Feeling really dumb here with my situation so here goes....


I recently yanked out the 305 out of my '88 RS and swapped with a low mileage rebuilt '72 350 bored .040 over. It retains the stock heads, with a new lunati voodoo cam (mild 207/213) new timing set and lifters with an edelbrock performer intake and carb, believed to be a 600 cfm. I got it from a friend about year ago and IIRC thats what he said it was. Only other mods are i put an HEI distributor in it (non comp style) and it has SLP shorties with the SLP dual Y-pipe into the Borla cat back. Obviously im very very inexperienced with carb set up cars, but am very interested in learn about them





My concern is this:

When I try to get a reading to set the timing (with the vacuum advance hose plugged)it shows that the timing mark is way advanced (its the original timing tab). If the timing tab had enough marks on it it'd probably read like 26* at idle!?!? What have i done wrong here?

I know the base timing for this engine should be somewheres around 8-10*. I know the centrifugal advance bushings are worn (gotta curve kit on order) and that they aren't sticking. A little over a year ago I replaced them and think i out the medium weight ones in.


Also the tach in the car was always off by like 500-600 RPM. When i did a tune up on (back when it had the 305 in it) I just dissconected the yellow lead going to the cap. Now with this new engine it was hooked up just for sh*ts and giggles to see what'd happen and its reading pegged way out. Like its hitting the oil pressure needle. I was thinking somewhere the ground isn't making contact. Anyone ever had this happen? Any suggestions?

Lastly just out of curiosity, the old style temp sensor for this '72 and the one that the 305 used are not the same size. The '72's is much bigger and I have tried using the '72 style but am getting no reading. The temp sensor worked fine with the 305. Does any one know if the Ohms are different in the 2 styles and maybe thats why im not getting a reading?


Thanks again guys!!!

 

Probably used the wrong balancer, if your advance weights aren't sticking.

Use the original temp sender for the car.

 

Its the original one of the engine.

 

The engine could have been anything. The sender isn't specific to the engine, it's specific to the instruments in the car. It's very likely the engine came out of a vehicle that only had a temperature light, not a gage, so it is basically a switch that grounds when the engine temp gets too high. Like Apeiron said, use the sender for the car - use an adapter if you need to.

In all likelihood, the 350 heads are terrible in one way or another - small valves, huge chambers, and probably both. But, that's not causing your "problems".

Not sure why you think it's impossible for the timing to be at 26 degrees. Doesn't take much distributor movement to do that.

 

Okay so use the factory 305 temp sensor but does any one know what size fitting and where to get one that'll adapt for an older SBC head to the newer 305 sensor?

I know the heads are junk, i mean they're 70's emissions era iron weights but until i get some extra cash for some summit vortec knock offs they'll have to do

 

Take the sender down to the local parts store and tell them you want a pipe bushing.

 

Okay cool that solves that problem thank you!

 

I've been playing with the timing for past 3 days. The only place it'll run is at least 24 or 26* advanced. Otherwise it'l die. On the way up here to SC the car back fired through the carb many times on I-95 and finally wouldn't run on its own so I had it towed from Pooler GA, here to Goose Creek SC. At the suggestion of 86IROC (brian) i pulled the distributor, brought the balancer to 0* on the timing tab and THEN put the distribtor back in at No.1 cyl. (o about 5:30). IF when i pulled the distributor i pulled it out when No. 1 was @ BDC would this exlain my situation? As to why the timing reads so far advanced when its running?

 

Check the accuracy of your TDC mark with a piston stop.

 

Apeiron,

Okay so do ole' pencil in spark plug hole to verify TRUE TDC with confimation from the balancer being @ TDC according to the timing tab

 

^
That is what you mean right?

 

Sort of, but I mean doing it more accurately with a proper piston stop.