POINTS DISTRIBUTOR --- UNKNOWNS WITH MOTOR

[Gk5188]

Good afternoon,
I have a 1980s/early 1990s Mercruiser 5.7L MIE that I pulled out of a 1991 Sylvan Ski Boat. The serial number that I found on the motor is C391836. I was able to cross this number to a 1987 - 1995 5.7 Competition Ski GM 350 V-8 by adding a zero before the C in the serial number; however, I was able to find out that this was not the original motor which was replaced because of poor winterization and a little shade tree mechanical modifications. I cannot confirm what platform (MCM or MIE) came making it hard to confirm type/model/fit for components.

The motor has very little hours on it, but has an electrical problem in the ignition system and with a distributer with points, I am on the hunt for a HEI replacement even moving up to a Thunderbolt IV or V would be better than what it has now.

So, here is my question: Is there a difference between the HEI ignition modules installed on MCM engine with a sterndrive and the HEI modules found in the MIE engine?

I appreciate any advice or thoughts on this. Eventually, I hope to have this engine back into a ski boat haul, but for now I just want to bring it forward into a slightly modern era.
Cheers, George

 

[Scott Danforth]

first, welcome aboard

points are easy. however to get it to fire in the spring or when ever it sits for more than 3 months, you will need to file the points, gap the points, then set dwell with a meter, prior to setting timing

dont think HEI. think Delco voyager EST or the TBV or even a Mallory YLM series. HEI denotes automotive.

the fact the motor has points means someone was in there prior. so the motor may not be what you think it is. doesnt matter if the motor was in front of an outdrive or an inboard gearbox. the block, heads, etc are the same. the difference comes in the ignition system. with or without a shift interrupt switch.

post the block and head casting numbers. may be a much older block in the boat than you are thinking.

If it was me, I would skip the ealy 80's vintage anything and swap to a 1996 or later block with a 1-piece RMS, roller cam, vortec heads and add roller rockers. however if you do have a 1988 or later block, you can simply swap to vortec heads as well.

 

[Gk5188]

first, welcome aboard

points are easy. however to get it to fire in the spring or when ever it sits for more than 3 months, you will need to file the points, gap the points, then set dwell with a meter, prior to setting timing

dont think HEI. think Delco voyager EST or the TBV or even a Mallory YLM series. HEI denotes automotive.

the fact the motor has points means someone was in there prior. so the motor may not be what you think it is. doesnt matter if the motor was in front of an outdrive or an inboard gearbox. the block, heads, etc are the same. the difference comes in the ignition system. with or without a shift interrupt switch.

post the block and head casting numbers. may be a much older block in the boat than you are thinking.

If it was me, I would skip the ealy 80's vintage anything and swap to a 1996 or later block with a 1-piece RMS, roller cam, vortec heads and add roller rockers. however if you do have a 1988 or later block, you can simply swap to vortec heads as well.

Thank you. Just getting into the project now and was looking at using this motor as a test to hone my skills since I already have it. Here are pics of some of the numbers casted in the block. The Single Number, I believe is 638 is on the sides of the block. The other pic is from the rear of the motor. I could not locate the casting numbers on the Heads unless the manifold is blocking them. Thank you for great information. Cheers, George

 

[Gk5188]

Now, here are the photos.

 

[Scott Danforth]

Head casting numbers are under the valve cover.

Block comes back as 1988-1995

 

[Gk5188]

Thank you. I am pulling the valve covers tomorrow. I check the numbers and send on. Thank you again.

 

[Scott06]

If you want to upgrade the ignition a delco est is the way to go. Thunderbolt systems work great but a lot of the modules are either insanely pricey or NLA.

 

[Fun Times]

0C391836 = 1988 MIE RH-1.0:1-RWC 5.7L SKI Model number 3570111AS, https://www.crowleymarine.com/mercruiser/oem-parts/inboard-engine/1988/3570111as?q=3570111AS

 

[Lou C]

Looks like that engine did still have points. I have a Prestolite on my 1988 4.3 and I usually put in a new set whenever they get pitted or burned. I get at least 5-6 seasons out of a set of points. The advance weights need a few drops of oil in the wick under the rotor.

 

[Gk5188]

Thank you everyone for the information and suggestions. It’s really appreciated. Now, I just need to decide on the replace / repair plan moving forward.

I do have one last question. I know the gear in the distributor needs to be made out of certain material based for specific motors. How can differentiate between the gears and know what is needed for this motor? Thanks again, George

 

[Scott Danforth]

Thank you everyone for the information and suggestions. It’s really appreciated. Now, I just need to decide on the replace / repair plan moving forward.

I do have one last question. I know the gear in the distributor needs to be made out of certain material based for specific motors. How can differentiate between the gears and know what is needed for this motor? Thanks again, George

Don't over think it. Buy Delco Voyager dizzy or use the points dizzy you have

You are not running any hardware that isn't compatible

 

[Gk5188]

Don't over think it. Buy Delco Voyager dizzy or use the points dizzy you have

You are not running any hardware that isn't compatible

Copy. I appreciate it. Thank you.

 

[Gk5188]

Ok, my last thing on this topic. I got the head casting numbers. It is 14086217. They are in good shape and very clean for the age of the motor. Cheers, George

 

[Lou C]

If the engine has been sitting a long time you might have to remove the points plate and free up and lube the centrifugal advance weights and springs. Oiling the wick that you will see in the distributor shaft after removing the rotor once a year will keep them working as they should. These units are very simple and easy to repair. If I had to I could (and have done it) replace the points & condenser with the boat in the water, just be careful not to drop screws where they don't belong.
Otherwise the advance rate can be checked with an old fashioned advance timing light against merc's specs, with the engine running at the specified RPM.
Old school tune up circa 1970s, my old boat is like a time machine...