Diesel swap (build thread)

[Dirty Duc]

It isn't obvious to me where this kind of thread goes, but I'll start here and someone can yell at me if it belongs somewhere else.

I have a 1984 Porsche 924 that is getting a D24 to race in the 24 Hours of LeMons.

The basics are that the engine will fit in the car with no cutting and will bolt to the bellhousing.

My plan is to find a flywheel from some other VW/Audi engine that will bolt on and accept the Porsche pressure plate...

I have 2 heads, one with turbo and one N/A; 3 injection pumps (one for the turbo, two N/A), an alternator, a starter, and a bunch of other stuff I don't need (like an automatic trans).

I have owned a VW diesel before, but that was last century. I'm sure I'll be asking all kinds of newbie questions...

[anders]

So the d24 bolts to the bellhousing of the 924?

[v8volvo]

Welcome, sounds like a fun project. Looking forward to following the pictures.

I'm moving this into the Garage section in the Showroom area, which is where most folks put their build threads. If you disagree or want it somewhere else, let me know.

Maybe we'll have to find you some D24T.com graphics to put on the car. :cool:

[Dirty Duc]

Thanks for the move and the welcome!

The 924 and 944 used the same transmission bolt pattern as the 5cyl VW/Audi engines... they used a torque tube and put the Audi transaxle at the back of the car.

It's a pretty neat setup.

Porsche laid the motor over further by about 15 degrees. I haven't decided how I am dealing with that yet.

[Dirty Duc]

I've got the engine partially assembled on the engine stand... no belts on yet. Am I understanding correctly that there is no key in either cam sprocket?

I found an "assembly guide" that talked about loosening off both sprockets and setting the cam with a feeler gauge.

[Dirty Duc]

Okay, looks like I have assembly instructions sorted.

It looks like this block has seen a heavy handed wrench... the alternator mount bolt holes on the block are broken, and the rear bolt on the mount is also broken. I'll be making a mount for that on the left side of the engine.

Next question: Can somebody tell me the approximate angle of the lean as installed in a 240 series?

Assuming it is closer to 40 degrees than 25 degrees, anybody want to swap oil pans and pickups?

I'm also looking for the turbo oil filter mount... because racecars have turbos!

[v8volvo]

The holes are broken or stripped? It sounds like the engine you got may have been from a car that was in an accident. The alternator mount also holds the fan bearing and in a front end hit could be in the line of impact. Hard for me to imagine someone breaking the bosses on the block just by working on it if that is the issue.

Regardless you will need to come up with a good repair for this, because the alternator bracket is what the crank counterhold tool rests against for tightening the center bolt on the crankshaft. Otherwise you'll need to find another way to hold the crank while you tighten the bolt to 350lbs plus. Failure to achieve the full required torque is guaranteed catastrophic destruction of the engine. There are various ways to do it but make sure you get it all the way tight.

I recommend getting a copy of the Volvo green book for the engine if you will be doing work on it. Correct, both cam pulleys have no key, similar to the 4cyl VW diesels and early TDIs. You need a sprocket counterhold tool to make sure the pulleys don't move as you torque them to the required spec. Volvo's 9995199 tool works well and is easy and cheap to find since it's still in common use on their gas engines too. In general you'll find this engine is a piece of cake to work on IF you have the required tools and complete information. Without them, sometimes the results are not good. Greenbooks are available from various sources online and the tools can be borrowed for free.

What pan and pickup do you have now? The 7 series is almost vertical, 2 series might be 20 or 25 degrees but definitely not 40. None of the stock Volvo pans or pickups will do the job without changes if that is what you need.

The installation in a Pinzgauer or Euro LT van is laid over further though. Maybe you'll want to start with a pan and pickup from one of them. Those pans have deep sumps but are steel instead of the aluminum used for the Volvos, so could be easier to modify.

[Dirty Duc]

The bolt holes are broken approximately in half.

I've got a leftover special tool from my rotary days for fixing the flywheel in place that I was planning on using.

I had a catastrophic failure on my long ago diesel Rabbit, but that was a timing belt failure. The camshaft broke into 9 pieces as I shifted on the governor in LA traffic.

I measured this at approximately 25 degrees, so it must be from a 2 series.

Finding the Euro LT oil pan (or one from what sounds like a fantastic truck!) sounds cost prohibitive over just re-clocking the torque tube-bellhousing mount. That's a simple cut and weld on steel.

Not too bad a price on the camshaft tool, but I might just make one for the practice welding/machining.

I downloaded what I think might be called a green book? it was a black and white scan, but it has all the procedures for assembling/timing/etc. that I can think of needing.

[Dirty Duc]

Engine is mounted.

https://photos.app.goo.gl/LVNysbgo3qIvYp423

[Dirty Duc]

It's in the car for real, now I just have to adjust the clutch arm, install the radiator and hoses, wire up the alternator, put oil and water in it, and go racing. Good thing, since the race is less than a week away!

