NewbVetteGuy

I'd love to understand a bit about the coil-on-plug / coil-near-plug options for a sequential multi-port fuel injection Gen1 SBC. It's kind of overwhelming right now.

I'm not interested in stock ECUs; I'll be using Holley EFI to control the whole thing.

I know this requires the ability to determine both the crank and cam position and that there are a few options there including:

• "Dual Sync" Distributor- can determing both crank and cam position and send them both to the ECU/EFI computer
• Crank trigger ala Vortec motor + some sort of signal from some kind of digital distributor
• Crank position sensor ala reluctor wheel attached to the outside of the crank/harmonic balancer +some sort of digital cam position signal from a digital distributor of some kind

--I think the Vortec motor crank position sensor / reluctor requires changing to a Vortec-style timing chain cover and might prevent the use of a double roller timing chain, and may even require using a narrower, non-standard harmonic balancer and if so this is absolutely a non-starter of an option for me. Are there any "known good" take-off coil packs I should look for by Model #? (I searched Ebay and they seem to be listed by model #.)

I'd definitely like to understand how the ECU is supposed to get the cam signal if you go with the crank sensor wheel attached outside of the harmonic balancer.


-Which of these options is most accurate? (I think any of the crank sensor options result in more accurate timing vs. the dual sync distributor.)



What about coils? LS engine take-off coil packs seem like a great and reasonable, but hard-to-find option. Are there meaningful differences between the coil packs between LS engine generations? -What about the coil packs between "true" LS engines and the LQ series truck motors including the little 5.3s?

Is there any concern buying used coil packs or are these pretty much good forever?

All the aftermarket options seem astronomically expensive; any ideas on getting an appropriate, high-performance set of coils for a decent price?



How the heck do you fit the coil packs onto a GEN1 SBC without welding?






Please don't derail my thread asking why I want what I want. I realize what you want may be different; that's fine, don't derail my thread, please. I want max MPG and max torque across the curve and just in general a lot of modern technology in my old #'s matching SBC and I don't mind spending money to do it.



Adam

7t9l82

Save your numbers matching engine and swap for an ls engine that has all that stuff. I really don't think modifying your engine to that degree is feesible and REALLY I don't think anyone wanting the original engine would be interested in something modified in that manner.
I know that isn't what you asked for, but just because you could do something doesn't make it a good idea.
​​​​​​

zwede

A dual sync distributor wouldn't make much sense. Yes it provides the signals you need, but then you have a rotor and dist cap that serves no purpose.

A crank trigger plus some form of 1X cam sync would be the easiest.

Something like this:

https://www.eficonnection.com/home/p...nd-bbc-engines



Like you suspected, a crank trigger is always more accurate than anything from a distributor.

Maybe find some space on the firewall and run longer plug wires? But if you want them on top of the valve covers welding may be required.

NewbVetteGuy

Thanks a million, Zwede!

That's just perfect! Only $125, vs the $350-$400 for a dual-sync distributor.

The EFI connection 24x / 58x conversion sets are just astronomically expensive; their vortec-style timing covers with cam buttons for roller conversion cams are $450 and you're just getting started then and need a special balancer.

Going with a crank trigger wheel that sits outside of the balancer and going with a single-sync (if that's what these are called) distributor for $125 and getting a junk yard LS coil pack take-off (if I can figure out the right one) seems like a great, reasonable way to go.

I know there are lots of places that make special mount kits for the coils to go on regular valve covers, I just need to investigate this more.

My intake (first fuel injection) will NOT fit a large-cap HEI distributor; only a small-cap distributor; any idea whether the distributor you linked to is the dimensions of a small or a large? (another thing I know nothing about)


I definitely want the stock-style, short LS coil plug wires- they're one of the benefits of going with CNP/COP, IMHO.



