Good timing!

[perezmaximus]

I recently check the timing on my 300ci engine. I turned it to 2 1/2 B.T.C at idle like the owners manual says.It made a difference in that it responds much quicker, however it seems to run a little hot and startups are rougher(more starter whinning).Is 2 1/2 BTC a good timing point for the 300ci or should I change it? Any suggestions would be great. Thanks

[Guest sixpack2639]

If your engine is running hotter and being harder to start I would think the timing was a little too far advanced. Out of curiosity did you disconnect and plug the vacuum advance line before you adjusted the timing? BTW 2 1/2 degrees BTDC is correct for the 300ci V8's

[Guest brh]

I have the 300, one summer I could not get this engine to run cool for love or money, (more money). Finally I took the radiator off into a shop who determined it was 30% blocked. After redoing the core I have not had any trouble at all, including bumper to bumper traffic. Check your cooling system to make sure its operating correctly. I went through all kinds of trouble including burning out the starter.

[perezmaximus]

I have not cleaned the radiator that might help but how about the hard starting? The plugs are new, and yes I disconnected the vacuum advance.Just to make sure 2 1/2 is between 0 and the 5 mark on the timing cover right?

[Guest sixpack2639]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I have not cleaned the radiator that might help but how about the hard starting? The plugs are new, and yes I disconnected the vacuum advance.Just to make sure 2 1/2 is between 0 and the 5 mark on the timing cover right? </div></div>

Yes, you are correct about the marks. As for the hard start are we talking about starter draging hard or excessive turnover before start hard? I would agree with Bruce about the radiator flush too. My 51 was slowly creeping up to running hot so I flushed (in both directions) the radiator, engine, and heater core all seperatly and installed a new t-stat. Now she sits slightly above cold, just into the normal range at sustaned 70mph with no problems. Carl

[perezmaximus]

I am talking about excesive turnover, and when it starts it runs rough for about 30 second then it idles great.

[Guest sixpack2639]

That sounds like you are too far advanced.

[Guest brh]

I am referring to excessive turnover with a hot engine. Reason is purculation in the carb and in my case the engine would get hot enough to cause vapor lock (air in the fuel pump). I could tell it was running too hot as I would be sitting in traffic and the idle would become rough, this would all happen before the idiot light came on. Hope this helps. Yes between the 0 and the 5 is correct for the high performance 300.

[Reatta Man]

If the car is hard to start when hot, it suggests worn points and condensor.

If it is hard to start when cold (even in a tropical climate like Puerto Rico) it suggests the choke isn't working.

By the way, a blocked radiator is even more critical in a tropical climate because the high humidity means the heat exchange effect doesn't work as well, so the engine needs all the cooling it can get.

As for other things to check, make sure you have a good fan shroud, fan blades and fan clutch. Also, make sure the exhaust system isn't partially blocked.

If your car didn't come with factory air, and it has a four-blade fan, you might want to consider going to a five-blade fan with a new thermal fan clutch. If your car doesn't have a radiator overflow bottle, consider adding an aftermarket unit. That way, your radiator is always full of coolant.

Joe

[perezmaximus]

I first eliminated the points condenser and installed an accel points eliminator, it worked perfectly. After eliminating the points I first decided to check the timing it was passed 15ºBTC, it ran sluggish but it started just fine, cold or hot. I proceeded to set it at 2 1/2ºBTC and thats when all my troubles started. All the problem is that cold or hot it will not start as fast as when it was at over 15ºBTC. Can it be that for some reason the distributor was removed and not set at Top Dead Center? It might be wrongly set and when I set it at 2 1/2ºBTC it might actually be higher? Can this be possible? Sorry for all the questions but I am a Buick newbie . If I had to remove the distributor and set it a TDC, do I have to do anything different than any other engine or is it as simple as a chevy engine?Thanks again!

[Guest sixpack2639]

There's nothing special to do. Check and set like you would a Chevy motor. Same rotation, same firing order. Carl

[Reatta Man]

I would try advancing the timing until it starts, then work from there.

You could possibly have a worn timing chain that has jumped one space, and the timing is waaaaay off. This could help explain the sluggish performance.

You could also have spark plug wires that are one space off on the distributor cap, causing you to have to rotate the distributor to offset the misplaced wires. If you are checking the wires, make sure they are in the right firing order. Also, of course, make sure there are no cracked wires that would allow the spark to jump between wires.

I've run into these 'mysteries' before where I was setting something the way it is supposed to be, but suddenly things get worse. I always go back to where the engine would run, then try to figure out what went wrong.

Good luck!

