Hot Rod Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
99 Posts
Discussion Starter #1
Wow, i have 4 years of solid engine and car mechanics experience. I feel like a complete idiot. I'm not 100% sure, but i think i just spent $1200 for no reason.

The used 454BBC i bought ran like crap and backfired all over that place and i couldn't adjust the carb mixture, i couln't even drive it, it was so bad, so i replaced the broken tooth timing gears and the streched out timing chain, didn't solve my problem.

SOO, i blew my carb up from the backfires and the cam was stock, so i replaced the cam, lifters, rockers, pushrods, intake, carb, distributor, wires, plugs, guideplates, fuel pump, and i'm waitng for shipping on some items before i put it together.

IN THE MEAN TIME, i was playing with my cam and distributor. I noticed that when the cam turns clockwise, as does the distributor. Now its too late to go back and check, but i think i had my firing order completely backwards.

IS IT POSSIBLE FOR A MOTOR TO STILL RUN W/ THE FIRING ORDER BACKWARDS?

I feel so dumb, i checked to make sure the order was right a million times, but never checked the direction of the order... Most of the parts needed replacing anyways, but still.....
 

·
Race it, Don't rice it!
Joined
·
7,810 Posts
It would if you turned the dist. around so far as to fire the next plug in the cycle of 72563481. You would be wasting the spark on 5 and be very very late on all the rest.
 

·
Registered
Joined
·
16 Posts
If the timing gears were broken the chain may have jumped. If it did you might have bent valves. That would cause popping out the carb too if the intake valve is bent. Sorry to add more to your list of troubles but it might be best to check before you put it all back together with new parts and find you have to take the heads off.
 

·
Registered
Joined
·
99 Posts
Discussion Starter #4
I ran a compression test, came up with 150psi on the dot on every cyl. .. No i know that the timing chain didn;t jump.. unless it jumped ALL the way around and ended up back where it started from. I'm supprised it didn't jump. But a compression test should tell me if my valves are bent. right? I didn't want to put it all together to find out i have bent valves.

JohnsonGrass1.... Yes... thats exactly the way it seemed.. it ran 55 degrees off which is almost ater the next cyl over... and it sounded like it was missing.. and it was running REALLY ROUGH. and if i just let it idel it would eventually just stop all of a sudden like the valve timing was barley enough to let it run

HOW DID YOU KNOW THAT IT WOULD RUN LIKE THAT?

I stared at my cam and turned it and thought of how it would get spark at certain posistions. But i wasn't 100% sure. JohnsonGrass1... could you explain this all too me, i would like to educate myself on this. THANKS SO MUCH!
 

·
Race it, Don't rice it!
Joined
·
7,810 Posts
I've done extensive research on firing order swaps to gain power. All I did was write down the correct firing order for a big chevy and write down what you thought it was and drew lines in the correct firing order to see what lines matched, all matched but 5 and the lines if kept at the same speed and order would be about 90' off. If your engine wouldn't run but at a assumed 55' degree's advanced that would put the spark at every 90'. 90-55=35 degree's late. I doubt it would run at 35 late but I assumed 35' was a guess because your scale doesn't run that far behind with out being marked on the balancer. I guessed it was more like 65 and that would give you 25 degree's late making the engine run, but not without problems.
 

·
Registered
Joined
·
99 Posts
Discussion Starter #6
Ok, i follow you somewhat.

I got the 55 by using a digital timing gun and viewed the balancer mark relative to the #1 wire, even though it was firing on the next plug over. The mark on the balancer was off the timing marks on the timing cover... it was at about the top of the balancer looking straight at the front of the motor. I used the digital operation on the timing gun to see exactly how far off TDC it was running and i came up w/ 55 degrees. But what you came up with, describes how my motor ran. I can't believe it could ever run with reverse spark order.

Could this have damaged my crank, rods, or pistons? Thanks.
 

·
Registered
Joined
·
16 Posts
Yes, It seems you got lucky. If you have 150 pounds of compression in all cylinders I'd say the cahain didn't jump and your valves are O.K.
Ted
 

·
Registered
Joined
·
99 Posts
Discussion Starter #8
Me?!?! ... LUCKY?!?!?!?! HA..... nono. wait until i get it all back together..i know ... I JUST KNOW i'll drop a valve or something... all the money i spent on the motor, i was going to spend anyways, cuz if this didn't/doesn't work, i was going to completely rebuild the motor, top to bottom. But hopefully i won't need to do all that for a while, Thanks for all your help guys...

Now then just to make sure.. when i set my rockers, i'm going to want to tighted the polylocks down until i can't move the pushrod up and down and then tighten it one half turn past that point, then tighten the allen screw threw the center of the polylock so it doeen't move when running?

I'm not using a bolt locking plate on my cam and timing strocket.... but this motor is also not HI-PERFORMANCE. The only kool stuff its got is a mild cam, intake, 700holley DP, and roller rockers, and a true roller timing chain that fits TIGHT.. sooooo i shouldn't have a problem with my cam bolts coming off and having my pistons destroy my valves and heads right? or no? Thatnks.
 
1 - 8 of 8 Posts
Top