Adam

NewbVetteGuy

For anyone who'd love to have a magazine article to start from on this subject:
http://www.hotrod.com/articles/ccrp-...ls-conversion/

http://www.superchevy.com/how-to/eng...gger-ignition/


It's cool that the EFIConversion.com stuff will allow you to control a fuel-injected SBC with an LS ECU, and the concept is in the direction I'm interested in going for sure, but I really like the Holley featureset and touch-screen interface and self-learning capability and the cost of both is the same even after paying the premium for the Holley EFI vs. a stock LS ecu.



Adam

zwede

Sorry, don't know the dimensions. Looks like a small HEI in the pic, but best to contact them and check.

I went another way on mine. I'm running sequential port injection so I needed a cam sync, but I kept the distributor.

I used a 4x MSD crank trigger and replaced the supplied magnetic sensor with a Holley hall-effect sensor (stronger signal, this is recommended by Holley). For the cam sync I modified a small cap HEI so it only generated one pulse, mounted another hall effect sensor and got rid of the module. The sensor is triggered by a small magnet that I drilled a hole for in the shaft. It has worked perfectly for years. For a low buck solution you could do this to any small cap HEI and then make a cover for it.

zwede

I would also think they Holley ECU is more flexible when it comes to inputs compared to a factory ECU. The Holley HP (which is what I'm running) is compatible with just about any crank and cam trigger.

lionelhutz

The EFI connection distributor is just a Vortec truck distributor with a blank cap on it. I'm not sure if anyone else sells blank covers for them or not. They do sell the cover only if you find one used or cheaper.

Richard454

I bought a box of like 36 GM LS2 LS3 LS4 LS7 Ignition Coils OEM 12573190 Round Style for my project- but have sold what was left. Had no problems with them... Selling the extra coils off- made mine almost free...

There are several ways to mount them- threaded rod is probably a good start...


BUT be careful of Chinese Knock-off that are now floating - like on eBay...

Different coils-

GM#12573190 ACDelco D514A LS2/LS7 Corvette
GM#10457730 ACDelco D585 LS2 Truck
GM#12611424 ACDelco D510C LS?
GM#12558948 ACDelco D580 LS1/LS6












I still have a couple sets of new- never run- used for mock-up AC-Delco 5146 plug wires

email me if interested-

richard454 at comcast dot net



My original idea to mount the coils- just threaded rod and ss tubing-



Ended up relocating them to the firewall- and put them all together-



And here's how a buddy of mine put them on his big block-

NewbVetteGuy

Umm. Wow; that's impressive, Zwede.

Far beyond me, but impressive nonetheless.


Adam

NewbVetteGuy

Wow. That's good insight. If I end up just pulling some coil packs and wires at a junk yard, I might as well try to find a Vortec distributor while I'm at it.


Adam

NewbVetteGuy

Thanks Richard, so are the GM 12573190's used on the LS2, LS3, LS4, & LS7s? -One coil across all these engines? -If so that seems like a good way to go as far as an OEM coil, right?


Do you know anything about the differences between the different coils?
Are the 12573190s a hotter/ better coil than say the truck variants? Is the difference on the inside or just the exterior dimensions?



When mounting the coils on the firewall or on the top of the engine, are you then resorting to making your own plug wires or buying custom wires? I definitely like the more SBC-look of having the coils somewhere other than on top of the valve covers, but I like the idea of use using the OEM wires and nice short lengths.



Adam

lionelhutz

You make your own wires. MSD 32129 is a plug wire set that would work. You could likely buy a cheaper LT1 fixed length kit and make it work too. Possibly buy some new plug ends and cut and crimp the set.

NewbVetteGuy

Ok, here's a few things I've learned:

the LS1/LS6 coils are inferior to the later LS2, LS3, LS4, LS7, LQ4, LQ9 coils, in terms of spark energy, the capability to support longer dwell times, and reliability/longevity.

The D514a coils are the Corvette, GTO, Avalanche standard coils.
The D585 coils are semi-famous for the best spark energy, and reliability and come with integrated, external heat sinks but are larger, and uglier and don't fit well on SBC valve covers that have breathers or oil fill caps. The D585 coils have two versions #12558693 Melco/Mitsubishi coils and the Delphi #19005218 Delphi coils; the Melco are square, Melco round and the Melco coils are better and are some of the best coils.



