Project: Engine

Orignal engine plans for this dragracer was a turboed Type 4 with 100mm bore and 78mm stroke. The cyliders would have been Nikasil plated from a Porsche 911 with custom made piston.

Current plans for the engine is to use bored out cylinders originally from a 1.7liter type 4. The new bore will be 90.5mm with custom made piston to fit the heads and be able to run a tight deck so innitial combustion is contained as close to the heads as possible.

Heads will have twin plugs. It eases combustion and hs been showed to increase torque at lower revs, higher overall power as well as helping with fuel consumption. All this can be done using less ignition timing than normally. The benefits of twin plugging is most notable with big bore or, as in my case, lots of boost.

Some fittings for the breather has been bought, and some paint have been sprayed on it. The oil return from the turbo is made with a JIC-1.1/16" thread and has atleast 19mm inner diameter, the return pipe will be more than 25mm ID just to make sure I don't run into any trouble aboute evacuating oil from the turbo.

After some planning and waiting there was time to start with something really exciting, the header system. Started to make a collector for the twin scroll HX50, it took awhile but it turned out quite nicely. The Type 4 engine has a ignintion sequnce of 1-4-3-2 so cylinder no. 1 and 3 will be mated and no. 2 and 4 will be the other pair. An easy ground role is that the front cylinder gets mated which each other and the same with the rear cylinders.

After calculations in PipeMax, the primary lenght came to 718 or 1192mm, with the location of the turbo the 1192mm option was the one to aim for. Cylinder 4 was the first to be made, it came out at about 1200mm, havn't measured accuratly but there are some adjustment avaiable. The pipe for no. 3 was a bit trickier but I got it quite good, then I ran out of bends. The pipes may hang a little low, but there will be very little off-roading with this.

I used flexible tube on the primaries so the system hopefully won't break since the turbo is going to be mounted in the chassi, and maybe easier to put on the engine since there are some flexibility. Unfortonatly the 90 degree bends are not mandrel bend so there is a area reduction in the bends, hopefully this won't effect things too much, but if it does I just have to find new ones.

From inside
From more angles
Mounting in the car
Cyl no. 3 & 4 ready
Fourth ready, third begun
dscf0289.jpg dscf0285.jpg
Mockup of first pipe
Fits on turbo
The pairs welded
dscf0265.jpg dscf0264.jpg
COllector in the making
Bottom valve
Breather painted
Flange mounted and match ported on turbo
Oil return flange
Fittings on breather
Barbed hose connection for 1 inch tube
With a filter and possible fitting
As finished as I can at the moment
Level tube
dscf0123.jpg dscf0122.jpg
Filter mounting
Welded water tight
Breather tank
Breather fittings
Filler cap
VW filler neck
Tube to see the level of fuel
Return fitting
With a ballvalve for filter changes
Sump for gastank
A pre filter
Plenty of room under he bonnet
New tank
Exhasut housing numbers
Turbine wheel
Compressor wheel
Exhasut and compressor housing
Probalble placement
HX50 on the left, Garrett GT47 on the left(76inx90out)
Exhaust housing 28
Holset HX50 67mm in, 77mm out
Tack welded, stainless
Template of new gas tank
New IC/inlet arragement
Started porting
Cam lobes look OK
Corresponding in heads
Nasty marks on the piston
Out of the car
After brake in
uscf0026.jpg uscf0024.jpg
uscf0016.jpg uscf0015.jpg uscf0013.jpg
Turbo placement

Older pictures

The fuel tank is nearly finished with all its fittings and such and I'm quite pleased with it. The original tank donated the filler pipe and cap, so a little VW heritage will be seen. A pipe has been added to be able to see how little fuel is left. The outlet is located in a little sump on, which is supposed to retain some fuel under acceleration, the return pipe goes near the top of the tank. There are three pre filters for the outlet so hopefully the pump will be happy. A breather, catch for crankcase ventilation, tank has been made out of an old fire extinguisher, it features three the inets which are taped for 1 inch pipe thread if I want threaded couplings, 60mm pipe for a filter and level checking tube. It can be emptied while in the car by just sticking in a 10mm plastic tube and opening a valve in the bottom. I will make it splittable.

New turbo is bought, capable of pumping air for more than 600 hp if the engine is build correct. It's a Holset HX50 from a truck that I found really cheap, however I will have to replace the bearings but they can also be found very cheap. The plans for the new engine is to use 1.7 liter cylinder and bore them to 90.5mm and use custom made pistons and running a very tight deck to keep as much combustion as possible in the head.

After some head- and heartaches, the engine was finally broken in. The spark came from distributor instead of the EDIS coil pack. However it was really loud under the brake in and the lifters were worn down by a great amount. Some debris also came lose from the intake and destroyed one piston and a combustion chamber in one head.

The engine is assembled. Exhaust and intake with intercooler and piping is fully welded and fitted to the engine. The fuel rails and holes for the injectors is welded on the intake. The trigger wheel of the original design is replaced by a old fashion distributor. The Megasquirt is done and wiring for it is done. It started after some fiddeling around and I thought it was time to brake it in, so I installed the engine properly and tidy up the wiring, but for some reason it wont start what ever I did. The engine is on hold for a while.

This week I've constructed an intake manifold. The intake runners ar made of 34 mm I.D. scrap tubing which I had lying around, they are about 380 mm from the top of the valve to the top of the runners. The plenum on each side is mad out of 76 mm I.D. exasut tubing about 200 mm long, and a 600 mm long, 76 mm I.D., tubing connectin the two sides. In the middle of the connecting pipe the flange for the throttle body is attached to a 63 mm pipe.

After a change of plans, I've decied to use the glass fibre cooling tins. They just needed a little more grinding. The inlets comes from a fuel injected type 4 engine, which have been cut down and runners is going to be welded on, connectng to a plenum.

With the trial fitting of the cylinder cooling tin and fan shroud I found out the glas fibre cylinder cooling tin was less than desireble fit, so I started to make my own out of thin sheet metal.

I've put a layer of paint on the valve covers and began trial fitting of the cylinder and cylinder head air deflection cover. Four oil galley plugs that are known to pop out during start up, or sometime later. The reason for this is that when your engine is newly rebuilt the oil pressure is high again that it could be too much for the atleast 20 years old plugs.

Autumn 2007
I began with the exhaust system but it didn't work out so I scrapped it and putted the work with the hardware on hold for a bit. I ordered a MegaSquirt kit from and began assembly. I nearly finished but since I didn't have all parts that I needed to get it too drive the coil I put this work on hold too.

Summer and autumn 2006
I bought the engine and began to stripping it down. After stripping it down I washed it clean, much nicer to work with after that.