307 to 403 Olds swap...info please?

[DoubleV]

For sure a '71 motor built as far as I can tell to stock specs. Set at 12...when warm. This is what the 1971 book calls for. Idle is still a tad low, but no pinging, and starts easy, even hot.

12* base timing is for points distributors. Fact is, running more base timing will give you more low end power, throttle response, and better idle and since your TOTAL timing of 28* is WAY too low, then bumping up the base is a very good idea in your case.

So if you CAN ( but don't really NEED ) run more base timing and you NEED more total timing, then increasing your BASE timing by about 8 will give you 20 base and 36 total, which is exactly around what a low comp Olds engine would like.

My engine is a 71 350 too, but I'm running 16* base timing and the only reason it's that low is because I know I have 20* mechanical advance and so i need it there to get my 36 total. When I was running on the computer, I was running about 22 base timing. My engine has more compression than yours and I've never once had a hard starting issue.

 

[olds307 and 403]

Depends on which pistons were used during the rebuild. My 8.3 to 1 403 likes alot of timing. 43 at idle with vacuum advance. 23 base and 36 total mechanical in just over 1500 rpm. Add 20 vacuum advance on top of that.

 

[81X11]

SO I sold my wife's '01 Grand Prix, but we've not bought her a new car yet. She's driving my Ram, and I'm actually commuting to work in my Cutlass. Never planned on that. Had to strap the kid seat in the back so I can drop off at daycare...looks funny in that car.

I re-charged the a/c Monday....man R12 is EXPENSIVE now, but it's blowing cold. I also got a big piece of cardboard and made me some t-top shades. Painted them silver on one side to reflect the heat and flat black on the bottom, which is what you see in the car. I need to get some REAL ones made out of headliner material, but for now, this works.

You’d be amazed what a difference the t-top shades made in the Cutlass! It's dark in there! It can now actually be used in the summertime in Texas...like a real car! Ha! Before it was like sitting under sunglasses, you just baked, and the a/c had no hope of keeping up in the afternoon. I ran errends after work in it yesterday, and after running it just a bit, it cooled down nicely inside. Wild!

The vents by the gauge cluster blow pretty strong….enough so that you can feel the a/c on your face. The long passenger side vent above the glove box though has almost no pressure. I opened the glove box door and dropped it down, and there is a bad seal or something in the ductwork in there. The INSIDE of the dashboard is getting all the a/c on that side...I could chill Cokes inside the glove box. Will see if I can sort that out this weekend.

In other news, the car is going to Taylor Muffler on Monday. Sadly, the new hippy tree-hugger law here requires a catalytic converter on vehicles 1983 and newer, even though after 25 years they no longer do the smog test itself. SO I’m getting a free-flow cat installed, than a Y-pipe to dual turbo mufflers, and dual pipes with chrome tips exiting behind the rear wheels, 80’s 442/Grand National style. Even though it will not be true duals, I bet it’ll sound a lot better.

Also, I changed the oil to Exxon high-mileage 10W30...which I'm told has more zinc in it for flat-tappet engines. Seems to run fine but plan to keep the oil changed often. Have not played with the timing yet. Starts easy and has good power, but still has a little shake at idle in gear.

Coming along!

-Mike

 

[dogsht]

Mike, Some ideas. You can (said a tester guy at our local sniffer testing site back when we had one) as long as its bolt in and not welded in, install a short piece of pipe as a "test pipe" in place of your cat for testing purposes to see if your cat is bad. If you get pulled over or run through a road side vehicle inspection again it has to be bolt in ie temporary and stated as being used as a "temporary test pipe" for the purpose of testing to see whether your cat is causing run problems and you will be fine ie no fine. Ack it should free up a few ponies help provide a lil better fuel economy and sound.

To my knowledge the only conventional oil due to federal regulation that still has the proper zinc or more specifically ZDDP additives is Valvoline "VR1 racing oil" which is last I checked available in the common 15W40 and also but never seen in shelves around here 10W30. It was on Valvolines site a year ish ago but I have not checked it since. The oil has the proper ZDDP for flat tappet cam engines such as yours. Othewise it is not in anyway racing specific except for the fact that it is and was always and prior to federal changes marketed as off road racing specific oil so it is exempted.

That said on a broke in & worn stock flat tappet cam and motor with original weak valve springs said motor would probably still run a very long time on the new near zinc less oil before rounding a cam lobe.

 

[81X11]

Mike, Some ideas. You can (said a tester guy at our local sniffer testing site back when we had one) as long as its bolt in and not welded in, install a short piece of pipe as a "test pipe" in place of your cat for testing purposes to see if your cat is bad. If you get pulled over or run through a road side vehicle inspection again it has to be bolt in ie temporary and stated as being used as a "temporary test pipe" for the purpose of testing to see whether your cat is causing run problems and you will be fine ie no fine. Ack it should free up a few ponies help provide a lil better fuel economy and sound.

To my knowledge the only conventional oil due to federal regulation that still has the proper zinc or more specifically ZDDP additives is Valvoline "VR1 racing oil" which is last I checked available in the common 15W40 and also but never seen in shelves around here 10W30. It was on Valvolines site a year ish ago but I have not checked it since. The oil has the proper ZDDP for flat tappet cam engines such as yours. Othewise it is not in anyway racing specific except for the fact that it is and was always and prior to federal changes marketed as off road racing specific oil so it is exempted.

That said on a broke in & worn stock flat tappet cam and motor with original weak valve springs said motor would probably still run a very long time on the new near zinc less oil before rounding a cam lobe.

All the recent talk about oil changes has had me worried. The 350 was rebuilt in 2005, so it's well worn in by now, but still, I wanted to take care of it, but also want off-the-shelf oil. Figured the high mileage was good. If anyone else wantsto comment on the new oils, would love to hear thoughts!

-Mike

 

[bill]

Here is a very well done write up about motor oils.... Happy Reading!

http://www.bobistheoilguy.com/

 

[two90west]

One question I plan on doing the same swap with a rebuilt 70 rocket 350, how is the take off in your car and how is over all power with your rocket.