The LS1/LS6 use one type of connector and harness and the LS2/LS3/LS4/LS6 another.


Interestingly enough, I also learned that there are a few places making adapters that allow you to run LS valve covers on SBC heads, but they're not cheap. Update: I read that wrong, they allow you to run SBC valve covers on LS heads.


I need to research solutions for fitting the coils to the valve covers more, next...


Adam

NewbVetteGuy

The D585s can be obtained from 2002-2005 Escalades, 2000-2006 Yukons, 1999-2006 Silverados, 2001-2005 Trail Blazers.


The coil mounting brakckets vary hugely by application and exact motor.

Most of the early aftermarket coils are inferior, especially in reliability; this includes MSD and Accel.


Adam

NewbVetteGuy

Now I need to find a good, reasonably priced source for either the D514A or D585 coil packs, if anyone's got one.

I saw them @ EFI Connection but $40 each for the 514As (MFG by AirTex/Wells) or $60 each for the D585s; that's just unreasonable. Junk yard picking will just steal time away from actually doing work so I'd love to find them online but I'm now scared of Chinese knock-offs... I think I'll go with the "superior" D585s if I can find them for a close enough price to the 514a, as the large size doesn't matter if I'm mounting them on the wheel wells.



I'm already going to have valve cover fitment issues with my combo of 1.6:1 Comp Ultra Pro Magnums and my FIRST Fuel Injection intake and raised valve cover rail Profiler heads AND I really don't like the look of coils on the valve covers so I've decide I'm going to see about mounting the coils on the fender wells and just making custom length wires.


Then when it comes to the crank trigger wheel, it seems like Holley only support 58X wheels (which they call 60-2 (60 minus 2)). I am NOT and I repeat absolutely NOT looking for an insanely expensive EFI Connection version that fits under the timing cover; one that mounts outside of the balancer and inside of the crank pulley seems to be the way to go, IMO.

Hall sensor pickup is an absolute must, but Holley Part # 556-110 for $244 seems like a horrible price. I'm very tempted to go Chinese on a simple spinning metal wheel...

I'm not totally clear on how to space out all my pulleys by 1/8", which is required because the wheel moves the crank pulley out by 1/8".



I don't know why I've been so scared / overwhelmed to tackle the ignition system for so long. It's nice to know that it's a good way to get another tiny increase in torque and MPG, too, given my goals in this area. This totally fits into my "2019 1979 Corvette" vision for my build, too.


Adam

NewbVetteGuy

QQ: Does going with an LS-style coil that's capable of a much "hotter" spark mean that I should go with a spark plug that is one level cooler than the stock recommendation from my head's MFGR?

(I'm going to be close to the detonation limit with my dynamic compression, long-runner intake, and the fact that I'm strongly considering getting the chambers coated with thermal barrier coating.)



Adam

NewbVetteGuy

Thanks for opening my idea to that possibility, Lionel. I want to mount the coils on the fenders so I think making my own wires is definitely the way to go for me.

Any recommendation on some really low ohm wire kits? Do the MSDs fit the bill? -I don't want to lose the benefits of going with CNP ignition by having long, high ohm, "lossy" plug wires.



Adam

NewbVetteGuy

I really like this option for mounting the coils, but it requires aluminum welding skills / equipment or knowing someone who can do it for you. Pretty great in the looks dept, IMHO.

zwede

For my crank trigger I didn't want to space out all the accessories, so I got a spacer made that together with the trigger wheel spaced out the crank pulley "one belt groove". I then re-arranged the belts and that way I didn't have to mess with any of the other pulleys.

As for DIY plug wires, I like the MSD 8.5mm stuff. I get a roll of wire, a bag of terminals and go to town. I highly recommend the MSD crimper tool. Excellent quality and makes crimping wires easy.