[perezmaximus]

OK, lets start at the begining what is the rotation order on the distributor cap is it 1843657? Also if I where looking at the distributor cap directly straight at the points adjustment window where should #1 plug cable be? Pics would be helpful.Thanks

[Guest brh]

I agree start from the beginning. If the car is not misfiring you have the cables in the correct order. You may want to reinstall the old points and condesor to see if you have the same problem. It is possible someone has put the dist in off to set you must make sure the piston is at tdc for number one and the rotor pointing to the contact, corresponding to the wire for number 1. Caution, make sure that piston is coming up for a compression stroke (valves closed). I had to do this a long time ago for a buddy and if I remember correctly we took the plug out, pulled the coil wire and took the cap off. Then I put my finger over number 1. As he cranked the engine I would note the position of the rotor as the compression stroke blew by my finger. It was a long time ago but it worked.

[perezmaximus]

Can someone tell me where the number 1 spark plug cable should be exactly located on the distributor cap?Also there is a 66' 300ci 4bbl intake manifold for sale but I notice that there isn't a rear heater water inlet on it, will this fit a 67' 300ci engine?

[Guest brh]

Sorry I don't have my book for 67 but I know for 65 the 300 was made in two versions. One was the high performance, burns premium, has 4barrel and 2 1/2 tdc timing. Could it be you are looking at the wrong specs for your year engine. If yours is a 2barrel running reg gas, it will probably have different timing but I don't know this for a fact.

[Reatta Man]

If the 300 is based on the 340 engine (and I think it is) then the #1 plug is the first plug on the PASSENGER side of the engine. Most other GM V-8s have #1 on the driver's side.

Joe

[perezmaximus]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">If the 300 is based on the 340 engine (and I think it is) then the #1 plug is the first plug on the PASSENGER side of the engine. Most other GM V-8s have #1 on the driver's side.

Joe </div></div>Now I am really cofused

[Guest my3buicks]

300 firing order 1-8-4-3-6-5-7-2

Cyl #'s 1-3-5-7- Front to rear left bank

cyl #'s 2-4-6-8 Front to rear right bank

Distributer # 1111158

Timing, Crankshaft Degrees before U.D.C. (WITH VACUUM HOSE DISCONNECTED AND ENGINE IDLING) 2- 1/2

Start ADvance@ RPM 550-750

Medium Advance, Degrees @ RPM 12-16 @ 1400

Max Advance, Degrees @ RPM 30-34 @ 4600

Vac Advance, Crankshaft Degrees and Inches of Vac

Start Advance, @ In. of Vacuum 6-8

Max Advance, Degrees @ In. of Vacuum 14-18 @ 16

Spark Plug Gap .035

Type 44S

Dwell Angle 30 degrees

breaker gap .016"

[perezmaximus]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">300 firing order 1-8-4-3-6-5-7-2

Cyl #'s 1-3-5-7- Front to rear left bank

cyl #'s 2-4-6-8 Front to rear right bank

Distributer # 1111158

Timing, Crankshaft Degrees before U.D.C. (WITH VACUUM HOSE DISCONNECTED AND ENGINE IDLING) 2- 1/2

Start ADvance@ RPM 550-750

Medium Advance, Degrees @ RPM 12-16 @ 1400

Max Advance, Degrees @ RPM 30-34 @ 4600

Vac Advance, Crankshaft Degrees and Inches of Vac

Start Advance, @ In. of Vacuum 6-8

Max Advance, Degrees @ In. of Vacuum 14-18 @ 16

Spark Plug Gap .035

Type 44S

Dwell Angle 30 degrees

breaker gap .016"

</div></div>NOW we are getting some where. Ok when you refer to left bank and right bank, which is passenger and which is driver side? Do you know, not on the engine but on the distributor cap which is the place for the #1 spark plug wire, where should the firing order start? The thing is I am going to check the engine at TDC and make sure the cables are where they are supposed to be.Thanks for all the info.

[Guest my3buicks]

No 1 spark plug wire is installed in the first distributer cap tower after the adjusting window, moving in direction of rotation - pic attached

[perezmaximus]

Thanks for the pic, that's what I needed to verify.Now I'll take the engine to TDC. By the way from what book did that pic came from?

[Guest my3buicks]

The Bible that every old car owner should own for their year car -Buick Chassis Service Manual - the are regularly on ebay and a must to own, another highly desireable book to have is your cars year Parts Book, the muliple year ones are good(and it's good to own one that goes beyond your cars year in case part #'s change), but the actual year ones are better.

[perezmaximus]

Ignition was off by one tooth, put the engine at TDC and ignition on the #1 spark plug. Started it and adjusted to 2 1/2 BTC, it started to run rough like before. Adjusted to 15 BTC and runs and starts smooth. Seems it's time for the timing chain to go.When replacing the timing chain and sprockets is there anything else I might consider changing?Thanks.

[Reatta Man]

Since you have to remove the water pump, I would replace it with a new one. Also replace the seal on the timing chain cover. And, be sure to use a quality chain and sprocket set, not jus the cheapest.

Some people would also suggest putting a new oil pump in at the same time, but on the 300 engine, I think you can replace the oil pump at any time.

Joe