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-   -   timing a chevy 350 question (http://www.wranglerforum.com/f118/timing-a-chevy-350-question-26114.html)

Felsengleiskette 01-31-2009 08:25 PM

timing a chevy 350 question
 
i'll ask in the YJ section in my build thread, but what is the timing supposed to be for a chevy 5.7L 350 w/ h.e.i ignition and vacuum advance. on a carb application?

jpdocdave 01-31-2009 09:06 PM

plug the vacuum advance, and set the timing by turning the distributor and looking at the timing mark on the crank with a timing light.

Felsengleiskette 01-31-2009 10:15 PM

yeah, i know how to set timing. but what do i set it to? 10 degrees + or 13? what number do i set to

jeepjeep 02-01-2009 12:30 AM

there are many factors compression ratio, altitude, what octane are you going to be running but 8 to 10 btc should work fine... you can be more agressive with timing if you use the higher octane.

ccrane2299 02-01-2009 12:44 AM

Turn it up until it pings under hard acceleration turn it down until it quits. When it gets hot you'll probably have to turn it down some more.

jpdocdave 02-01-2009 10:09 AM

ya there's some factors. i just did an el camino thats been restored, the manual said 6 degrees btdc, but it really wasn't enough. 8-10 is probably good, and then see how it likes it, like already said.

Felsengleiskette 02-01-2009 03:13 PM

thanks guys. maybe i didnt know how to set timing after all! lol. i had set it w/ vacuum on and air cleaner off. until i got to 10 btdc. so now i'll set it w/ air cleaner on and vacuum plugged at carb. compression ratio is low, like 8.5-9 to 1. cheap gas. 76cc heads flat top pistons stock spec bore , normal stroke.

Coyote_94YJ 02-01-2009 05:56 PM

Ya, for your setup start out with 8-10* BTDC and go from there. I have mine at about 12* but I'm bored over w/10:1 pistons and have a hotter cam. One thing I did notice in your redux thread, in the top picture it appears you have the vacuum advance hose on the wrong vacuum port on the carb. It should be on the full time vacuum (driver side) not the ported vacuum (passenger side) on that Edelbrock. What size carb did you go with? 600?

Felsengleiskette 02-02-2009 12:45 AM

wow, intresting. i have the 600 electric choke carb (edel) now the installation cd and booklet said to use the passenger side. but this is wrong???

Felsengleiskette 02-02-2009 12:48 AM

man, i gotta check that out right now and make sure i got that right.

Coyote_94YJ 02-02-2009 02:59 AM

The ported vacuum on the passenger side has a delay for computer controlled engines. You don't want a delay in the advance. As soon as you push on the pedal you want it to advance so you can go. You'll get a much better throttle response if you hook that up to the driver side. :D

Lancem 02-02-2009 11:51 AM

Quote:

Originally Posted by coyote_94yj (Post 317786)
The ported vacuum on the passenger side has a delay for computer controlled engines. You don't want a delay in the advance. As soon as you push on the pedal you want it to advance so you can go. You'll get a much better throttle response if you hook that up to the driver side. :D

Sorry, but when you push on the gas the vacuum goes away, vacuum advance really only comes on when you are off the throttle, so that emissions are reduced. :)

There has always been a debate as to wether to connect it to ported or unported vacuum, I agree on unported as the way to go on a performance engine.

Coyote_94YJ 02-02-2009 02:01 PM

Oops. Your right.... It should read like this.

The ported vacuum on the passenger side has a delay for computer controlled engines. You don't want a delay in the retard. As soon as you push on the pedal you want it to retard so you can go. You'll get a much better throttle response if you hook that up to the driver side. :D

I was in a hurry to get out the door and on my way to work....in the SNOW!! :D

Felsengleiskette 02-02-2009 02:37 PM

now wait a minute. i just checked the installation cd and booklet, and called the tech line for edelbrock and they said the drivers side is manifold vacuum and is used for an automatic transmission which i have. so i am supposed to hook it up the way i already have it. the passenger side (ported) is for the vacuum advance. why is there a conflict with what your saying?

Felsengleiskette 02-02-2009 02:42 PM

i built only a slightly better than stock engine. not really a performance engine. wanted a fuel ecenomical 350.

Coyote_94YJ 02-02-2009 03:06 PM

Well you can run it on either side depending on the application. Since your running an automatic you can run the driver side to the tranny and the passenger side to the distributor. For some reason I thought your were running a 4 speed. I have tried both ways and they both work. I get a quicker throttle response by running it on the driver side, and have heard the same from other people. You can leave yours how it is for your automatic. My 350 is very mildly built. It is by no means a race engine. It was built for low end torque and mild performance while trying to keep the gas guzzling to a minimum.

Lancem 02-02-2009 04:22 PM

Quote:

Originally Posted by Felsengleiskette (Post 317892)
i built only a slightly better than stock engine. not really a performance engine. wanted a fuel ecenomical 350.

