[Hodgdon Extreme]

This is the design for the coil bracket I've come up with. Anybody have thoughts/critique on this?

The outboard holes are 0.62", which is to accomodate the rubber grommet mounting eyelets the plate will be fastened to - which will be coaxial with the valve cover bolts.

The holes to mount the coils themselves to the plate are 0.13". These holes will need to be drilled/tapped, which the laser-cut process can't achieve, so the 0.13 holes are there to create a centerpoint for a drill so I can ( hopefully) simply just drill them out for the M6x1 tap - and they'll be in the right spot...

 

[Pnut00]

Is there a reason why you went so thin around the outside of the coil pack holes? I would imagine this will vibrate a lot and destroy the packs over time.

Can you not brace it a bit like the image below? Im a belts and braces designer though so lol

 

[Hodgdon Extreme]

No particular reason aside from having spent a lot of time with racecars and avoiding unnecessary material/weight as much as possible - and the bracket I took inspiration from didn't have it either:

There are 8 mounting points, and only about a 6.5" span between them - plus it'll be mounted in rubber grommets (using the same ones Mercury Marine used on their coil bracket for isolation from vibration)

[EDIT 04/05/23]: The bracket is plenty stiff once installed. However, I should have made it 3/16" or perhaps 1/4" thick so it could be tapped for the M6x1 coil mounting screws.

 

[Pnut00]

You are probably right, sounds like you have more experience using these brackets and I'm just going off gut feel

 

[ill_mannered]

As I have not really read much into the particular coils you want use, will GM truck coils not work? The LQ9 coils are great and there are brackets that will fit the GE head. MA performance makes some for relatively cheap and LQ9 coils aren’t expensive at all.

 

[Kris OK]

will GM truck coils not work?

They will work just fine, but have a lower output than the IGN1 style. GM coils are 30mJ (similar to the Yaris coil) compared to the IGN1 @ 100mJ. What this means, I’m not sure in his situation. Would allow for a wider plug gap, and more boost. Beyond that, I don’t know?

 

[Hodgdon Extreme]

As mentioned, LQ9 coils are just fine. However, they're not much less expensive and if I'm going to go thru the effort of an upgrade, I see no reason not to go with the super high output IGN1A units; especially when they're actually free for me.

 

[ill_mannered]

….especially when they're actually free for me.

This is what I was thinking. You must have some readily available.

 

[Hodgdon Extreme]

Fabricated the patch-plates for the valve cover and welded them in:

Here it is mocked up:

And with the coils about where they'll be installed once my bracket is made:

I think I'm going to go ahead and weld the patch plates on the outside, too - and then grind/sand them down to hopefully make it look like one piece.

 

[Pnut00]

Ahh, for some reason i had it pictured in my mind that they were positioned on top of the plug like oem, yeah that bracket should be sweet then.

Love your fabrication skills, wish i had some but mine is more machining than anything else. You might find weld, grind and bead blast will make it all look the same, or paint. It will never look perfect given one is cast and the other rolled plate, and who knows the casting grade of ali.

 

[Hodgdon Extreme]

Got the intake cam cover fully welded and fared down:

Scalped the top off the front "hump" of the exhaust cover, harvested the oil filler bung from the "hump" I cut off the intake cover, and prepared it for splicing:

Still need to drill/tap the oil filler so I can re-use the original baffle - the original bolt holes were lost in the harvesting process:

 

[Hodgdon Extreme]

Nailed down my scheme for crankcase ventilation. I'm going to join the two covers via a 5/8" line, then use a 1" line from the exhaust cover going to a Mann & Hummel 200L/min oil separator. I positioned the 5/8" vent points so they are NOT aligned with cam lobes - hopefully to minimize windage. The outlet in the intake cover is unbaffled, so I suspect there will be substantial oil entrained in the blowby gases exiting that cover. Those gases will enter the exhaust cover, into the unbaffled area. However, note the 1" outlet (to go to the catch can/oil separator) is in the baffled portion of the exhaust cover. I've included some pics of the fairly elaborate OEM Toyota baffling arrangement.

All that's left to do is powder coat these covers - I've got wrinkle black textured powder on the way.

 

[ill_mannered]

Wrinkle black will look great. I love wrinkles. VHT stuff in the can works very good if you haven’t tried it. So long as the instructions are followed.

 

[Kris OK]

Progress looks good, and I think it will work well. It’s unique for sure, never seen a JZ with the oil fill port on the exhaust side. I have seen where fabricators fill in the “valley” on the GE covers to make them look more like GTE covers.

It must really sling the oil in there, judging by the amount of traps and baffles.