[Dirty Duc]

https://www.facebook.com/24hoursoflemons/videos/10155241079919495/

[Dirty Duc]

Alright.

The engine runs well... better after we remedied the injection pump timing. Part of the problem with that was the need to use a different pump because the first was leaking around the pump head, and the engine was in the car.

It's not what I'd call a fast Porsche, but we only used 30 gallons of fuel the whole weekend. Teams with fast cars use 15 gallons every hour or two.

Now to work on the handling...

Pictures from the organizers:
http://www.murileemartin.com/UG/LBW17/0269-DSC_5094.jpg
http://www.murileemartin.com/UG/LBW17/1136-IMG_6597.jpg
http://www.murileemartin.com/UG/LBW17/1139-IMG_6600.jpg

There's more on the website.

[Dirty Duc]

Quick walkaround video
https://www.youtube.com/watch?v=pnb8vvHlc84&t=3s

[Goteborg Vapenfabrik]

I've been to a Lemons race and a NASCAR race, the Lemons race was far more fun to watch. A Nissan sentra won. The most unforgettable was a pink Saab called " Swede little pigs". You refuel once for the whole weekend with that D24.

[Goteborg Vapenfabrik]

Correction; it was a ChumpCar race. It was in January so the weather was tolerable.

[Dirty Duc]

I've been to a Lemons race and a NASCAR race, the Lemons race was far more fun to watch. A Nissan sentra won. The most unforgettable was a pink Saab called " Swede little pigs". You refuel once for the whole weekend with that D24.
Pretty close.

It's only got an 11 gallon tank (or so) and the fuel cap was leaky so we only put 5 gallons in the first fill. Then it turns out there is some damn overfill protector hose that dumps fuel right back on the ground if you don't have an automatic shut-off like on a pump.:o

[Dirty Duc]

https://www.youtube.com/watch?v=yqyN8wqkvvM

[Dirty Duc]

Time to rebuild injection pumps. One N/A pump leaked between the bodies on initial install, the second one leaks now from the top cover.

Is there a good source for turbo pistons/rods? I'm thinking compound turbos for shock value... probably regulated to 16-20 psi.

[Dirty Duc]

https://youtu.be/JcstvYfhibc

I think it's pretty good, they estimated hp vs some kind of formula I wasn't privy to. The numbers are all rwhp.

[Dirty Duc]

An update for the interested...

Significant blowby calls for a set of rings, we'll add rod and main bearings for good measure.

It turns out it's got a 19 or so gallon tank, and can basically run on track all day without needing fueling.

I should probably fix it so my drivers don't turn it so tight though. I'm thinking 4500 rpm for best longevity without any pump mods.

[v8volvo]

Nice. You definitely have the only one of these. Cool that it worked out and actually made it through some events.

You will probably find the mains and rods are in good condition to reuse and can save some money there. They virtually never wear at all unless the engine gets run out of oil. But you might discover a rebore and a set of pistons will be required to bring the blowby under control. These engines are almost completely immune to bore wear when synthetic oil is used but many of them had poor quality conventional oils used in the early parts of their lives and Volvo specified long oil change intervals to make matters worse. Deposits behind the rings led to rapid ring and bore wear under those conditions. If blowby is an issue you may find a pretty big ridge and some taper and then fresh rings won't be much use to you. But you can rest assured that if you keep good oil in it in the future it won't happen again.

If you're digging into the bottom end and thinking of adding a turbo someday you may just want to start fresh with a turbo block and rotating assembly. The turbo bottom end provides piston cooling jets and a bigger oil pump and other upgrades that will help it survive at the boost levels you mentioned. Not much point in spending money going through the NA engine if you plan to add a turbo. To make use of the turbo boost you will also need a turbo injection pump or to do a lot of work to your NA pump to retrofit the turbo aneroid device.

As for the fuel leaks you mentioned, the top cover seal can be replaced without rebuilding the pump, though you need to know what you are doing and work carefully to avoid damage or contamination and get it dialed back in after the work is done.

Someone did compound turbos and it worked out well, but be cautious with your injection timing settings and consider head studs if you want to run significant boost and keep it reliable for an enduro. Wouldn't be much fun to pop a head gasket halfway through. 20 psi should be perfectly fine for reliability if the engine is built well and you keep EGT and EOT well within reason and ensure it makes no smoke. Too much fuel will cause more damage than too much air.

[Dirty Duc]

I already went to studs...

An excellent time to mention the top end of the pump... I took both NA pumps apart without referencing/marking the throttle arm.

Now I know.

Long wearing rods and mains sounds good. I heard no unfortunate noises, so maybe they'll be fine. It's been turned pretty tight though... I'd guess 5500 or so.

[Dirty Duc]

Also, it might have been a little low on oil as evidenced at the end of this video...
https://youtu.be/CqKBcnySHcI