Tuesday, June 11, 2013


 Every V4 Saab owner's dream: A hot dog V4 engine with the legendary cross-ram intake manifold and a pair of Weber DCOE carburetors---WOW! This is one of two such engines that I built for a pair of Peking to Paris Saab 96 rally cars some years back. Note the special distributor, necessary to clear the intake runner for the right carburetor. Most, if not all, of these special intake manifolds were made up in England for Saab in enough quantity for Saab to qualify for homologation according to international rally competition rules. The manifold set you see here is the "factory" set-up.
 There were several "wannabe" intake manifold builders so if you run into a cross-ram set-up it may or may not be what you see in the top photo.  Each wannabe also made up some sort of distributor extension. In this photo, the distributor on the left is the Bosch unit made specifically for Saab for the rally cars. The distributor in the middle has an extension that uses a standard distributor. The distributor on the right is a stock unit, though the drive gear at the bottom has not been installed.
 Here is a good look at the Bosch distributor made up for Saab. You can see that the distributor body and the extended shaft housing are all cast in one unit.
 This is a third distributor for a cross-ram manifold set. The housing extension is different [shorter] than the one shown above. I just rebuilt this distributor for a customer. The add-on housing looks OK in the photo but is actually really crude and looks like it was done by two guys under a pepper tree with a hammer, hack saw and bastard file after the second six-pack of Bud....
The reconditioning of the distributor was straightforward, and I made the extension work, but a much better extension should be machined from a bar of good quality aluminum. I have made up machine drawings for just such an extension.

Does the vacuum advance unit look different? It's a much modified Hitachi with a special adaptor mount. I get the exact advance curve I want with this unit, but it is NOT "Plug & Play", with MUCH testing on the SUN distributor machine to be sure I have the correct modifications to get the right advance curve.

It is important to understand that advance curves--both mechanical and vacuum--must be tailored to the way a given engine will be USED; the goal being to promote performance while preventing pre-ignition [detonation] that can destroy an engine. Fun stuff, but as they say in the ads, "Don't try this at home..."