gen 1 or 2 hemi coil on plug?

Hi, does anyone make coils for coil on plug installation entirely within the spark plug tubes of a gen 1 or 2 Hemi?
Thanks,
Joel

I don't think so. Some people use a Lexus pencil type coil but I'm not sure how well it works. Give Rich at FAST Man EFI a call and talk to him. He did a Hemi that way once.

Yep I did it using Lexus coils. It worked but the coils were not hot enough for a race engine with high compression.

I have seen articles about using Yota coils on Mopar HEMI engines like Andy probably seen the same article. Being a Toyota tech I have a selection of "known good" coils for testing misfires. I could send you a few different length coils for test fitting if you want
Gus

Usually, it's really not the coil that is any longer or shorter. It's the boot and wire. There are some boot kits available aftermarket (I know the Jeep 4.0 coil assembly has available boot kits). Wouldn't be impossible to make up some of your own. Just use the proper connection from the coil to the plug.

He's talking about a coil pack that fits down inside the tube so there is no wire.
Gus

What I have in mind is something that would look old school. Like a coil package that will fit entireley within the spark plug tube, and be concealed by a stock rubber tube cover. The 2 coil wires would be hid inside a rubber tube that would look like a traditional spark plug wire.

On the valve covers in my signature picture, the spark plug tubes are recessed in. So from the top of the valve cover to the top of the spark plug tube is 1.1". This recess is 1.6" diameter. The spark plug tube itself is 1.1" inside diameter. From the top of the spark plug to the top of the valve cover is 4.85".

Does anyone have a coil that fits this dimension?

maybe something like THIS BOSCH

Did you look at the picture I posted? The Lexus coils fit rather nice.

Rich, I did look at that thanks. Maybe I'm seeing it wrong, but it dosen't look like I could hide those under a stock rubber dust boot. What's your take on that?

There are no coils that I know that are small enough in diameter at the top.

I thought about putting coil on plug while building my Hemi, just not that informed as most on what would work. Whats the point of hiding the coils in the tubes? You still have #14 gauge wire coming out of the hole to the box. Or is there a plan to hide those also.

The coils in rich’s pick look very similar to the coils you will find on most ford mod motors. I’ve used the ford coils in remote mount situations. You can put a plug wire on the ford coil.

I get what you are trying to do. And I like the idea. The ford coils are small enough that they would fit in a “simulated” distributor cap. Maybe try that route?

Or there are these... not sure of dimensions.

I think he wants to hide them under the original covers.

Would coil near plug work? You could hide the coil packs at the back of the engine.

Kevin

Edit

Just read it again. Not what your looking for... lol

Kevin, that would work. I could mount coils on the inside of the firewall.I was just fishing for a more compact way of doing it.

The problem I am trying to solve is that on my coupe the throttle pivot ended up in a bad spot on the firewall, right where the distributor is, almost touching. And the support for the throttle pivot comes off the cage. Plus the hi-rise x-ram intake and carbs hinders access to the dist for maintenance. It's a small car with a lot going on, packaging is an issue. So I can move the throttle things and gain a little room around the dist, but I have to cut and reweld the support to the cage under the cowl. Or get rid of the distributor and gain the benefits of distributorless. I've never done distributorless before, I'm try to learn so I can decide which way to go. THe whole concept of the car is old school, so I can't just slap coils on the valve covers.

8 of those Stromberg 97 TBI's could hide quite nicely in plain site.

Is a throttle cable too new school for your theme?

Kevin

THe classes I plan to race in prohibit EFI. Or else I'd have a hilborn with 8 caliope stacks! THrottle cable is an idea to consider. It hadn't crossed my feeble old mind.

Im not sure about interchange, but I do have an old aluminum timing cover with a mag. It fits a baby red ram hemi. Guaranteed not to have any interference with the firewall, and quite period correct.

For gen II, since there is room for a second plug tube, couldn't you custom build an aluminum shell around the coil, then cut and weld the top and bottom of your spark plug tube to the shell? Then you wouldn't have to worry about fitting the whole works in a tube, just need to fit under the valve cover amongst the rocker assembly.

Something shaped like a muffler with the entrance and exit offset. Just need somebody with a TIG welder.

Like TRENDZ said, Ford has coils that fit into the Gen II spark plug tube. The ones I was looking at were Coyote specific. 2011-2015 5.0 Coyote coils seem like the best for repurposing. On 2/24/16, Ford changed the electrical connector on the Coyote coil to a different style. Most aftermarket COP applications (FAST XIM) come with the earlier style connector. Take a look at: https://www.summitracing.com/parts/msd-82488

These coils are about 3/8" too long to be a perfect fit. But they have a stainless steel spring that compresses against spark plug electrode at the top. There is no "click" when the coil is pushed onto the spark plug. I trimmed off ~3/8" from the coil boot where it slips over the top of the spark plug and test fit everything. The connector spring in the coil is like 1-1/2" long so it just compresses a bit more. Works great. I then connected the coil to a battery with a starter motor bump switch and triggered the coil a few times. There was a nice fat spark.

I see your nice polished cast Gen I valve covers ... if they use the same dimension spark plug tubes as the Gen II, you would have to figure out how to run that spark plug wire cover (like in Twostick's picture) that would hold the coils down against the plugs and hide the fact that you're running COP. And you better check into the rules you mentioned. If they won't allow EFI then they probably aren't going to be real happy that you're running COP.

Here's some clicks of my research:

Also you need to be aware that there are “smart” & “dumb” coils when doing combinations of components. Whatever your choice of controller is, will dictate what coil you can use.
Generally speaking, two wire connection on the coil is “dumb”
Any more than two wires are “smart”.

Joel, take a took at these.



Linky -> ebay.com/INDY-RACE-CAR-IRL-DELCO-CHEVY-ENGINE-COIL-PACK-ELECTRONIC-SPARK-DALLARA-G-FORCE

You'll have to get by the Brand X label, but this may work out. There more that show up at the bottom of the epay page for me.