Mechanical Advance Timing - Page 3 - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #31 (permalink)  
Old 09-23-2012, 10:19 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,153
Wiki Edits: 0

Thanks: 5
Thanked 380 Times in 374 Posts
Yes the springs you use will matter. Try a set of springs from a Mr Gasket advance kit for a HEI.
Check the free length when the spring is at rest. Check the weights for free movement.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #32 (permalink)  
Old 09-23-2012, 09:25 PM
ggevaert's Avatar
Registered User
 
Last photo:
Join Date: May 2011
Location: Ontario, Canada
Posts: 104
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Springs

Thanks F-BIRD'88, I have already ordered MSD PN 8248 (the proper spring advance set for my distributor) which should be in tuesday and I'm also going to look into the mrgasket one you noted. I also found a moroso HEI spring set sitting around and tried it as well but still got stuck at the 32 degree mark. (although those springs were tiny compared to the pro-billet ones)

A couple of questions:
1. These kits come with weights, are these supposed to replace the weights in the distributor to work in conjunction with the springs included in the kit or are they only there in case you need new weights because the current ones are old/worn? I have a brand new MSD so the weights are working smoothly so I thought I would not need to change.

2. Can you elaborate on what you mean with
Quote:
"Check the free length when the spring is at rest. Check the weights for free movement"
.
I think I know what you mean with the first one; Some of the springs I did note were really tiny and I had to open them quite a bit to put them on so I can see them being limited. As for the weights; they are snug and not moving when I jiggle them at rest; they move smoothly out and snap right back. With 'free movement' do you mean they should not move (i.e. slop in them) when at rest or do you mean they move easily out and back?

Thank You!
Reply With Quote Quick reply to this message
  #33 (permalink)  
Old 09-28-2012, 08:58 AM
ggevaert's Avatar
Registered User
 
Last photo:
Join Date: May 2011
Location: Ontario, Canada
Posts: 104
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
When I run the distributor without springs and with the stop screw installed (36 degree stop) it goes to 36 degrees but then starts to go backwards when I get above 3000; not an issue, just wondering why it does that? I went to 4500 and it went all the way back to 30 degrees on the timing tape. Interesting.
Reply With Quote Quick reply to this message
  #34 (permalink)  
Old 09-28-2012, 03:40 PM
Registered User
 
Last photo:
Join Date: Mar 2007
Location: Corinth, MS
Posts: 607
Wiki Edits: 0

Thanks: 0
Thanked 30 Times in 29 Posts
Try a different timing light, one without a dial back function. MSD ignitions have been know to mess with lights, especially if its a dial back type.
Good luck,
ssmonty
Reply With Quote Quick reply to this message
  #35 (permalink)  
Old 09-28-2012, 05:03 PM
ggevaert's Avatar
Registered User
 
Last photo:
Join Date: May 2011
Location: Ontario, Canada
Posts: 104
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
timing light

Thanks ssmonty,

I'll pull my old light out of semi-retirement and check it out. it has no dialback feature on it.

I actually went out and bought a brand new OTC 3367 last weekend because of the concern with MSD (and I needed one that would work with an MSD ignition box for my impala restoration).

I'll update when I compare the two readings tonight.
Reply With Quote Quick reply to this message
  #36 (permalink)  
Old 09-29-2012, 09:29 AM
ggevaert's Avatar
Registered User
 
Last photo:
Join Date: May 2011
Location: Ontario, Canada
Posts: 104
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Stumped

Ok, I'm officially stumped and need some assistance. I'm using the MSD HEI advance medium springs. Initial is set at 17 degrees

1. with no springs and the stop advance screw in it stops at 36 degrees perfectly all the way up
2. With medium springs an NO stop advance screw I get 42 degrees at 4500
3. with medium springs and a stop advance is stops at 31 degrees all the way up.

huh? if the springs by themselves go over 36 and the stop stops it at 36 would that not have it stop at 36? I just don't get it.

I have played with over 3 different companies springs (Morose, MSD pro billet springs, MSD HEI springs and I have a mr gasket HEI kit on order). I have played with light all the way to heavy and numerous combinations of lights, mediums).

