landfish

Building a 502 MPI that is MEFI 1 bolt onto new Gen 6 GM Marine 502. Generally a stock build. Everything I thought would swap over from my gen 4 454 didn't, and were way over budget now.

any ideas on easy and reliable ignition system for it?
Can/should I use my old Thunderbolt 4 module with a new distributor and coil?
Delco GM Voyager EST Marine set up?
Or Crane set up?
or?

and if someone has some old gear that fits this need, we are not opposed to slightly used gear, so make an offer to sell it to us

-Rich

F-2 Speedy

LF ur inbox is full, I tried to reply to your pm, I have one distributor and coil for a merc efi harness......150.00 plus shipping

AllDodge

What is the problem?
I installed a MEFI 1 on a 502 and is was plug n play for the most part. When the motor was rebuilt much of it was removed when I went to MEFI 3, still have most the stuff

If going carb, use Delco EST

dereknkathy

so merc never used a delco voyager ignition system. BUT they used the same ignition system on just about every efi engine from a 5.0 alpha to a 500 efi. delco small cap hei. as long as the advance is controlled by the ecm, it is not voyager. that distributor is everywhere. and they run forever. if you are running MEFI, why would you want a stand-alone ignition like T-bolt? here is the mercruiser version. 400 bucks...MerCruiser V8 Electronic Ignition Distributor Kit 18-5514 FREE S&H OVERSTOCK | eBay DUI version. 200 bucks. says non-marine, but I doubt any diff.Davis Unified Ignition GM Computer-Controlled Distributor 12620BK | eBay cheap Chinese version. 50 bucks. CHEVY SBC 305 350 & BBC 454 DISTRIBUTOR LATE EFI TBI THROTTLE BODY 350 6652-R | eBay

AllDodge

Must be missing something but my original 502 MEFI-1 used the EST distributor and so does the current build 509 MEFI-3. Maybe it has something to do with the term Voyager but the distributor is the same

dereknkathy

it is the same distributor. I don't think it is called voyager unless it has a module inside it that provides advance without input from ecm. and I am pretty sure GM picked thru their modules and found one with enough advance in limp home mode that they could call it stand-alone...but I have heard several places that merc never used delco voyager ignition. and a voyager module can be had on ebay to convert any TBI era distributor to a stand alone ignition. the other one I like is a large cap hei with the vacuum block-off plate. then you can actually tweak the advance curve old school.

AllDodge

Again no expert but I firmly believe your way off base. The EST module provides no advance, its all done with weights in the distributor based on RPM's,. This is the reason there are different distributors for different motors. The same module is used for 3.0, 4.3, V8, etc, etc

dereknkathy

the large cap hei uses weights and springs. the small cap was designed in the TBI era for computer controlled advance. no vacuum can, no centrifugal advance. looks like this inside... A1 Cardone Distributor Fits Chevy GMC Oldsmobile 1982-1996 V6 4.3 EFI TBI | eBay here is a thread about the voyager. main complaint is the curve comes in 10 deg at idle and all in by 2800 or so. http://www.offshoreonly.com/forums/g...ml#post4562929

AllDodge

So far you have proven nothing, and I'm getting the impression you have no idea what your talking about.

My MEFI 1 and MEFI 3 uses the tall cap and ECM can retard but not advance timing, but not full advance.

dereknkathy

Mefi has full spark control. Take the cap off your distributor and look at the weights. They ain't there. I have 6 of this dist in the garage. I built a voyager setup from a 10 buck ebay car dist last year. Delco Electronic Spark Timing...EST.