CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

180* out, conflicting stories

Can a SBC run 180* out?

  • yes, and it can actually be driven, but poorly.

    Votes: 18 18.2%
  • No, it'll never crank, just backfire wickedly.

    Votes: 50 50.5%
  • I time my motors Nekkid.

    Votes: 31 31.3%

  • Total voters
    99

78Suburban

1/2 ton status
Joined
Jul 4, 2005
Posts
2,609
Reaction score
0
Location
Georgia
Just curious, because I've heard so many different stories on this. Several people have sworn to me that a vehicle will idle fine at 180* out, and run ok untill you drive it under load. Then other people tell me that it will backfire out of both ends and never run at all. So have any of you seen a vehicle run when the dizzy has been dropped in 180* out?
 
when i put in my new motor. i was 180 out a few time and new it right away. i think you would definitely know when its out. i was out one click once and moved it over one spot and she purred!!
 
won't run 180 out...and I've probably done that a half dozen times.:doah:

Rene
 
78Suburban said:
Just curious, because I've heard so many different stories on this. Several people have sworn to me that a vehicle will idle fine at 180* out, and run ok untill you drive it under load. Then other people tell me that it will backfire out of both ends and never run at all. So have any of you seen a vehicle run when the dizzy has been dropped in 180* out?

Funny avatar :haha:

As far as the engine running....if my calculations are correct...NO. Depending on whether the distributor is exactly 180 out or not, and what type of cam you have (overlap) will depend on what you will hear. If it's advanced, it's going to backfire out through the exhaust as the piston is coming up on TDC exhaust stroke when a cylinder fires 180 degrees out, if it's retarded it will backfire through the carb as it's starting it's intake stroke. A cam with a big overlap can backfire through the exhaust and carb if both valves are open.

The motor may seem like it wants to run especially if it's slightly retarded but it won't. Again this is based off of calculating where each piston is when the plug fires when a distributor is 180 degrees off. My math/logic could be wrong, so somebody please correct me if it is.
 
What you described has been my real world experince with disty's 180 out...

Rene
 
If it's 180 out it will backfire flames out the carb...you will definitely know. Now here is the fun part, you can make the motor run with the dist 180 out. I actually had a friend that didn't know much about the dist install it 180 out and he fixed the timing by then rotating the dist 1/2 a turn. This changed where the firing order was on the dist cap but it ran fine.:rolleyes:
 
yeah thats impossible, when its running 180 out it should be firing on in intake stroke, which makes the engine run not so good, i have done this before and your motor will def not work anywhere near correctly
 
I voted for yes cause it will run with the cam 180 out doesn't run well but it will run. Almost like it got something holding it back.
 
kgblazerfive said:
I voted for yes cause it will run with the cam 180 out doesn't run well but it will run. Almost like it got something holding it back.

This isn't the first place I've heard this.. I've read it on Pirate and I think on here before. I have had one 180* out before and it wouldn't crank up. But alot of people have told me its possible. I guess I could just pull the #1 plug wire and put it on #6 spot on the cap, and just work the timing order out from there... Just in case I'm 180 out... I honestly think I would be backfireing alot more if I was 180 out.

kgblazerfive, have you ever seen this happen before?
thanks :bow:
 
my first mistake was turd ranger with 2.9 motor. then replaced heads my self and forgot to top dead thhe motor before install of dist. then fired up good and reved good. but lacked power after 2500 rpm or so.

drove it to friends house 5 miles away. we couldnt figure it out. ( when i got there the exaust manifolds were glowing orange. )

drove home slower to help on over heat problem not building up from rpms. later found dist in 180* off . so it is a p.i.t.a big time to pull it and spin it. so i just 180*ed the wires bam problem solved.

sold truck later. forgot to tell them . hope thay didnt do a tune up and have runing problems after the fact. ( i swa it later sitting for more than 2-3 years in the new owners side yard not moved at all. ):D
 
sweetk30 said:
my first mistake was turd ranger with 2.9 motor. then replaced heads my self and forgot to top dead thhe motor before install of dist. then fired up good and reved good. but lacked power after 2500 rpm or so.

drove it to friends house 5 miles away. we couldnt figure it out. ( when i got there the exaust manifolds were glowing orange. )

drove home slower to help on over heat problem not building up from rpms. later found dist in 180* off . so it is a p.i.t.a big time to pull it and spin it. so i just 180*ed the wires bam problem solved.

sold truck later. forgot to tell them . hope thay didnt do a tune up and have runing problems after the fact. ( i swa it later sitting for more than 2-3 years in the new owners side yard not moved at all. ):D

you are my freakin hero.. This sounds like my truck.. If this is the whole problem, I'm going to kick myself, then I'm gonna go jump for joy.... That would be AWSOME if I am only 180 out.. :bow: :bow: :bow: what an easy fix.. maybe I'll find some time to try it tomorrow and see if thats the problem..
 
