Nerd’s Eye View: Lancia Delta HF Integrale

by Khiem Dinh

Khiem Dinh is an engineer for Honeywell Turbo Technologies at the time of this writing.  All statements and opinions expressed by Khiem Dinh are solely those of Khiem Dinh and not reflective of Honeywell Turbo Technologies.

The Lancia Delta HF Integrale dominated Group A rally racing after the unlimited insaneness of the Group B rally cars was abolished. While the Group A cars had only a fraction of the horsepower of the former top-level Group B cars in an attempt to make the cars safer, they were still by no means slow.


The largest engine to be offered in the Delta was a 2.0L turbocharged gasoline engine. The engine is placed quite far forward in the engine bay which I am guessing is to make space for the 4WD system. The basic layout of the engine with the exhaust manifold at the front and the intake manifold at the rear was the common layout up until the turn of the century where now many cars have the intake manifold up front and the exhaust manifold against the rear firewall. This particular inline-4 does appear to be tilted forward a bit which is not common. I am pretty sure the fan you see in the duct at the back of the engine bay is just to pump air into the cabin.
The intake manifold reminds me of the one on my good ole SR20. No coil-on-plug coil packs back in the day when this engine was made, just good ole spark plug wires.
Magneti Marelli electronics are used to control the engine. This appears to be a fancy for the era distributor for the ignition system. Perhaps it was required for an anti-lag system. It’s certainly not the simple cap and rotor typically seen on more pedestrian cars. Below and to the right of the distributor is a big copper grounding strap. Connecting the engine to the chassis is the rod on the right used to limit engine movement. Notice this design uses a bushing to absorb some of the engine vibrations. The big black cylinder is some type of pressure accumulator for which I do not know the purpose. Anyone have some insight?
The cap on the coolant reservoir is safety wired. Because racecar! The strut tower appears to have some additional bracing from the rod welded into it in the lower left.
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Monday, July 28, 2014 12:35 AM
The big black cylinder in the engine bay looks a lot like an Accusump
Dan DeRosia
Dan DeRosialink
Monday, July 28, 2014 4:14 AM
Agreed. Regarding the box on the end of the cylinder head, I bet it's a cam angle sensor; I'd wager the box the spark plugs go into is some form of coil per plug setup and the engine originally had a distributor cap where that box on the driver side of the cylinder head is.

Cool stuff! And the engine being tilted forwards is weird, but hey, packaging and production car constraints probably drove that. I think Group A at that point really was fairly close to what it was intended to be, a bunch of mostly production cars with a few added bits running around.
Monday, July 28, 2014 7:13 AM
I was debating on if that was an accusump or not. The pressure gauge is reading something while the car is off. I wouldn't think an oil accusump system would maintain pressure.

Good call on that being a cam angle sensor which should connected to that ignition distributor box thingy.
Dan DeRosia
Dan DeRosialink
Monday, July 28, 2014 8:05 AM
Usually you pressurize the backside of the accusump a bit; adjustable air spring in addition to the main spring so you can control when oil is flowing in or out of the accusump.
Monday, July 28, 2014 9:54 AM
Underneath the lock nuts for the struts are some fancy looking washers. They look like they might be of the serrated belleville variety, or nord-lock but I don't think those were invented yet.

Interesting roll cage. No diagonal in the main hoop. Also, what's going on with the rear bars that make a light bend.
Monday, July 28, 2014 10:55 AM
If the cylinder under the hood is an accusump, it's possible that it has an electrical solenoid which allows the cylinder to maintain pressure with the engine off to aid in cold start lubrication.

this is a really well preserved example of a Group A car! most of these cars that i've seen are still covered in mud from the last event they ran over a decade ago (the way rally cars should be kept!)
Der Bruce
Der Brucelink
Tuesday, July 29, 2014 9:04 AM
Hahaha! I love these 80s Rally cars! Too bad wheels like that are harder to come by. Good stuff Khiem!!
Thursday, July 31, 2014 9:11 PM
That's definitely an Accusump, right down to the 4 screws in the end cap and the Schrader valve in front of the pressure gauge. That's the precharge valve, and it will hold pressure while the engine is off, which is what the precharge is for. There's a piston that separates the oil and the air chamber, so the air chamber acts as a lightly preloaded air spring.

That type of CV joint is very common in racing. There is usually a flanged stub axle that goes into the trans, which the CV then bolts to, or the stub axle is not flanged and the CV housing is integral to the stub axle. The bolts you see either through-bolt the CV joint and the boot flange plate to the stub axle flange, or just fasten the boot flange plate to the CV housing if the CV housing is integral. This makes it easy to service/replace the axle or the CV joint without needing to remove and replace the entire axle assembly. Most of the motorsport CV stuff of that type is based on the Porsche-style CV joints. Makes for nice modular axle construction with really strong joints.
Thursday, July 31, 2014 9:16 PM
@Der Bruce:
Compomotive can help you out with your wheel needs, if you're looking for a 16 or 17 inch in that style...
Sunday, August 03, 2014 8:28 PM
Great write up Kheim. Proper group A car, lots of little Ti bits. Audi "invented" antilag during Group B. Once Group A came around in 87 and they had to rely on homologated parts, TTE/Toyota were the first to implement it in 1993. 94 everyone had some version of it. More Group A reviews!!!
Monday, August 04, 2014 8:42 AM
I work for Canton Racing Products. That is 100% an Accusump. They used to be made by a company called Mecca as you can see on the gauge. After mecca decided to hang it up we started producing them ourselves. To clarify about the gauge. The Accusump is set up with a pre-charge of air 7 - 10 psi. When the car is off it will read that amount. @spdracerut
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