Jump to content
HybridZ
4.6 CobraZ

4.6 DOHC / 280Z

Recommended Posts

Joined Hybridz, and just got my Z car today.

 

I built a nasty all alloy supercharged 4.6 for my 97 Cobra a few years ago and had crazy HP, basically fell in love with DOHC Modular motors.

 

For the 280Z I will be doing a NA Cobra motor (2001 Cobra), 300 HP in the Z will be fine I figure.

 

Looks like it's been done here (notheredave, yellowoctupus, and mitchnandy) so I will need to tap into their experience.

 

post-48773-0-04907600-1425511856_thumb.jpg

Edited by 4.6 CobraZ

Share this post


Link to post
Share on other sites

Hey you and me both. I'll subscribe to this thread and we'll see who can get theirs on the road first. You have a 6 car head start though, since my list of operations has 6 other projects for me to finish before I get to this one, so I'll let you be the guinea pig, haha. I picked up an aluminator 4.6 32v that has burned valves (imagine that) so after rebuilding it with terminator internals and fixing the heads I'll plan on running the eaton for a while just like your setup. If you get yours running before mine you should post a vid to motivate me through the final stretch of my project list.

 

I don't know what you're doing for the transmission but I currently have an lt1 t56 for mine that I was going to try and adapt to the 4.6. For whatever reason everyone thinks the ford t56 has diamond internals and typically want too much money for them, and I picked up the lt1 t56 for a pretty good price.  I already have the ford bellhousing bolted up, and I know a lot of the high hp guys swap the 10 spline over to the 26 spline, which is what comes factory with the lt1 t56, so it has that going for it. What were you planning on for mounts?

Share this post


Link to post
Share on other sites

I'm going with a normally aspirated 4.6, like a 2001 Cobra motor. I don't want a modified hood. There are 3 other guys on this forum who did the 4.6 so I know they will fit. The lincoln Mark 8 motors are readily available so that's an option (super low profile intake on those motors). I'm hoping a 2001 Cobra intake will fit under the stock Z hood. I'll post the motor mount pics I got off this forum.

Edited by 4.6 CobraZ

Share this post


Link to post
Share on other sites

The all alloy Terminator motor in my 97 Cobra was about 650 HP and even with 305's out back traction was non existent. For this Z project I'm looking at a much more sedate 4.6 (Lincoln Mark VIii motor with flat top Pistons and a 01 Cobra intake). Should come in around 300 HP. My 97 Cobra was stupid over the top (dropped $14K on the motor alone). I want something I can drive daily during the spring and summer.

Edited by 4.6 CobraZ

Share this post


Link to post
Share on other sites

Oh gotcha, I saw the picture of the supercharged 4.6 and assumed that's what you were using, thinking you may plan to modify oil pan / engine mounting to drop the engine low enough to clear the hood with the eaton. I've followed yellowoctopus's build so yeah I was reassured the dohc will fit lol. I was planning on cutting mounts off a 2001 mustang gt shell I have and welding them to the Z, but was just curious what you had planned out already. Have you figured out what trans you're using yet?

Share this post


Link to post
Share on other sites

So far so good on the T45 on my end.  The DOHC (NA) has basically the same torque output as the SOHC, so overall strength shouldn't be an issue between the two.  I definetly suggest you check out the clutch setup I'm using now. WAY easier to work with and those freakin' Wilwood pull cylinders suck.  They're just a crappy design and the o-rings wear out really fast.  Don't ask me how many times I had to drive home from work, or home at midnight from the airport or home from WHEREVER with no clutch!!!!!  (Oh yeah, and when they go, they really go.  At night, when the slave is coolest, all of your brake fluid sneaks by your shrunk o-rings (because the thermal expansion of rubber is higher than aluminum).

 

Anyhow, awesome to see some more mod motor guys out there.  The DOHC is definitely worth any extra bother in my opinion.  It pulls so well, right through 6k, where I didn't even know my ecu had a 6k rev limiter with the SOHC; the SOHC just fell on it's face after 5k.  Feel free to PM me if either of you guys have questions.

Share this post


Link to post
Share on other sites

I've read your thread top to bottom, pretty much why I joined this forum. I noticed a ton of SBC stuff but it took a little searching to find the 4.6 DOHC. I was gonna look for a 2001 or 97 to 98 Cobra motor but I actually think the Lincoln Mark 8 with its lighter weight nodular crank will save a few pounds and rev quicker. Also cheaper. Are you finding 300 HP to be sick enough or do you wish you had more? I'm wanting a spirited daily driver, not a super car.

Edited by 4.6 CobraZ

Share this post


Link to post
Share on other sites

I have aviator motor in my 93 fox coupe (same as mach 1 minus the intake) I have a stock eaton on it at 9 PSI (one more PSI than stock) and it makes 660 whp 440 TQ. Eaton will stick through the hood. I picked up tyhe motor complete for 1000 from the wreckers. Mods are the twin 62mm tb and cai. 96 intake, and stock exhaust cams were used. Car runs [email protected] on 17' drag radials. Car weighs 3108 lbs no driver. Drop that setup in a datsun and it will be fun!

Share this post


Link to post
Share on other sites

I liked my 97 Cobra, and had similar HP as you (way too much power really) but I have to say after buying the Z it feels like a go cart, smallest car I've ever messed with. Hard to believe a DOHC Modular drops in. Really beautiful body lines too, pretty excited about this project.

Share this post


Link to post
Share on other sites

The thing I would do differently is to not take breaks from working on it. I would take a couple months off and forget what I was doing, especially the electronics.

 

My objectives were to keep the stock appearance (more or less), no hood modification, keep the center of gravity low and keep the engine as far toward the rear as possible. This is gonna be a track car, it is nearly there.

Share this post


Link to post
Share on other sites

Stock steering on mine, with cast Cobra manifolds.  Getting an oil filter out is TIGHT, but it will fit.  I also didn't have to cut my oil sending unit casting as I've seen one or two others do.   Not sure why they did...

 

Exhaust, have fun.  Drivers side is cake, passenger's side is going to take a while to get those first 8" done. After that, no problem.

Share this post


Link to post
Share on other sites

Making my steering, exhaust and oil filter all work together was a nightmare.

I used the Cobra intake to allow the engine to mount as far rearward as possible and the engine is mounted low for a low center of gravity (and to accommodate the Cobra intake)....the result was cutting and welding the exhaust, replacing the oil filter mount with an adapter (Moroso Remote Filter Adapter 23681). My steering rod is very close to the adapter as it is. One of my pictures shows this mess.

Share this post


Link to post
Share on other sites

Got a built lightning motor I was gonna put in my 4x4 f150 but after the local track opened up again I'm wanting to shoe horn it into my 280z that's been sitting. I know it won't fit under the hood with the S/C and being a 5.4 so I'm hoping to pick yalls brains as well as the others that have done this swap.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×