If you think that you are 180 and really aren't sure then just start over. Pull the plug #1 and crank it over till you get to the compression stroke your finger will tell you when you are there and then see where the rotor is at.
 
kgblazerfive said:
If you think that you are 180 and really aren't sure then just start over. Pull the plug #1 and crank it over till you get to the compression stroke your finger will tell you when you are there and then see where the rotor is at.

See, that's one of the problems. I turned it over with a wrench, and my buddy told me he felt pressure when the rotor was goint toward #1. He didn't say he felt pressure when it was on the previous cycle. And I also took this time to put a screw driver in #1 plug hole, and felt the piston. This is why I was thinking I wasn't 180* out. I guess I'll try to swap the wire around a full cycle, just for kicks and giggles. If that doesn't work, I'll be pulling the valve covers and taking a bath in some motor oil :eek1:. The engine expert buddy :wink1: I talk to on the phone last night gave me the good idea of disconnecting my dizzy and unhooking/pinching my fuel line to aviod washing the poor old cyclynders down with gas. This seems like a pretty good idea, as long as my battery is healty, and its a brand new optima, so it should be :bow: So I guess I'll troubleshoot just a little longer before I give up and go to a mechanic. The thought has also crossed my mind to just give up on wheeling all summer and buy a crate engine and quit battling this.. I hate to give up so sooon.........and I could do alot of damage with that much money (like a dana 60 and crossover). I'll let yall know. Hopefully I can get to the bottom of this and stop wasting ck5 bandwidth with these posts.
 
If you pull the valve cover you can watch the rockers to see where its at also. Have someone tap it over while your finger is in it then you know. If its close it should run but if its doing the backfireing thing its probally close. Do the compression test, check the balencer to timing mark, then look to see where the rotor is. I would not move wires yet until you have done all that.
 
kgblazerfive said:
If you pull the valve cover you can watch the rockers to see where its at also. Have someone tap it over while your finger is in it then you know. If its close it should run but if its doing the backfireing thing its probally close. Do the compression test, check the balencer to timing mark, then look to see where the rotor is. I would not move wires yet until you have done all that.

All clyinders are holding btwn 130 and 150 psi, dry. 40 oil psi upon startup, drops to 20 upon warm up. The balancer mark is in the correct location. I trusted my buddy to feel for the compession, but I suppose it would be easy enough to check for it again. I know you could feel a little air on the exhaust stroke, but he didn't seem to, so I guess it was all going out the exhaust valve. He did say he distinctly felt air pushing when the rotor came to #1, so i assumed this was compression stroke. The last option before pulling the valve cover, is to try the wire swapping thing... it couldn't take more than 5 minutes... and the worst case senario is that I completely rule out the 180* out thing :bow: But I gotta jump on a ton of homework for college right now.
thanks,
James
 
You will know when its on compression it will take a lot of effort to hold your finger on the plug hole.
 
kgblazerfive said:
You will know when its on compression it will take a lot of effort to hold your finger on the plug hole.

Yeah, and I turned it over once, and my buddy sat there grinning... the second time around he shouted "WOW, THAT'S IT!!!!".....thus why I'm leaning away from it being 180* out. I'm almost to the point of going a head and pulling the cover and looking for mis adjusted valves, dead lifter, bent valve or pushrod, pulled stud, or my very favorite and most reccomended to me by multiple people: WIPED OUT CAM LOBE :bow: Time to start diagnosing. Hopefull I will be able to. We'll just have to wait and see. :wink1:
 
I was 180* out on a '67 firebird.

When I cranked it over it backfired so bad I flattend out the internals in a set of Flowmasters.:doah:
The driveway was base rock and there was no rock under the turn downs, just holes about 5" wide, 10" long and 1.5" deep. Dad's Accord behind me was a mess.

I voted no cause mine wouldn't drive or idle.
 
yeah, that's why I started this thread, because its suck a mystery to me how some motors backfire so violently out both ends that its rediculous, while other motors can actually drive around 180* out. I suppose there are alot of factors involved in what makes an engnine acts how it does when 180* out. I'm still hoping it might be my problem, but really doubting it.
 
Top Bottom