Hi Guys I am the proud owner of a 72 challenger with a 69 stock 340 in it with a edelbrock 600 carb,headers,other than that its stock,I am having some problems with it!.#1 when i put my timing light on it at idle the mark is nowhere to be found! If I dial it up to 32* it comes up to where it is suppose to be at 5* BTDC..WHATS going on there? balancer slipped? car runs ok, but is only making 9 inches of vacuum too! and drop it in gear barely runs!.Also the damn thing is running very hot, not according to the gauge ,but u shut it off and u can hear it boiling , would the timing effect that? or could the radiator be plugged?,,Its very frustrating as I spent some good money for this car!

 

With regards to the rad, when it's cool and you pull the rad cap can you see the coolant circulating ? Do you have a shroud on the rad ? Hows the thermostat ? Is the rad holding pressure ? No leaks anywhere ?
With regards to the timing, has anyone changed the cam in the motor ? Just thinking maybe someone changed the cam and didn't index the timing chain properly or has it skipped a tooth or two ? By rights the harmonic balancer shouldn't move, that's not to say that it hasn't though. Keep us posted man. If we can help we will.

 

Yes has shroud, new thermostat, holding pressure no leaks anywhere... I seem to remember yes it is circulating... the car was fine warming up ,but once the thermostat opened it was damn hot!.. Hotter than I know it should be... The cam deal I dunno.. was told it was whatever was stock for 69 340, but with 9" inches of vacuum I am thinking its not stock! I dunno it seems to rev out ok etc... I would think if cam was screwed up it wouldn't sound good.. THe timing deal is the biggest thing...Why do I have to dial the light to 32 degrees to get it to line up at 5 degrees BTDC at idle? I know on GM cars u only dial it up when setting total not just checking initial.. I am not even checking total at this point yet cause of the mark being so far off at idle

 

Ok cool, I am thinking it's running hot because of the timing now. Is it possible the harmonic was changed ? Do you have a digital timing light ? I am just wondering what the timing is at idle vs rpm ?

 

Yea thats the question to be asked,lol.. I can't even see the mark with my sears dial back light put on zero.. I have to move it to 32 to see the mark line up with the 5 BTDC mark at idle! I have a 74 Charger 318 and put the light on it with dial at zero and its right at 10 BTDC like it should be!.. Dunno if someone changed balancer or not?

 

Sorry bro, I think I am stumped. It's hard to say from my desk to your car..lol. We'll keep trying, someone else may have some insight or something I am missing.

 

Have you ever done a leakdown test on the motor ?
As far as the cam goes and don't quote me on this but something tells me the 340's in 69 all came with the automatic tranny grind specs from 68. And that timing chain should be the double if it's stock.

 

Have not done a leak down test yet.. was going to do a comp test too, just to see what I come up with there.. Do U have the specs for that cam?

 

340 4 barrel 68 man trans Hydraulic 444/453 276/284
340 4 barrel Hydraulic 430/444 268/276
340 70 six pak Hydraulic 430/444 268/276 (adjustable rockers)

 

you might want to try the old tree method and bring the #1 piston to tdc and see where your rotor is at if its pointing to the #1 on the cap and check to see if the balancer is at tdc with the rotor and piston in tune ... but it could be something as simple as your vaccum line is on the wrong one on the carb but i would just start with checking to be sure all is in sequence with one another than i would adjust your carb to it

 

quote=challenger;24851]you might want to try the old tree method and bring the #1 piston to tdc and see where your rotor is at if its pointing to the #1 on the cap and check to see if the balancer is at tdc with the rotor and piston in tune ... but it could be something as simple as your vaccum line is on the wrong one on the carb but i would just start with checking to be sure all is in sequence with one another than i would adjust your carb to it[/quote]


Yea I did that.. and when piston was at TDC zero on balancer.. the rotor was actually a a little past number one plug terminal more towards 8.. like in between the two? but a tad closer to #1 then 8 ,lol... But I didn't want to screw with anything under the dist at that point... But Now thinking it may need to lift that shaft and gear and turn it back one tooth? to get it closer to the #1 terminal, But would that explain why that timing mark is nowhere to be found at idle? car seems to run good , but is getting damn hot to me... could it be that? I suppose if dist gear is retarded a little it would run hot?