If you only drive half sane you'll get better MPG than either of my stock YJs :D

Lancem 02-02-2009 04:24 PM

Quote:

Originally Posted by coyote_94yj (Post 317882)

I was in a hurry to get out the door and on my way to work....in the SNOW!! :D

That's right you guys got a bit over there didn't you! Well you are welcome to all the rest we're going to get here and any we get next year too :D

Felsengleiskette 02-02-2009 07:25 PM

thanks guys...i took it to a shop to have everything checked out. i timed it w/ advance off and capped at the carb, and it still shuts down with a load (driving) maybe its something else...fuel metering/air,vacuum leak somewhere...idunnno. this is beyond my experience. but from accross the pond and everyone else thanks! i'll let you know how it turns out.

Coyote_94YJ 02-03-2009 12:09 AM

Well best of luck. I do have one other question. I'm assuming that carb is/was new in the box when you got it. Did you set the float level?

Felsengleiskette 02-03-2009 12:25 AM

uhh no. its out of the box. whats that?

Felsengleiskette 02-03-2009 12:35 AM

Quote:

Originally Posted by Lancem (Post 317923)
If you only drive half sane you'll get better MPG than either of my stock YJs :D

yeah my old setup: 2.5L ax5/4" +2"BL on 33's w/ 4.10's was only getting at best 10mpg. when i took it on the freeway it was worse...the fuel lvl gauge moved damn near as fast as my 10/th mile wheel!

Felsengleiskette 02-03-2009 12:48 AM

hey coyote, what belly pan is that? it's kinda what i'd need due to the further back my t-case is now from the final conversion length.<-my front shaft is further back, and now needs to drop into my stock pan. esp. when axle articulates ( i will eventually go soa).

Coyote_94YJ 02-03-2009 05:22 AM

Quote:

Originally Posted by Felsengleiskette (Post 318300)
uhh no. its out of the box. whats that?

If you didn't set the float level that could be your problem with it. The float level should be set at the factory (I've been told) but when I got mine one was off by a whole inch and the other was off by about 3/4" and my jeep would about die when going around turns or under hard acceleration.

Quote:

Originally Posted by Felsengleiskette (Post 318312)
hey coyote, what belly pan is that? it's kinda what i'd need due to the further back my t-case is now from the final conversion length.<-my front shaft is further back, and now needs to drop into my stock pan. esp. when axle articulates ( i will eventually go soa).

The belly pan on my jeep is one I made. Eventually I want just a piece of thick flat steel from the front spring buckets to the rear spring buckets with cutouts for the drive lines.

Felsengleiskette 02-03-2009 10:00 AM

man, i was lookin' ovr your rig pics and you did a stellar job! could you maybe shoot me a shot of your pan design so i have an idea of how it needs 2 b constructed? like how its re-enforced, and thickness of steel i should get? i still need to re-clock my t-case (hangs just past the current pan a bit) i like the complete skid your talkin' about from leaf to leaf<---nice protection. but as of now i cant even fit my front shaft.

Felsengleiskette 02-03-2009 10:05 AM

and i also see you retained your jeeps computer...how come? does it still control some stuff? mines sittin' on the garage floor.

Coyote_94YJ 02-03-2009 12:00 PM

Thanks. Distortedtj had a hand in its disassembly and reconstruction.

My jeep is currently getting its MOT inspection (Ministry of Transportation) and a new windshield. I won't get it back till tomorrow night so I won't be able to get you measurements till then. There should be some pics of just the crossmember as it was being built in with the other pics somewhere. I can tell you that the triangle pieces are 1/4" thick from chunks of scrap armor plating. :D So you might say it's bulletproof.

The computer is there to get wires through the firewall. It isn't used for anything else really. I cut out all the wires that weren't needed clear back to the ECU and re-loomed the entire engine bay. It might do one or 2 things that I can't think. I can't imagine the amount of codes that thing has probably stored up. :rofl:

Felsengleiskette 02-04-2009 07:38 PM

well, an update of my situation is that my problem isnt timing at all! the shop doesnt have the culprit yet but what it is doing is idling then the engine just shuts down like the key was turned off. so they are leaning towards ignition system. i got a mallory hei, w/ a mallory hyfire igniotion box. i took the mod out of the distributor, to be able to wire it correctly to the control box. <--this was spelled out how to do by mallory. so i think the distr. is working fine. the control box is a basic solid state type electronics, so im to assume if it powers up it is running fine....now, i do have my control box mounted on the fire wall directly behind the distributor. its like 3"inches away from it. when mallory asked where my box is mounted in relation to the distributor he said that was most likly causeing my problem, and the control box needs mounted further away from the distributor due to the static interference that is being generated by the distributor causing the engine (or control box) to shut down. does this sound like a valid point? mallory says that the control box should be at least 18 inches away from the distributor. i've never heard this before. is it a special circumstance due to the pairing of a hei in close relation to the ignition box???

Coyote_94YJ 02-05-2009 04:21 AM

I don't know but it sounds plausible. Electronics are a funny thing and it is possible that's what your problem is. It's worth a shot to try it.

Felsengleiskette 02-06-2009 03:26 PM

ok, the jeeps running fine. it turned out to be a bad control box (my luck) now should be last question...i have no experience w/ hedman headers. my header tubes get damn hot...to where you can just start to see a glow. not red hot but pretty damn hot! is this normal? could i be to lean on the gas? just need to know if this is a tuning problem or a mechanical problem due to building the engine?


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