I fired up my 383 for the first time this afternoon, I'm trying to break in the cam so I guess it's 2200 RPM for 20 minutes, I had to shut it down right off the bat because of a fuel leak, I fixed that and started it again, I shut it down a few more times because of miscomunication with the wife and me (bless her heart), I rotated the distibutor counter clock wise almost as far as the vacumm advance canister would let me to get it running some what smooth, I had to shut it down after a few minutes again because the exhaust was leaking from the exhaust pipe dognuts, It also back fired at shut down, I tightened the 3 manifold bolts on each side and retorqued the manifold to head bolts to help seat the dognuts and gaskets and started it again, this time I cranked the distibutor counter clock wise as far as the vacumm advance canister would let me, it hits the trans module steel hose, it ran for about 8 minutes before it hit 250 deg and I shut it down again, I think I've got vaper lock, I also think I need to pull the distibutor and rotate it a tooth or two, recheck the exhaust that's still leaking and buy a coolant pressure pump for the vaper lock before I go further. A few questions, is rotating the distibutor clock wise advancing or retarding the timing? Also I've got maybe 10-12 minutes run time on 3-4 different starts on this cam, I really want to slow the RPM down to time it right with my light, do you think this is enough time? Thanks

 

Sounds like you need to rotate the shaft another tooth. In order to determine which way to rotate, you will rotate it the opposite direction from which you are turning the cap. For example, if you are turning the cap clockwise as far as it will go, you need to rotate the shaft one tooth counterclockwise. If you are rotating the cap counterclockwise, you need to rotate the shaft one tooth clockwise.

If you get the shaft on the right tooth and have the timing light set up, it should only take you a few seconds to turn the distributor to an adequate time so that you can complete the cam break-in.

 

Rotating the distributor clockwise is advancing the timining. Not sure of your second question but you need to break in the cam with the engine up to temp for 15-20 minutes. I'd not worry too much about a couple of start/stops in between if you have to. However, best bet is to break in the cam and then worry about final timing. Get the beast running first, keep an eye on temps and adjust timing if you have to as you break in the cam. Usually, retarding the timing (counter clockwise) will reduce temps if the timing is initially too advanced. However it is normal for a newly rebuilt engine to run a little higher temps until it is broken in.

 

Correct. And burp the cooling system too. Maybe drill holes in the thermostat if you have one, so that you're sure you have correct circulation.

You don't need to worry about base timing though. Run her at 2500 RPM and watch for 35* to maybe 38* total timing. That's what you need to watch for... not base timing. Exhaust leaks are not a reason for shut down. I did mine with open headers.

 

no don't slow it down until after 20 minutes of cam break in time over 2k.....stopping the break in process each time increases the chance of wiping a cam lobe... i would let it hit 20 minutes of over 2k RPM and hope for the best...

 

I'm some what confused at where my timing is on this, I've got Keith Black pistons that shouldn't be running over 34 Deg total timing or I'll have msvetteman type engine problems, the more I clock the distibutor counter clock wise the faster it runs, the last time I shut it down it was desieling really bad, I cranked the distibutor the opposit way to stop it. I left the radiator cap off so I could fill it with water, while it was running it stayed at 200 deg with about a half gallon or so burping out the the radiator fill hole, I put the cap back on and within a minute the temp went up to 250 deg, that's when I shut it down. I wonder if being advanced is over heating the engine. If I choke off the vacumm advance at the distibutor would this help?

 

The exhaust leaks where bad, I didn't want to worpe any valves. I just bought a dial back light from Sears and have to figure out how to use it. Can it be used at 2200 Rpm?

 

sure it can be used at 2200 rpm......just set to 36* at 2500 rpm and you will be at a good spot.

 

When motor is running, distributor shaft & rotor do rotate clockwise (when viewed from above). When viewed from above distributor ... rotating dist CLOCKWISE RETARDS timing ... COUNTER-CLOCKWISE ADVANCES. Suggest DO NOT breakin a motor without a timing light. No offense intended, but as far as rotation goes; below is incorrect.

 

I re-clocked my distibutor 2 teeth, fixed the exhaust and water and fired it back up. WOW what a difference! It stayed at 180 deg, runs smooth with no leaks. I really dig the new sound (cam, side exhaust ect..). I set base timing at 8 deg and total timing is at 30 deg at 2500 RPM. The cam is now broken in so I've got to hook up my vacuum gauge and dial in the carb.
What a relief, I was getting really stressed out over this, I've got my ****, alot of time and wallet into this, there is a great feeling of gratification when you build one for your self, it almost amazes me that it works with so many parts rotating in harmany

 

I just set my timing Saturday, and wanted to retard it 2 degrees. I rotated CLOCKWISE to RETARD. Agree with post.

 

alot of good advice! your on the right track. personally i dont care where the timing is on the break in as long as its running well enough. i set all timing after the break in. do a search on the overheating thing. on our vettes the rad cap is not the highest point, so air can get trapped easily. there are ways around this. also your are recieveing good advice on the whole timing thing. a few fellows here are supposedly running 54 deg. totall timing it was news to me

 

Congrats. Now enjoy.