I made another screw and shaved it down to stop at 40; testing with springs showed it to stop, yup you guessed it, at 31.

I'm not sure where to look next. Any thoughts are appreciated.

I used a screw as the picture that F-Bird'88 sent, maybe another approach is needed? what are the alternatives (short of buying the pro-billet one with the built-in stop)

BTW, confirmed timing with another timing gun, a non-dial back light.

Thanks for any help
Gary
Attached Thumbnails
Click image for larger version

Name:	Sept 29 001-web.jpg
Views:	105
Size:	127.9 KB
ID:	68176   Click image for larger version

Name:	Sept 29 002-web.jpg
Views:	98
Size:	121.6 KB
ID:	68177   Click image for larger version

Name:	Sept 29 007-web.jpg
Views:	87
Size:	140.1 KB
ID:	68178  

Last edited by ggevaert; 09-29-2012 at 09:56 AM.
Reply With Quote Quick reply to this message
  #37 (permalink)  
Old 09-29-2012, 06:12 PM
Registered User
 
Last photo:
Join Date: Mar 2007
Location: Corinth, MS
Posts: 607
Wiki Edits: 0

Thanks: 0
Thanked 30 Times in 29 Posts
Just my two cents,
Your distributor looks just like the MSD HEI Streetfire that I have laying around. I had issues with the advance mechanism not being as smooth as I thought it should be in certain positions. With no spring yours may let one weight get out in front of the other and bind(see pic,near thumb). I had to grind the end of one weight to keep it from catching. It may never have got to that position in normal use with springs. I'm just too picky(anal).
I swapped the weights out with a MSD Advance Kit PN 8428 and it seemed to be smoother.
However, I bought a MSD rev limiter module that was advertised to fit Stock and aftermarket HEI's, but low and behold it wouldn't fit in the streetfire????
I made a mod to it to get it to fit, but was still disapointed.
I decided to use an older MSD 8365 Pro Billet I had on another engine instead.
Something sure doesn't make sense with your timing being more advanced with springs vrs none. You sure the harmonic balancer outer ring isn't moving around on the hub(doubt it on a new engine)? Brush a thin line of paint across the two(from center outward) to be certain. You'll alwas know in the future if it has if the lines aren't straight.
I suspect the weights aren't as smooth as they should be, but thats just me. Might try the kit I mentioned.
Good Luck!
ssmonty
Attached Thumbnails
Click image for larger version

Name:	DSC03595 (Small).JPG
Views:	81
Size:	47.9 KB
ID:	68192   Click image for larger version

Name:	DSC03596 (Small).JPG
Views:	80
Size:	23.0 KB
ID:	68193   Click image for larger version

Name:	DSC03597.JPG
Views:	108
Size:	1.54 MB
ID:	68194  

Last edited by ssmonty; 09-29-2012 at 06:20 PM.
Reply With Quote Quick reply to this message
  #38 (permalink)  
Old 09-29-2012, 06:33 PM
Registered User
 
Last photo:
Join Date: Mar 2007
Location: Corinth, MS
Posts: 607
Wiki Edits: 0

Thanks: 0
Thanked 30 Times in 29 Posts
Sorry, I forgot to mention that I had to trim the bushings to get them to fit under the e-clips that hold the weights in place with the advance kit.
ssmonty
Reply With Quote Quick reply to this message
  #39 (permalink)  
Old 10-06-2012, 11:32 AM
ggevaert's Avatar
Registered User
 
Last photo:
Join Date: May 2011
Location: Ontario, Canada
Posts: 104
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Ongoing distributor saga

Hi SSmonty,

I tried swapping out weights with the advance kit specified from MSD for the streetfire and I didn't like it; the timing came in all at once at around 1800 (from 18 to 32 in about 200 rpm). All the different kinds of springs did was move the all-in point around but there wasn't a smooth curve so I went back to the stock setup. I have not played with shaving or changing the weights as that would be somewhat final so don't want to go there yet.

I checked the weights movement and there is no binding anywhere.

