15 is enough vacuum... Could you get higher with some tuning? Maybe... Do you care to try to get higher vacuum? If so try the suggestions we gave earlier in the thread. Your English seems fine to me!
It can advance the timing at idle, and that can give you a bit more vacuum. Might not work depending on the cam, and the vacuum you already have.
I have a 1971 Skylark 350 with a 4 barrel manifold similar to yours and recently did a lot of the same adjustments to idle speed , timing and carb mixture. I was noticing in your pictures at the beginning of this thread that you had a view of the intake manifold in front of the carb that showed the layout of the vacuum lines and incoming fuel line, etc. This picture shows a couple of differences between the layout of the components on your manifold and mine; the location of the vacuum tree and the temp sensor are reversed and tree vac ports where my vac advance is attached are plugged?!. I also noticed that your carb is also missing the TCS solenoid and its connection point to the carb is plugged. I assume your car is an automatic trans like mine is and maybe the layout and hook up of these vacuum points is causing you some problems with advance and reading manifold pressure. Also, when I hooked up the vacuum gauge to my car, I used the outlet at the back of the carb where the accessory vac tank hooks up to the carb and I was able to get a good stable manifold reading off this point (around 17 psi as I recall). My car also has the emissions decal still on top of the radiator brace that shows the proper layout of all these vacuum lines and points at which they attach to the carb and other manifold fittings. I certainly don't have the tune up experience of many of the folks on this site but maybe some of this info will help get you back on track with proper readings and better mileage.
I found a set of 1974 buick le sabre 350 heads and i was thinking that I could try to do some porting work on them. Will those heads fit on my 71 350? Is there any big difrens betwen the 71 and 74 350 heads?
68-72 heads will work on 68-80 350s,but 73-80 heads won't work on 68-72 blocks unless a couple coolant passags are blocked off on the later heads. Plus the earlier 68-72 heads respond better to port work than the later 73-80 heads. Spend your time porting your 71 350 heads,you'll get better results.GL Derek PS Happy Thanksgiving! To everyone.
Is it posible to figure out what cam is in the engine whit out remowing the cam from the engine? I was thinking if I mesure the lift on a intake and exhaust pushrod.
You could degree the cam in the car. That would tell you duration and lift. Just measuring lift isn't going to tell you much.
New question.Whan kinda horspower and torque could I expect to get from a engine like this whit some head work, bumping up the compresjon some numbers, TA212 cam (or simular), stock steel intake, quadrajet and stock exhaust manifold? The main reason for asking is that I plan to buy a new trans and it would be nice to kinda now how strong it needs to be. HD
If you run something over 9.5 compression with 212 cam, port heads with big valves with good tuning I would bet 300-325 would be easy to get. 400-425 lbs. Just estimated from similar builds.
Today I run 95 unleaded fuel by European raitings RON. If i manage to bump my compresjon up to 9.0-9-5, can I continue to use the same fuel? HD
