. However I think the tins/cooling need some help and want to run my diagnosis past everyone.

Recap motor is a 1.7 with 914 tins, domed pistons, C25 cam, MS-EFI controlling spark and fuel through a set of stock FI runners and plenum. Exhaust is basically a set of "j-tubes" going into a modified 2.0l Monza exhaust.

In my opinion the motor is running hot especially on the highway. It'll touch 375 up to almost 400 even on only a 80-90° day. (gauge is temp compensated so should be reasonably accurate) This seems much hotter than most T4 motors in T3s.

All tins are in place *except* bottom tins, which while recommended the 914 bottom tins would be backwards so would not help. Does the lack of sled tins create extra turbulence under the motor and make it harder for hot air to escape? I am considering making some lower tins out of sheet metal but unsure of what the best design would be? Curve down from the bottom of the existing tin and head straight back? Airfoil shape under the pushrod tubes? Slant down on the exit to promote flow?

I also would like to seal the engine compartment so the engine isn't sucking hot air and messing with my AFRs. Should I go over the alternator and fan boot or under it?

Tue Oct 06, 2020 9:39 pm

Your thermostat may not open up without the sleds. I have read that the thermostat sits low enough that passing air can keep it closed.
I cut my own sleds since as you said the 914 sleds would be backwards. I made them very similar to the bus.
Is that temp range head temp?
I originally made tins to seal the motor compartment then took them out because I figured the compartment would just become a hot box. On the bus or 914 outside air is being drawn through the compartment and that would not be the case here.
I took out the rear tins I made and it is more like the T3 was originally.
I assume you have the bellows connected...

Wed Oct 07, 2020 9:00 am

djway3474 wrote: Your thermostat may not open up without the sleds. I have read that the thermostat sits low enough that passing air can keep it closed.
I cut my own sleds since as you said the 914 sleds would be backwards. I made them very similar to the bus.
Is that temp range head temp?
I originally made tins to seal the motor compartment then took them out because I figured the compartment would just become a hot box. On the bus or 914 outside air is being drawn through the compartment and that would not be the case here.
I took out the rear tins I made and it is more like the T3 was originally.
I assume you have the bellows connected...

Hadn't thought of that, the bellows does open at least when sitting still but no way of seeing it while going down the highway.
And yep that's from under the no. 3 spark plug.

Hmmm so you went non sealed compartment, how to you get fresh air to your intake? My air filter sits right above the "heater hole" in the 914 tin and I think it's getting heat from the exhaust instead of fresh cool air. (old cut down filter in the photo, new one came in since then so have proper filtration, but shows the location, you can't quite see it from this angle but the exhaust is just a bit to the left of that big hole in the tin.)

Wed Oct 07, 2020 10:16 am

I pull in fresh air from the same location the car did originally

Wed Oct 07, 2020 10:18 am

djway3474 wrote:
I pull in fresh air from the same location the car did originally

Is that an inline filter? Got a link?
I just have a foam oiled filter there so no cool air for me. Would love to use the port in the body for fresh air.

Wed Oct 07, 2020 10:25 am

Yes on in-line filter.
No link right now.
I came across it when I wa searching for t silicon T I used to attack throttle body to plenum that I could attach case vent to.
I will check later today for a link. Remind me if I don’t post one up.

Wed Oct 07, 2020 8:47 pm

https://www.amazon.com/gp/product/B005N6WXYM/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1

This is the filter I purchased

Thu Oct 08, 2020 8:46 am

Thank you sir! And you have no starvation issues from pulling from the stock port in the body huh? What size motor did you end up with again? (I think I should read through your thread again perhaps)

Thu Oct 08, 2020 12:45 pm

I am still in the build phase so starvation issues are unknown.
That said 5k rpm would be on the high side as a shift point so starvation is not as likely.
I rebuilt the AFM and I had the spring tension to high making the mixture to lean. I loosened the spring to the point the motor started easy and the mixture is around 13.4 at idle.
It has not been timed other than 7.5 btdc static as I am just getting to the point of being able to time.
I am also finalizing what components to use, location etc so I finish one start and check mixture then go to the next.
I think I only have to determine which distributor I will use and add the decel valve.
After that I will be tinkering with the spring, wiper and air bypass. This can’t be done until the car is on the road so I ca watch mixture under various loads. None of this could be accomplished without the Wideband O2 gauge.