Who Can Change the Amount of Mechanical Advance My Distributor Adds?
jim larson said
Feb 17, 2011
Now that I have torn down my engine and put it back together I am trying to get it to run a little better and a little cooler.
Based on the cam that I found in the engine, I would like to run the initial base timing at 16-18* and have the distributor changed so it adds only 18*of mechanical advance with all in around 3000 rpm , so I would have a total timing of 34-36*. The distributor is a stock distributor from 66 with stock weights and springs that the books says adds 0* at 900 rpm increasing up to 30* @ 5000 rpm. Stock timing was set at 4* advance base timing.
Any suggestions or recommendations as to where I might have this done. Do they just put in lighter weights?
Thanks,
-- Edited by jim larson on Thursday 17th of February 2011 08:55:11 AM
Bowtieman427 said
Feb 17, 2011
Accel, Mallory, MSD, and what not use to sell weights and spring kits. I would think you would start with the springs. Others will chime in that know more.
jim larson said
Feb 17, 2011
Not to up on these kits; but I thought that the spring kits will just determine when the mechanical advance is added according to rpsm. I am looking to reduced to total mechanical advance from 30* to 18*. I see there is a weight and spring kit with 3 different bushings that allow you to limit the amount of mechanical advance; but that is for a special distributor. Not an original Delco. I would think the weight would need to be changed.
Lost in the 60s said
Feb 17, 2011
Here's a Moroso kit for our cars. http://www.jegs.com/i/Moroso/710/72310/10002/-1 The profile on the inside of the pointed end of the weight is what dictates mechanical advance. If they allow too much, you tach a small weld bead on and then check. Ideally, the advance is too little and the bead is then hand filed down to stop where you want it. This CAN be done with the distributor in the engine and an advancing timing light but it is a long, hot task. It's much quicker to have it done in a Sun machine. I had mine done by a guy down In Shakopee while I waited. I had already dis-assembled, cleaned and lubricated it and installed a Pertronix III.
I would think some of the performance engine builders on the south side of the cities would have a Sun distributor machine or know where you could take it.
-- Edited by Lost in the 60s on Thursday 17th of February 2011 05:44:02 PM
jim larson said
Feb 17, 2011
Would prefere the south side as its closer to home. This way I could keep my old weights and springs. I still have the olds points set up. So it looks like you are recommending the Pertronix III? thanks.
Lost in the 60s said
Feb 17, 2011
I went with the Pertronix III and matching 45,000 volt coil in Black to look original. I was able to open the plug gap up to .042 also and it made a world of difference on starting and high rpm ignition stability. If you consider the Pertronix, look at StreetSide Auto in Kansas City. I found the best price on-line and then called them. They matched the price and ANY order over $50 gets FREE shipping. Summit and Jegs won't match that !!
SShink said
Feb 18, 2011
If you get up to the Cities, Competition Engines in Eagan has a spin up machine for disty's. They're going to check mine before the dyno clock starts.
Let me know if you want their phone/address.
jim larson said
Feb 19, 2011
SShink wrote:
If you get up to the Cities, Competition Engines in Eagan has a spin up machine for disty's. They're going to check mine before the dyno clock starts.
Let me know if you want their phone/address.
Thanks Stan. Do they actually change the amount of advance the distributor will add and also when the advance comes in or do they just test the distributor and tell you how much advance it has and when it is coming in?
I found a shop in Shakopee that will modify the distributor to limit the amount of advance and when it comes in. He says it involves complete disassembly of distributor 2 or 3 time to get it correct. Around $105.
SShink said
Feb 19, 2011
I think they will make spring and weight adjustments and then re-spin it for testing. They shot me a price of $20 to do this.
I'm sure they could handle the disassembly part of that if required. Not sure if they would have to go to that much work though.
Lost in the 60s said
Feb 19, 2011
jim larson wrote:
SShink wrote:
If you get up to the Cities, Competition Engines in Eagan has a spin up machine for disty's. They're going to check mine before the dyno clock starts.
Let me know if you want their phone/address.
Thanks Stan. Do they actually change the amount of advance the distributor will add and also when the advance comes in or do they just test the distributor and tell you how much advance it has and when it is coming in?
I found a shop in Shakopee that will modify the distributor to limit the amount of advance and when it comes in. He says it involves complete disassembly of distributor 2 or 3 time to get it correct. Around $105.
That's probably Jeff ? He did my Camaro distributor. He welds on the main shaft to limit the advance instead of the weights. That also includes complete cleaning and lube, which I had already done, so my charge was $65. I was going to suggest him, but it's a long way for you. He's actually closer to Jordan. I would call Competition Engines in Eagan and ask what they do. If you don't want permanent changes to your original distributor shaft, I think I have some stock weights around here I could build up with weld and then they could be filed down to get where you want to be.
jim larson said
Feb 19, 2011
Yes, that was Jeff S...., I won't be doing this for a little while after I run the car this spring when the snow melts. Just doing the research ahead of time. I have a set of springs that I played with a little the last couple of years, so a extra set of weights to change the profile like you mentioned might be a good idea. Will get in touch with you regarding this in the spring.
Leaving soon to spend some time in FL visiting our daughter and family. Only the hood left to install. Thanks.
Based on the cam that I found in the engine, I would like to run the initial base timing at 16-18* and have the distributor changed so it adds only 18*of mechanical advance with all in around 3000 rpm , so I would have a total timing of 34-36*. The distributor is a stock distributor from 66 with stock weights and springs that the books says adds 0* at 900 rpm increasing up to 30* @ 5000 rpm. Stock timing was set at 4* advance base timing.
Any suggestions or recommendations as to where I might have this done. Do they just put in lighter weights?
Thanks,
-- Edited by jim larson on Thursday 17th of February 2011 08:55:11 AM
http://www.jegs.com/i/Moroso/710/72310/10002/-1
The profile on the inside of the pointed end of the weight is what dictates mechanical advance. If they allow too much, you tach a small weld bead on and then check. Ideally, the advance is too little and the bead is then hand filed down to stop where you want it. This CAN be done with the distributor in the engine and an advancing timing light but it is a long, hot task. It's much quicker to have it done in a Sun machine. I had mine done by a guy down In Shakopee while I waited. I had already dis-assembled, cleaned and lubricated it and installed a Pertronix III.
I would think some of the performance engine builders on the south side of the cities would have a Sun distributor machine or know where you could take it.
-- Edited by Lost in the 60s on Thursday 17th of February 2011 05:44:02 PM
If you consider the Pertronix, look at StreetSide Auto in Kansas City. I found the best price on-line and then called them. They matched the price and ANY order over $50 gets FREE shipping. Summit and Jegs won't match that !!
Let me know if you want their phone/address.
Thanks Stan. Do they actually change the amount of advance the distributor will add and also when the advance comes in or do they just test the distributor and tell you how much advance it has and when it is coming in?
I found a shop in Shakopee that will modify the distributor to limit the amount of advance and when it comes in. He says it involves complete disassembly of distributor 2 or 3 time to get it correct. Around $105.
I'm sure they could handle the disassembly part of that if required. Not sure if they would have to go to that much work though.