1G CAS clearance + crank/cam sensor options for 4G64/63 hybrid (RWD / Starion)

[Tux]

Hey all,

I’m putting together a 4G64/4G63 hybrid for a RWD Starion swap and have a few CAS / trigger questions that I haven’t been able to find a clear, first-hand answer to.

Setup:

• Wide-block 4G64 (Asia-sourced short block)
• 1G 4G63 DOHC head (bare head)
• RWD application (Starion chassis)
• Bosch DBW Throttlebody
• Honda K-Series smart coils
• MaxxECU Race ECU
• Still sourcing cams, lifters, cam pulleys, timing components, rockers, pistons, rods, etc

From what I’ve read, the 1G CAS on the back of the intake cam may interfere with the firewall in a Starion. Some posts say it will hit unless the engine is moved forward and a custom driveshaft is made, while others say it does clear but is very tight.

Questions:

1. Has anyone here run a 1G CAS on a DOHC head in a Starion without moving the engine forward? If so, how tight is the clearance in practice?
2. Are there alternative cam/crank trigger setups that work cleanly with a 1G head in a RWD chassis?
3. I understand the 2G CAS won’t work on a 1G head — but can a 2G crank trigger/sensor be adapted to a wide-block 4G64 for engine position, with a different cam signal?
4. What are people actually running for crank + cam phase on this combo when firewall clearance is a concern?

I’m open to OEM DSM / Hyundai / Kia solutions or aftermarket trigger setups, just trying to understand the real-world options before committing to engine placement.

Pictures are greatly appreciated.

Thanks — any firsthand experience is appreciated.

 

[TurboSportTSi]

Checking in to see if you've found any info on this yet.

I've wanted to do your exact swap for over 20 years! I no longer have a starquest, but am planning to swap a 2.2L destroker (narrow block) with T56 into an S13, which will have many of the same challenges & configurations.

Looking forward to following your build and will post up anything helpful I come across.

 

[Justin DuBois]

I’m familiar with the anatomy of 1G and 2G sensors, but I’m not familiar with the space limitations or ECU of the Starion.

I’ll assume for the moment the MaxxECU Race ECU is like a 1G/2G/EVO ECU, and the 1G CAS would work if space were not a problem.

A 1G CAS provides two 5v square wave signals to the ECU. One for Cam position, and the other for spark that simulates the crank position.

If the 1G CAS won’t fit against the firewall - what about the 2Gb CAM position sensor? It fits on a 1G head, is slightly smaller, fixed position. This would be 1/2 the solution as the 2Gb sensor only has one signal for the cam position.

In addition to the 2Gb CAM sensor, you need a signal from the crank. Kiggly makes a sensor mount that works with 6-Bolt oil pumps if you are not running balance shafts.

If the 4G64 front case oil pump is like a 2G pump with a crank sensor mount, then a 2G crank sensor would make more sense.

If you have a picture of the timing belt side of the engine, I can confirm.

-j

 

[trogador2005]

I'm actually working on an elegant solution to this exact problem right now!

The biggest problem you're going to have with this setup is, that block's front case most likely doesn't have provisions for a crank sensor, and that head doesn't have provisions for the 95-96 2g style cam sensor. which are the ideal sensors for this setup.

The solution involves removing your balance shafts and running the Kiggly crank trigger. that's 1/2 of the problem solved.

For the cam sensor (this is what I'm working on), I'm working on mounting a zf (cherry) style hall effect sensor in the backing plate for the timing cover that sits behind the intake cam gear, and using adjustable cam gears so they're aluminum, running a longer steel adjuster bolt through the back on the cam pulley to trigger the cam sensor.

this way you have nothing on the back of the head against the firewall.

This is all in theory and I'm working on a prototype right now. It also requires a standalone ecu for the cam trigger to work, so you should be good. Although i'm not familiar with the Maxx stuff. This is being designed around a Haltech!

 

[Justin DuBois]

What will you do about the water neck? it sticks back farther than the CAS.

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[trogador2005]

Best bet is to relocate to the front with something from jayracing! But idk if OP has that planned out.

 

[Tux]

I found a couple of solutions for the thermostat. Have not yet settled on what I’ll do yet.

I like the idea of a 2g sensor, that may be a good option. I do like trogadors solution, sounds cleaner for wiring.

I have a 420a that I don’t need but the sensor for that is super thin.

I’m wondering if maybe I can make that work

 

[Tyeler18]

Mighty max not starion but similar situation here. I used a 7 bolt head with an evo 8/9 intake so that everything was a bolt on rwd configuration. 2gb cas didn't clear the firewall so I went to a 95/96 trigger on the cam gear with a kiggly 6 bolt crank adapter. This worked great on a stock evo ecu with the firing order switched but im on a haltech now and had to get a little creative with the trigger offset angle to get it to work properly since the cam sensor is inverted from a stock setup. If you're not stuck on the 6 bolt head the 7 bolt head made things easier.

 

[Tux]

Unfortunately I’ve already married the 6 bolt head