The MSD advance kit 8428 is the one I'm using now (since it is the one actually for this unit - the pro-billet kit was not)

I put a bright green line on the balancer since the day I got the engine and its still bang on.

I'm now actively saving up for a pro-billet unit but until that time I'm going to play with the Holley setup and maybe, when I have patience back, play with the ignition advance again

Thanks for all your continued help
Gary
Reply With Quote Quick reply to this message
  #40 (permalink)  
Old 10-06-2012, 01:42 PM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,153
Wiki Edits: 0

Thanks: 5
Thanked 380 Times in 374 Posts
Now I know why I stick with using Good used Stock OEM GM HEI distributors. That I modify to get the curve I want.
I have never had a problem getting a smooth consistant advance curve. Usually using the stock OEM weights and just swapping the spring and establishing the mechanical advance limit with the machine head screw.
The stock weights and center piece usually allows a 20-22 deg advance curve.
In your pictures the advance weight appear warped......

????????
Reply With Quote Quick reply to this message
  #41 (permalink)  
Old 10-06-2012, 01:48 PM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,153
Wiki Edits: 0

Thanks: 5
Thanked 380 Times in 374 Posts
You have multiple threads on the go all related to the same issue.
What camshaft? what torque converter?
Reply With Quote Quick reply to this message
  #42 (permalink)  
Old 10-06-2012, 11:24 PM
ggevaert's Avatar
Registered User
 
Last photo:
Join Date: May 2011
Location: Ontario, Canada
Posts: 104
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
distributor

Thanks F-Bird'88, I'm going to check the advanced weights but since the whole distributor is new I don't think it would be warped; then again you never know.
I am more convinced now that the pro-billet (made in US of A) is the way to go. I read an article about a week ago where MSD was indicating their streetfire was chinese made and was their attempt to stay in the market they were losing to low cost alternatives. The way I read it they were pretty much apologizing for the lower quality of the unit.
Personally I don't like to scrimpt on certain things and the streetfire was a mistake so I'm going to correct that with a pro-billet. I already have a friend who will take the streetfire off my hands for a stock application and he will give me 90% of the units value so that helps.

I have multiple threads but they are not related. One is for mechanical advance (this one), one if for holley setup - transfer slot and one is for Holley setup - Choke. I guess you could say they were all related to engine tuning but I personally like to keep subjects separate as change-of-topic questions get lost in the discussion sometimes.

As for Cam shaft and torque converter specs; they are:
Cam: 450 lift, 224 duration, 206 lobe centre
Torque converter: new 1500 stall unit from GM - 2 years old now. (long story, had a 2500 in there and it went bye-bye when the transmission fried and now I have a rebuilt thm-375 tranny with 1500 staff as recommended by the tranny shop).

Thanks for the feedback, I guess my next step in this thread is to get the HEI Pro-Billet and go from there. I'll update how that goes when it comes in.

Cheers

Last edited by ggevaert; 10-06-2012 at 11:32 PM.
Reply With Quote Quick reply to this message
  #43 (permalink)  
Old 10-07-2012, 12:03 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,153
Wiki Edits: 0

Thanks: 5
Thanked 380 Times in 374 Posts
You have the wrong converter for this 224 -106 LSA cam.
That is why it drops rpm in gear so much.
The 106 LSA cam needs 24 to 26deg initial timing and a 10" 3000 stall.

Shorten the timing curve to 10deg to allow this, using a screw with a bigger head diameter to restrict the advance travel more.
Reply With Quote Quick reply to this message
  #44 (permalink)  
Old 10-07-2012, 11:00 PM
ggevaert's Avatar
Registered User
 
Last photo:
Join Date: May 2011
Location: Ontario, Canada
Posts: 104
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Torque converter

Thanks! I'll play with the timing tomorrow.
The torque converter is a bit trickier as I have to order one, drop to the tranny, blah blah blah, you know the deal.

