I have a 1971 skylark with a ssb 350. Tha car and engine had been sitting for about 5 years when I bought it. The engine was maybe started ones a year before I got it. The engine was last rebuilt in 1994. The engine ran nice when I got it, but was realy bad for gas milage. So I figured that I would do some service and upgrades to it. This is what I have done: -new plugs -new plug wires -new rotor and cap -upgraded the points to Ignitor II and Ingnitor II coil -instaled a crane vacuume adv kit -new airfilter -new oil and oilfilter on engine and trans -new fuel hoses an vacuume hoses. My plan was to OH the carb, but it was junk. So i bought an OH one from Carmantx. I have bolted on the new carb and adjusted it as good as I can so fare. I have also done the power timing. When I adjusted the idle mix, I could not get more then 15-15.5 in vacuume. I adjusted it with the engine hot and in drive. I set the idle to 800rpm in park. It droped down to 650rpm in drive. I hooked the vacuume gauge up to the manifoild. Is this vacuume to low? Have I got al my vacuume Lines hooked up right. I took some pictures and short movies. ---------- Post added at 11:19 AM ---------- Previous post was at 11:14 AM ----------
Initial timing are at 9* at 750rpm with vacuume blocked. Total timing are at 32* at 2200rpm with wacuume blocked. I instaled silver springs. ---------- Post added at 01:48 PM ---------- Previous post was at 01:36 PM ---------- My Mech adv is up to 24* at 1000rpm. 29* at 1500rpm. 29* at 1750rpm. 30* at 2000rpm.
This is a link to a discussion on what cam it could be. http://www.v8buick.com/showthread.php?273061-Help-to-id-cam&highlight= Onely thing I know about it, is that its called CS709, but I cant find any info on it. It was replaced when the engine was rebuilt. Unless it was bough for a diferent engine. ---------- Post added at 02:21 PM ---------- Previous post was at 02:13 PM ---------- Here are the results off a comp test I did.
Without knowing the cam specs, we would only be guessing. A larger cam will make less vacuum. A stock engine should make very close to 20" of vacuum. Those cylinder pressures look low overall to me. Was the engine at operating temperature, and was the throttle blocked open?
My gues would be that the cam is a stock replacment of some kind. Everything ells on the engine and car is stock, so I don't see a reason way they would have put in a diferent cam. I don't think the engine had fully operating temp and I did not block open the throttle. I guess I should do it again.
My guess is the cam is bigger. See if you can contact whoever did the rebuild to find out about the engine and cam. The engine parts need to be up to temperature for those results to be valid, and you want the throttle wide open. Remove all the spark plugs.
I guess that it would be this company. It is 20 years ago. I guess I could give them a cal if they are still in bisnis and I can figure out the time diference between CA and Norway.
How many screws out from seated are the idle mixture screws set? I bet you could raise the vacuum at idle by shortening the amount of mechanical advance with a bushing and then running 14-16 degrees initial timing and still having 32 total. This would result in stronger idle and less throttle required to hold idle in gear.
Late timing would give you low vacuum, but 9 degrees isn't that late. The vacuum reading isn't that bad. At least its a steady reading. If it runs good and doesn't have a vacuum leak, I would just leave it be and drive it
Just My point of view, Swap the Red Plug to where you have your Vacuum hose, and put your vacuum hose where the Red plug is. PONCH
Isent the vacuume adv supose to be hooked up to porten vacuume? I don't think that hose is leaking. I already tested it with spray. I guess I could put on a hose clamp to make sure. The hose is Brand new. Actualy I never checked the hose that is on the other end of that pipe were the pipe goes into the modulator. ---------- Post added at 11:38 PM ---------- Previous post was at 11:33 PM ---------- Do you you want me to put the vacuume adv hose were the red plug is or the PCV vale to were to red plug is? I thought that the charcoal canister was supose to bee hooked up to that one? ---------- Post added at 11:40 PM ---------- Previous post was at 11:38 PM ---------- Or do you mean the red plug that is just under the fuel line to the right?
This is what I wrote in a recent thread on the Bench about Vacuum Advance. There are different opinions on which port to run the vacuum advance. There are 2 kinds of vacuum ports on most carburetors, ported, and manifold vacuum. Ported comes from a source located ABOVE the throttle blades, therefore, there should be little to no vacuum present at idle, but vacuum should rise rapidly as the throttle is opened. Manifold vacuum is from a source below the throttle blades, so at idle, manifold vacuum will be ever present, and higher. As engine load increases, manifold vacuum will decrease, and as engine load decreases, manifold vacuum increases. Some argue that this is precisely why you should connect the vacuum advance to manifold vacuum. Under light load, manifold vacuum will increase vacuum advance for better gas mileage, and as load increases, the manifold vacuum will drop, and vacuum advance will decrease. The vacuum advance canister has a spring inside that opposes the vacuum pull. When vacuum drops as it does during wide throttle openings and high load, the spring pulls the added advance out. Manifold vacuum will also give extra advance at idle and low speed, and that will make the engine run cooler during stop and go traffic in the heat of summer. There will be no difference between ported and manifold vacuum at part throttle steady state cruising. Everyone should experiment with manifold and ported sources for their vacuum advance. See which one you like better. There is no right or wrong. With some bigger cams, running manifold vacuum can result in a bigger drop in RPM when going from Park/Neutral to in gear. Ported vacuum might work better in that case. Again, there is no right or wrong, there is only what works better for your particular combination. http://www.v8buick.com/showthread.php?63475-Power-Timing-your-Buick-V8 This all covered in my thread. I know it is long, but read it all.
Yes it has fresh gas in it. When I bought it 6 months ago, I drow it 50m to the closet gas station and fild it up. The reason for me to starting to change and upgraing things is that the car had been sitting for 5 years. Hoses, gaskets and stuff had started to dry up and braking. The reason for changing the carb was that it had alot of vacuume leaks. It was cheaper to buy a new then to OH it. The stuff I have done so fare ar mostly servicing and needed TLC. I am planing to do the upgrades later this winter or after next summer. I plan to put on header, new 2,5" dual exhaust (have 1 7/8" dual now), diferent cam, some head porting and gasket matching, change the rear end gears +++
Yes the gas mileage was realy bad befor I started to chang everything. It has improved some, but I onely got to test it one trip after I put on the new carb. The summer season is over in Norway. The rods will start to get icy sone and they will start to put SALT on the roads. Salt does not work good with old cars....... The car ran good befor I started, but the carb kept acting strange sometims. When I put the pedal to the flor it would hesitate and some times one could heare that the second stage would not open. But those problems should be fixed now with the new carb. I have not mesured it becase the trip odometer ( or what it is called ) dosent show corectly. Wrong tires. I onely know how often I had to stop for gas I used more gas on the Buick for one month then I do on the volvo for 12 months.....hehehe..... What I am trying to do now is to adjust at tune every thing as good as I can. Maybe I get lucky and get a warmer and dry day for some road testing. My biggest consern now was that i dident get more then 15" vacuume and I read everywere they it should be 18-20". So I am tryng to figur out if it is good inuf or if there is something I could do to get it higher.
Couldn't he just crank the initial timing to 25 degrees and accomplish the same thing? The engine should make 19-21 inches of vacuum with the factory timing setting. The fact that the engine makes 17" of vacuum at idle with 9 degrees of initial timing isn't going to change
Where do you get 17" vacuume from? I onely get 15". The isue is that I onely get 15" and I want to try to get it higher. But if 15 is good inuf I will leave it as it is. I know my writing english is bad, but I did not know it was that bad.
