I know the exact stuff your looking for...goto your local motorcycle shop and pick up a bottle of "CYCLE WASH". This stuff is down right amazing on engine compartments(and dirt bikes). Its safe on everything and all you have to do is spray it on(preferably a cold engine as it will dry) and hose it off. Its soap based so there's no residual oily junk left over. for heavier build up use a tooth brush to get it and a little more cycle wash..its not bad on paint but you will see where it might take wax off so try to keep it and the over spray(spray on and off over spray that is) off the fenders..the cycle wash runs about $20 a gallon, and the bottle runs $8-12,and a bottle will wash the about 2 engine compartments(i dont skimp on use,the more the better)...you'll still have to armoral the rubber(hoses,etc) for that detailed look, but the cycle wash cleans all the chrome and painted pieces like you've never seen before...good luck
On my 65's I cover the carb and dist. Then hose the whole engine and fire wall down . I try not to get any on the ext paint. I put towels over the fenders when spraying the cleaner. Let it sit for a few, washer her down with water. Then go in with the towel to wipe up all the water. Check my gallery out. You'll know what I'm talking about.