Distributor Swap

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Ken B

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I have an 85 350 with electronic spark control ( been bypassed/ jumpered), I want to replace the distributor and get the engine running well. Is there anything out of the ordinary to swapping out the old with a new distributor?
Donor engine, and want to get everything working well before I pull it....so I can run it and test it for a while.
 

bucket

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It really is as simple as removing the old and dropping the new one in. My go-to is the MSD Street Fire distributor. They work well, seem to have quality parts and you can even get them from places like Advance and O'reilly's.
 

Ricko1966

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I am confused does the donor engine not have a distributor?
 

Ken B

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It does, I was referring to the Electronic Spark Control. I was asking (poorly) if there was anything special needed to be done to change out the ESC distributor.
 

Ricko1966

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If the donor has a distributor, leave the distributor in the donor motor it is probably the correct one for that engine.
 

Ken B

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I was thinking about changing the distributor to get rid of the two wires twisted together to bypass the ESC.
That was my reason.
 

Ricko1966

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I am so confused about what you are doing.Are just swapping distributors, are you swapping engines.Why are you swapping distributors from engine to another. If the donor engine has a working distributor your best using the distributor that is in the donor engine, even if it is a bypassed ESC distributor. If your car has the bypassed ESC distributor your best using it rather than swapping distributors. All distributors do not have the same curve, all distributors do not have the same amount of centrifugal advance or rate of advance, all vacuum cans do not have the same amount of advance, all vacuum cans do not operate with the same amount of vacuum. Your best bet is use the distributor that by the factory was designed with the proper curve and vacuum can for your engine. Now please tell us as clearly and completely what your goal is and why you are trying to swap distributors.
 

Ken B

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I apologize for the confusion.
I am swapping the engine and I was looking into replacing the distributor to eliminate the esc.
I can absolutely leave distributor and be done. I am wanting to get the 350 donor motor running as best I can prior to pulling it out and putting it I. My project .
 

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I'm battling with an ESC distributor now but am trying to keep things as original as possible so I'm doing what I can for the reasons Ricko mentioned above.

You say you have the ESC jumpered now so you have basically eliminated it already. It should run well as is, might have to play with the timing a little though.

If it was me I'd get the engine running well as is, do the swap and see how things go.
 

Bextreme04

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I apologize for the confusion.
I am swapping the engine and I was looking into replacing the distributor to eliminate the esc.
I can absolutely leave distributor and be done. I am wanting to get the 350 donor motor running as best I can prior to pulling it out and putting it I. My project .
As @Ricko1966 said, if there isn’t anything wrong with it now, I wouldn’t mess with it. Especially if it’s just a fully stock motor. If you start messing with compression ratios, heads, intakes, cams.... then all bets are off and you should be dialing in your specific engines timing curve and then you can use whatever distributor you want.

Bottom line is you won’t gain anything by changing out the distributor unless there is something wrong with the one you have or you have custom stuff in your engine. However, you can really screw up a perfectly good running engine by trying to mess with something that isn’t broken, yet.
 

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Thank you all. If it ain't broken I ain't gonna fix it.
 

AuroraGirl

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Thank you all. If it ain't broken I ain't gonna fix it.
the only thing I would say is if you change it, change the advance weights. but you arent going to touch it, so no need to worry.
I have a shelf of distributors but I think im just gonna refurb one and keep it for a rainy day
 

Ricko1966

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the only thing I would say is if you change it, change the advance weights. but you arent going to touch it, so no need to worry.
I have a shelf of distributors but I think im just gonna refurb one and keep it for a rainy day
There is a lot more in there than weights.There are different tension springs, there are eccentrics with different shapes, there are different length slots for centrifugal, there are bunches of different vacuum cans that bring in different amounts of advance and bring it in at different vacuum levels.
 

Ricko1966

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I'm battling with an ESC distributor now but am trying to keep things as original as possible so I'm doing what I can for the reasons Ricko mentioned above.

You say you have the ESC jumpered now
so you have basically eliminated it already. It should run well as is, might have to play with the timing a little though.

If it was me I'd get the engine running well as is, do the swap and see how things go.[/QUOTE
If I had a failed esc computer.



I wouldn't even play with the timing then he'll lose total. I'd use a d1940 ignition module it is a 5 pin but not the same as a square body 5 pin when the odd pin is grounded it pulls 5 degrees out of the timing it was an early knock sensor attempt. I would run my odd pin to a momentary contact switch, a toggle or possibly a Hobbs switch so I wouldn't lose timing all the time. I'd lose timing only when I needed to lose timing.

I'm battling with an ESC distributor now but am trying to keep things as original as possible so I'm doing what I can for the reasons Ricko mentioned above.

You say you have the ESC jumpered now
so you have basically eliminated it already. It should run well as is, might have to play with the timing a little though.

If it was me I'd get the engine running well as is, do the swap and see how things go.[/QUOTE

If I had a failed esc computer

I wouldn't even play with the timing then he'll lose total. I'd use a d1940 ignition module it is a 5 pin but not the same as a square body 5 pin when the odd pin is grounded it pulls 5 degrees out of the timing it was an early knock sensor attempt. I would run my odd pin to a momentary contact switch, a toggle or possibly a Hobbs switch so I wouldn't lose timing all the time. I'd lose timing only when I needed to lose timing



If I had a failed esc computer

I wouldn't even play with the timing then he'll lose total. I'd use a d1940 ignition module it is a 5 pin but not the same as a square body 5 pin when the odd pin is grounded it pulls 5 degrees out of the timing it was an early knock sensor attempt. I would run my odd pin to a momentary contact switch, a toggle or possibly a Hobbs switch so I wouldn't lose timing all the time. I'd lose timing only when I needed to lose timing
 

bucket

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There is a lot more in there than weights.There are different tension springs, there are eccentrics with different shapes, there are different length slots for centrifugal, there are bunches of different vacuum cans that bring in different amounts of advance and bring it in at different vacuum levels.

But the 80's units were set up for optimal emissions and economy though, right? With less concern for performance?

I've never done a good back to back comparison. The aftermarket units I've installed were always replacing a worn out original. But the aftermarket ones seemed to increase all around performance.
 

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