Ignition Timing

[rags]

Because?

Kevin

'cause manifold vacuum for timing is bu11$hit. no offense. where's cbarge when i need him?!

 

[70bigblockdodge]

'cause manifold vacuum for timing is bu11$hit. no offense. where's cbarge when i need him?!

It depends on the engine some can be crutched by putting it to manifold vacuum and if it runs better who cares.

 

[rags]

crutched

thanks. oops put it gear. where'd my vacuum go? where'd my timing go? where'd my idle speed go? stalled it! a/c load? same. p/s load? same. turn the head lights on. blower on high. charging load. same. just pass.

 

[70bigblockdodge]

thanks. oops put it gear. where'd my vacuum go? where'd my timing go? where'd my idle speed go? stalled it! a/c load? same. p/s load? same. turn the head lights on. blower on high. charging load. same. just pass.

You must run into the car in front of you alot if your vacuum on a stock car is that bad.

 

[rags]

You must run into the car in front of you alot if your vacuum on a stock car is that bad.

seems more they'd be running into me. next.

 

[70bigblockdodge]

seems more they'd be running into me. next.

What? Put your vacuum where you want. Superfragle seemed confused, a couple of us gave him some opinions and options and tried to eliminate his confusion thats all wedid not tell him he had to put the vacuum in one place and one place only per FSM which is for a stock engine and his is not. Sure the right way to do it is to figure out how much initial it wants to idle with highest vacuum and if it will start hot with that much initial weld to slots up to limit the mechanical advance from initial to total. You keep putting it on the ported spot and I will put it where the engine runs best.
Next. Whatever that means.

 

[rags]

[QUOTE="70bigblockdodge, post: 336815, member: 1739 a couple of us gave him some opinions and options[/QUOTE]
no doubt. as is said so often here, thank you for contributing. i actually appreciate all the help that you and so many others give on this site. next: ball is in your court.

 

[70bigblockdodge]

You gave no options only opinions thank you for quoting service manual with no explanation. Thanks. Just keep the ball

 

[rags]

the service manual doesn't say "manifold vacuum for timing is bu11Shit". i'm saying it. just happened that it's true. maybe we could let superfragle try the options that have been offered to him and let him get back to us. truce?

 

[superfragl]

thanks. oops put it gear. where'd my vacuum go? where'd my timing go? where'd my idle speed go? stalled it! a/c load? same. p/s load? same. turn the head lights on. blower on high. charging load. same. just pass.

I don`t see a problem here - I can tweak the vacuum advance can to kick in at 5 inches, then even in gear I will still have same vacuum advance timing. The load (PS, blower, etc.) on the other hand is something different and I am not sure how much it will affect the idle..

I built a run-in stand last night, hooked up the old torque converter and transmission and put the motor on the stand. Still have to do a temporary wiring, exhaust, a few other things. I hope by next weekend I will be able to fire it up, brake it in and figure out the timing.

 

[rags]

the point i was making, in all seriousness, was that manifold vacuum varies with different engine loads especially at idle. turn on the a/c, turn the power steering, etc will all lower the manifold vacuum and reduce the timing, then the idle, which reduces vacuum more. ported vacuum isn't a factor at idle so changes in load have less effect. ported provides a steady strong vacuum off idle when it's needed, where manifold won't. there were so many low compression smog motors during the eighties that used manifold vacuum. i had to switch EVERY one to ported where possible, both to get them to pass emissions in ct, and run good. strange then that all the high comp. motors from the sixties came factory with ported, and the low comp. smoggers cam with manifold. to run it in have a timing light real handy. get the timing in range as quickly as possible. i'd leave the vacuum adv. disconnected just so the timing stays stable. i think that's most important at this stage. my apologies for any unpleasantness.

 

[superfragl]

I have fired up the motor last night. Did not complete the break in due to engine getting hot. I set RPM to 2000 and with vacuum advance disconnected and timing set at 36. Ran like this for 10 min and temp got up to 210, then I shut it off. Will try to run it again tonight. Should I advance timing even more? I was thinking - at this PRM vacuum advance would have kicked in full (i get 22 in of vacuum) giving me 18 degrees, plus initial 10, plus mechanical another 10-15, it is around 40 in total?..
I am running 160 t-stat. I pulled it out and checked again for proper operation - it starts opening at 165 and fully opens at 195. Perhaps, I should replace it.
All I have for fan right now is a window fan that is large enough to cover the whole radiator, but the air flow is not that great, which could have contributed to overheating. The radiator is 26" aluminum from Speed cooling - 2 rows of 1" tubes.
Should I be concerned? A rebuilt motor would always run a bit hotter in the beginning?

 

[twostick]

No engine driven fan? A window fan won't cut it alone.

Also verify that it really is running running what the temp gauge says with a laser thermometer if you have one. I had a heat gauge once that was off over 30 degrees.

Kevin

 

[superfragl]

Yep, was testing with infra-red gun.
I will put the water pump fan on tonight, however, I do not have the shroud yet.

 

[rags]

God help ya', no more timing! the word "BOOM" comes to mind! just to run it on a stand, i'd say 25 tops. a 160 stat that fully opens at 195 is junk. checked it with the heat gun in pan of boiling water? parts store thermostats all need to be checked. coolant temp should run no hotter than regulated by stat. also use the heat gun to check exhaust manifold temps against timing. if it's too late or mixture too rich manifolds get red hot. fan shroud would go a long way. please sir, don't get injured running it like this. stay safe, SG

 

[superfragl]

Replaced the thermostat with new 160 from Napa (checked before installing ) and put the fan on. What a difference! The engine is running 160 no matter what you do.
Why would I limit the timing at 25? Please explain.
Here's what I did. Tried manifold vacuum and the timing at idle would be jumping between 12 and 20 with initial timing set to 10. Switched to ported and set initial to 20 - engine seems to idle smoother. When I set rpm to 2000 mech advance plus vacuum give me 40 degrees. No backfire or any hard starting. A couple times after I sharply open-close the throttle it would slightly pop in the mufflers, but I think it is due to extra gas not burning completely and no load on engine.

 

[65sporty]

If it runs good at 40 leave it, but it will be different in the car because of load. You may have to tweak it a little but it sounds like you are on the right path.

 

[rags]

set initial to 20

on the street i'd run 8-10 with ported (of course). on the stand my only concern would have been total timing at break in rpm. 2000 rpm, 25 to me sounds right. the advance added 20. start at 10 that gives 30. running on a stand, no load, start at 5. with advance gives 25. not bad hmm? how's the exhaust manifold temp? too hot, bump the timing up a little. coolant temp should always be +/- 5 degrees of properly functioning stat spec. you're right about the backfire. great to see that it's all working out. again, stay safe.