I think I need to read up on the torque converter and how it works as I know the basics but not how/when it kicks in when you have a 1500 vs a 3000. i.e. does putting a 3000 in gear do nothing when the idle is at 1000 or does the car try to move (my 1500 will try to move). Do you need to be reving at 3000 (or close to that) before the car starts the move. Not that familiar, yet, with workings of the torque converter when it comes to actually when they engage. Another area for me to read up on; exciting!
There was probably a good reason why the engine/tranny combo came with a 2500 stall.
When I destroyed the tranny pump, and therefore parts of the tranny, through improper spacing of the torque converter (another lesson learnerd) the tranny shop recommended/put in a 1500 unit. But they never asked what engine setup I have. jeez.

I did not pick the specs on this engine so what's the deal with this setup F-Bird88, is it a street/strip type of setup or more agressive than that?
I do want to be able to drive the setup on the road and I'm concerned about the high stall.

Thanks for all your continued help!

Ps. the mech advance stop will be much easier when I get my MSD 8365 in

Last edited by ggevaert; 10-07-2012 at 11:19 PM.
Reply With Quote Quick reply to this message
  #45 (permalink)  
Old 10-08-2012, 12:44 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,153
Wiki Edits: 0

Thanks: 5
Thanked 380 Times in 374 Posts
the stall of a 3000 converter is progressive relative to power input (Throttle)
yes the car will move fine with small throttle inputs. A torque converter is not a on off switch.

The max stall is not achieved untill full throttle is applyed from a stop assuming you have good traction.
The hyd coupling is loser at idle allowing a cammed up motor to idle easily in gear.

Overall part throttle low speed driving.: instead of hugging the 1300 to 2000 rpm range when driving from a stop at part throttle the engine rpm will hug the 2000 to 2500 rpm range on initial acceleration from a stop.
Heavyier throttle input results in higher engine rpm rise on acceleration, relative to throttle input.
Up to the point of full throttle. The car still move but the engine rpm is higher.
Once the vehicle reaches the desired steady cruising road speed, converter coupling is very near 1:1, much like a stock low stall converter. Engine rpm is very near normal. You only see the difference (higher engine rpm) when accelerating. It takes a few weeks driving to get used to a high stall converter, compared to a "stock" low stall converter..
Do not combine with low numerical gears. like 2.73:1 or 3.08:1.

GM th-350 and th400 torque converters.

A GM 13: converter stalls about 1300 to 1500 dehind a 350
a GM 12" converter stalls about 2100 rpm behind a 350.
A GM 11" converter stalls at 2800 behind a 350.
A GM 10" converter ( tight design) stalls about 3000-3200
a GM 10" "3500stall) stalls around 3500-3600 behind a 350
A GM 10" converter can be tuned to stall up to about 4500 behind a 350 ( race converter)
9" and 8" race converters can be tuned to stall anywhere from 3200 to 7000 rpm for a 350.
Race converters do no act like a switch and still drive well on the street as long as the gearing is agressive.

the same converter using behind a 300CID motr wil stal about 500rpm less
The same converter used behind a 454cid motor will show a higher max stall ( about 500-700rpm)
The max stall speed seen is relative to engine torque input.

If you want to know what torque converter you need, call the torque converter company.
B&M TCI, ATI Hughes. etc.
Ya get what you pay for.
A good 10" 3500 stall cost about $350-$450
A good full race converter cost $500 to $1200 (custom built)

if you ask the local trans shop what torque converter you need they will sell you what they have in stock want to sell you, not what you really need.

Last edited by F-BIRD'88; 10-08-2012 at 01:05 AM.
Reply With Quote Quick reply to this message

Tags
chevy

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 2 (0 members and 2 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
vacume advance or mechanical advance? BigBlockT Engine 1 06-08-2009 07:05 PM
Limiting Mechanical Advance Greg T Engine 10 07-06-2008 06:11 AM
Total advance, initial, mechanical and vaccum advance Can anyone break it down Please Brawler Engine 2 09-07-2007 07:25 PM
Vacuum Vs. mechanical advance stinky jinx Engine 7 11-02-2004 11:09 AM
distibutor mechanical advance only camaroguy_1967 Engine 5 07-03-2003 11:22 PM


All times are GMT -6. The time now is 03:27 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.