 

[Timszee]

Just picked up a GTE manifold from Dan from Rad on Facebook and got the adapter he makes to go with it. Anyways, I saw you notched the hood to clear the manifold, did you figure out what TB you are going to use and if there will be anymore clearance issues with it moving forward? My plan was to use the stock VVTI GTE upper and TB and was wondering if it will still clear with what notching you've already done or if you think there will be more or if it won't even fit.

Thanks for your help!

Tim.

 

[Hodgdon Extreme]

I'll be using a 68mm Bosch drive-by-wire throttle. I looked into a GTE-VVTi throttle, but they seemed to be fetching around $500 used and I was simply not going to give that much $ for an old used throttle.

I bought an adaptor from TAARKS in Australia, to mate the Bosch throttle to the GTE upper manifold, but there was zero chance in hell it was going to clear the hood with any amount of notching. It would have required a hole in the hood for it to stick up through.

[EDIT: Previous comment assumes use of one of the adaptor plates to marry a GTE plenum to the GE lower runners. Those adaptors place the plenum about 35mm higher and 35mm further outboard in the car - and thus the TAARKS throttle body adaptor sits much too high. I ended up solving this altogether by using Dodo Racing GE-T lower runners, which place the GTE plenum in same position it'd be in if mounted to GTE lower runners]

I did not attempt a test fit of an OEM GTE-VVTi throttle, but I don't see how it would have been possible to fit under the hood. I could be wrong...

Instead, I'm fabricating an "adaptor elbow" that comes off the manifold and immediately begins a 45* downward bend towards the throttle. If you look through this thread, there is a link to another thread with some more details about the adaptor elbow.

 

[Timszee]

I'll be using a 68mm Bosch drive-by-wire throttle. I looked into a GTE-VVTi throttle, but they seemed to be fetching around $500 used and I was simply not going to give that much $ for an old used throttle.

I bought an adaptor from TAARKS in Australia, to mate the Bosch throttle to the GTE upper manifold, but there was zero chance in hell it was going to clear the hood with any amount of notching. It would have required a hole in the hood for it to stick up through.

I did not attempt a test fit of an OEM GTE-VVTi throttle, but I don't see how it would have been possible to fit under the hood. I could be wrong...

Instead, I'm fabricating an "adaptor elbow" that comes off the manifold and immediately begins a 45* downward bend towards the throttle. If you look through this thread, there is a link to another thread with some more details about the adaptor elbow.

Thanks for clearing that up. Well looks like I'll have a VVTI upper manifold and TB, and RADs GE to GTE adapter for sale next week!

 

[Hodgdon Extreme]

Valve covers done. Coil bracket should be here next week. Still gotta nail down the final details on my engine harness and get that ordered. Still waiting on millwork for my throttle elbow, but good chance I can get it done over Thanksgiving break.

 

[Hodgdon Extreme]

Valve covers installed:

The coil bracket in the flesh:
It's only 1/8" thick and I was uncomfortable tapping it directly for the m6x1 coil bolts, so I attempted helicoils - which was a failure in that thin material. So I resorted to using Rivnuts instead. To do it all over again, I think I'd simply step up the thickness of the bracket to 3/16 or even perhaps 1/4" - and then just drill/tap the bracket directly. Or perhaps just tack weld some discs to the underside of the bracket to give the bolts more material to engage into.

By the way, I can have more of these made if anybody is interested. Unsure how much I'd charge, but I'd be willing to re-create this valvecover shave + coil bracket arrangement for others going thru a similar process in the future.

The throttle adaptor elbow in the flesh:
These pictures make it look like a giant schnoz, but it doesn't look ungainly in person. I'll be shaving off the extraneous bolt bosses from the upper manifold and powder coating the manifold and elbow metallic silver.

I made 5 sets of these flanges, and I'll be building a weld fixture so that I can build some more of these...

It points down right where it needs to, for the charge pipe to come up from below:

 

[clckwork99]

The coil bracket in the flesh:
It's only 1/8" thick and I was uncomfortable tapping it directly for the m6x1 coil bolts, so I attempted helicoils - which was a failure in that thin material. So I resorted to using Rivnuts instead. To do it all over again, I think I'd simply step up the thickness of the bracket to 3/16 or even perhaps 1/4" - and then just drill/tap the bracket directly. Or perhaps just tack weld some discs to the underside of the bracket to give the bolts more material to engage into.

These flush mount press fit nuts would work perfectly in place of the rivnuts, https://www.pemnet.com/fastening_products/pdf/fdata.pdf. I run a sheet metal fab shop and we use and stock a lot of these types of fasteners. If you want to re-do what you have, let me know and i will send you some.