[MrWrestlingII]

I need some help with the HEI timing curve for my 461, 230/236 @.050 HR, ehead build.

The HEI is setup to trigger a MSD 6AL using the green/purple wires. I’m thinking it’s a chevy unit but not sure, #’s stamped on the outside housing are 1103314 and 8M11 there’s also a raised 4D stamped on the inside. The center plate is stamped 364 and was installed with the stamping facing down, there are no markings on the weights. One of the springs is strong and the other is weak. With this setup the mechanical advance is 17*-18*, not sure at what RPM it’s all in as I was working alone. The vacuum advance canister is adding 10* and hooked to a ported source. My ehead setup is liking 36* (w/o vacuum advance), so to get there I need around 18*-19* initial which is more than the motor likes.


Searching on this site I found Rocky’s center plate/weight chart and see the 364 CP between 16*-18* facing up and 22* facing down. I’m thinking the weights in my unit are pulling it down to 17* facing down and if I flipped the CP I’m thinking it would drop further. So if I want 36* total with 14* initial then I’ll need a CP/weight setup that gets 22*. There are a number of CP/Weight combos on Rocky’s chart that do this. I’m thinking I’ll put the unit back together and run it as is while I try to locate the parts needed to get it setup correctly.

So the first question is, what CP/Weight/Spring combo will get the timing curve needed? The second question is, does SunTuned or anybody else sell these parts?

Thanks for any help,
Todd

[MrWrestlingII]

Attached is Rocky's chart and an old thread that helped me immensely with understanding how the timing curve works.

http://forums.maxperformanceinc.com/...erplate&page=3

[george kujanski]

Can`t be a chevy unit, they turn opposite to ponchos. The location of your vac advance shows it to be a Pontiac.

George

[MrWrestlingII]

Originally Posted by george kujanski

Can`t be a chevy unit, they turn opposite to ponchos. The location of your vac advance shows it to be a Pontiac.

George

Makes sense, thank George.

[Dr.Corvette]

Here is a link to good article about timmig. http://www.chevytalk.org/fusionbb/sh...post/last/m/1/

[MrWrestlingII]

Originally Posted by Dr.Corvette

Here is a link to good article about timmig. http://www.chevytalk.org/fusionbb/sh...post/last/m/1/

I took a quick look at the article. One thing that has been debated on this forum at length is the ported/manifold source for the vacuum advance. My engine likes the ported source over the manifold source.

It idles just fine with the initial set between 10*-14* when using a ported source. Last evening I was testing for intial/mech advance with the vacuum disconnected. As I increased the initial I started getting run-on when shutting down the motor. I've read where others experienced the starter buck with too much initial. Heat plays into this also, and it was in the 70's here last night, so I figure it will only get worse with more heat.

At 14* initial my part throttle response really improves over lower initial values. Thinking about this maybe I'd be better off shooting for initial at 10* range and adding 4* to the vacuum advance. This way I'm thinking I'd still get the best part throttle response and the lower initial timing would be advantateous since the idle is good at the lower value.

Any thoughts?

[Rocky Rotella]

Give Sun Tuned a call, or send him a PM or email. He has produced a centerplate with the proper shape to get the 22 degrees of centrifugal advance you need for your combo. Otherwise you can hunt down a 375 centerplate and accomplish about the same.

[jonmachota78]

Work your way backwards. With the vac adv disconnected set the total advance to 35 by reving the motor until the timing stops advancing. Set at 35 and lock it down. You can do this yourself with a dial back light or additional marks on the balancer(just don't wear a neck tie). Then check and see where timing lands at idle. If you don't like where it ends up at idle then hunt for different center plate based on Rocky's chart. If timing is all in before 2800 rpm, or timing is not stable at idle then consider heavier springs. Last step is hook vac adv back up and limit it if necessary to eliminate ping.

[Sun Tuned]

Mr wrestling,
Erased your number by accident!
Call me back and ill finish what we started earlier today. Ill call you right back on my dime.

[Sun Tuned]

I also see why your not getting the 22 crank degrees you need.

Those weights are Moroso weights....

What you want/need is a set of factory weights, and those in the top picture ain't them!

Call anytime tonight, if you wish.

[abefromen]

Sorry for the hijack...

Bob any news on my distributor? Sent weeks ago.

[Sun Tuned]

What name is on the box?

Call me 901-412-4414

[Sun Tuned]

Too add to the chart Rocky had done search for the one I did also...

Search for the link

"
Hei advance curve values"

[MrWrestlingII]

Sun Tuned, I'll give you a call tomorrow to get the parts ordered up. I'll search for your chart and post it here also, I think that I know the one your talking about.

[Sun Tuned]

Man I apologize about not calling you back.

Not 5 mins after we got off the phone I goofed and cleared the call list!

What a dummy!

[MrWrestlingII]

It's really no problem, don't sweat it.

[MrWrestlingII]

Sun Tuned, I believe this is the chart you're referring to. As we discussed it shows the 364 CP with 12* at the distributor (24* crank), stamping down I assume, and 139 weights. For my setup this would require another 12* initial timing for a total of 36*. I did some testing on my initial timing and have no issues down to 10* at 800 rpm.

Question. If idle characteristics are good at lower intial settings is there any advantage to running a higher initial value? I'm thinking I would taylor my vacuum cannister for additional advance if the motor wants more timing at part throttle.

Centerplate=======Weights=======Dist.Degrees
368=================139=============10======
406=================139=============12======
349=================139=============15+=====
371=================139==============9======
489=================139==============14=====
375=================139==============13+====
364=================139==============12=====
397=================139==============12=====
370=================139==============12=====
346=================139==============11=====
396=================139==============11.5===
398=================139==============10.25==
383=================139==============12=====