CJ3A Volkswagon TDI

Geez I wish I had your ability to wrench, very impressive.

 

mTDI?

And thanks for the tip, I will have to look into some of those. I am not familiar with SBF.

So you are saying just change the bellhousing on the T90 to a later 76-79 model and then maybe there is a ALH to AMC plate? Hmmm... Worth investigating, thanks!

 

Looks like there are a couple SBC adapters too so that route will also work. T90 to SBC, SBC bell, SBC to TDI

mTDI it a setup where a mechanical pump is installed on a TDI. This removes the need for any computer in the setup.

 

Please post links because I’m not aware of an adapter for a tdi to amc. There are adapter for ax-15 which went behind a 4.0 so there may be some crossover there but I haven’t seen anyone putting tdi’s in amc Jeeps without a lot of custom work. Mtdi simply means they converted a tdi engine to a mechanic injection pump.

 

All that being said. I may be making a few t90-tdi adapters in the near future.

 

AMC adapter:

Jeep

I knew there was another out there as well from a high end import shop, but more fancy.

 

If you do, please add me to an "interested in buying" list!

 

How about a t18 to tdi adaptor?

(I say that as I'm almost $2500 into my dauntless rebuild, so wouldn't happen any time soon lol)

 

Do you think the granny low trans (sm420 and the like) is still worth it/needed? Been thinking a cj5 ALH m-tdi sm420 and od. Best of both worlds. Seeing as the cash oulay would mean it will need to pay for its self as a means of transportation.

 

Depends on goals. I think the Roxor’s 1st is “narrow ratio” ish - in the 4.X. In low, 1st feels pretty comically low. That is with 3.73 axles.

Depending on tire size and axle ratio, you might be more worried about top speed efficiency than low end.

 

Kinda my point. Thinking keep the 373 and use either a truck trans or terra low to keep off road still fun. On 33s 373 maybe a lil high though.

 

I wanna set of skinny 32s for the Roxor, so I can give proper feedback. With heavy 30s (BFG KO2) and 3.73, it does not struggle at all, so I don't imagine that'd be an issue. The diesel does cover up plenty of low end gearing.

I wanna toss that Kubota in a CJ5 (not sure which one yet), and I don't plan on using a different transmission initially.

 

Also keep in mind, wide ratio transmissions might have a RPM drop between gears that is not ideal to drive with a diesel.

 

Yes this is a problem with my mercedes and the t-18..... With the TDi, its a non issue. That has a t-18 as well but the tiny variable geometry turbo has almost no lag so it handles the rpm drop really well.... Whereas the old school wastegate turbo on the benz takes a long time to spool up. I can hit 10psi of boost at 1500 rpm with the tdi and it reaches 20psi aroun 1800 and then pull strong up until around 3800 then the little snail starts running out of air. I do most of my cruising in the 1800-2500 range so its perfect.

 

I have been thinking real hard about an m-tdi.
Since mech pumping a roxor has proven harder to research and fond info on.
Do you like the t90 with tdi? I know my sm420 would be easier to adapt(theres a tdi to gm kit)

 

Yes, the t90 works great with the tdi, the only reason I switched was because I wanted the lower first gear... I also like the 4 speed because it doesn’t have the second gear issues of the t90. Any of the truck 4speeds are great! Sm420/465 np435, t18/19/98 they’re all great options! A lot of people like mechanical pumps.....but The tuning/performance and reliability of the tdi pump is really great!

 

thanks for the info. Whats so unreliable about the mechanical pump system ive read it works very reliably for alot of people. Guess im just simple lol i think the tdi may just be the ticket. If you fit it in a flattie should be a nice fit in a 5

 

I’m of the opinion that mechanical pumped diesels will be much more reliable and cheaper to own over time by removing a significant number of points of failure.

In doing so you give up the fine tunability offered by the EFI system. The same EFI system can change from providing max MPG to max power with flickering a switch at the cost of complexity (aka cost to own and more points of failure).

 

Mechanical pump systems are very reliable. What I’m saying is so are the electronic systems. You will be very happy with either my issue with mechanical pumps is that when you convert a tdi to an mtdi you have to know what you’re doing or pay someone who does to tune the pump properly. But when done right they are great! Another thing to consider is how many people switch from carbs to Efi and no one says boo....food for thought. Many tdi engines share the same pump they just have electrical controls. I’m the end it comes down to personal preference. Both are great!

 

Something else to consider when deciding is that a mechanical pump is not automatically cheaper than an electronic pump. If you can find a mechanical Vw engine then yes.... it’s simple cheap and reliable. But most people want to convert tdi engines to mechanical because they can make a lot more power. Then it’s not cheap. The turbos on those engines are vgt or vnt so you will need a new turbo and manifold. And there is no bolt on pump replacement. You have to use a Land Rover, 4bt or a 1.6 Vw hybrid pump that has been converted for the newer engine. And then if you have a problem you have to buy/build/tune another one. If my tdi pump goes I can get a junk yard pump for $100 and keep driving. I’m not knocking mechanical I’m just saying it’s not as black and white as most people say. If you like mechanical pumps i would start with a mechanical. I have had many diesels... mechanical and electronic. I love them all and they all have pros and cons. Just my .02