View Full Version : changing regular 3.8 to supercharged 3.8

09-18-2002, 12:55 AM
I have a 1991 Mercury Cougar with the standard 3.8 v-6. For a long time now I have been wanting to take a a supercharged motor from a wrecked SC and drop it in. Does anyone know anything about this, any points, tips, or sugggestions? I was thinking of taking my heads which are 9.0:1 compression ready and throw them on the supercharged motor which is only 8.2:1 compression. Does anyone think this is a good idea? Any suggestions would be great. Thanx.


09-18-2002, 01:02 AM
The heads on our sc engines are made in such a way as to strengthen the gaskets ability to stay sealed. I am not an expert on it but I believe that if you use a head that is not desinged to hold up to boost and it is already a more compression head then you might just not be in the fast lane very long. I don't think the gaskets will hold, or even worse they may crack and do some heavy duty dammage to the engine. We allready have trouble with too much back pressure and think that to combo you thought of would be even worse.


09-18-2002, 01:04 AM
First off, the heads have the same size combustion chambers so the compression ratio will not change plus SC heads have more metal and are stronger. The pistons decide the Comp. Ratio. 9.0:1 will kill your headgaskets quick. With Sc'd and turboed applications, you need a lower compression ratio. When you take into account the SC, the compression ratio is more like 11:1. Anyway. Changing this motor will be a pain and cost more than just buying an SC. You have to change the entire power train. Motor, Tranny, Driveshaft, differential, axles everything. That SC motor will tear up your powertrain with no problem ( when you consider +70hp and +95ft-lbs over the NA 3.8 (naturally aspirated)). Your best bet would be finding a wrecked SC for parts. You may also want to upgrade your brakes (an SC rear axle has disc brakes). It's not an easy upgrade but it's doable.