So I'd like to put some adjustable pushrods in my 350, only problem is the evaporator box is in the way and wont let me get the last few push rods out. I have never removed the evap box/ heater core/ ac components before and would really like to avoid it if possible ( heard its a pain) is there an easy way to get the clearance I need to remove the push rods without removing the whole evaporator box and assembly?
Removing the evaporator housing is a major deal. You can try removing the fender well, but you'll probably wind up having to remove the hood, bumper and fender. You definitely don't want to do that. Take the right side long motor mount bolt out and lift the engine off the mount. You may have to remove the screws for the fan shroud. That should get you the clearance you need
Wow... I hadn't thought of that but i love that idea. Still might be a little bit of a pain but not as bad as removing the box. I posted a while back about some issues I was having with my freshly rebuilt engine, which I just now realized you commented on and I rudely never responded http://v8buick.com/index.php?threads/valve-lash-350.323077/#post-2698882 But I feel like I still may have a valve or two that could be better adjusted. Figured I'd try the adjustable pushrods, plus I did reuse my old pushrods for the rebuild, so I figured maybe better to just get new ones anyway. It has been a while since I have had a vacuum gauge on the engine but responding to your comment from the last thread, I don't think ive ever seen the vacuum above 14 lbs and it seemed to be bouncing between about 9-13lbs
14 inches of vacuum. So your goal is to make the engine run smoother and get a higher vacuum reading? That TA cam has a lope to it at idle. Does the engine run bad? lack of power? Late timing will give you a low vacuum reading.
When I start the car right now the thing lopes worse than I expect it should. To the point sometimes when I sit at a red light I pop it into neutral because the thing starts rockin pretty good. Even at idle in park the engine has a rock to it. For a rebuilt engine with head work/mild performance upgrades I would expect it to have much more power. I went from a 2 barrel stock intake to the 4 barrel with all upgrades and it feels like I might only have a bit more power than before. I've adjusted the timing every which way. Never seen more than 14 inches on that gauge.
Here's what I did: I bottomed out the mixture screws (lightly!), started 1 1/2 turns from seated on both of em, got it to idle as low as I could (was 500rpm in park). I removed and plugged the vac advance hose, then set my timing where I wanted it, in my case 10* base timing, and adjusted the mixture screws EVENLY in 1/2 increments for MAX engine vacuum. I got it from 14 to 18. Engine is a stock '70 SP 350 with a crower level 3 cam. With proper adjustment with the 212 cam you should be seeing more than 14. Finding and setting your timing, then adjusting the carb will get you in the right direction, if not solve it. You mentioned you swapped from a two barrel to a 4 barrel, did you do it, or the guy that built the motor? If it's not the ignition or carb, it's a vacuum leak. My vacuum reading slowly walks from 18 to 19. Here's a cool chart from Summit:
I am getting spark at each plug, that's not to say there may not be some other issue with the ignition where it is misfiring periodically ( enough to cause the engine to rock?) I have a brand new HEI distributor. Is there a more precise way to check it for proper function? Every part that was not stock to the engine was checked and installed by the engine builder and confirmed to be okay with my set up ( including the push rods ) When I couldn't tune it myself, I brought the car to the guy who rebuilt the q jet and he said the car was taking adjustment perfectly and that I must have another issue. I previously set the ignition at around 14 degrees, total timing 36. That's also where it seemed to run best. The guy who tried to tune the carb made some slight adjustments by ear but we ended putting it back exactly to where it was before with no improvement to the vacuum readings or engine performance. Ive previously checked for vacuum leaks by plugging any non accessory vacuum lines, spraying carb cleaner around the carb gasket, listening for leaks and using my vacuum gauge. no changes in vacuum, and no indication of leaks after spraying the carb cleaner
Best and easiest method to check for a vacuum leak is to slowly restrict the airflow to the carb by placing your hand over the top of the carb. As you slowly choke the airflow to the carb, watch the gauge and listen to the engine. If you have a vacuum leak, the vacuum reading and engine rpm will go up. The engine will also start to run smoother. If there is no vacuum leak, the engine will start to stumbe and try to die out from lack of air. If the engine rpm and vacuum reading go up, it could also be that the engine is running super lean which would give you coincidentally, a miss fire To check for a misfire, take each plug wire off the spark plug with an insulated pair of pliers (don't electrocute yourself, its not fun). When you take each wire off, you should hear an audible drop in rpm and you should feel a dead miss. The cylinder that doesn't change is usually the one with the problem Im not saying that your diagnosis is wrong, but Im just very skeptical.
On the pushrod removal try actually removing the motor mount. This may let the engine down far enough to remove them. If getting closer but need a little more try removing the frame pad for the mount. DON'T forget about the shroud. Is the vacuum line off the distributor when adjusting initial timing??? Just a thought.
Tom,you might have a good idea,but you failed to explain that the removal would be on the other side,left side to be sure.Removing the right side,would make it closer to the AC box.But I'm with Jason on this,the easiest will be the driver side removal of the bolt.Bruno.
I’m going to get back in the garage this weekend, Check for vacuum leak again using the hand method. See what I pull for vacuum and rpm doing this as well as pulling the spark plug wires again. I’m also going to take the valve covers off and turn the engine by hand to Check rocker arm travel and push rods again. I’m going to see if I can find a leak down tester and do that test as well if the other tests yield no results. I’ve really got to figure this thing out, it’s driving me nuts.
Just an FYI.. The adjustable tips are 1/4-28 thread, with a oil hole running thru. They can possibly snap!
Well, I definitely don't want that to happen to one of my push rods.... What are the chances my valves are too tight? I've read other places this can cause a very low vacuum reading at idle and in gear. ( In gear I remember having readings as low as 6 and 7 inches. Are there any notable symptoms of having valves that are too tight? Also for a freshly rebuilt engine should I expect compression better than 141-148 lbs?
If you have no lifter noise, that's good. They may be pre-loaded on the heavy side (.030-.050) from head shaving. I used to run sml blk chebbys set at 1/2 to 1 full turn from zero lash, so I think you are experiencing vacuum leakage somewhere. Your cam should have around 15+ish at idle. No where near 6 to 7. Keep checking....
Bruno, If you remove the left mount the engine will RISE on the right side,NOT drop down. On the valves. You could try to loosen the rocker shaft bolts about 1/2 turn & start the engine to see if it makes the situation any better. The cam as far as I'm concerned is a little too much for your combination. I don't believe your running enough valve spring pressures to even worry about breaking ANY pushrod tips. Again, just my thoughts.