 

Ok not sure how you did the tdc check but there is two times tdc comes by so what you should do pull plug one out rotate engine with your finger over plug hole until it blows your finger off then check balacner and dist. make sure all plug wires are in proper postion on cap. Two things i can think of is that you might be 180* out or your off a tooth on dist. and a two far advanced timing will cause over heating.

 

X 2 on that.

 

Did you disconnect the vacuum advance?

 

Just throwing this out there, but I've seen stranger stuff. Did you check your centrifigal advance? Are they stuck advanced, or are the springs weak or broken? Just fishin. Vacuum advance stuck? An extra 28Deg is about whats in the centrifigal set-up.

 

Was just thinking that.

 

Yes I stuck My finger in there and waited till it pushed it out then looked at balancer it was close to zero so turned it just slightly to get it to line up and took off cap and number one is a little past its terminal.. atleast to me it is.. Also thats what i was thinking too maybe the weights are stuck? I had the vac hose off yes...

 

Ok I'm thinking that someone put the dist. in wrong but to make sure put the balancer on 32* BTDC and see if the rotor matches up with one. If it does its of a tooth so what the easy thing to do is pull the dist. move the engine back to 5* BTDC put the dist back in with rotor at number one. then check timing. If this is not the case then it might be the weights.

 

ok How do I do this? the balancer is only marked with one line then a timing tab on engine...5 I can understand how to do, but a little lost with the 32 one?.. What is the diameter of the balancer? could figure out how far past the zero mark is and make a new mark for 32?

 

I always thought retarded timing makes a car run hot?

 

well, it definetly makes the headers glow
so, i agree, it makes the engine run hotter

 

I think I have found the problem... Was doing some research today and seen that 71 and later used timing covers have the pointer on the drivers side.... well this being a 69 340 shouldn't the pointer be on the passenger side then... so that would explain why I have to dial so much degrees on my light to get it to line up.. its probably pretty close if I was actually looking at the mark from the pass side i bet?.. So I would need a different damper then for a later engine? what do u guys think?

 

It makes sense but it doesn't at the same time. How would some be able to time the engine with out the markings right?

 

I am thinking the guy put a later timing cover on this 69 340... Looks like 70 and up the marks are on the drivers side from what I am seeing.. I need to verify the timing marks on the covers and the earlier balancers I bet their different from the relation to the keyway

 

Can Someone Please verify what the 68-69 340 timing covers and balancers are like? are they different than the 70 and up? tx!!

 

yes the timing marks were switched from one side to the other but I thought it was 71. This also corresponds to the changing of the lower water pump outlet being changed. If indeed you had a 68 340 and put a later timing cover with the old balancer, you definitely would have problems timing the engine. Must make a new mark on the balancer or get a new style balancer. Your 340 is internally balanced from the factory as are all 318's. Find a 318 dampner {mid to late 70's} and, using the keyway as a guide, line up the two dampners. now just transfer the tdc mark {0}. [use a good square] measure the other timing marks and transfer them also if you want or just use a dial type of timing light.

 

Thanks!.. Its definately a 69 340 verified by the stamping on the block, and its definantely has a later cover as the marks are on the drivers side...Thats a very good idea on getting another balancer and then transferring the marks!... First tho I have to make sure when its at TDC My rotor is pointing at #1 since I now know the cover is wrong!.. Going to be checking that again on friday... Hopefully getting closer to getting this baby running right!!

 

also one other thing, does this 69 have adjustable rockers?...What if someone put a bigger cam in it then would it? How can I tell pull cover and see if it has adjustable nuts and allens?

 

easiest way would be to pull the cover
you'd know right away