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#1
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Timing chain replacement with new cam.
I replaced the cam on our old 400 motor. I also replaced the timing chain. Now the engine won't start. It spudders and spits, and backfires like crazy while spinning the starter.. Makes me believe that the timing is out 180*.
When installing the timing chain, I set the engine to TDC. I put the timing chain on with the dot on the crank sprocket at 12:00, and the cam sprocket at 6:00. So I screwed up by trying to start it with the distributor set to the number 1 position. So now what do I do? I thought that TDC was only one position, but are #1 and #6 exactly the same at TDC? If the #6 cylinder is approaching TDC, then would I still feel the pressure with my finger on the hole on the #1 cylinder? This has got me stumped. I've got to line it all up again. |
#2
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I was just doing some research and seeing that I may have an issue with having the '67 Balancer installed with a '74 timing cover? I need the '67 balancer and pulleys to line up with the AC compressor and everything.
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#3
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You need to find #1 TDC on Compression stroke. Means, both Intake and Exh valve closed and piston at TDC. If your balancer is wrong to the timing cover marks, you will need a degree wheel and a piston stop to find true TDC and then remark your balancer for that. Then, put Dizzy in pointing at #1 and wire the plugs up.
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#4
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Sounds like you set the gears up 180 out.
Yank the Dizzy out and install it with the rotor spun around 180 from where you pulled it out, this will completely compensate for the Cam being 180 out.
__________________
I do stuff for reasons. |
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#5
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Yep. Turn the dizzy 180 degrees and re stab. You have TDC on #6.
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#6
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Thanks, guys, I'll try rotating it 180*. With all of the farting around, do you think that I should coat the cam again with assembly lube? I coated everything pretty good before, but the engine was sitting for a day and I've tried to turn it over a few times now. I have been priming the engine each time. It would be a pain in the butt taking the intake and valley pan all off again.
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#7
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Even just to take a peek, and reapply if needed, yes I would!
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I do stuff for reasons. |
#8
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You didn't say if you had the plug wires all off or if you were replacing the wires as part of the service. If you did, find #1 position, one post away from the points window, and remember rotation is counter-clockwise. Just a thought.
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#9
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Well, I really screwed this one up, and I can't figure out how or why. I took the timing cover off and confirmed that the dots were correct. In this case, the dot on the crank sprocket at 12:00 and and the camshaft sprocket at 6:00. I know that in this case to stab the distributor at the #6 terminal. I did all that and fired it up with the distributor not too advanced or retarded. Checked it all again and tried to fire it up. The thing popped and backfired like a SOB. Wouldn't rev, didn't run anywhere near smooth. It ran for a bit at about 500 RPM's, but kept stalling with a backfire. So I guess that I effed up the cam. I'm not worried about the cam, I can get another one. But why does it seem as the engine fires when either an intake or exhaust valve is open? We're going to put the old cam back in and see what happens. Pretty bummed out at this time. Losing a lot of precious Canadian summer weather to enjoy the car.
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#10
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Pic of timing chain and sprocket alignment.
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#11
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Quote:
And where in Canada are you? Shuswap BC myself. About redy to drop my 470 into my bird soon as I locate a hoist long enough to clear the nose. |
#12
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A hoist?
That’s why God made tall trees with long strong branches! Lol!
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I do stuff for reasons. |
#13
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Personally, I follow the docs that come with the gearset, and if you didn't get one, use the Service Manual.
So it would be cam gear = DOT DOWN Crank gear = DOT UP That way you can actually see the tooth pointing to the recess of the other gear. I know other ways may work, but have been doing that for over 40 years without a problem. .
__________________
. 1970 GTO Judge Tribute Pro-Tour Project 535 IA2 http://forums.maxperformanceinc.com/...d.php?t=760624 1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car https://forums.maxperformanceinc.com...ght=procharger Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be |
The Following User Says Thank You to HWYSTR455 For This Useful Post: | ||
#14
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OK, I'm going to try to fix this up today. I'll update later. I'm thinking that I had the timing off one way or another. Nothing else makes sense.
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#15
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Is this your first time or do you have experience with this? Do you know anyone who can help?
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Will Rivera '69 Firebird 400/461, 290+ E D-Ports, HR 230/236, 4l80E, 8.5 Rear, 3.55 gears '64 LeMans 400/461, #16 Heads, HR 230/236, TKO600, 9inch Rear, 3.89 gears '69 LeMans Vert, 350, #47 heads: Non-running project |
#16
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Quote:
I had this problem a couple of times. Once I had the dizzy set too far retarded. Another time I had it trying to fire #8 instead of #1-way too far advanced. The last time I did it I set the balancer at 12* and set the dizzy rotor on or just past the trailing edge of the cap terminal.
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Frank M. 75 Firebird 68 Firebird 400 RAIII 66 Chevy II 461 Pontiac in AZ Last edited by tooski; 08-13-2022 at 10:46 AM. |
#17
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Yep, it was the timing alright. I guess that I wasn't good at trying to line up the #6 on the distributor. Then it was running like crap, so I tried to advance the distributor, only making things worse. I pulled it and restabbed it more carefully this time (still #6) and the engine fired right up and I could hear that it was running well. That being said, I told my son to shut it down and I ordered another cam. I'm thinking that this one I just installed, hard started 5 or 6 times, and ran at 500RPM for a bit is not worth chancing to run it. 100 bucks or so, but not the end of the world. I actually feel much better knowing that we will get it running nice and being quite familiar with the process now. So thanks for everyone's help. I don't want to do this again for a while!
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#18
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Quote:
As you can imagine, the only place to go to have fun if you're from "Deadmonton" is to head over your way to Penticton and Kelowna. I've been there many times. |
#19
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Ok, real EZ to explain....with the dots lined up like your picture is, it's firing 180 out .All you have to do is with the dots lined up as your picture, your rotor will be at the #1 position.remove the distributor and spin the rotor by hand so it points to the #6 position on your cap, then drop it back in.
Your distributor will slide right back in, you won't have even have to realign the oil pump drive. |
#20
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Some may find this useful.
When I do timing gears, I mark the dots with a silver sharpie, to make it easier to view/line up. Here's a pic of the one that I did within the last 2 years, showing the dots, and the relationship of the teeth between the cam & crank gears. .
__________________
. 1970 GTO Judge Tribute Pro-Tour Project 535 IA2 http://forums.maxperformanceinc.com/...d.php?t=760624 1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car https://forums.maxperformanceinc.com...ght=procharger Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be |
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